/* $Header$ */ /* * tkGC.c -- * * This file maintains a database of read-only graphics contexts * for the Tk toolkit, in order to allow GC's to be shared. * * Copyright (c) 1990-1994 The Regents of the University of California. * Copyright (c) 1994 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tkgc.c,v 1.1.1.1 2001/06/13 05:01:12 dtashley Exp $ */ #include "tkPort.h" #include "tkInt.h" /* * One of the following data structures exists for each GC that is * currently active. The structure is indexed with two hash tables, * one based on the values in the graphics context and the other * based on the display and GC identifier. */ typedef struct { GC gc; /* Graphics context. */ Display *display; /* Display to which gc belongs. */ int refCount; /* Number of active uses of gc. */ Tcl_HashEntry *valueHashPtr;/* Entry in valueTable (needed when deleting * this structure). */ } TkGC; typedef struct { XGCValues values; /* Desired values for GC. */ Display *display; /* Display for which GC is valid. */ int screenNum; /* screen number of display */ int depth; /* and depth for which GC is valid. */ } ValueKey; /* * Forward declarations for procedures defined in this file: */ static void GCInit _ANSI_ARGS_((TkDisplay *dispPtr)); /* *---------------------------------------------------------------------- * * Tk_GetGC -- * * Given a desired set of values for a graphics context, find * a read-only graphics context with the desired values. * * Results: * The return value is the X identifer for the desired graphics * context. The caller should never modify this GC, and should * call Tk_FreeGC when the GC is no longer needed. * * Side effects: * The GC is added to an internal database with a reference count. * For each call to this procedure, there should eventually be a call * to Tk_FreeGC, so that the database can be cleaned up when GC's * aren't needed anymore. * *---------------------------------------------------------------------- */ GC Tk_GetGC(tkwin, valueMask, valuePtr) Tk_Window tkwin; /* Window in which GC will be used. */ register unsigned long valueMask; /* 1 bits correspond to values specified * in *valuesPtr; other values are set * from defaults. */ register XGCValues *valuePtr; /* Values are specified here for bits set * in valueMask. */ { ValueKey valueKey; Tcl_HashEntry *valueHashPtr, *idHashPtr; register TkGC *gcPtr; int new; Drawable d, freeDrawable; TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr; if (!dispPtr->gcInit) { GCInit(dispPtr); } /* * Must zero valueKey at start to clear out pad bytes that may be * part of structure on some systems. */ memset((VOID *) &valueKey, 0, sizeof(valueKey)); /* * First, check to see if there's already a GC that will work * for this request (exact matches only, sorry). */ if (valueMask & GCFunction) { valueKey.values.function = valuePtr->function; } else { valueKey.values.function = GXcopy; } if (valueMask & GCPlaneMask) { valueKey.values.plane_mask = valuePtr->plane_mask; } else { valueKey.values.plane_mask = (unsigned) ~0; } if (valueMask & GCForeground) { valueKey.values.foreground = valuePtr->foreground; } else { valueKey.values.foreground = 0; } if (valueMask & GCBackground) { valueKey.values.background = valuePtr->background; } else { valueKey.values.background = 1; } if (valueMask & GCLineWidth) { valueKey.values.line_width = valuePtr->line_width; } else { valueKey.values.line_width = 0; } if (valueMask & GCLineStyle) { valueKey.values.line_style = valuePtr->line_style; } else { valueKey.values.line_style = LineSolid; } if (valueMask & GCCapStyle) { valueKey.values.cap_style = valuePtr->cap_style; } else { valueKey.values.cap_style = CapButt; } if (valueMask & GCJoinStyle) { valueKey.values.join_style = valuePtr->join_style; } else { valueKey.values.join_style = JoinMiter; } if (valueMask & GCFillStyle) { valueKey.values.fill_style = valuePtr->fill_style; } else { valueKey.values.fill_style = FillSolid; } if (valueMask & GCFillRule) { valueKey.values.fill_rule = valuePtr->fill_rule; } else { valueKey.values.fill_rule = EvenOddRule; } if (valueMask & GCArcMode) { valueKey.values.arc_mode = valuePtr->arc_mode; } else { valueKey.values.arc_mode = ArcPieSlice; } if (valueMask & GCTile) { valueKey.values.tile = valuePtr->tile; } else { valueKey.values.tile = None; } if (valueMask & GCStipple) { valueKey.values.stipple = valuePtr->stipple; } else { valueKey.values.stipple = None; } if (valueMask & GCTileStipXOrigin) { valueKey.values.ts_x_origin = valuePtr->ts_x_origin; } else { valueKey.values.ts_x_origin = 0; } if (valueMask & GCTileStipYOrigin) { valueKey.values.ts_y_origin = valuePtr->ts_y_origin; } else { valueKey.values.ts_y_origin = 0; } if (valueMask & GCFont) { valueKey.values.font = valuePtr->font; } else { valueKey.values.font = None; } if (valueMask & GCSubwindowMode) { valueKey.values.subwindow_mode = valuePtr->subwindow_mode; } else { valueKey.values.subwindow_mode = ClipByChildren; } if (valueMask & GCGraphicsExposures) { valueKey.values.graphics_exposures = valuePtr->graphics_exposures; } else { valueKey.values.graphics_exposures = True; } if (valueMask & GCClipXOrigin) { valueKey.values.clip_x_origin = valuePtr->clip_x_origin; } else { valueKey.values.clip_x_origin = 0; } if (valueMask & GCClipYOrigin) { valueKey.values.clip_y_origin = valuePtr->clip_y_origin; } else { valueKey.values.clip_y_origin = 0; } if (valueMask & GCClipMask) { valueKey.values.clip_mask = valuePtr->clip_mask; } else { valueKey.values.clip_mask = None; } if (valueMask & GCDashOffset) { valueKey.values.dash_offset = valuePtr->dash_offset; } else { valueKey.values.dash_offset = 0; } if (valueMask & GCDashList) { valueKey.values.dashes = valuePtr->dashes; } else { valueKey.values.dashes = 4; } valueKey.display = Tk_Display(tkwin); valueKey.screenNum = Tk_ScreenNumber(tkwin); valueKey.depth = Tk_Depth(tkwin); valueHashPtr = Tcl_CreateHashEntry(&dispPtr->gcValueTable, (char *) &valueKey, &new); if (!new) { gcPtr = (TkGC *) Tcl_GetHashValue(valueHashPtr); gcPtr->refCount++; return gcPtr->gc; } /* * No GC is currently available for this set of values. Allocate a * new GC and add a new structure to the database. */ gcPtr = (TkGC *) ckalloc(sizeof(TkGC)); /* * Find or make a drawable to use to specify the screen and depth * of the GC. We may have to make a small pixmap, to avoid doing * Tk_MakeWindowExist on the window. */ freeDrawable = None; if (Tk_WindowId(tkwin) != None) { d = Tk_WindowId(tkwin); } else if (valueKey.depth == DefaultDepth(valueKey.display, valueKey.screenNum)) { d = RootWindow(valueKey.display, valueKey.screenNum); } else { d = Tk_GetPixmap(valueKey.display, RootWindow(valueKey.display, valueKey.screenNum), 1, 1, valueKey.depth); freeDrawable = d; } gcPtr->gc = XCreateGC(valueKey.display, d, valueMask, &valueKey.values); gcPtr->display = valueKey.display; gcPtr->refCount = 1; gcPtr->valueHashPtr = valueHashPtr; idHashPtr = Tcl_CreateHashEntry(&dispPtr->gcIdTable, (char *) gcPtr->gc, &new); if (!new) { panic("GC already registered in Tk_GetGC"); } Tcl_SetHashValue(valueHashPtr, gcPtr); Tcl_SetHashValue(idHashPtr, gcPtr); if (freeDrawable != None) { Tk_FreePixmap(valueKey.display, freeDrawable); } return gcPtr->gc; } /* *---------------------------------------------------------------------- * * Tk_FreeGC -- * * This procedure is called to release a graphics context allocated by * Tk_GetGC. * * Results: * None. * * Side effects: * The reference count associated with gc is decremented, and * gc is officially deallocated if no-one is using it anymore. * *---------------------------------------------------------------------- */ void Tk_FreeGC(display, gc) Display *display; /* Display for which gc was allocated. */ GC gc; /* Graphics context to be released. */ { Tcl_HashEntry *idHashPtr; register TkGC *gcPtr; TkDisplay *dispPtr = TkGetDisplay(display); if (!dispPtr->gcInit) { panic("Tk_FreeGC called before Tk_GetGC"); } idHashPtr = Tcl_FindHashEntry(&dispPtr->gcIdTable, (char *) gc); if (idHashPtr == NULL) { panic("Tk_FreeGC received unknown gc argument"); } gcPtr = (TkGC *) Tcl_GetHashValue(idHashPtr); gcPtr->refCount--; if (gcPtr->refCount == 0) { Tk_FreeXId(gcPtr->display, (XID) XGContextFromGC(gcPtr->gc)); XFreeGC(gcPtr->display, gcPtr->gc); Tcl_DeleteHashEntry(gcPtr->valueHashPtr); Tcl_DeleteHashEntry(idHashPtr); ckfree((char *) gcPtr); } } /* *---------------------------------------------------------------------- * * GCInit -- * * Initialize the structures used for GC management. * * Results: * None. * * Side effects: * Read the code. * *---------------------------------------------------------------------- */ static void GCInit(dispPtr) TkDisplay *dispPtr; { dispPtr->gcInit = 1; Tcl_InitHashTable(&dispPtr->gcValueTable, sizeof(ValueKey)/sizeof(int)); Tcl_InitHashTable(&dispPtr->gcIdTable, TCL_ONE_WORD_KEYS); } /* End of tkgc.c */