shared_source/c_tk_base_7_5_w_mods/tkbind.c

/* $Header$ */

/* 
 * tkBind.c --
 *
 *      This file provides procedures that associate Tcl commands
 *      with X events or sequences of X events.
 *
 * Copyright (c) 1989-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 *  RCS: @(#) $Id: tkbind.c,v 1.1.1.1 2001/06/13 04:54:18 dtashley Exp $
 */

#include "tkPort.h"
#include "tkInt.h"

#ifdef __WIN32__
#include "tkWinInt.h"
#endif

/*
 * File structure:
 *
 * Structure definitions and static variables.
 *
 * Init/Free this package.
 *
 * Tcl "bind" command (actually located in tkCmds.c).
 * "bind" command implementation.
 * "bind" implementation helpers.
 *
 * Tcl "event" command.
 * "event" command implementation.
 * "event" implementation helpers.
 *
 * Package-specific common helpers.
 *
 * Non-package-specific helpers.
 */


/*
 * The following union is used to hold the detail information from an
 * XEvent (including Tk's XVirtualEvent extension).
 */
typedef union {
    KeySym      keySym;     /* KeySym that corresponds to xkey.keycode. */
    int         button;     /* Button that was pressed (xbutton.button). */
    Tk_Uid      name;       /* Tk_Uid of virtual event. */
    ClientData  clientData; /* Used when type of Detail is unknown, and to
                             * ensure that all bytes of Detail are initialized
                             * when this structure is used in a hash key. */
} Detail;

/*
 * The structure below represents a binding table.  A binding table
 * represents a domain in which event bindings may occur.  It includes
 * a space of objects relative to which events occur (usually windows,
 * but not always), a history of recent events in the domain, and
 * a set of mappings that associate particular Tcl commands with sequences
 * of events in the domain.  Multiple binding tables may exist at once,
 * either because there are multiple applications open, or because there
 * are multiple domains within an application with separate event
 * bindings for each (for example, each canvas widget has a separate
 * binding table for associating events with the items in the canvas).
 *
 * Note: it is probably a bad idea to reduce EVENT_BUFFER_SIZE much
 * below 30.  To see this, consider a triple mouse button click while
 * the Shift key is down (and auto-repeating).  There may be as many
 * as 3 auto-repeat events after each mouse button press or release
 * (see the first large comment block within Tk_BindEvent for more on
 * this), for a total of 20 events to cover the three button presses
 * and two intervening releases.  If you reduce EVENT_BUFFER_SIZE too
 * much, shift multi-clicks will be lost.
 * 
 */

#define EVENT_BUFFER_SIZE 30
typedef struct BindingTable {
    XEvent eventRing[EVENT_BUFFER_SIZE];/* Circular queue of recent events
                                         * (higher indices are for more recent
                                         * events). */
    Detail detailRing[EVENT_BUFFER_SIZE];/* "Detail" information (keySym,
                                         * button, Tk_Uid, or 0) for each
                                         * entry in eventRing. */
    int curEvent;                       /* Index in eventRing of most recent
                                         * event.  Newer events have higher
                                         * indices. */
    Tcl_HashTable patternTable;         /* Used to map from an event to a
                                         * list of patterns that may match that
                                         * event.  Keys are PatternTableKey
                                         * structs, values are (PatSeq *). */
    Tcl_HashTable objectTable;          /* Used to map from an object to a
                                         * list of patterns associated with
                                         * that object.  Keys are ClientData,
                                         * values are (PatSeq *). */
    Tcl_Interp *interp;                 /* Interpreter in which commands are
                                         * executed. */
} BindingTable;

/*
 * The following structure represents virtual event table.  A virtual event
 * table provides a way to map from platform-specific physical events such
 * as button clicks or key presses to virtual events such as <<Paste>>,
 * <<Close>>, or <<ScrollWindow>>.
 *
 * A virtual event is usually never part of the event stream, but instead is
 * synthesized inline by matching low-level events.  However, a virtual
 * event may be generated by platform-specific code or by Tcl scripts.  In
 * that case, no lookup of the virtual event will need to be done using
 * this table, because the virtual event is actually in the event stream.
 */

typedef struct VirtualEventTable {
    Tcl_HashTable patternTable;     /* Used to map from a physical event to
                                     * a list of patterns that may match that
                                     * event.  Keys are PatternTableKey
                                     * structs, values are (PatSeq *). */
    Tcl_HashTable nameTable;        /* Used to map a virtual event name to
                                     * the array of physical events that can
                                     * trigger it.  Keys are the Tk_Uid names
                                     * of the virtual events, values are
                                     * PhysicalsOwned structs. */
} VirtualEventTable;

/*
 * The following structure is used as a key in a patternTable for both 
 * binding tables and a virtual event tables.
 *
 * In a binding table, the object field corresponds to the binding tag
 * for the widget whose bindings are being accessed.
 *
 * In a virtual event table, the object field is always NULL.  Virtual
 * events are a global definiton and are not tied to a particular
 * binding tag.
 *
 * The same key is used for both types of pattern tables so that the 
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */
typedef struct PatternTableKey {
    ClientData object;          /* For binding table, identifies the binding
                                 * tag of the object (or class of objects)
                                 * relative to which the event occurred.
                                 * For virtual event table, always NULL. */
    int type;                   /* Type of event (from X). */
    Detail detail;              /* Additional information, such as keysym,
                                 * button, Tk_Uid, or 0 if nothing
                                 * additional. */
} PatternTableKey;

/*
 * The following structure defines a pattern, which is matched against X
 * events as part of the process of converting X events into Tcl commands.
 */

typedef struct Pattern {
    int eventType;              /* Type of X event, e.g. ButtonPress. */
    int needMods;               /* Mask of modifiers that must be
                                 * present (0 means no modifiers are
                                 * required). */
    Detail detail;              /* Additional information that must
                                 * match event.  Normally this is 0,
                                 * meaning no additional information
                                 * must match.  For KeyPress and
                                 * KeyRelease events, a keySym may
                                 * be specified to select a
                                 * particular keystroke (0 means any
                                 * keystrokes).  For button events,
                                 * specifies a particular button (0
                                 * means any buttons are OK).  For virtual
                                 * events, specifies the Tk_Uid of the
                                 * virtual event name (never 0). */
} Pattern;

/*
 * The following structure defines a pattern sequence, which consists of one
 * or more patterns.  In order to trigger, a pattern sequence must match
 * the most recent X events (first pattern to most recent event, next
 * pattern to next event, and so on).  It is used as the hash value in a
 * patternTable for both binding tables and virtual event tables.
 *
 * In a binding table, it is the sequence of physical events that make up
 * a binding for an object.
 * 
 * In a virtual event table, it is the sequence of physical events that
 * define a virtual event.
 *
 * The same structure is used for both types of pattern tables so that the 
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */

typedef struct PatSeq {
    int numPats;                /* Number of patterns in sequence (usually
                                 * 1). */
    TkBindEvalProc *eventProc;  /* The procedure that will be invoked on
                                 * the clientData when this pattern sequence
                                 * matches. */
    TkBindFreeProc *freeProc;   /* The procedure that will be invoked to
                                 * release the clientData when this pattern
                                 * sequence is freed. */
    ClientData clientData;      /* Arbitray data passed to eventProc and
                                 * freeProc when sequence matches. */
    int flags;                  /* Miscellaneous flag values; see below for
                                 * definitions. */
    int refCount;               /* Number of times that this binding is in
                                 * the midst of executing.  If greater than 1,
                                 * then a recursive invocation is happening.
                                 * Only when this is zero can the binding
                                 * actually be freed. */
    struct PatSeq *nextSeqPtr;  /* Next in list of all pattern sequences
                                 * that have the same initial pattern.  NULL
                                 * means end of list. */
    Tcl_HashEntry *hPtr;        /* Pointer to hash table entry for the
                                 * initial pattern.  This is the head of the
                                 * list of which nextSeqPtr forms a part. */
    struct VirtualOwners *voPtr;/* In a binding table, always NULL.  In a
                                 * virtual event table, identifies the array
                                 * of virtual events that can be triggered by
                                 * this event. */
    struct PatSeq *nextObjPtr;  /* In a binding table, next in list of all
                                 * pattern sequences for the same object (NULL
                                 * for end of list).  Needed to implement
                                 * Tk_DeleteAllBindings.  In a virtual event
                                 * table, always NULL. */
    Pattern pats[1];            /* Array of "numPats" patterns.  Only one
                                 * element is declared here but in actuality
                                 * enough space will be allocated for "numPats"
                                 * patterns.  To match, pats[0] must match
                                 * event n, pats[1] must match event n-1, etc.
                                 */
} PatSeq;

/*
 * Flag values for PatSeq structures:
 *
 * PAT_NEARBY           1 means that all of the events matching
 *                      this sequence must occur with nearby X
 *                      and Y mouse coordinates and close in time.
 *                      This is typically used to restrict multiple
 *                      button presses.
 * MARKED_DELETED       1 means that this binding has been marked as deleted
 *                      and removed from the binding table, but its memory
 *                      could not be released because it was already queued for
 *                      execution.  When the binding is actually about to be
 *                      executed, this flag will be checked and the binding
 *                      skipped if set.
 */

#define PAT_NEARBY              0x1
#define MARKED_DELETED          0x2

/*
 * Constants that define how close together two events must be
 * in milliseconds or pixels to meet the PAT_NEARBY constraint:
 */

#define NEARBY_PIXELS           5
#define NEARBY_MS               500


/*
 * The following structure keeps track of all the virtual events that are
 * associated with a particular physical event.  It is pointed to by the
 * voPtr field in a PatSeq in the patternTable of a  virtual event table.
 */

typedef struct VirtualOwners {
    int numOwners;                  /* Number of virtual events to trigger. */
    Tcl_HashEntry *owners[1];       /* Array of pointers to entries in
                                     * nameTable.  Enough space will
                                     * actually be allocated for numOwners
                                     * hash entries. */
} VirtualOwners;

/*
 * The following structure is used in the nameTable of a virtual event
 * table to associate a virtual event with all the physical events that can
 * trigger it.
 */
typedef struct PhysicalsOwned {
    int numOwned;                   /* Number of physical events owned. */
    PatSeq *patSeqs[1];             /* Array of pointers to physical event
                                     * patterns.  Enough space will actually
                                     * be allocated to hold numOwned. */
} PhysicalsOwned;

/*
 * One of the following structures exists for each interpreter.  This
 * structure keeps track of the current display and screen in the
 * interpreter, so that a script can be invoked whenever the display/screen
 * changes (the script does things like point tkPriv at a display-specific
 * structure).
 */

typedef struct {
    TkDisplay *curDispPtr;      /* Display for last binding command invoked
                                 * in this application. */
    int curScreenIndex;         /* Index of screen for last binding command. */
    int bindingDepth;           /* Number of active instances of Tk_BindEvent
                                 * in this application. */
} ScreenInfo;

/*
 * The following structure is used to keep track of all the C bindings that
 * are awaiting invocation and whether the window they refer to has been
 * destroyed.  If the window is destroyed, then all pending callbacks for
 * that window will be cancelled.  The Tcl bindings will still all be
 * invoked, however.  
 */

typedef struct PendingBinding {
    struct PendingBinding *nextPtr;
                                /* Next in chain of pending bindings, in
                                 * case a recursive binding evaluation is in
                                 * progress. */
    Tk_Window tkwin;            /* The window that the following bindings
                                 * depend upon. */
    int deleted;                /* Set to non-zero by window cleanup code
                                 * if tkwin is deleted. */
    PatSeq *matchArray[5];      /* Array of pending C bindings.  The actual
                                 * size of this depends on how many C bindings
                                 * matched the event passed to Tk_BindEvent.
                                 * THIS FIELD MUST BE THE LAST IN THE
                                 * STRUCTURE. */
} PendingBinding;

/*
 * The following structure keeps track of all the information local to
 * the binding package on a per interpreter basis.
 */

typedef struct BindInfo {
    VirtualEventTable virtualEventTable;
                                /* The virtual events that exist in this
                                 * interpreter. */
    ScreenInfo screenInfo;      /* Keeps track of the current display and
                                 * screen, so it can be restored after
                                 * a binding has executed. */
    PendingBinding *pendingList;/* The list of pending C bindings, kept in
                                 * case a C or Tcl binding causes the target
                                 * window to be deleted. */
    int deleted;                /* 1 the application has been deleted but
                                 * the structure has been preserved. */
} BindInfo;
    
/*
 * In X11R4 and earlier versions, XStringToKeysym is ridiculously
 * slow.  The data structure and hash table below, along with the
 * code that uses them, implement a fast mapping from strings to
 * keysyms.  In X11R5 and later releases XStringToKeysym is plenty
 * fast so this stuff isn't needed.  The #define REDO_KEYSYM_LOOKUP
 * is normally undefined, so that XStringToKeysym gets used.  It
 * can be set in the Makefile to enable the use of the hash table
 * below.
 */

#ifdef REDO_KEYSYM_LOOKUP
typedef struct {
    char *name;                         /* Name of keysym. */
    KeySym value;                       /* Numeric identifier for keysym. */
} KeySymInfo;
static KeySymInfo keyArray[] = {
#ifndef lint
#include "ks_names.h"
#endif
    {(char *) NULL, 0}
};
static Tcl_HashTable keySymTable;       /* keyArray hashed by keysym value. */
static Tcl_HashTable nameTable;         /* keyArray hashed by keysym name. */
#endif /* REDO_KEYSYM_LOOKUP */

/*
 * Set to non-zero when the package-wide static variables have been
 * initialized.
 */

static int initialized = 0;
TCL_DECLARE_MUTEX(bindMutex)

/*
 * A hash table is kept to map from the string names of event
 * modifiers to information about those modifiers.  The structure
 * for storing this information, and the hash table built at
 * initialization time, are defined below.
 */

typedef struct {
    char *name;                 /* Name of modifier. */
    int mask;                   /* Button/modifier mask value,                                                   * such as Button1Mask. */
    int flags;                  /* Various flags;  see below for
                                 * definitions. */
} ModInfo;

/*
 * Flags for ModInfo structures:
 *
 * DOUBLE -             Non-zero means duplicate this event,
 *                      e.g. for double-clicks.
 * TRIPLE -             Non-zero means triplicate this event,
 *                      e.g. for triple-clicks.
 * QUADRUPLE -          Non-zero means quadruple this event,
 *                      e.g. for 4-fold-clicks.
 * MULT_CLICKS -        Combination of all of above.
 */

#define DOUBLE          1
#define TRIPLE          2
#define QUADRUPLE       4
#define MULT_CLICKS     7

static ModInfo modArray[] = {
    {"Control",         ControlMask,    0},
    {"Shift",           ShiftMask,      0},
    {"Lock",            LockMask,       0},
    {"Meta",            META_MASK,      0},
    {"M",               META_MASK,      0},
    {"Alt",             ALT_MASK,       0},
    {"B1",              Button1Mask,    0},
    {"Button1",         Button1Mask,    0},
    {"B2",              Button2Mask,    0},
    {"Button2",         Button2Mask,    0},
    {"B3",              Button3Mask,    0},
    {"Button3",         Button3Mask,    0},
    {"B4",              Button4Mask,    0},
    {"Button4",         Button4Mask,    0},
    {"B5",              Button5Mask,    0},
    {"Button5",         Button5Mask,    0},
    {"Mod1",            Mod1Mask,       0},
    {"M1",              Mod1Mask,       0},
    {"Command",         Mod1Mask,       0},
    {"Mod2",            Mod2Mask,       0},
    {"M2",              Mod2Mask,       0},
    {"Option",          Mod2Mask,       0},
    {"Mod3",            Mod3Mask,       0},
    {"M3",              Mod3Mask,       0},
    {"Mod4",            Mod4Mask,       0},
    {"M4",              Mod4Mask,       0},
    {"Mod5",            Mod5Mask,       0},
    {"M5",              Mod5Mask,       0},
    {"Double",          0,              DOUBLE},
    {"Triple",          0,              TRIPLE},
    {"Quadruple",       0,              QUADRUPLE},
    {"Any",             0,              0},     /* Ignored: historical relic. */
    {NULL,              0,              0}
};
static Tcl_HashTable modTable;

