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cpython-source-deps/generic/tkGC.c
Cheryl Sabella 8e57feeeb9 Import Tk 8.6.8
2018-02-22 14:31:15 -05:00

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/*
* 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.
*/
#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 functions defined in this file:
*/
static void GCInit(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 function, 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(
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 isNew;
Drawable d, freeDrawable;
TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
if (dispPtr->gcInit <= 0) {
GCInit(dispPtr);
}
/*
* Must zero valueKey at start to clear out pad bytes that may be part of
* structure on some systems.
*/
memset(&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, &isNew);
if (!isNew) {
gcPtr = 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 = 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, &isNew);
if (!isNew) {
Tcl_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 function 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 *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) {
Tcl_Panic("Tk_FreeGC called before Tk_GetGC");
}
if (dispPtr->gcInit < 0) {
/*
* The GCCleanup has been called, and remaining GCs have been freed.
* This may still get called by other things shutting down, but the
* GCs should no longer be in use.
*/
return;
}
idHashPtr = Tcl_FindHashEntry(&dispPtr->gcIdTable, (char *) gc);
if (idHashPtr == NULL) {
Tcl_Panic("Tk_FreeGC received unknown gc argument");
}
gcPtr = Tcl_GetHashValue(idHashPtr);
gcPtr->refCount--;
if (gcPtr->refCount == 0) {
XFreeGC(gcPtr->display, gcPtr->gc);
Tcl_DeleteHashEntry(gcPtr->valueHashPtr);
Tcl_DeleteHashEntry(idHashPtr);
ckfree(gcPtr);
}
}
/*
*----------------------------------------------------------------------
*
* TkGCCleanup --
*
* Frees the structures used for GC management. We need to have it called
* near the end, when other cleanup that calls Tk_FreeGC is all done.
*
* Results:
* None.
*
* Side effects:
* GC resources are freed.
*
*----------------------------------------------------------------------
*/
void
TkGCCleanup(
TkDisplay *dispPtr) /* display to clean up resources in */
{
Tcl_HashEntry *entryPtr;
Tcl_HashSearch search;
TkGC *gcPtr;
for (entryPtr = Tcl_FirstHashEntry(&dispPtr->gcIdTable, &search);
entryPtr != NULL; entryPtr = Tcl_NextHashEntry(&search)) {
gcPtr = Tcl_GetHashValue(entryPtr);
XFreeGC(gcPtr->display, gcPtr->gc);
Tcl_DeleteHashEntry(gcPtr->valueHashPtr);
Tcl_DeleteHashEntry(entryPtr);
ckfree(gcPtr);
}
Tcl_DeleteHashTable(&dispPtr->gcValueTable);
Tcl_DeleteHashTable(&dispPtr->gcIdTable);
dispPtr->gcInit = -1;
}
/*
*----------------------------------------------------------------------
*
* GCInit --
*
* Initialize the structures used for GC management.
*
* Results:
* None.
*
* Side effects:
* Read the code.
*
*----------------------------------------------------------------------
*/
static void
GCInit(
TkDisplay *dispPtr)
{
if (dispPtr->gcInit < 0) {
Tcl_Panic("called GCInit after GCCleanup");
}
dispPtr->gcInit = 1;
Tcl_InitHashTable(&dispPtr->gcValueTable, sizeof(ValueKey)/sizeof(int));
Tcl_InitHashTable(&dispPtr->gcIdTable, TCL_ONE_WORD_KEYS);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/