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Diffstat (limited to 'generic/tkGC.c')
| -rw-r--r-- | generic/tkGC.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/generic/tkGC.c b/generic/tkGC.c new file mode 100644 index 0000000..f68db12 --- /dev/null +++ b/generic/tkGC.c @@ -0,0 +1,363 @@ +/* + * 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. + * + * SCCS: @(#) tkGC.c 1.18 96/02/15 18:53:32 + */ + +#include "tkPort.h" +#include "tk.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; + +/* + * Hash table to map from a GC's values to a TkGC structure describing + * a GC with those values (used by Tk_GetGC). + */ + +static Tcl_HashTable valueTable; +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; + +/* + * Hash table for <display + GC> -> TkGC mapping. This table is used by + * Tk_FreeGC. + */ + +static Tcl_HashTable idTable; +typedef struct { + Display *display; /* Display for which GC was allocated. */ + GC gc; /* X's identifier for GC. */ +} IdKey; + +static int initialized = 0; /* 0 means static structures haven't been + * initialized yet. */ + +/* + * Forward declarations for procedures defined in this file: + */ + +static void GCInit _ANSI_ARGS_((void)); + +/* + *---------------------------------------------------------------------- + * + * 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; + IdKey idKey; + Tcl_HashEntry *valueHashPtr, *idHashPtr; + register TkGC *gcPtr; + int new; + Drawable d, freeDrawable; + + if (!initialized) { + GCInit(); + } + + /* + * 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(&valueTable, (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; + idKey.display = valueKey.display; + idKey.gc = gcPtr->gc; + idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &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. */ +{ + IdKey idKey; + Tcl_HashEntry *idHashPtr; + register TkGC *gcPtr; + + if (!initialized) { + panic("Tk_FreeGC called before Tk_GetGC"); + } + + idKey.display = display; + idKey.gc = gc; + idHashPtr = Tcl_FindHashEntry(&idTable, (char *) &idKey); + 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() +{ + initialized = 1; + Tcl_InitHashTable(&valueTable, sizeof(ValueKey)/sizeof(int)); + Tcl_InitHashTable(&idTable, sizeof(IdKey)/sizeof(int)); +} |