/*
 * This module also keeps a hash table mapping from event names
 * to information about those events.  The structure, an array
 * to use to initialize the hash table, and the hash table are
 * all defined below.
 */

typedef struct {
    char *name;                 /* Name of event. */
    int type;                   /* Event type for X, such as
                                 * ButtonPress. */
    int eventMask;              /* Mask bits (for XSelectInput)
                                 * for this event type. */
} EventInfo;

/*
 * Note:  some of the masks below are an OR-ed combination of
 * several masks.  This is necessary because X doesn't report
 * up events unless you also ask for down events.  Also, X
 * doesn't report button state in motion events unless you've
 * asked about button events.
 */

static EventInfo eventArray[] = {
    {"Key",             KeyPress,               KeyPressMask},
    {"KeyPress",        KeyPress,               KeyPressMask},
    {"KeyRelease",      KeyRelease,             KeyPressMask|KeyReleaseMask},
    {"Button",          ButtonPress,            ButtonPressMask},
    {"ButtonPress",     ButtonPress,            ButtonPressMask},
    {"ButtonRelease",   ButtonRelease,
            ButtonPressMask|ButtonReleaseMask},
    {"Motion",          MotionNotify,
            ButtonPressMask|PointerMotionMask},
    {"Enter",           EnterNotify,            EnterWindowMask},
    {"Leave",           LeaveNotify,            LeaveWindowMask},
    {"FocusIn",         FocusIn,                FocusChangeMask},
    {"FocusOut",        FocusOut,               FocusChangeMask},
    {"Expose",          Expose,                 ExposureMask},
    {"Visibility",      VisibilityNotify,       VisibilityChangeMask},
    {"Destroy",         DestroyNotify,          StructureNotifyMask},
    {"Unmap",           UnmapNotify,            StructureNotifyMask},
    {"Map",             MapNotify,              StructureNotifyMask},
    {"Reparent",        ReparentNotify,         StructureNotifyMask},
    {"Configure",       ConfigureNotify,        StructureNotifyMask},
    {"Gravity",         GravityNotify,          StructureNotifyMask},
    {"Circulate",       CirculateNotify,        StructureNotifyMask},
    {"Property",        PropertyNotify,         PropertyChangeMask},
    {"Colormap",        ColormapNotify,         ColormapChangeMask},
    {"Activate",        ActivateNotify,         ActivateMask},
    {"Deactivate",      DeactivateNotify,       ActivateMask},
    {"MouseWheel",      MouseWheelEvent,        MouseWheelMask},
    {(char *) NULL,     0,                      0}
};
static Tcl_HashTable eventTable;

/*
 * The defines and table below are used to classify events into
 * various groups.  The reason for this is that logically identical
 * fields (e.g. "state") appear at different places in different
 * types of events.  The classification masks can be used to figure
 * out quickly where to extract information from events.
 */

#define KEY                     0x1
#define BUTTON                  0x2
#define MOTION                  0x4
#define CROSSING                0x8
#define FOCUS                   0x10
#define EXPOSE                  0x20
#define VISIBILITY              0x40
#define CREATE                  0x80
#define DESTROY                 0x100
#define UNMAP                   0x200
#define MAP                     0x400
#define REPARENT                0x800
#define CONFIG                  0x1000
#define GRAVITY                 0x2000
#define CIRC                    0x4000
#define PROP                    0x8000
#define COLORMAP                0x10000
#define VIRTUAL                 0x20000
#define ACTIVATE                0x40000

#define KEY_BUTTON_MOTION_VIRTUAL       (KEY|BUTTON|MOTION|VIRTUAL)

static int flagArray[TK_LASTEVENT] = {
   /* Not used */               0,
   /* Not used */               0,
   /* KeyPress */               KEY,
   /* KeyRelease */             KEY,
   /* ButtonPress */            BUTTON,
   /* ButtonRelease */          BUTTON,
   /* MotionNotify */           MOTION,
   /* EnterNotify */            CROSSING,
   /* LeaveNotify */            CROSSING,
   /* FocusIn */                FOCUS,
   /* FocusOut */               FOCUS,
   /* KeymapNotify */           0,
   /* Expose */                 EXPOSE,
   /* GraphicsExpose */         EXPOSE,
   /* NoExpose */               0,
   /* VisibilityNotify */       VISIBILITY,
   /* CreateNotify */           CREATE,
   /* DestroyNotify */          DESTROY,
   /* UnmapNotify */            UNMAP,
   /* MapNotify */              MAP,
   /* MapRequest */             0,
   /* ReparentNotify */         REPARENT,
   /* ConfigureNotify */        CONFIG,
   /* ConfigureRequest */       0,
   /* GravityNotify */          GRAVITY,
   /* ResizeRequest */          0,
   /* CirculateNotify */        CIRC,
   /* CirculateRequest */       0,
   /* PropertyNotify */         PROP,
   /* SelectionClear */         0,
   /* SelectionRequest */       0,
   /* SelectionNotify */        0,
   /* ColormapNotify */         COLORMAP,
   /* ClientMessage */          0,
   /* MappingNotify */          0,
   /* VirtualEvent */           VIRTUAL,
   /* Activate */               ACTIVATE,           
   /* Deactivate */             ACTIVATE,
   /* MouseWheel */             KEY
};

/*
 * The following table is used to map between the location where an
 * generated event should be queued and the string used to specify the
 * location.
 */
 
static TkStateMap queuePosition[] = {
    {-1,                        "now"},
    {TCL_QUEUE_HEAD,            "head"},
    {TCL_QUEUE_MARK,            "mark"},
    {TCL_QUEUE_TAIL,            "tail"},
    {-2,                        NULL}
};

/*
 * The following tables are used as a two-way map between X's internal
 * numeric values for fields in an XEvent and the strings used in Tcl.  The
 * tables are used both when constructing an XEvent from user input and
 * when providing data from an XEvent to the user.
 */

static TkStateMap notifyMode[] = {
    {NotifyNormal,              "NotifyNormal"},
    {NotifyGrab,                "NotifyGrab"},
    {NotifyUngrab,              "NotifyUngrab"},
    {NotifyWhileGrabbed,        "NotifyWhileGrabbed"},
    {-1, NULL}
};

static TkStateMap notifyDetail[] = {
    {NotifyAncestor,            "NotifyAncestor"},
    {NotifyVirtual,             "NotifyVirtual"},
    {NotifyInferior,            "NotifyInferior"},
    {NotifyNonlinear,           "NotifyNonlinear"},
    {NotifyNonlinearVirtual,    "NotifyNonlinearVirtual"},
    {NotifyPointer,             "NotifyPointer"},
    {NotifyPointerRoot,         "NotifyPointerRoot"},
    {NotifyDetailNone,          "NotifyDetailNone"},
    {-1, NULL}
};

static TkStateMap circPlace[] = {
    {PlaceOnTop,                "PlaceOnTop"},
    {PlaceOnBottom,             "PlaceOnBottom"},
    {-1, NULL}
};

static TkStateMap visNotify[] = {
    {VisibilityUnobscured,          "VisibilityUnobscured"},
    {VisibilityPartiallyObscured,   "VisibilityPartiallyObscured"},
    {VisibilityFullyObscured,       "VisibilityFullyObscured"},
    {-1, NULL}
};

/*
 * Prototypes for local procedures defined in this file:
 */

static void             ChangeScreen _ANSI_ARGS_((Tcl_Interp *interp,
                            char *dispName, int screenIndex));
static int              CreateVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                            VirtualEventTable *vetPtr, char *virtString,
                            char *eventString));
static int              DeleteVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                            VirtualEventTable *vetPtr, char *virtString,
                            char *eventString));
static void             DeleteVirtualEventTable _ANSI_ARGS_((
                            VirtualEventTable *vetPtr));
static void             ExpandPercents _ANSI_ARGS_((TkWindow *winPtr,
                            char *before, XEvent *eventPtr, KeySym keySym,
                            Tcl_DString *dsPtr));
static void             FreeTclBinding _ANSI_ARGS_((ClientData clientData));
static PatSeq *         FindSequence _ANSI_ARGS_((Tcl_Interp *interp,
                            Tcl_HashTable *patternTablePtr, ClientData object,
                            char *eventString, int create, int allowVirtual,
                            unsigned long *maskPtr));
static void             GetAllVirtualEvents _ANSI_ARGS_((Tcl_Interp *interp,
                            VirtualEventTable *vetPtr));
static char *           GetField _ANSI_ARGS_((char *p, char *copy, int size));
static void             GetPatternString _ANSI_ARGS_((PatSeq *psPtr,
                            Tcl_DString *dsPtr));
static int              GetVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                            VirtualEventTable *vetPtr, char *virtString));
static Tk_Uid           GetVirtualEventUid _ANSI_ARGS_((Tcl_Interp *interp,
                            char *virtString));
static int              HandleEventGenerate _ANSI_ARGS_((Tcl_Interp *interp,
                            Tk_Window main, int objc,
                            Tcl_Obj *CONST objv[]));
static void             InitVirtualEventTable _ANSI_ARGS_((
                            VirtualEventTable *vetPtr));
static PatSeq *         MatchPatterns _ANSI_ARGS_((TkDisplay *dispPtr,
                            BindingTable *bindPtr, PatSeq *psPtr,
                            PatSeq *bestPtr, ClientData *objectPtr,
                            PatSeq **sourcePtrPtr));
static int              NameToWindow _ANSI_ARGS_((Tcl_Interp *interp,
                            Tk_Window main, Tcl_Obj *objPtr,
                            Tk_Window *tkwinPtr));
static int              ParseEventDescription _ANSI_ARGS_((Tcl_Interp *interp,
                            char **eventStringPtr, Pattern *patPtr,
                            unsigned long *eventMaskPtr));
static void             DoWarp _ANSI_ARGS_((ClientData clientData));

/*
 * The following define is used as a short circuit for the callback
 * procedure to evaluate a TclBinding.  The actual evaluation of the
 * binding is handled inline, because special things have to be done
 * with a Tcl binding before evaluation time.
 */

#define EvalTclBinding  ((TkBindEvalProc *) 1)


/*
 *---------------------------------------------------------------------------
 *
 * TkBindInit --
 *
 *      This procedure is called when an application is created.  It
 *      initializes all the structures used by bindings and virtual
 *      events.  It must be called before any other functions in this
 *      file are called.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory allocated.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindInit(mainPtr)
    TkMainInfo *mainPtr;        /* The newly created application. */
{
    BindInfo *bindInfoPtr;

    if (sizeof(XEvent) < sizeof(XVirtualEvent)) {
        panic("TkBindInit: virtual events can't be supported");
    }

    /*
     * Initialize the static data structures used by the binding package.
     * They are only initialized once, no matter how many interps are
     * created.
     */

    if (!initialized) {
        Tcl_MutexLock(&bindMutex);
        if (!initialized) {
            Tcl_HashEntry *hPtr;
            ModInfo *modPtr;
            EventInfo *eiPtr;
            int dummy;

#ifdef REDO_KEYSYM_LOOKUP
            KeySymInfo *kPtr;

            Tcl_InitHashTable(&keySymTable, TCL_STRING_KEYS);
            Tcl_InitHashTable(&nameTable, TCL_ONE_WORD_KEYS);
            for (kPtr = keyArray; kPtr->name != NULL; kPtr++) {
                hPtr = Tcl_CreateHashEntry(&keySymTable, kPtr->name, &dummy);
                Tcl_SetHashValue(hPtr, kPtr->value);
                hPtr = Tcl_CreateHashEntry(&nameTable, (char *) kPtr->value,
                        &dummy);
                Tcl_SetHashValue(hPtr, kPtr->name);
            }
#endif /* REDO_KEYSYM_LOOKUP */

            Tcl_InitHashTable(&modTable, TCL_STRING_KEYS);
            for (modPtr = modArray; modPtr->name != NULL; modPtr++) {
                hPtr = Tcl_CreateHashEntry(&modTable, modPtr->name, &dummy);
                Tcl_SetHashValue(hPtr, modPtr);
            }
    
            Tcl_InitHashTable(&eventTable, TCL_STRING_KEYS);
            for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
                hPtr = Tcl_CreateHashEntry(&eventTable, eiPtr->name, &dummy);
                Tcl_SetHashValue(hPtr, eiPtr);
            }
            initialized = 1;
        }
        Tcl_MutexUnlock(&bindMutex);
    }

    mainPtr->bindingTable = Tk_CreateBindingTable(mainPtr->interp);

    bindInfoPtr = (BindInfo *) ckalloc(sizeof(BindInfo));
    InitVirtualEventTable(&bindInfoPtr->virtualEventTable);
    bindInfoPtr->screenInfo.curDispPtr = NULL;
    bindInfoPtr->screenInfo.curScreenIndex = -1;
    bindInfoPtr->screenInfo.bindingDepth = 0;
    bindInfoPtr->pendingList = NULL;
    bindInfoPtr->deleted = 0;
    mainPtr->bindInfo = (TkBindInfo) bindInfoPtr;

    TkpInitializeMenuBindings(mainPtr->interp, mainPtr->bindingTable);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindFree --
 *
 *      This procedure is called when an application is deleted.  It
 *      deletes all the structures used by bindings and virtual events.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory freed.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindFree(mainPtr)
    TkMainInfo *mainPtr;        /* The newly created application. */
{
    BindInfo *bindInfoPtr;
    
    Tk_DeleteBindingTable(mainPtr->bindingTable);
    mainPtr->bindingTable = NULL;

    bindInfoPtr = (BindInfo *) mainPtr->bindInfo;
    DeleteVirtualEventTable(&bindInfoPtr->virtualEventTable);
    bindInfoPtr->deleted = 1;
    Tcl_EventuallyFree((ClientData) bindInfoPtr, Tcl_Free);
    mainPtr->bindInfo = NULL;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBindingTable --
 *
 *      Set up a new domain in which event bindings may be created.
 *
 * Results:
 *      The return value is a token for the new table, which must
 *      be passed to procedures like Tk_CreateBinding.
 *
 * Side effects:
 *      Memory is allocated for the new table.
 *
 *--------------------------------------------------------------
 */

Tk_BindingTable
Tk_CreateBindingTable(interp)
    Tcl_Interp *interp;         /* Interpreter to associate with the binding
                                 * table:  commands are executed in this
                                 * interpreter. */
{
    BindingTable *bindPtr;
    int i;

    /*
     * Create and initialize a new binding table.
     */

    bindPtr = (BindingTable *) ckalloc(sizeof(BindingTable));
    for (i = 0; i < EVENT_BUFFER_SIZE; i++) {
        bindPtr->eventRing[i].type = -1;
    }
    bindPtr->curEvent = 0;
    Tcl_InitHashTable(&bindPtr->patternTable,
            sizeof(PatternTableKey)/sizeof(int));
    Tcl_InitHashTable(&bindPtr->objectTable, TCL_ONE_WORD_KEYS);
    bindPtr->interp = interp;
    return (Tk_BindingTable) bindPtr;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBindingTable --
 *
 *      Destroy a binding table and free up all its memory.
 *      The caller should not use bindingTable again after
 *      this procedure returns.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory is freed.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteBindingTable(bindingTable)
    Tk_BindingTable bindingTable;       /* Token for the binding table to
                                         * destroy. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *nextPtr;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    /*
     * Find and delete all of the patterns associated with the binding
     * table.
     */

    for (hPtr = Tcl_FirstHashEntry(&bindPtr->patternTable, &search);
            hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
                psPtr != NULL; psPtr = nextPtr) {
            nextPtr = psPtr->nextSeqPtr;
            psPtr->flags |= MARKED_DELETED;
            if (psPtr->refCount == 0) {
                if (psPtr->freeProc != NULL) {
                    (*psPtr->freeProc)(psPtr->clientData);
                }
                ckfree((char *) psPtr);
            }
        }
    }

    /*
     * Clean up the rest of the information associated with the
     * binding table.
     */

    Tcl_DeleteHashTable(&bindPtr->patternTable);
    Tcl_DeleteHashTable(&bindPtr->objectTable);
    ckfree((char *) bindPtr);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBinding --
 *
 *      Add a binding to a binding table, so that future calls to
 *      Tk_BindEvent may execute the command in the binding.
 *
 * Results:
 *      The return value is 0 if an error occurred while setting
 *      up the binding.  In this case, an error message will be
 *      left in the interp's result.  If all went well then the return
 *      value is a mask of the event types that must be made
 *      available to Tk_BindEvent in order to properly detect when
 *      this binding triggers.  This value can be used to determine
 *      what events to select for in a window, for example.
 *
 * Side effects:
 *      An existing binding on the same event sequence may be
 *      replaced.  
 *      The new binding may cause future calls to Tk_BindEvent to
 *      behave differently than they did previously.
 *
 *--------------------------------------------------------------
 */

unsigned long
Tk_CreateBinding(interp, bindingTable, object, eventString, command, append)
    Tcl_Interp *interp;         /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                                /* Table in which to create binding. */
    ClientData object;          /* Token for object with which binding is
                                 * associated. */
    char *eventString;          /* String describing event sequence that
                                 * triggers binding. */
    char *command;              /* Contains Tcl command to execute when
                                 * binding triggers. */
    int append;                 /* 0 means replace any existing binding for
                                 * eventString; 1 means append to that
                                 * binding.  If the existing binding is for a
                                 * callback function and not a Tcl command
                                 * string, the existing binding will always be
                                 * replaced. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;
    char *new, *old;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
            1, 1, &eventMask);
    if (psPtr == NULL) {
        return 0;
    }
    if (psPtr->eventProc == NULL) {
        int new;
        Tcl_HashEntry *hPtr;
        
        /*
         * This pattern sequence was just created.
         * Link the pattern into the list associated with the object, so
         * that if the object goes away, these bindings will all
         * automatically be deleted.
         */

        hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
                &new);
        if (new) {
            psPtr->nextObjPtr = NULL;
        } else {
            psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
        }
        Tcl_SetHashValue(hPtr, psPtr);
    } else if (psPtr->eventProc != EvalTclBinding) {
        /*
         * Free existing procedural binding.
         */

        if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
        }
        psPtr->clientData = NULL;
        append = 0;
    }

    old = (char *) psPtr->clientData;
    if ((append != 0) && (old != NULL)) {
        int length;

        length = strlen(old) + strlen(command) + 2;
        new = (char *) ckalloc((unsigned) length);
        sprintf(new, "%s\n%s", old, command);
    } else {
        new = (char *) ckalloc((unsigned) strlen(command) + 1);
        strcpy(new, command);
    }
    if (old != NULL) {
        ckfree(old);
    }
    psPtr->eventProc = EvalTclBinding;
    psPtr->freeProc = FreeTclBinding;
    psPtr->clientData = (ClientData) new;
    return eventMask;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkCreateBindingProcedure --
 *
 *      Add a C binding to a binding table, so that future calls to
 *      Tk_BindEvent may callback the procedure in the binding.
 *
 * Results:
 *      The return value is 0 if an error occurred while setting
 *      up the binding.  In this case, an error message will be
 *      left in the interp's result.  If all went well then the return
 *      value is a mask of the event types that must be made
 *      available to Tk_BindEvent in order to properly detect when
 *      this binding triggers.  This value can be used to determine
 *      what events to select for in a window, for example.
 *
 * Side effects:
 *      Any existing binding on the same event sequence will be
 *      replaced.  
 *
 *---------------------------------------------------------------------------
 */

unsigned long
TkCreateBindingProcedure(interp, bindingTable, object, eventString,
        eventProc, freeProc, clientData)
    Tcl_Interp *interp;         /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                                /* Table in which to create binding. */
    ClientData object;          /* Token for object with which binding is
                                 * associated. */
    char *eventString;          /* String describing event sequence that
                                 * triggers binding. */
    TkBindEvalProc *eventProc;  /* Procedure to invoke when binding
                                 * triggers.  Must not be NULL. */
    TkBindFreeProc *freeProc;   /* Procedure to invoke when binding is
                                 * freed.  May be NULL for no procedure. */
    ClientData clientData;      /* Arbitrary ClientData to pass to eventProc
                                 * and freeProc. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
            1, 1, &eventMask);
    if (psPtr == NULL) {
        return 0;
    }
    if (psPtr->eventProc == NULL) {
        int new;
        Tcl_HashEntry *hPtr;
        
        /*
         * This pattern sequence was just created.
         * Link the pattern into the list associated with the object, so
         * that if the object goes away, these bindings will all
         * automatically be deleted.
         */

        hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
                &new);
        if (new) {
            psPtr->nextObjPtr = NULL;
        } else {
            psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
        }
        Tcl_SetHashValue(hPtr, psPtr);
    } else {

        /*
         * Free existing callback.
         */

        if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
        }
    }

    psPtr->eventProc = eventProc;
    psPtr->freeProc = freeProc;
    psPtr->clientData = clientData;
    return eventMask;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBinding --
 *
 *      Remove an event binding from a binding table.
 *
 * Results:
 *      The result is a standard Tcl return value.  If an error
 *      occurs then the interp's result will contain an error message.
 *
 * Side effects:
 *      The binding given by object and eventString is removed
 *      from bindingTable.
 *
 *--------------------------------------------------------------
 */

int
Tk_DeleteBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;                 /* Used for error reporting. */
    Tk_BindingTable bindingTable;       /* Table in which to delete binding. */
    ClientData object;                  /* Token for object with which binding
                                         * is associated. */
    char *eventString;                  /* String describing event sequence
                                         * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    unsigned long eventMask;
    Tcl_HashEntry *hPtr;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
            0, 1, &eventMask);
    if (psPtr == NULL) {
        Tcl_ResetResult(interp);
        return TCL_OK;
    }

    /*
     * Unlink the binding from the list for its object, then from the
     * list for its pattern.
     */

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
        panic("Tk_DeleteBinding couldn't find object table entry");
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    if (prevPtr == psPtr) {
        Tcl_SetHashValue(hPtr, psPtr->nextObjPtr);
    } else {
        for ( ; ; prevPtr = prevPtr->nextObjPtr) {
            if (prevPtr == NULL) {
                panic("Tk_DeleteBinding couldn't find on object list");
            }
            if (prevPtr->nextObjPtr == psPtr) {
                prevPtr->nextObjPtr = psPtr->nextObjPtr;
                break;
            }
        }
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
    if (prevPtr == psPtr) {
        if (psPtr->nextSeqPtr == NULL) {
            Tcl_DeleteHashEntry(psPtr->hPtr);
        } else {
            Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
        }
    } else {
        for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
            if (prevPtr == NULL) {
                panic("Tk_DeleteBinding couldn't find on hash chain");
            }
            if (prevPtr->nextSeqPtr == psPtr) {
                prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                break;
            }
        }
    }

    psPtr->flags |= MARKED_DELETED;
    if (psPtr->refCount == 0) {
        if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
        }
        ckfree((char *) psPtr);
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetBinding --
 *
 *      Return the command associated with a given event string.
 *
 * Results:
 *      The return value is a pointer to the command string
 *      associated with eventString for object in the domain
 *      given by bindingTable.  If there is no binding for
 *      eventString, or if eventString is improperly formed,
 *      then NULL is returned and an error message is left in
 *      the interp's result.  The return value is semi-static:  it
 *      will persist until the binding is changed or deleted.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

char *
Tk_GetBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;                 /* Interpreter for error reporting. */
    Tk_BindingTable bindingTable;       /* Table in which to look for
                                         * binding. */
    ClientData object;                  /* Token for object with which binding
                                         * is associated. */
    char *eventString;                  /* String describing event sequence
                                         * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
            0, 1, &eventMask);
    if (psPtr == NULL) {
        return NULL;
    }
    if (psPtr->eventProc == EvalTclBinding) {
        return (char *) psPtr->clientData;
    }
    return "";
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetAllBindings --
 *
 *      Return a list of event strings for all the bindings
 *      associated with a given object.
 *
 * Results:
 *      There is no return value.  The interp's result is modified to
 *      hold a Tcl list with one entry for each binding associated
 *      with object in bindingTable.  Each entry in the list
 *      contains the event string associated with one binding.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

void
Tk_GetAllBindings(interp, bindingTable, object)
    Tcl_Interp *interp;                 /* Interpreter returning result or
                                         * error. */
    Tk_BindingTable bindingTable;       /* Table in which to look for
                                         * bindings. */
    ClientData object;                  /* Token for object. */

{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    Tcl_DString ds;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
        return;
    }
    Tcl_DStringInit(&ds);
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
            psPtr = psPtr->nextObjPtr) {
        /* 
         * For each binding, output information about each of the
         * patterns in its sequence.
         */
         
        Tcl_DStringSetLength(&ds, 0);
        GetPatternString(psPtr, &ds);
        Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteAllBindings --
 *
 *      Remove all bindings associated with a given object in a
 *      given binding table.
 *
 * Results:
 *      All bindings associated with object are removed from
 *      bindingTable.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteAllBindings(bindingTable, object)
    Tk_BindingTable bindingTable;       /* Table in which to delete
                                         * bindings. */
    ClientData object;                  /* Token for object. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    PatSeq *nextPtr;
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
        return;
    }
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
            psPtr = nextPtr) {
        nextPtr  = psPtr->nextObjPtr;

        /*
         * Be sure to remove each binding from its hash chain in the
         * pattern table.  If this is the last pattern in the chain,
         * then delete the hash entry too.
         */

        prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
        if (prevPtr == psPtr) {
            if (psPtr->nextSeqPtr == NULL) {
                Tcl_DeleteHashEntry(psPtr->hPtr);
            } else {
                Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
            }
        } else {
            for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
                if (prevPtr == NULL) {
                    panic("Tk_DeleteAllBindings couldn't find on hash chain");
                }
                if (prevPtr->nextSeqPtr == psPtr) {
                    prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                    break;
                }
            }
        }
        psPtr->flags |= MARKED_DELETED;

        if (psPtr->refCount == 0) {
            if (psPtr->freeProc != NULL) {
                (*psPtr->freeProc)(psPtr->clientData);
            }
            ckfree((char *) psPtr);
        }
    }
    Tcl_DeleteHashEntry(hPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_BindEvent --
 *
 *      This procedure is invoked to process an X event.  The
 *      event is added to those recorded for the binding table.
 *      Then each of the objects at *objectPtr is checked in
 *      order to see if it has a binding that matches the recent
 *      events.  If so, the most specific binding is invoked for
 *      each object.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Depends on the command associated with the matching binding.
 *
 *      All Tcl bindings scripts for each object are accumulated before
 *      the first binding is evaluated.  If the action of a Tcl binding
 *      is to change or delete a binding, or delete the window associated
 *      with the binding, all the original Tcl binding scripts will still
 *      fire.  Contrast this with C binding procedures.  If a pending C
 *      binding (one that hasn't fired yet, but is queued to be fired for
 *      this window) is deleted, it will not be called, and if it is
 *      changed, then the new binding procedure will be called.  If the
 *      window itself is deleted, no further C binding procedures will be
 *      called for this window.  When both Tcl binding scripts and C binding
 *      procedures are interleaved, the above rules still apply. 
 *
 *---------------------------------------------------------------------------
 */

void
Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)
    Tk_BindingTable bindingTable;       /* Table in which to look for
                                         * bindings. */
    XEvent *eventPtr;                   /* What actually happened. */
    Tk_Window tkwin;                    /* Window on display where event
                                         * occurred (needed in order to
                                         * locate display information). */
    int numObjects;                     /* Number of objects at *objectPtr. */
    ClientData *objectPtr;              /* Array of one or more objects
                                         * to check for a matching binding. */
{
    BindingTable *bindPtr;
    TkDisplay *dispPtr;
    ScreenInfo *screenPtr;
    BindInfo *bindInfoPtr;
    TkDisplay *oldDispPtr;
    XEvent *ringPtr;
    PatSeq *vMatchDetailList, *vMatchNoDetailList;
    int flags, oldScreen, i, deferModal;
    unsigned int matchCount, matchSpace;
    Tcl_Interp *interp;
    Tcl_DString scripts, savedResult;
    Detail detail;
    char *p, *end;
    PendingBinding *pendingPtr;
    PendingBinding staticPending;
    TkWindow *winPtr = (TkWindow *)tkwin;
    PatternTableKey key;

    /*
     * Ignore events on windows that don't have names: these are windows
     * like wrapper windows that shouldn't be visible to the
     * application.
     */

    if (winPtr->pathName == NULL) {
        return;
    }

    /*
     * Ignore the event completely if it is an Enter, Leave, FocusIn,
     * or FocusOut event with detail NotifyInferior.  The reason for
     * ignoring these events is that we don't want transitions between
     * a window and its children to visible to bindings on the parent:
     * this would cause problems for mega-widgets, since the internal
     * structure of a mega-widget isn't supposed to be visible to
     * people watching the parent.
     */

    if ((eventPtr->type == EnterNotify)  || (eventPtr->type == LeaveNotify)) {
        if (eventPtr->xcrossing.detail == NotifyInferior) {
            return;
        }
    }
    if ((eventPtr->type == FocusIn)  || (eventPtr->type == FocusOut)) {
        if (eventPtr->xfocus.detail == NotifyInferior) {
            return;
        }
    }

    bindPtr = (BindingTable *) bindingTable;
    dispPtr = ((TkWindow *) tkwin)->dispPtr;
    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;

    /*
     * Add the new event to the ring of saved events for the
     * binding table.  Two tricky points:
     *
     * 1. Combine consecutive MotionNotify events.  Do this by putting
     *    the new event *on top* of the previous event.
     * 2. If a modifier key is held down, it auto-repeats to generate
     *    continuous KeyPress and KeyRelease events.  These can flush
     *    the event ring so that valuable information is lost (such
     *    as repeated button clicks).  To handle this, check for the
     *    special case of a modifier KeyPress arriving when the previous
     *    two events are a KeyRelease and KeyPress of the same key.
     *    If this happens, mark the most recent event (the KeyRelease)
     *    invalid and put the new event on top of the event before that
     *    (the KeyPress).
     */

    if ((eventPtr->type == MotionNotify)
            && (bindPtr->eventRing[bindPtr->curEvent].type == MotionNotify)) {
        /*
         * Don't advance the ring pointer.
         */
    } else if (eventPtr->type == KeyPress) {
        int i;
        for (i = 0; ; i++) {
            if (i >= dispPtr->numModKeyCodes) {
                goto advanceRingPointer;
            }
            if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
                break;
            }
        }
        ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
        if ((ringPtr->type != KeyRelease)
                || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
            goto advanceRingPointer;
        }
        if (bindPtr->curEvent <= 0) {
            i = EVENT_BUFFER_SIZE - 1;
        } else {
            i = bindPtr->curEvent - 1;
        }
        ringPtr = &bindPtr->eventRing[i];
        if ((ringPtr->type != KeyPress)
                || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
            goto advanceRingPointer;
        }
        bindPtr->eventRing[bindPtr->curEvent].type = -1;
        bindPtr->curEvent = i;
    } else {
        advanceRingPointer:
        bindPtr->curEvent++;
        if (bindPtr->curEvent >= EVENT_BUFFER_SIZE) {
            bindPtr->curEvent = 0;
        }
    }
    ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
    memcpy((VOID *) ringPtr, (VOID *) eventPtr, sizeof(XEvent));
    detail.clientData = 0;
    flags = flagArray[ringPtr->type];
    if (flags & KEY) {
        detail.keySym = TkpGetKeySym(dispPtr, ringPtr);
        if (detail.keySym == NoSymbol) {
            detail.keySym = 0;
        }
    } else if (flags & BUTTON) {
        detail.button = ringPtr->xbutton.button;
    } else if (flags & VIRTUAL) {
        detail.name = ((XVirtualEvent *) ringPtr)->name;
    }
    bindPtr->detailRing[bindPtr->curEvent] = detail;

    /*
     * Find out if there are any virtual events that correspond to this
     * physical event (or sequence of physical events).
     */

    vMatchDetailList = NULL;
    vMatchNoDetailList = NULL;
    memset(&key, 0, sizeof(key));

    if (ringPtr->type != VirtualEvent) {
        Tcl_HashTable *veptPtr;
        Tcl_HashEntry *hPtr;

        veptPtr = &bindInfoPtr->virtualEventTable.patternTable;

        key.object  = NULL;
        key.type    = ringPtr->type;
        key.detail  = detail;

        hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
        if (hPtr != NULL) {
            vMatchDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
        }

        if (key.detail.clientData != 0) {
            key.detail.clientData = 0;
            hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
            if (hPtr != NULL) {
                vMatchNoDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
            }
        }
    }

    /*
     * Loop over all the binding tags, finding the binding script or
     * callback for each one.  Append all of the binding scripts, with
     * %-sequences expanded, to "scripts", with null characters separating
     * the scripts for each object.  Append all the callbacks to the array
     * of pending callbacks.  
     */
               
    pendingPtr = &staticPending;
    matchCount = 0;
    matchSpace = sizeof(staticPending.matchArray) / sizeof(PatSeq *);
    Tcl_DStringInit(&scripts);

    for ( ; numObjects > 0; numObjects--, objectPtr++) {
        PatSeq *matchPtr, *sourcePtr;
        Tcl_HashEntry *hPtr;

        matchPtr = NULL;
        sourcePtr = NULL;

        /*
         * Match the new event against those recorded in the pattern table,
         * saving the longest matching pattern.  For events with details
         * (button and key events), look for a binding for the specific
         * key or button.  First see if the event matches a physical event
         * that the object is interested in, then look for a virtual event.
         */

        key.object = *objectPtr;
        key.type = ringPtr->type;
        key.detail = detail;
        hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
        if (hPtr != NULL) {
            matchPtr = MatchPatterns(dispPtr, bindPtr, 
                    (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
                    &sourcePtr);
        }

        if (vMatchDetailList != NULL) {
            matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchDetailList,
                    matchPtr, objectPtr, &sourcePtr);
        }

        /*
         * If no match was found, look for a binding for all keys or buttons
         * (detail of 0).  Again, first match on a virtual event.
         */

        if ((detail.clientData != 0) && (matchPtr == NULL)) {
            key.detail.clientData = 0;
            hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
            if (hPtr != NULL) {
                matchPtr = MatchPatterns(dispPtr, bindPtr,
                        (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
                        &sourcePtr);
            }

            if (vMatchNoDetailList != NULL) {
                matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchNoDetailList,
                        matchPtr, objectPtr, &sourcePtr);
            }

        }
    
        if (matchPtr != NULL) {
            if (sourcePtr->eventProc == NULL) {
                panic("Tk_BindEvent: missing command");
            }
            if (sourcePtr->eventProc == EvalTclBinding) {
                ExpandPercents(winPtr, (char *) sourcePtr->clientData,
                        eventPtr, detail.keySym, &scripts);
            } else {
                if (matchCount >= matchSpace) {
                    PendingBinding *new;
                    unsigned int oldSize, newSize;
                    
                    oldSize = sizeof(staticPending)
                            - sizeof(staticPending.matchArray)
                            + matchSpace * sizeof(PatSeq*);
                    matchSpace *= 2;
                    newSize = sizeof(staticPending)
                            - sizeof(staticPending.matchArray)
                            + matchSpace * sizeof(PatSeq*);
                    new = (PendingBinding *) ckalloc(newSize);
                    memcpy((VOID *) new, (VOID *) pendingPtr, oldSize);
                    if (pendingPtr != &staticPending) {
                        ckfree((char *) pendingPtr);
                    }
                    pendingPtr = new;
                }
                sourcePtr->refCount++;
                pendingPtr->matchArray[matchCount] = sourcePtr;
                matchCount++;
            }
            /*
             * A "" is added to the scripts string to separate the
             * various scripts that should be invoked.
             */

            Tcl_DStringAppend(&scripts, "", 1);
        }
    }
    if (Tcl_DStringLength(&scripts) == 0) {
        return;
    }

    /*
     * Now go back through and evaluate the binding for each object,
     * in order, dealing with "break" and "continue" exceptions
     * appropriately.
     *
     * There are two tricks here:
     * 1. Bindings can be invoked from in the middle of Tcl commands,
     *    where the interp's result is significant (for example, a widget
     *    might be deleted because of an error in creating it, so the
     *    result contains an error message that is eventually going to
     *    be returned by the creating command).  To preserve the result,
     *    we save it in a dynamic string.
     * 2. The binding's action can potentially delete the binding,
     *    so bindPtr may not point to anything valid once the action
     *    completes.  Thus we have to save bindPtr->interp in a
     *    local variable in order to restore the result.
     */

    interp = bindPtr->interp;
    Tcl_DStringInit(&savedResult);

    /*
     * Save information about the current screen, then invoke a script
     * if the screen has changed.
     */

    Tcl_DStringGetResult(interp, &savedResult);
    screenPtr = &bindInfoPtr->screenInfo;
    oldDispPtr = screenPtr->curDispPtr;
    oldScreen = screenPtr->curScreenIndex;
    if ((dispPtr != screenPtr->curDispPtr)
            || (Tk_ScreenNumber(tkwin) != screenPtr->curScreenIndex)) {
        screenPtr->curDispPtr = dispPtr;
        screenPtr->curScreenIndex = Tk_ScreenNumber(tkwin);
        ChangeScreen(interp, dispPtr->name, screenPtr->curScreenIndex);
    }

    if (matchCount > 0) {
        /*
         * Remember the list of pending C binding callbacks, so we can mark
         * them as deleted and not call them if the act of evaluating a C
         * or Tcl binding deletes a C binding callback or even the whole
         * window.
         */

        pendingPtr->nextPtr = bindInfoPtr->pendingList;
        pendingPtr->tkwin = tkwin;
        pendingPtr->deleted = 0;
        bindInfoPtr->pendingList = pendingPtr;
    }
    
    /*
     * Save the current value of the TK_DEFER_MODAL flag so we can
     * restore it at the end of the loop.  Clear the flag so we can
     * detect any recursive requests for a modal loop.
     */

    flags = winPtr->flags;
    winPtr->flags &= ~TK_DEFER_MODAL;

    p = Tcl_DStringValue(&scripts);
    end = p + Tcl_DStringLength(&scripts);
    i = 0;

    /*
     * Be carefule when dereferencing screenPtr or bindInfoPtr.  If we
     * evaluate something that destroys ".", bindInfoPtr would have been
     * freed, but we can tell that by first checking to see if
     * winPtr->mainPtr == NULL.
     */

    Tcl_Preserve((ClientData) bindInfoPtr);
    while (p < end) {
        int code;
        
        if (!bindInfoPtr->deleted) {
            screenPtr->bindingDepth++;
        }
        Tcl_AllowExceptions(interp);

        if (*p == '\0') {
            PatSeq *psPtr;
            
            psPtr = pendingPtr->matchArray[i];
            i++;
            code = TCL_OK;
            if ((pendingPtr->deleted == 0)
                    && ((psPtr->flags & MARKED_DELETED) == 0)) {
                code = (*psPtr->eventProc)(psPtr->clientData, interp, eventPtr,
                        tkwin, detail.keySym);
            }
            psPtr->refCount--;
            if ((psPtr->refCount == 0) && (psPtr->flags & MARKED_DELETED)) {
                if (psPtr->freeProc != NULL) {
                    (*psPtr->freeProc)(psPtr->clientData);
                }
                ckfree((char *) psPtr);
            }
        } else {
            code = Tcl_GlobalEval(interp, p);
            p += strlen(p);
        }
        p++;

        if (!bindInfoPtr->deleted) {
            screenPtr->bindingDepth--;
        }
        if (code != TCL_OK) {
            if (code == TCL_CONTINUE) {
                /*
                 * Do nothing:  just go on to the next command.
                 */
            } else if (code == TCL_BREAK) {
                break;
            } else {
                Tcl_AddErrorInfo(interp, "\n    (command bound to event)");
                Tcl_BackgroundError(interp);
                break;
            }
        }
    }

    if (matchCount > 0 && !pendingPtr->deleted) {
        /*
         * Restore the original modal flag value and invoke the modal loop
         * if needed.
         */

        deferModal = winPtr->flags & TK_DEFER_MODAL;
        winPtr->flags = (winPtr->flags & (unsigned int) ~TK_DEFER_MODAL) 
            | (flags & TK_DEFER_MODAL);
        if (deferModal) {
            (*winPtr->classProcsPtr->modalProc)(tkwin, eventPtr);
        }
    }

    if (!bindInfoPtr->deleted && (screenPtr->bindingDepth != 0)
            && ((oldDispPtr != screenPtr->curDispPtr)
                    || (oldScreen != screenPtr->curScreenIndex))) {

        /*
         * Some other binding script is currently executing, but its
         * screen is no longer current.  Change the current display
         * back again.
         */

        screenPtr->curDispPtr = oldDispPtr;
        screenPtr->curScreenIndex = oldScreen;
        ChangeScreen(interp, oldDispPtr->name, oldScreen);
    }
    Tcl_DStringResult(interp, &savedResult);
    Tcl_DStringFree(&scripts);

    if (matchCount > 0) {
        if (!bindInfoPtr->deleted) {
            /*
             * Delete the pending list from the list of pending scripts
             * for this window.
             */
             
            PendingBinding **curPtrPtr;

            for (curPtrPtr = &bindInfoPtr->pendingList; ; ) {
                if (*curPtrPtr == pendingPtr) {
                    *curPtrPtr = pendingPtr->nextPtr;
                    break;
                }
                curPtrPtr = &(*curPtrPtr)->nextPtr;
            }
        }
        if (pendingPtr != &staticPending) {
            ckfree((char *) pendingPtr);
        }
    }
    Tcl_Release((ClientData) bindInfoPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindDeadWindow --
 *
 *      This procedure is invoked when it is determined that a window is
 *      dead.  It cleans up bind-related information about the window
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Any pending C bindings for this window are cancelled.
 *
 *---------------------------------------------------------------------------
 */
 
void
TkBindDeadWindow(winPtr)
    TkWindow *winPtr;           /* The window that is being deleted. */
{
    BindInfo *bindInfoPtr;
    PendingBinding *curPtr;

    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;
    curPtr = bindInfoPtr->pendingList;
    while (curPtr != NULL) {
        if (curPtr->tkwin == (Tk_Window) winPtr) {
            curPtr->deleted = 1;
        }
        curPtr = curPtr->nextPtr;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * MatchPatterns --
 *
 *      Given a list of pattern sequences and a list of recent events,
 *      return the pattern sequence that best matches the event list,
 *      if there is one.
 *
 *      This procedure is used in two different ways.  In the simplest
 *      use, "object" is NULL and psPtr is a list of pattern sequences,
 *      each of which corresponds to a binding.  In this case, the
 *      procedure finds the pattern sequences that match the event list
 *      and returns the most specific of those, if there is more than one.
 *
 *      In the second case, psPtr is a list of pattern sequences, each
 *      of which corresponds to a definition for a virtual binding.
 *      In order for one of these sequences to "match", it must match
 *      the events (as above) but in addition there must be a binding
 *      for its associated virtual event on the current object.  The
 *      "object" argument indicates which object the binding must be for.
 *
 * Results:
 *      The return value is NULL if bestPtr is NULL and no pattern matches
 *      the recent events from bindPtr.  Otherwise the return value is
 *      the most specific pattern sequence among bestPtr and all those
 *      at psPtr that match the event list and object.  If a pattern
 *      sequence other than bestPtr is returned, then *bestCommandPtr
 *      is filled in with a pointer to the command from the best sequence.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
static PatSeq *
MatchPatterns(dispPtr, bindPtr, psPtr, bestPtr, objectPtr, sourcePtrPtr)
    TkDisplay *dispPtr;         /* Display from which the event came. */
    BindingTable *bindPtr;      /* Information about binding table, such as
                                 * ring of recent events. */
    PatSeq *psPtr;              /* List of pattern sequences. */
    PatSeq *bestPtr;            /* The best match seen so far, from a
                                 * previous call to this procedure.  NULL
                                 * means no prior best match. */
    ClientData *objectPtr;      /* If NULL, the sequences at psPtr
                                 * correspond to "normal" bindings.  If
                                 * non-NULL, the sequences at psPtr correspond
                                 * to virtual bindings; in order to match each
                                 * sequence must correspond to a virtual
                                 * binding for which a binding exists for
                                 * object in bindPtr. */
    PatSeq **sourcePtrPtr;      /* Filled with the pattern sequence that
                                 * contains the eventProc and clientData
                                 * associated with the best match.  If this
                                 * differs from the return value, it is the
                                 * virtual event that most closely matched the
                                 * return value (a physical event).  Not
                                 * modified unless a result other than bestPtr
                                 * is returned. */
{
    PatSeq *matchPtr, *bestSourcePtr, *sourcePtr;

    bestSourcePtr = *sourcePtrPtr;

    /*
     * Iterate over all the pattern sequences.
     */

    for ( ; psPtr != NULL; psPtr = psPtr->nextSeqPtr) {
        XEvent *eventPtr;
        Pattern *patPtr;
        Window window;
        Detail *detailPtr;
        int patCount, ringCount, flags, state;
        int modMask;

        /*
         * Iterate over all the patterns in a sequence to be
         * sure that they all match.
         */

        eventPtr = &bindPtr->eventRing[bindPtr->curEvent];
        detailPtr = &bindPtr->detailRing[bindPtr->curEvent];
        window = eventPtr->xany.window;
        patPtr = psPtr->pats;
        patCount = psPtr->numPats;
        ringCount = EVENT_BUFFER_SIZE;
        while (patCount > 0) {
            if (ringCount <= 0) {
                goto nextSequence;
            }
            if (eventPtr->xany.type != patPtr->eventType) {
                /*
                 * Most of the event types are considered superfluous
                 * in that they are ignored if they occur in the middle
                 * of a pattern sequence and have mismatching types.  The
                 * only ones that cannot be ignored are ButtonPress and
                 * ButtonRelease events (if the next event in the pattern
                 * is a KeyPress or KeyRelease) and KeyPress and KeyRelease
                 * events (if the next pattern event is a ButtonPress or
                 * ButtonRelease).  Here are some tricky cases to consider:
                 * 1. Double-Button or Double-Key events.
                 * 2. Double-ButtonRelease or Double-KeyRelease events.
                 * 3. The arrival of various events like Enter and Leave
                 *    and FocusIn and GraphicsExpose between two button
                 *    presses or key presses.
                 * 4. Modifier keys like Shift and Control shouldn't
                 *    generate conflicts with button events.
                 */

                if ((patPtr->eventType == KeyPress)
                        || (patPtr->eventType == KeyRelease)) {
                    if ((eventPtr->xany.type == ButtonPress)
                            || (eventPtr->xany.type == ButtonRelease)) {
                        goto nextSequence;
                    }
                } else if ((patPtr->eventType == ButtonPress)
                        || (patPtr->eventType == ButtonRelease)) {
                    if ((eventPtr->xany.type == KeyPress)
                            || (eventPtr->xany.type == KeyRelease)) {
                        int i;

                        /*
                         * Ignore key events if they are modifier keys.
                         */

                        for (i = 0; i < dispPtr->numModKeyCodes; i++) {
                            if (dispPtr->modKeyCodes[i]
                                    == eventPtr->xkey.keycode) {
                                /*
                                 * This key is a modifier key, so ignore it.
                                 */
                                goto nextEvent;
                            }
                        }
                        goto nextSequence;
                    }
                }
                goto nextEvent;
            }
            if (eventPtr->xany.window != window) {
                goto nextSequence;
            }

            /*
             * Note: it's important for the keysym check to go before
             * the modifier check, so we can ignore unwanted modifier
             * keys before choking on the modifier check.
             */

            if ((patPtr->detail.clientData != 0)
                    && (patPtr->detail.clientData != detailPtr->clientData)) {
                /*
                 * The detail appears not to match.  However, if the event
                 * is a KeyPress for a modifier key then just ignore the
                 * event.  Otherwise event sequences like "aD" never match
                 * because the shift key goes down between the "a" and the
                 * "D".
                 */

                if (eventPtr->xany.type == KeyPress) {
                    int i;

                    for (i = 0; i < dispPtr->numModKeyCodes; i++) {
                        if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
                            goto nextEvent;
                        }
                    }
                }
                goto nextSequence;
            }
            flags = flagArray[eventPtr->type];
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                state = eventPtr->xkey.state;
            } else if (flags & CROSSING) {
                state = eventPtr->xcrossing.state;
            } else {
                state = 0;
            }
            if (patPtr->needMods != 0) {
                modMask = patPtr->needMods;
                if ((modMask & META_MASK) && (dispPtr->metaModMask != 0)) {
                    modMask = (modMask & ~META_MASK) | dispPtr->metaModMask;
                }
                if ((modMask & ALT_MASK) && (dispPtr->altModMask != 0)) {
                    modMask = (modMask & ~ALT_MASK) | dispPtr->altModMask;
                }

                if ((state & META_MASK) && (dispPtr->metaModMask != 0)) {
                    state = (state & ~META_MASK) | dispPtr->metaModMask;
                }
                if ((state & ALT_MASK) && (dispPtr->altModMask != 0)) {
                    state = (state & ~ALT_MASK) | dispPtr->altModMask;
                }

                if ((state & modMask) != modMask) {
                    goto nextSequence;
                }
            }
            if (psPtr->flags & PAT_NEARBY) {
                XEvent *firstPtr;
                int timeDiff;

                firstPtr = &bindPtr->eventRing[bindPtr->curEvent];
                timeDiff = (Time) firstPtr->xkey.time - eventPtr->xkey.time;
                if ((firstPtr->xkey.x_root
                            < (eventPtr->xkey.x_root - NEARBY_PIXELS))
                        || (firstPtr->xkey.x_root
                            > (eventPtr->xkey.x_root + NEARBY_PIXELS))
                        || (firstPtr->xkey.y_root
                            < (eventPtr->xkey.y_root - NEARBY_PIXELS))
                        || (firstPtr->xkey.y_root
                            > (eventPtr->xkey.y_root + NEARBY_PIXELS))
                        || (timeDiff > NEARBY_MS)) {
                    goto nextSequence;
                }
            }
            patPtr++;
            patCount--;
            nextEvent:
            if (eventPtr == bindPtr->eventRing) {
                eventPtr = &bindPtr->eventRing[EVENT_BUFFER_SIZE-1];
                detailPtr = &bindPtr->detailRing[EVENT_BUFFER_SIZE-1];
            } else {
                eventPtr--;
                detailPtr--;
            }
            ringCount--;
        }

        matchPtr = psPtr;
        sourcePtr = psPtr;

        if (objectPtr != NULL) {
            int iVirt;
            VirtualOwners *voPtr;
            PatternTableKey key;

            /*
             * The sequence matches the physical constraints.
             * Is this object interested in any of the virtual events
             * that correspond to this sequence?  
             */

            voPtr = psPtr->voPtr;

            memset(&key, 0, sizeof(key));
            key.object = *objectPtr;
            key.type = VirtualEvent;
            key.detail.clientData = 0;

            for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
                Tcl_HashEntry *hPtr = voPtr->owners[iVirt];

                key.detail.name = (Tk_Uid) Tcl_GetHashKey(hPtr->tablePtr,
                        hPtr);
                hPtr = Tcl_FindHashEntry(&bindPtr->patternTable,
                        (char *) &key);
                if (hPtr != NULL) {

                    /*
                     * This tag is interested in this virtual event and its
                     * corresponding physical event is a good match with the
                     * virtual event's definition.
                     */

                    PatSeq *virtMatchPtr;

                    virtMatchPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
                    if ((virtMatchPtr->numPats != 1)
                            || (virtMatchPtr->nextSeqPtr != NULL)) {
                        panic("MatchPattern: badly constructed virtual event");
                    }
                    sourcePtr = virtMatchPtr;
                    goto match;
                }
            }

            /*
             * The physical event matches a virtual event's definition, but
             * the tag isn't interested in it.
             */
            goto nextSequence;
        }
        match:

        /*
         * This sequence matches.  If we've already got another match,
         * pick whichever is most specific.  Detail is most important,
         * then needMods.
         */

        if (bestPtr != NULL) {
            Pattern *patPtr2;
            int i;

            if (matchPtr->numPats != bestPtr->numPats) {
                if (bestPtr->numPats > matchPtr->numPats) {
                    goto nextSequence;
                } else {
                    goto newBest;
                }
            }
            for (i = 0, patPtr = matchPtr->pats, patPtr2 = bestPtr->pats;
                    i < matchPtr->numPats; i++, patPtr++, patPtr2++) {
                if (patPtr->detail.clientData != patPtr2->detail.clientData) {
                    if (patPtr->detail.clientData == 0) {
                        goto nextSequence;
                    } else {
                        goto newBest;
                    }
                }
                if (patPtr->needMods != patPtr2->needMods) {
                    if ((patPtr->needMods & patPtr2->needMods)
                            == patPtr->needMods) {
                        goto nextSequence;
                    } else if ((patPtr->needMods & patPtr2->needMods)
                            == patPtr2->needMods) {
                        goto newBest;
                    }
                }
            }
            /*
             * Tie goes to current best pattern.
             *
             * (1) For virtual vs. virtual, the least recently defined
             * virtual wins, because virtuals are examined in order of
             * definition.  This order is _not_ guaranteed in the
             * documentation.
             *
             * (2) For virtual vs. physical, the physical wins because all
             * the physicals are examined before the virtuals.  This order
             * is guaranteed in the documentation.
             *
             * (3) For physical vs. physical pattern, the most recently
             * defined physical wins, because physicals are examined in
             * reverse order of definition.  This order is guaranteed in
             * the documentation.
             */

            goto nextSequence;  
        }
        newBest:
        bestPtr = matchPtr;
        bestSourcePtr = sourcePtr;

        nextSequence:
        continue;
    }

    *sourcePtrPtr = bestSourcePtr;
    return bestPtr;
}

/*
 *--------------------------------------------------------------
 *
 * ExpandPercents --
 *
 *      Given a command and an event, produce a new command
 *      by replacing % constructs in the original command
 *      with information from the X event.
 *
 * Results:
 *      The new expanded command is appended to the dynamic string
 *      given by dsPtr.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

static void
ExpandPercents(winPtr, before, eventPtr, keySym, dsPtr)
    TkWindow *winPtr;           /* Window where event occurred:  needed to
                                 * get input context. */
    char *before;               /* Command containing percent expressions
                                 * to be replaced. */
    XEvent *eventPtr;           /* X event containing information to be
                                 * used in % replacements. */
    KeySym keySym;              /* KeySym: only relevant for KeyPress and
                                 * KeyRelease events). */
    Tcl_DString *dsPtr;         /* Dynamic string in which to append new
                                 * command. */
{
    int spaceNeeded, cvtFlags;  /* Used to substitute string as proper Tcl
                                 * list element. */
    int number, flags, length;
#define NUM_SIZE 40
    char *string;
    Tcl_DString buf;
    char numStorage[NUM_SIZE+1];

    Tcl_DStringInit(&buf);

    if (eventPtr->type < TK_LASTEVENT) {
        flags = flagArray[eventPtr->type];
    } else {
        flags = 0;
    }
    while (1) {
        /*
         * Find everything up to the next % character and append it
         * to the result string.
         */

        for (string = before; (*string != 0) && (*string != '%'); string++) {
            /* Empty loop body. */
        }
        if (string != before) {
            Tcl_DStringAppend(dsPtr, before, string-before);
            before = string;
        }
        if (*before == 0) {
            break;
        }

        /*
         * There's a percent sequence here.  Process it.
         */

        number = 0;
        string = "??";
        switch (before[1]) {
            case '#':
                number = eventPtr->xany.serial;
                goto doNumber;
            case 'a':
                if (flags & CONFIG) {
                    TkpPrintWindowId(numStorage, eventPtr->xconfigure.above);
                    string = numStorage;
                }
                goto doString;
            case 'b':
                number = eventPtr->xbutton.button;
                goto doNumber;
            case 'c':
                if (flags & EXPOSE) {
                    number = eventPtr->xexpose.count;
                }
                goto doNumber;
            case 'd':
                if (flags & (CROSSING|FOCUS)) {
                    if (flags & FOCUS) {
                        number = eventPtr->xfocus.detail;
                    } else {
                        number = eventPtr->xcrossing.detail;
                    }
                    string = TkFindStateString(notifyDetail, number);
                }
                goto doString;
            case 'f':
                number = eventPtr->xcrossing.focus;
                goto doNumber;
            case 'h':
                if (flags & EXPOSE) {
                    number = eventPtr->xexpose.height;
                } else if (flags & (CONFIG)) {
                    number = eventPtr->xconfigure.height;
                }
                goto doNumber;
            case 'k':
                number = eventPtr->xkey.keycode;
                goto doNumber;
            case 'm':
                if (flags & CROSSING) {
                    number = eventPtr->xcrossing.mode;
                } else if (flags & FOCUS) {
                    number = eventPtr->xfocus.mode;
                }
                string = TkFindStateString(notifyMode, number);
                goto doString;
            case 'o':
                if (flags & CREATE) {
                    number = eventPtr->xcreatewindow.override_redirect;
                } else if (flags & MAP) {
                    number = eventPtr->xmap.override_redirect;
                } else if (flags & REPARENT) {
                    number = eventPtr->xreparent.override_redirect;
                } else if (flags & CONFIG) {
                    number = eventPtr->xconfigure.override_redirect;
                }
                goto doNumber;
            case 'p':
                string = TkFindStateString(circPlace, eventPtr->xcirculate.place);
                goto doString;
            case 's':
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                    number = eventPtr->xkey.state;
                } else if (flags & CROSSING) {
                    number = eventPtr->xcrossing.state;
                } else if (flags & VISIBILITY) {
                    string = TkFindStateString(visNotify,
                            eventPtr->xvisibility.state);
                    goto doString;
                }
                goto doNumber;
            case 't':
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                    number = (int) eventPtr->xkey.time;
                } else if (flags & CROSSING) {
                    number = (int) eventPtr->xcrossing.time;
                } else if (flags & PROP) {
                    number = (int) eventPtr->xproperty.time;
                }
                goto doNumber;
            case 'v':
                number = eventPtr->xconfigurerequest.value_mask;
                goto doNumber;
            case 'w':
                if (flags & EXPOSE) {
                    number = eventPtr->xexpose.width;
                } else if (flags & CONFIG) {
                    number = eventPtr->xconfigure.width;
                }
                goto doNumber;
            case 'x':
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                    number = eventPtr->xkey.x;
                } else if (flags & CROSSING) {
                    number = eventPtr->xcrossing.x;
                } else if (flags & EXPOSE) {
                    number = eventPtr->xexpose.x;
                } else if (flags & (CREATE|CONFIG|GRAVITY)) {
                    number = eventPtr->xcreatewindow.x;
                } else if (flags & REPARENT) {
                    number = eventPtr->xreparent.x;
                }
                goto doNumber;
            case 'y':
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                    number = eventPtr->xkey.y;
                } else if (flags & EXPOSE) {
                    number = eventPtr->xexpose.y;
                } else if (flags & (CREATE|CONFIG|GRAVITY)) {
                    number = eventPtr->xcreatewindow.y;
                } else if (flags & REPARENT) {
                    number = eventPtr->xreparent.y;
                } else if (flags & CROSSING) {
                    number = eventPtr->xcrossing.y;

                }
                goto doNumber;
            case 'A':
                if (flags & KEY) {
                    Tcl_DStringFree(&buf);
                    string = TkpGetString(winPtr, eventPtr, &buf);
                }
                goto doString;
            case 'B':
                number = eventPtr->xcreatewindow.border_width;
                goto doNumber;
            case 'D':
                /*
                 * This is used only by the MouseWheel event.
                 */
                    
                number = eventPtr->xkey.keycode;
                goto doNumber;
            case 'E':
                number = (int) eventPtr->xany.send_event;
                goto doNumber;
            case 'K':
                if (flags & KEY) {
                    char *name;

                    name = TkKeysymToString(keySym);
                    if (name != NULL) {
                        string = name;
                    }
                }
                goto doString;
            case 'N':
                number = (int) keySym;
                goto doNumber;
            case 'R':
                TkpPrintWindowId(numStorage, eventPtr->xkey.root);
                string = numStorage;
                goto doString;
            case 'S':
                TkpPrintWindowId(numStorage, eventPtr->xkey.subwindow);
                string = numStorage;
                goto doString;
            case 'T':
                number = eventPtr->type;
                goto doNumber;
            case 'W': {
                Tk_Window tkwin;

                tkwin = Tk_IdToWindow(eventPtr->xany.display,
                        eventPtr->xany.window);
                if (tkwin != NULL) {
                    string = Tk_PathName(tkwin);
                } else {
                    string = "??";
                }
                goto doString;
            }
            case 'X': {
                Tk_Window tkwin;
                int x, y;
                int width, height;

                number = eventPtr->xkey.x_root;
                tkwin = Tk_IdToWindow(eventPtr->xany.display,
                        eventPtr->xany.window);
                if (tkwin != NULL) {
                    Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
                    number -= x;
                }
                goto doNumber;
            }
            case 'Y': {
                Tk_Window tkwin;
                int x, y;
                int width, height;

                number = eventPtr->xkey.y_root;
                tkwin = Tk_IdToWindow(eventPtr->xany.display,
                        eventPtr->xany.window);
                if (tkwin != NULL) {
                    Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
                    number -= y;
                }
                goto doNumber;
            }
            default:
                numStorage[0] = before[1];
                numStorage[1] = '\0';
                string = numStorage;
                goto doString;
        }

        doNumber:
        sprintf(numStorage, "%d", number);
        string = numStorage;

        doString:
        spaceNeeded = Tcl_ScanElement(string, &cvtFlags);
        length = Tcl_DStringLength(dsPtr);
        Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
        spaceNeeded = Tcl_ConvertElement(string,
                Tcl_DStringValue(dsPtr) + length,
                cvtFlags | TCL_DONT_USE_BRACES);
        Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
        before += 2;
    }
    Tcl_DStringFree(&buf);
}

/*
 *----------------------------------------------------------------------
 *
 * ChangeScreen --
 *
 *      This procedure is invoked whenever the current screen changes
 *      in an application.  It invokes a Tcl procedure named
 *      "tkScreenChanged", passing it the screen name as argument.
 *      tkScreenChanged does things like making the tkPriv variable
 *      point to an array for the current display.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Depends on what tkScreenChanged does.  If an error occurs
 *      them tkError will be invoked.
 *
 *----------------------------------------------------------------------
 */

static void
ChangeScreen(interp, dispName, screenIndex)
    Tcl_Interp *interp;                 /* Interpreter in which to invoke
                                         * command. */
    char *dispName;                     /* Name of new display. */
    int screenIndex;                    /* Index of new screen. */
{
    Tcl_DString cmd;
    int code;
    char screen[TCL_INTEGER_SPACE];

    Tcl_DStringInit(&cmd);
    Tcl_DStringAppend(&cmd, "tkScreenChanged ", 16);
    Tcl_DStringAppend(&cmd, dispName, -1);
    sprintf(screen, ".%d", screenIndex);
    Tcl_DStringAppend(&cmd, screen, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&cmd));
    if (code != TCL_OK) {
        Tcl_AddErrorInfo(interp,
                "\n    (changing screen in event binding)");
        Tcl_BackgroundError(interp);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * Tk_EventCmd --
 *
 *      This procedure is invoked to process the "event" Tcl command.
 *      It is used to define and generate events.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tk_EventObjCmd(clientData, interp, objc, objv)
    ClientData clientData;      /* Main window associated with interpreter. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int objc;                   /* Number of arguments. */
    Tcl_Obj *CONST objv[];      /* Argument objects. */
{
    int index;
    Tk_Window tkwin;
    VirtualEventTable *vetPtr;
    TkBindInfo bindInfo;
    static char *optionStrings[] = {
        "add",          "delete",       "generate",     "info",
        NULL
    };
    enum options {
        EVENT_ADD,      EVENT_DELETE,   EVENT_GENERATE, EVENT_INFO
    };

    tkwin = (Tk_Window) clientData;
    bindInfo = ((TkWindow *) tkwin)->mainPtr->bindInfo;
    vetPtr = &((BindInfo *) bindInfo)->virtualEventTable;

    if (objc < 2) {
        Tcl_WrongNumArgs(interp, 1, objv, "option ?arg?");
        return TCL_ERROR;
    }
    if (Tcl_GetIndexFromObj(interp, objv[1], optionStrings, "option", 0,
            &index) != TCL_OK) {
        return TCL_ERROR;
    }

    switch ((enum options) index) {
        case EVENT_ADD: {
            int i;
            char *name, *event;
            
            if (objc < 4) {
                Tcl_WrongNumArgs(interp, 2, objv,
                        "virtual sequence ?sequence ...?");
                return TCL_ERROR;
            }
            name = Tcl_GetStringFromObj(objv[2], NULL);
            for (i = 3; i < objc; i++) {
                event = Tcl_GetStringFromObj(objv[i], NULL);
                if (CreateVirtualEvent(interp, vetPtr, name, event) != TCL_OK) {
                    return TCL_ERROR;
                }
            }
            break;
        }
        case EVENT_DELETE: {
            int i;
            char *name, *event;
            
            if (objc < 3) {
                Tcl_WrongNumArgs(interp, 2, objv,
                        "virtual ?sequence sequence ...?");
                return TCL_ERROR;
            }
            name = Tcl_GetStringFromObj(objv[2], NULL);
            if (objc == 3) {
                return DeleteVirtualEvent(interp, vetPtr, name, NULL);
            }
            for (i = 3; i < objc; i++) {
                event = Tcl_GetStringFromObj(objv[i], NULL);
                if (DeleteVirtualEvent(interp, vetPtr, name, event) != TCL_OK) {
                    return TCL_ERROR;
                }
            }
            break;
        }
        case EVENT_GENERATE: {
            if (objc < 4) {
                Tcl_WrongNumArgs(interp, 2, objv, "window event ?options?");
                return TCL_ERROR;
            }
            return HandleEventGenerate(interp, tkwin, objc - 2, objv + 2);
        }
        case EVENT_INFO: {
            if (objc == 2) {
                GetAllVirtualEvents(interp, vetPtr);
                return TCL_OK;
            } else if (objc == 3) {     
                return GetVirtualEvent(interp, vetPtr,
                        Tcl_GetStringFromObj(objv[2], NULL));
            } else {
                Tcl_WrongNumArgs(interp, 2, objv, "?virtual?");
                return TCL_ERROR;
            }
        }
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * InitVirtualEventTable --
 *
 *      Given storage for a virtual event table, set up the fields to
 *      prepare a new domain in which virtual events may be defined.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      *vetPtr is now initialized.
 *
 *---------------------------------------------------------------------------
 */

static void
InitVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;  /* Pointer to virtual event table.  Memory
                                 * is supplied by the caller. */
{
    Tcl_InitHashTable(&vetPtr->patternTable,
            sizeof(PatternTableKey) / sizeof(int));
    Tcl_InitHashTable(&vetPtr->nameTable, TCL_ONE_WORD_KEYS);
}

/*
 *---------------------------------------------------------------------------
 *
 * DeleteVirtualEventTable --
 *
 *      Delete the contents of a virtual event table.  The caller is
 *      responsible for freeing any memory used by the table itself.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory is freed.
 *
 *---------------------------------------------------------------------------
 */

static void
DeleteVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;  /* The virtual event table to delete. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    PatSeq *psPtr, *nextPtr;

    hPtr = Tcl_FirstHashEntry(&vetPtr->patternTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
        for ( ; psPtr != NULL; psPtr = nextPtr) {
            nextPtr = psPtr->nextSeqPtr;
            ckfree((char *) psPtr->voPtr);
            ckfree((char *) psPtr);
        }
    }
    Tcl_DeleteHashTable(&vetPtr->patternTable);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        ckfree((char *) Tcl_GetHashValue(hPtr));
    }
    Tcl_DeleteHashTable(&vetPtr->nameTable);
}

/*
 *----------------------------------------------------------------------
 *
 * CreateVirtualEvent --
 *
 *      Add a new definition for a virtual event.  If the virtual event
 *      is already defined, the new definition augments those that
 *      already exist.
 *
 * Results:
 *      The return value is TCL_ERROR if an error occured while
 *      creating the virtual binding.  In this case, an error message
 *      will be left in the interp's result.  If all went well then the
 *      return value is TCL_OK.
 *
 * Side effects:
 *      The virtual event may cause future calls to Tk_BindEvent to
 *      behave differently than they did previously.
 *
 *----------------------------------------------------------------------
 */

static int
CreateVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;         /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to augment virtual event. */
    char *virtString;           /* Name of new virtual event. */
    char *eventString;          /* String describing physical event that
                                 * triggers virtual event. */
{
    PatSeq *psPtr;
    int dummy;
    Tcl_HashEntry *vhPtr;
    unsigned long eventMask;
    PhysicalsOwned *poPtr;
    VirtualOwners *voPtr;
    Tk_Uid virtUid;
    
    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create physical event
     */

    psPtr = FindSequence(interp, &vetPtr->patternTable, NULL, eventString,
            1, 0, &eventMask);
    if (psPtr == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create virtual event.
     */

    vhPtr = Tcl_CreateHashEntry(&vetPtr->nameTable, virtUid, &dummy);

    /*
     * Make virtual event own the physical event.
     */

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    if (poPtr == NULL) {
        poPtr = (PhysicalsOwned *) ckalloc(sizeof(PhysicalsOwned));
        poPtr->numOwned = 0;
    } else {
        /*
         * See if this virtual event is already defined for this physical
         * event and just return if it is.
         */

        int i;
        for (i = 0; i < poPtr->numOwned; i++) {
            if (poPtr->patSeqs[i] == psPtr) {
                return TCL_OK;
            }
        }
        poPtr = (PhysicalsOwned *) ckrealloc((char *) poPtr,
                sizeof(PhysicalsOwned) + poPtr->numOwned * sizeof(PatSeq *));
    }   
    Tcl_SetHashValue(vhPtr, (ClientData) poPtr);
    poPtr->patSeqs[poPtr->numOwned] = psPtr;
    poPtr->numOwned++;

    /*
     * Make physical event so it can trigger the virtual event.
     */

    voPtr = psPtr->voPtr;
    if (voPtr == NULL) {
        voPtr = (VirtualOwners *) ckalloc(sizeof(VirtualOwners));
        voPtr->numOwners = 0;
    } else {
        voPtr = (VirtualOwners *) ckrealloc((char *) voPtr,
                sizeof(VirtualOwners)
                + voPtr->numOwners * sizeof(Tcl_HashEntry *));
    }
    psPtr->voPtr = voPtr;
    voPtr->owners[voPtr->numOwners] = vhPtr;
    voPtr->numOwners++;

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * DeleteVirtualEvent --
 *
 *      Remove the definition of a given virtual event.  If the 
 *      event string is NULL, all definitions of the virtual event
 *      will be removed.  Otherwise, just the specified definition
 *      of the virtual event will be removed.
 *
 * Results:
 *      The result is a standard Tcl return value.  If an error
 *      occurs then the interp's result will contain an error message.
 *      It is not an error to attempt to delete a virtual event that
 *      does not exist or a definition that does not exist.
 *
 * Side effects:
 *      The virtual event given by virtString may be removed from the
 *      virtual event table.  
 *
 *--------------------------------------------------------------
 */

static int
DeleteVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;         /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to delete event. */
    char *virtString;           /* String describing event sequence that
                                 * triggers binding. */
    char *eventString;          /* The event sequence that should be deleted,
                                 * or NULL to delete all event sequences for
                                 * the entire virtual event. */
{
    int iPhys;
    Tk_Uid virtUid;
    Tcl_HashEntry *vhPtr;
    PhysicalsOwned *poPtr;
    PatSeq *eventPSPtr;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }
    
    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }
    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);

    eventPSPtr = NULL;
    if (eventString != NULL) {
        unsigned long eventMask;

        /*
         * Delete only the specific physical event associated with the
         * virtual event.  If the physical event doesn't already exist, or
         * the virtual event doesn't own that physical event, return w/o
         * doing anything.
         */

        eventPSPtr = FindSequence(interp, &vetPtr->patternTable, NULL,
                eventString, 0, 0, &eventMask);
        if (eventPSPtr == NULL) {
            char *string;

            string = Tcl_GetStringResult(interp); 
            return (string[0] != '\0') ? TCL_ERROR : TCL_OK;
        }
    }

    for (iPhys = poPtr->numOwned; --iPhys >= 0; ) {
        PatSeq *psPtr = poPtr->patSeqs[iPhys];
        if ((eventPSPtr == NULL) || (psPtr == eventPSPtr)) {
            int iVirt;
            VirtualOwners *voPtr;
            
            /*
             * Remove association between this physical event and the given
             * virtual event that it triggers.
             */

            voPtr = psPtr->voPtr;
            for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
                if (voPtr->owners[iVirt] == vhPtr) {
                    break;
                }
            }
            if (iVirt == voPtr->numOwners) {
                panic("DeleteVirtualEvent: couldn't find owner");
            }
            voPtr->numOwners--;
            if (voPtr->numOwners == 0) {
                /*
                 * Removed last reference to this physical event, so
                 * remove it from physical->virtual map.
                 */
                PatSeq *prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
                if (prevPtr == psPtr) {
                    if (psPtr->nextSeqPtr == NULL) {
                        Tcl_DeleteHashEntry(psPtr->hPtr);
                    } else {
                        Tcl_SetHashValue(psPtr->hPtr,
                                psPtr->nextSeqPtr);
                    }
                } else {
                    for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
                        if (prevPtr == NULL) {
                            panic("DeleteVirtualEvent couldn't find on hash chain");
                        }
                        if (prevPtr->nextSeqPtr == psPtr) {
                            prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                            break;
                        }
                    }
                }
                ckfree((char *) psPtr->voPtr);
                ckfree((char *) psPtr);
            } else {
                /*
                 * This physical event still triggers some other virtual
                 * event(s).  Consolidate the list of virtual owners for
                 * this physical event so it no longer triggers the
                 * given virtual event.
                 */
                voPtr->owners[iVirt] = voPtr->owners[voPtr->numOwners];
            }

            /*
             * Now delete the virtual event's reference to the physical
             * event.
             */

            poPtr->numOwned--;
            if (eventPSPtr != NULL && poPtr->numOwned != 0) {
                /*
                 * Just deleting this one physical event.  Consolidate list
                 * of owned physical events and return.
                 */

                poPtr->patSeqs[iPhys] = poPtr->patSeqs[poPtr->numOwned];
                return TCL_OK;
            }
        }
    }

    if (poPtr->numOwned == 0) {
        /*
         * All the physical events for this virtual event were deleted,
         * either because there was only one associated physical event or
         * because the caller was deleting the entire virtual event.  Now
         * the virtual event itself should be deleted.
         */

        ckfree((char *) poPtr);
        Tcl_DeleteHashEntry(vhPtr);
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetVirtualEvent --
 *
 *      Return the list of physical events that can invoke the
 *      given virtual event.
 *
 * Results:
 *      The return value is TCL_OK and the interp's result is filled with the
 *      string representation of the physical events associated with the
 *      virtual event; if there are no physical events for the given virtual
 *      event, the interp's result is filled with and empty string.  If the
 *      virtual event string is improperly formed, then TCL_ERROR is
 *      returned and an error message is left in the interp's result.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

static int
GetVirtualEvent(interp, vetPtr, virtString)
    Tcl_Interp *interp;         /* Interpreter for reporting. */
    VirtualEventTable *vetPtr;/* Table in which to look for event. */
    char *virtString;           /* String describing virtual event. */
{
    Tcl_HashEntry *vhPtr;
    Tcl_DString ds;
    int iPhys;
    PhysicalsOwned *poPtr;
    Tk_Uid virtUid;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }

    Tcl_DStringInit(&ds);

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    for (iPhys = 0; iPhys < poPtr->numOwned; iPhys++) {
        Tcl_DStringSetLength(&ds, 0);
        GetPatternString(poPtr->patSeqs[iPhys], &ds);
        Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * GetAllVirtualEvents --
 *
 *      Return a list that contains the names of all the virtual
 *      event defined.
 *
 * Results:
 *      There is no return value.  The interp's result is modified to
 *      hold a Tcl list with one entry for each virtual event in 
 *      nameTable.  
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

static void
GetAllVirtualEvents(interp, vetPtr)
    Tcl_Interp *interp;         /* Interpreter returning result. */
    VirtualEventTable *vetPtr;/* Table containing events. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    Tcl_DString ds;

    Tcl_DStringInit(&ds);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        Tcl_DStringSetLength(&ds, 0);   
        Tcl_DStringAppend(&ds, "<<", 2);
        Tcl_DStringAppend(&ds, Tcl_GetHashKey(hPtr->tablePtr, hPtr), -1);
        Tcl_DStringAppend(&ds, ">>", 2);
        Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }

    Tcl_DStringFree(&ds);
}

/*
 *---------------------------------------------------------------------------
 *
 * HandleEventGenerate --
 *
 *      Helper function for the "event generate" command.  Generate and
 *      process an XEvent, constructed from information parsed from the
 *      event description string and its optional arguments.
 *
 *      argv[0] contains name of the target window.
 *      argv[1] contains pattern string for one event (e.g, <Control-v>).
 *      argv[2..argc-1] contains -field/option pairs for specifying
 *                      additional detail in the generated event.
 *
 *      Either virtual or physical events can be generated this way.
 *      The event description string must contain the specification
 *      for only one event.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      When constructing the event, 
 *       event.xany.serial is filled with the current X serial number.
 *       event.xany.window is filled with the target window.
 *       event.xany.display is filled with the target window's display.
 *      Any other fields in eventPtr which are not specified by the pattern
 *      string or the optional arguments, are set to 0.
 *
 *      The event may be handled sychronously or asynchronously, depending
 *      on the value specified by the optional "-when" option.  The
 *      default setting is synchronous.
 *
 *---------------------------------------------------------------------------
 */
static int
HandleEventGenerate(interp, mainWin, objc, objv)
    Tcl_Interp *interp;         /* Interp for errors return and name lookup. */
    Tk_Window mainWin;          /* Main window associated with interp. */
    int objc;                   /* Number of arguments. */
    Tcl_Obj *CONST objv[];      /* Argument objects. */
{
    XEvent event;    
    char *name, *p, *windowName;
    int count, flags, synch, i, number, warp;
    Tcl_QueuePosition pos;
    Pattern pat;
    Tk_Window tkwin, tkwin2;
    TkWindow *mainPtr;
    unsigned long eventMask;
    static char *fieldStrings[] = {
        "-when",        "-above",       "-borderwidth", "-button",
        "-count",       "-delta",       "-detail",      "-focus",
        "-height",
        "-keycode",     "-keysym",      "-mode",        "-override",
        "-place",       "-root",        "-rootx",       "-rooty",
        "-sendevent",   "-serial",      "-state",       "-subwindow",
        "-time",        "-warp",        "-width",       "-window",
        "-x",           "-y",   NULL
    };
    enum field {
        EVENT_WHEN,     EVENT_ABOVE,    EVENT_BORDER,   EVENT_BUTTON,
        EVENT_COUNT,    EVENT_DELTA,    EVENT_DETAIL,   EVENT_FOCUS,
        EVENT_HEIGHT,
        EVENT_KEYCODE,  EVENT_KEYSYM,   EVENT_MODE,     EVENT_OVERRIDE,
        EVENT_PLACE,    EVENT_ROOT,     EVENT_ROOTX,    EVENT_ROOTY,
        EVENT_SEND,     EVENT_SERIAL,   EVENT_STATE,    EVENT_SUBWINDOW,
        EVENT_TIME,     EVENT_WARP,     EVENT_WIDTH,    EVENT_WINDOW,
        EVENT_X,        EVENT_Y
    };

    windowName = Tcl_GetStringFromObj(objv[0], NULL);
    if (!windowName[0]) {
        tkwin = mainWin;
    } else if (NameToWindow(interp, mainWin, objv[0], &tkwin) != TCL_OK) {
        return TCL_ERROR;
    }

    mainPtr = (TkWindow *) mainWin;
    if ((tkwin == NULL)
            || (mainPtr->mainPtr != ((TkWindow *) tkwin)->mainPtr)) {
        char *name;

        name = Tcl_GetStringFromObj(objv[0], NULL);
        Tcl_AppendResult(interp, "window id \"", name,          
                "\" doesn't exist in this application", (char *) NULL);
        return TCL_ERROR;
    }

    name = Tcl_GetStringFromObj(objv[1], NULL);

    p = name;
    eventMask = 0;
    count = ParseEventDescription(interp, &p, &pat, &eventMask);
    if (count == 0) {
        return TCL_ERROR;
    }
    if (count != 1) {
        Tcl_SetResult(interp, "Double or Triple modifier not allowed",
                TCL_STATIC);
        return TCL_ERROR;
    }
    if (*p != '\0') {
        Tcl_SetResult(interp, "only one event specification allowed",
                TCL_STATIC);
        return TCL_ERROR;
    }

    memset((VOID *) &event, 0, sizeof(event));
    event.xany.type = pat.eventType;
    event.xany.serial = NextRequest(Tk_Display(tkwin));
    event.xany.send_event = False;
    if (windowName[0]) {
        event.xany.window = Tk_WindowId(tkwin);
    } else {
        event.xany.window = RootWindow(Tk_Display(tkwin), Tk_ScreenNumber(tkwin));
    }
    event.xany.display = Tk_Display(tkwin);

    flags = flagArray[event.xany.type];
    if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
        event.xkey.state = pat.needMods;
        if ((flags & KEY) && (event.xany.type != MouseWheelEvent)) {
            TkpSetKeycodeAndState(tkwin, pat.detail.keySym, &event);
        } else if (flags & BUTTON) {
            event.xbutton.button = pat.detail.button;
        } else if (flags & VIRTUAL) {
            ((XVirtualEvent *) &event)->name = pat.detail.name;
        }
    }
    if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG|GRAVITY|CIRC)) {
        event.xcreatewindow.window = event.xany.window;
    }

    /*
     * Process the remaining arguments to fill in additional fields
     * of the event.
     */

    synch = 1;
    warp = 0;
    pos = TCL_QUEUE_TAIL;
    for (i = 2; i < objc; i += 2) {
        Tcl_Obj *optionPtr, *valuePtr;
        int index;
        
        optionPtr = objv[i];
        valuePtr = objv[i + 1];

        if (Tcl_GetIndexFromObj(interp, optionPtr, fieldStrings, "option",
                TCL_EXACT, &index) != TCL_OK) {
            return TCL_ERROR;
        }
        if (objc & 1) {
            /*
             * This test occurs after Tcl_GetIndexFromObj() so that
             * "event generate <Button> -xyz" will return the error message
             * that "-xyz" is a bad option, rather than that the value
             * for "-xyz" is missing.
             */

            Tcl_AppendResult(interp, "value for \"",
                    Tcl_GetStringFromObj(optionPtr, NULL), "\" missing",
                    (char *) NULL);
            return TCL_ERROR;
        }

        switch ((enum field) index) {
            case EVENT_WARP: {
                if (Tcl_GetBooleanFromObj(interp, valuePtr, &warp) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (!(flags & (KEY_BUTTON_MOTION_VIRTUAL))) {
                    goto badopt;
                }
                break;
            }
            case EVENT_WHEN: {
                pos = (Tcl_QueuePosition) TkFindStateNumObj(interp, optionPtr, 
                        queuePosition, valuePtr);
                if ((int) pos < -1) {
                    return TCL_ERROR;
                }
                synch = 0;
                if ((int) pos == -1) {
                    synch = 1;
                }
                break;
            }
            case EVENT_ABOVE: {
                if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & CONFIG) {
                    event.xconfigure.above = Tk_WindowId(tkwin2);
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_BORDER: {
                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (CREATE|CONFIG)) {
                    event.xcreatewindow.border_width = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_BUTTON: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & BUTTON) {
                    event.xbutton.button = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_COUNT: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & EXPOSE) {
                    event.xexpose.count = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_DELTA: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if ((flags & KEY) && (event.xkey.type == MouseWheelEvent)) {
                    event.xkey.keycode = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_DETAIL: {
                number = TkFindStateNumObj(interp, optionPtr, notifyDetail,
                        valuePtr);
                if (number < 0) {
                    return TCL_ERROR;
                }
                if (flags & FOCUS) {
                    event.xfocus.detail = number;
                } else if (flags & CROSSING) {
                    event.xcrossing.detail = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_FOCUS: {
                if (Tcl_GetBooleanFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & CROSSING) {
                    event.xcrossing.focus = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_HEIGHT: {
                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & EXPOSE) {
                     event.xexpose.height = number;
                } else if (flags & CONFIG) {
                    event.xconfigure.height = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_KEYCODE: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if ((flags & KEY) && (event.xkey.type != MouseWheelEvent)) {
                    event.xkey.keycode = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_KEYSYM: {
                KeySym keysym;
                char *value;

                value = Tcl_GetStringFromObj(valuePtr, NULL);
                keysym = TkStringToKeysym(value);
                if (keysym == NoSymbol) {
                    Tcl_AppendResult(interp, "unknown keysym \"", value, "\"",
                            (char *) NULL);
                    return TCL_ERROR;
                }

                TkpSetKeycodeAndState(tkwin, keysym, &event);
                if (event.xkey.keycode == 0) {
                    Tcl_AppendResult(interp, "no keycode for keysym \"", value,
                            "\"", (char *) NULL);
                    return TCL_ERROR;
                }
                if (!(flags & KEY) || (event.xkey.type == MouseWheelEvent)) {
                    goto badopt;
                }
                break;
            }
            case EVENT_MODE: {
                number = TkFindStateNumObj(interp, optionPtr, notifyMode,
                        valuePtr);
                if (number < 0) {
                    return TCL_ERROR;
                }
                if (flags & CROSSING) {
                    event.xcrossing.mode = number;
                } else if (flags & FOCUS) {
                    event.xfocus.mode = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_OVERRIDE: {
                if (Tcl_GetBooleanFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & CREATE) {
                    event.xcreatewindow.override_redirect = number;
                } else if (flags & MAP) {
                    event.xmap.override_redirect = number;
                } else if (flags & REPARENT) {
                    event.xreparent.override_redirect = number;
                } else if (flags & CONFIG) {
                    event.xconfigure.override_redirect = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_PLACE: {
                number = TkFindStateNumObj(interp, optionPtr, circPlace,
                        valuePtr);
                if (number < 0) {
                    return TCL_ERROR;
                }
                if (flags & CIRC) {
                    event.xcirculate.place = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_ROOT: {
                if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.root = Tk_WindowId(tkwin2);
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_ROOTX: {
                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.x_root = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_ROOTY: {
                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.y_root = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_SEND: {
                CONST char *value;

                value = Tcl_GetStringFromObj(valuePtr, NULL);
                if (isdigit(UCHAR(value[0]))) {
                    /*
                     * Allow arbitrary integer values for the field; they
                     * are needed by a few of the tests in the Tk test suite.
                     */

                    if (Tcl_GetIntFromObj(interp, valuePtr, &number)
                            != TCL_OK) {
                        return TCL_ERROR;
                    }
                } else {
                    if (Tcl_GetBooleanFromObj(interp, valuePtr, &number)
                            != TCL_OK) {
                        return TCL_ERROR;
                    }
                }
                event.xany.send_event = number;
                break;
            }
            case EVENT_SERIAL: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                event.xany.serial = number;
                break;
            }
            case EVENT_STATE: {
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    if (Tcl_GetIntFromObj(interp, valuePtr, &number)
                            != TCL_OK) {
                        return TCL_ERROR;
                    }
                    if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                        event.xkey.state = number;
                    } else {
                        event.xcrossing.state = number;
                    }
                } else if (flags & VISIBILITY) {
                    number = TkFindStateNumObj(interp, optionPtr, visNotify,
                            valuePtr);
                    if (number < 0) {
                        return TCL_ERROR;
                    }
                    event.xvisibility.state = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_SUBWINDOW: {
                if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.subwindow = Tk_WindowId(tkwin2);
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_TIME: {
                if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.time = (Time) number;
                } else if (flags & PROP) {
                    event.xproperty.time = (Time) number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_WIDTH: {
                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number)
                        != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & EXPOSE) {
                    event.xexpose.width = number;
                } else if (flags & (CREATE|CONFIG)) {
                    event.xcreatewindow.width = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_WINDOW: {
                if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
                    return TCL_ERROR;
                }
                if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG
                        |GRAVITY|CIRC)) {
                    event.xcreatewindow.window = Tk_WindowId(tkwin2);
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_X: {
                int rootX, rootY;

                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number)
                        != TCL_OK) {
                    return TCL_ERROR;
                }
                Tk_GetRootCoords(tkwin, &rootX, &rootY);
                rootX += number;
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {     
                    event.xkey.x = number;
                    event.xkey.x_root = rootX;
                } else if (flags & EXPOSE) {
                    event.xexpose.x = number;
                } else if (flags & (CREATE|CONFIG|GRAVITY)) { 
                    event.xcreatewindow.x = number;
                } else if (flags & REPARENT) {          
                    event.xreparent.x = number;
                } else {
                    goto badopt;
                }
                break;
            }
            case EVENT_Y: {
                int rootX, rootY;

                if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr, &number)
                        != TCL_OK) {
                    return TCL_ERROR;
                }
                Tk_GetRootCoords(tkwin, &rootX, &rootY);
                rootY += number;
                if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
                    event.xkey.y = number;
                    event.xkey.y_root = rootY;
                } else if (flags & EXPOSE) {
                    event.xexpose.y = number;
                } else if (flags & (CREATE|CONFIG|GRAVITY)) {
                    event.xcreatewindow.y = number;
                } else if (flags & REPARENT) {
                    event.xreparent.y = number;
                } else {
                    goto badopt;
                }
                break;
            }
        }
        continue;
        
        badopt:
        Tcl_AppendResult(interp, name, " event doesn't accept \"",
                Tcl_GetStringFromObj(optionPtr, NULL), "\" option", NULL);
        return TCL_ERROR;
    }
    if (synch != 0) {
        Tk_HandleEvent(&event);
    } else {
        Tk_QueueWindowEvent(&event, pos);
    }
    /*
     * We only allow warping if the window is mapped
     */
    if ((warp != 0) && Tk_IsMapped(tkwin)) {
        TkDisplay *dispPtr;
        dispPtr = TkGetDisplay(event.xmotion.display);
        if (!dispPtr->warpInProgress) {
            Tcl_DoWhenIdle(DoWarp, (ClientData) dispPtr);
            dispPtr->warpInProgress = 1;
        }
        dispPtr->warpWindow = event.xany.window;
        dispPtr->warpX = event.xkey.x;
        dispPtr->warpY = event.xkey.y;
    }
    Tcl_ResetResult(interp);
    return TCL_OK;
                
}
static int
NameToWindow(interp, mainWin, objPtr, tkwinPtr)
    Tcl_Interp *interp;         /* Interp for error return and name lookup. */
    Tk_Window mainWin;          /* Main window of application. */
    Tcl_Obj *objPtr;            /* Contains name or id string of window. */
    Tk_Window *tkwinPtr;        /* Filled with token for window. */
{
    char *name;
    Tk_Window tkwin;
    int id;
    
    name = Tcl_GetStringFromObj(objPtr, NULL);
    if (name[0] == '.') {
        tkwin = Tk_NameToWindow(interp, name, mainWin);
        if (tkwin == NULL) {
            return TCL_ERROR;
        }
        *tkwinPtr = tkwin;
    } else {
        if (TkpScanWindowId(NULL, name, &id) != TCL_OK) {
            Tcl_AppendResult(interp, "bad window name/identifier \"",
                    name, "\"", (char *) NULL);
            return TCL_ERROR;
        }
        *tkwinPtr = Tk_IdToWindow(Tk_Display(mainWin), (Window) id);
    }
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------------
 *
 * DoWarp --
 *
 *      Perform Warping of X pointer. Executed as an idle handler only.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      X Pointer will move to a new location.
 *
 *-------------------------------------------------------------------------
 */
static void
DoWarp(clientData)
    ClientData clientData;
{
    TkDisplay *dispPtr = (TkDisplay *) clientData;

    XWarpPointer(dispPtr->display, (Window) None, (Window) dispPtr->warpWindow,
                     0, 0, 0, 0, (int) dispPtr->warpX, (int) dispPtr->warpY);
    XForceScreenSaver(dispPtr->display, ScreenSaverReset);
    dispPtr->warpInProgress = 0;
}

/*
 *-------------------------------------------------------------------------
 *
 * GetVirtualEventUid --
 *
 *      Determine if the given string is in the proper format for a
 *      virtual event.
 *
 * Results:
 *      The return value is NULL if the virtual event string was
 *      not in the proper format.  In this case, an error message
 *      will be left in the interp's result.  Otherwise the return
 *      value is a Tk_Uid that represents the virtual event.
 *
 * Side effects:
 *      None.
 *
 *-------------------------------------------------------------------------
 */
static Tk_Uid
GetVirtualEventUid(interp, virtString)
    Tcl_Interp *interp;
    char *virtString;
{
    Tk_Uid uid;
    int length;

    length = strlen(virtString);

    if (length < 5 || virtString[0] != '<' || virtString[1] != '<' ||
            virtString[length - 2] != '>' || virtString[length - 1] != '>') {
        Tcl_AppendResult(interp, "virtual event \"", virtString,
                "\" is badly formed", (char *) NULL);
        return NULL;
    }
    virtString[length - 2] = '\0';
    uid = Tk_GetUid(virtString + 2);
    virtString[length - 2] = '>';

    return uid;
}


/*
 *----------------------------------------------------------------------
 *
 * FindSequence --
 *
 *      Find the entry in the pattern table that corresponds to a
 *      particular pattern string, and return a pointer to that
 *      entry.
 *
 * Results:
 *      The return value is normally a pointer to the PatSeq
 *      in patternTable that corresponds to eventString.  If an error
 *      was found while parsing eventString, or if "create" is 0 and
 *      no pattern sequence previously existed, then NULL is returned
 *      and the interp's result contains a message describing the problem.
 *      If no pattern sequence previously existed for eventString, then
 *      a new one is created with a NULL command field.  In a successful
 *      return, *maskPtr is filled in with a mask of the event types
 *      on which the pattern sequence depends.
 *
 * Side effects:
 *      A new pattern sequence may be allocated.
 *
 *----------------------------------------------------------------------
 */

static PatSeq *
FindSequence(interp, patternTablePtr, object, eventString, create,
        allowVirtual, maskPtr)
    Tcl_Interp *interp;         /* Interpreter to use for error
                                 * reporting. */
    Tcl_HashTable *patternTablePtr; /* Table to use for lookup. */
    ClientData object;          /* For binding table, token for object with
                                 * which binding is associated.
                                 * For virtual event table, NULL. */
    char *eventString;          /* String description of pattern to
                                 * match on.  See user documentation
                                 * for details. */
    int create;                 /* 0 means don't create the entry if
                                 * it doesn't already exist.   Non-zero
                                 * means create. */
    int allowVirtual;           /* 0 means that virtual events are not
                                 * allowed in the sequence.  Non-zero
                                 * otherwise. */
    unsigned long *maskPtr;     /* *maskPtr is filled in with the event
                                 * types on which this pattern sequence
                                 * depends. */
{

    Pattern pats[EVENT_BUFFER_SIZE];
    int numPats, virtualFound;
    char *p;
    Pattern *patPtr;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    int flags, count, new;
    size_t sequenceSize;
    unsigned long eventMask;
    PatternTableKey key;

    /*
     *-------------------------------------------------------------
     * Step 1: parse the pattern string to produce an array
     * of Patterns.  The array is generated backwards, so
     * that the lowest-indexed pattern corresponds to the last
     * event that must occur.
     *-------------------------------------------------------------
     */

    p = eventString;
    flags = 0;
    eventMask = 0;
    virtualFound = 0;

    patPtr = &pats[EVENT_BUFFER_SIZE-1];
    for (numPats = 0; numPats < EVENT_BUFFER_SIZE; numPats++, patPtr--) {
        while (isspace(UCHAR(*p))) {
            p++;
        }
        if (*p == '\0') {
            break;
        }

        count = ParseEventDescription(interp, &p, patPtr, &eventMask);
        if (count == 0) {
            return NULL;
        }

        if (eventMask & VirtualEventMask) {
            if (allowVirtual == 0) {
                Tcl_SetResult(interp, 
                        "virtual event not allowed in definition of another virtual event",
                        TCL_STATIC);
                return NULL;
            }
            virtualFound = 1;
        }

        /*
         * Replicate events for DOUBLE, TRIPLE, QUADRUPLE.
         */

        while ((count-- > 1) && (numPats < EVENT_BUFFER_SIZE-1)) {
            flags |= PAT_NEARBY;
            patPtr[-1] = patPtr[0];
            patPtr--;
            numPats++;
        }
    }

    /*
     *-------------------------------------------------------------
     * Step 2: find the sequence in the binding table if it exists,
     * and add a new sequence to the table if it doesn't.
     *-------------------------------------------------------------
     */

    if (numPats == 0) {
        Tcl_SetResult(interp, "no events specified in binding", TCL_STATIC);
        return NULL;
    }
    if ((numPats > 1) && (virtualFound != 0)) {
        Tcl_SetResult(interp, "virtual events may not be composed",
                TCL_STATIC);
        return NULL;
    }
    
    patPtr = &pats[EVENT_BUFFER_SIZE-numPats];
    memset(&key, 0, sizeof(key));
    key.object = object;
    key.type = patPtr->eventType;
    key.detail = patPtr->detail;
    hPtr = Tcl_CreateHashEntry(patternTablePtr, (char *) &key, &new);
    sequenceSize = numPats*sizeof(Pattern);
    if (!new) {
        for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
                psPtr = psPtr->nextSeqPtr) {
            if ((numPats == psPtr->numPats)
                    && ((flags & PAT_NEARBY) == (psPtr->flags & PAT_NEARBY))
                    && (memcmp((char *) patPtr, (char *) psPtr->pats,
                    sequenceSize) == 0)) {
                goto done;
            }
        }
    }
    if (!create) {
        if (new) {
            Tcl_DeleteHashEntry(hPtr);
        }
        /*
         * No binding exists for the sequence, so return an empty error.
         * This is a special error that the caller will check for in order
         * to silently ignore this case.  This is a hack that maintains
         * backward compatibility for Tk_GetBinding but the various "bind"
         * commands silently ignore missing bindings.
         */
        
        return NULL;
    }
    psPtr = (PatSeq *) ckalloc((unsigned) (sizeof(PatSeq)
            + (numPats-1)*sizeof(Pattern)));
    psPtr->numPats = numPats;
    psPtr->eventProc = NULL;
    psPtr->freeProc = NULL;
    psPtr->clientData = NULL;
    psPtr->flags = flags;
    psPtr->refCount = 0;
    psPtr->nextSeqPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    psPtr->hPtr = hPtr;
    psPtr->voPtr = NULL;
    psPtr->nextObjPtr = NULL;
    Tcl_SetHashValue(hPtr, psPtr);

    memcpy((VOID *) psPtr->pats, (VOID *) patPtr, sequenceSize);

    done:
    *maskPtr = eventMask;
    return psPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * ParseEventDescription --
 *
 *      Fill Pattern buffer with information about event from
 *      event string.
 *
 * Results:
 *      Leaves error message in interp and returns 0 if there was an
 *      error due to a badly formed event string.  Returns 1 if proper
 *      event was specified, 2 if Double modifier was used in event
 *      string, or 3 if Triple was used.
 *
 * Side effects:
 *      On exit, eventStringPtr points to rest of event string (after the
 *      closing '>', so that this procedure can be called repeatedly to
 *      parse all the events in the entire sequence.
 *
 *---------------------------------------------------------------------------
 */

static int
ParseEventDescription(interp, eventStringPtr, patPtr,
        eventMaskPtr)
    Tcl_Interp *interp;         /* For error messages. */
    char **eventStringPtr;      /* On input, holds a pointer to start of
                                 * event string.  On exit, gets pointer to
                                 * rest of string after parsed event. */
    Pattern *patPtr;            /* Filled with the pattern parsed from the
                                 * event string. */
    unsigned long *eventMaskPtr;/* Filled with event mask of matched event. */
                                 
{
    char *p;
    unsigned long eventMask;
    int count, eventFlags;
#define FIELD_SIZE 48
    char field[FIELD_SIZE];
    Tcl_HashEntry *hPtr;

    p = *eventStringPtr;

    patPtr->eventType = -1;
    patPtr->needMods = 0;
    patPtr->detail.clientData = 0;

    eventMask = 0;
    count = 1;
    
    /*
     * Handle simple ASCII characters.
     */

    if (*p != '<') {
        char string[2];

        patPtr->eventType = KeyPress;
        eventMask = KeyPressMask;
        string[0] = *p;
        string[1] = 0;
        patPtr->detail.keySym = TkStringToKeysym(string);
        if (patPtr->detail.keySym == NoSymbol) {
            if (isprint(UCHAR(*p))) {
                patPtr->detail.keySym = *p;
            } else {
                char buf[64];
                
                sprintf(buf, "bad ASCII character 0x%x", (unsigned char) *p);
                Tcl_SetResult(interp, buf, TCL_VOLATILE);
                return 0;
            }
        }
        p++;
        goto end;
    }

    /*
     * A fancier event description.  This can be either a virtual event
     * or a physical event.
     *
     * A virtual event description consists of:
     *
     * 1. double open angle brackets.
     * 2. virtual event name.
     * 3. double close angle brackets.
     *
     * A physical event description consists of:
     *
     * 1. open angle bracket.
     * 2. any number of modifiers, each followed by spaces
     *    or dashes.
     * 3. an optional event name.
     * 4. an option button or keysym name.  Either this or
     *    item 3 *must* be present;  if both are present
     *    then they are separated by spaces or dashes.
     * 5. a close angle bracket.
     */

    p++;
    if (*p == '<') {
        /*
         * This is a virtual event: soak up all the characters up to
         * the next '>'.
         */

        char *field = p + 1;        
        p = strchr(field, '>');
        if (p == field) {
            Tcl_SetResult(interp, "virtual event \"<<>>\" is badly formed",
                    TCL_STATIC);
            return 0;
        }           
        if ((p == NULL) || (p[1] != '>')) {
            Tcl_SetResult(interp, "missing \">\" in virtual binding",
                    TCL_STATIC);
            return 0;
        }
        *p = '\0';
        patPtr->eventType = VirtualEvent;
        eventMask = VirtualEventMask;
        patPtr->detail.name = Tk_GetUid(field);
        *p = '>';

        p += 2;
        goto end;
    }

    while (1) {
        ModInfo *modPtr;
        p = GetField(p, field, FIELD_SIZE);
        if (*p == '>') {
            /*
             * This solves the problem of, e.g., <Control-M> being
             * misinterpreted as Control + Meta + missing keysym
             * instead of Control + KeyPress + M.
             */
             break;
        }
        hPtr = Tcl_FindHashEntry(&modTable, field);
        if (hPtr == NULL) {
            break;
        }
        modPtr = (ModInfo *) Tcl_GetHashValue(hPtr);
        patPtr->needMods |= modPtr->mask;
        if (modPtr->flags & (MULT_CLICKS)) {
            int i = modPtr->flags & MULT_CLICKS;
            count = 2;
            while (i >>= 1) count++;
        }
        while ((*p == '-') || isspace(UCHAR(*p))) {
            p++;
        }
    }

    eventFlags = 0;
    hPtr = Tcl_FindHashEntry(&eventTable, field);
    if (hPtr != NULL) {
        EventInfo *eiPtr;
        eiPtr = (EventInfo *) Tcl_GetHashValue(hPtr);

        patPtr->eventType = eiPtr->type;
        eventFlags = flagArray[eiPtr->type];
        eventMask = eiPtr->eventMask;
        while ((*p == '-') || isspace(UCHAR(*p))) {
            p++;
        }
        p = GetField(p, field, FIELD_SIZE);
    }
    if (*field != '\0') {
        if ((*field >= '1') && (*field <= '5') && (field[1] == '\0')) {
            if (eventFlags == 0) {
                patPtr->eventType = ButtonPress;
                eventMask = ButtonPressMask;
            } else if (eventFlags & KEY) {
                goto getKeysym;
            } else if ((eventFlags & BUTTON) == 0) {
                Tcl_AppendResult(interp, "specified button \"", field,
                        "\" for non-button event", (char *) NULL);
                return 0;
            }
            patPtr->detail.button = (*field - '0');
        } else {
            getKeysym:
            patPtr->detail.keySym = TkStringToKeysym(field);
            if (patPtr->detail.keySym == NoSymbol) {
                Tcl_AppendResult(interp, "bad event type or keysym \"",
                        field, "\"", (char *) NULL);
                return 0;
            }
            if (eventFlags == 0) {
                patPtr->eventType = KeyPress;
                eventMask = KeyPressMask;
            } else if ((eventFlags & KEY) == 0) {
                Tcl_AppendResult(interp, "specified keysym \"", field,
                        "\" for non-key event", (char *) NULL);
                return 0;
            }
        }
    } else if (eventFlags == 0) {
        Tcl_SetResult(interp, "no event type or button # or keysym",
                TCL_STATIC);
        return 0;
    }

    while ((*p == '-') || isspace(UCHAR(*p))) {
        p++;
    }
    if (*p != '>') {
        while (*p != '\0') {
            p++;
            if (*p == '>') {
                Tcl_SetResult(interp,
                        "extra characters after detail in binding",
                        TCL_STATIC);
                return 0;
            }
        }
        Tcl_SetResult(interp, "missing \">\" in binding", TCL_STATIC);
        return 0;
    }
    p++;

end:
    *eventStringPtr = p;
    *eventMaskPtr |= eventMask;
    return count;
}

/*
 *----------------------------------------------------------------------
 *
 * GetField --
 *
 *      Used to parse pattern descriptions.  Copies up to
 *      size characters from p to copy, stopping at end of
 *      string, space, "-", ">", or whenever size is
 *      exceeded.
 *
 * Results:
 *      The return value is a pointer to the character just
 *      after the last one copied (usually "-" or space or
 *      ">", but could be anything if size was exceeded).
 *      Also places NULL-terminated string (up to size
 *      character, including NULL), at copy.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
GetField(p, copy, size)
    char *p;            /* Pointer to part of pattern. */
    char *copy; /* Place to copy field. */
    int size;                   /* Maximum number of characters to
                                 * copy. */
{
    while ((*p != '\0') && !isspace(UCHAR(*p)) && (*p != '>')
            && (*p != '-') && (size > 1)) {
        *copy = *p;
        p++;
        copy++;
        size--;
    }
    *copy = '\0';
    return p;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetPatternString --
 *
 *      Produce a string version of the given event, for displaying to
 *      the user.  
 *
 * Results:
 *      The string is left in dsPtr.
 *
 * Side effects:
 *      It is the caller's responsibility to initialize the DString before
 *      and to free it after calling this procedure.
 *
 *---------------------------------------------------------------------------
 */
static void
GetPatternString(psPtr, dsPtr)
    PatSeq *psPtr;
    Tcl_DString *dsPtr;
{
    Pattern *patPtr;
    char c, buffer[TCL_INTEGER_SPACE];
    int patsLeft, needMods;
    ModInfo *modPtr;
    EventInfo *eiPtr;

    /*
     * The order of the patterns in the sequence is backwards from the order
     * in which they must be output.
     */

    for (patsLeft = psPtr->numPats, patPtr = &psPtr->pats[psPtr->numPats - 1];
            patsLeft > 0; patsLeft--, patPtr--) {

        /*
         * Check for simple case of an ASCII character.
         */

        if ((patPtr->eventType == KeyPress)
                && ((psPtr->flags & PAT_NEARBY) == 0) 
                && (patPtr->needMods == 0)
                && (patPtr->detail.keySym < 128)
                && isprint(UCHAR(patPtr->detail.keySym))
                && (patPtr->detail.keySym != '<')
                && (patPtr->detail.keySym != ' ')) {

            c = (char) patPtr->detail.keySym;
            Tcl_DStringAppend(dsPtr, &c, 1);
            continue;
        }

        /*
         * Check for virtual event.
         */

        if (patPtr->eventType == VirtualEvent) {
            Tcl_DStringAppend(dsPtr, "<<", 2);
            Tcl_DStringAppend(dsPtr, patPtr->detail.name, -1);
            Tcl_DStringAppend(dsPtr, ">>", 2);
            continue;
        }

        /*
         * It's a more general event specification.  First check
         * for "Double", "Triple", "Quadruple", then modifiers,
         * then event type, then keysym or button detail.
         */

        Tcl_DStringAppend(dsPtr, "<", 1);
        if ((psPtr->flags & PAT_NEARBY) && (patsLeft > 1)
                && (memcmp((char *) patPtr, (char *) (patPtr-1),
                        sizeof(Pattern)) == 0)) {
            patsLeft--;
            patPtr--;
            if ((patsLeft > 1) && (memcmp((char *) patPtr,
                    (char *) (patPtr-1), sizeof(Pattern)) == 0)) {
                patsLeft--;
                patPtr--;
                    if ((patsLeft > 1) && (memcmp((char *) patPtr,
                            (char *) (patPtr-1), sizeof(Pattern)) == 0)) {
                        patsLeft--;
                        patPtr--;
                        Tcl_DStringAppend(dsPtr, "Quadruple-", 10);
                    } else {
                        Tcl_DStringAppend(dsPtr, "Triple-", 7);
                    }
            } else {
                Tcl_DStringAppend(dsPtr, "Double-", 7);
            }
        }
        for (needMods = patPtr->needMods, modPtr = modArray;
                needMods != 0; modPtr++) {
            if (modPtr->mask & needMods) {
                needMods &= ~modPtr->mask;
                Tcl_DStringAppend(dsPtr, modPtr->name, -1);
                Tcl_DStringAppend(dsPtr, "-", 1);
            }
        }
        for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
            if (eiPtr->type == patPtr->eventType) {
                Tcl_DStringAppend(dsPtr, eiPtr->name, -1);
                if (patPtr->detail.clientData != 0) {
                    Tcl_DStringAppend(dsPtr, "-", 1);
                }
                break;
            }
        }

        if (patPtr->detail.clientData != 0) {
            if ((patPtr->eventType == KeyPress)
                    || (patPtr->eventType == KeyRelease)) {
                char *string;

                string = TkKeysymToString(patPtr->detail.keySym);
                if (string != NULL) {
                    Tcl_DStringAppend(dsPtr, string, -1);
                }
            } else {
                sprintf(buffer, "%d", patPtr->detail.button);
                Tcl_DStringAppend(dsPtr, buffer, -1);
            }
        }
        Tcl_DStringAppend(dsPtr, ">", 1);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * EvalTclBinding --
 *
 *      The procedure that is invoked by Tk_BindEvent when a Tcl binding
 *      is fired.  
 *
 * Results:
 *      A standard Tcl result code, the result of globally evaluating the
 *      percent-substitued binding string.
 *
 * Side effects:
 *      Normal side effects due to eval.
 *
 *---------------------------------------------------------------------------
 */

static void
FreeTclBinding(clientData)
    ClientData clientData;
{
    ckfree((char *) clientData);
}

/*
 *----------------------------------------------------------------------
 *
 * TkStringToKeysym --
 *
 *      This procedure finds the keysym associated with a given keysym
 *      name.
 *
 * Results:
 *      The return value is the keysym that corresponds to name, or
 *      NoSymbol if there is no such keysym.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

KeySym
TkStringToKeysym(name)
    char *name;                 /* Name of a keysym. */
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;
    KeySym keysym;

    hPtr = Tcl_FindHashEntry(&keySymTable, name);
    if (hPtr != NULL) {
        return (KeySym) Tcl_GetHashValue(hPtr);
    }
    if (strlen(name) == 1) {
        keysym = (KeySym) (unsigned char) name[0];
        if (TkKeysymToString(keysym) != NULL) {
            return keysym;
        }
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XStringToKeysym(name);
}

/*
 *----------------------------------------------------------------------
 *
 * TkKeysymToString --
 *
 *      This procedure finds the keysym name associated with a given
 *      keysym.
 *
 * Results:
 *      The return value is a pointer to a static string containing
 *      the name of the given keysym, or NULL if there is no known name.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

char *
TkKeysymToString(keysym)
    KeySym keysym;
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&nameTable, (char *)keysym);
    if (hPtr != NULL) {
        return (char *) Tcl_GetHashValue(hPtr);
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XKeysymToString(keysym);
}

/*
 *----------------------------------------------------------------------
 *
 * TkCopyAndGlobalEval --
 *
 *      This procedure makes a copy of a script then calls Tcl_GlobalEval
 *      to evaluate it.  It's used in situations where the execution of
 *      a command may cause the original command string to be reallocated.
 *
 * Results:
 *      Returns the result of evaluating script, including both a standard
 *      Tcl completion code and a string in the interp's result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
TkCopyAndGlobalEval(interp, script)
    Tcl_Interp *interp;                 /* Interpreter in which to evaluate
                                         * script. */
    char *script;                       /* Script to evaluate. */
{
    Tcl_DString buffer;
    int code;

    Tcl_DStringInit(&buffer);
    Tcl_DStringAppend(&buffer, script, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&buffer));
    Tcl_DStringFree(&buffer);
    return code;
}

/* End of tkbind.c */