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-rw-r--r--libXmu/src/CloseHook.c297
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diff --git a/libXmu/src/CloseHook.c b/libXmu/src/CloseHook.c
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+/* $Xorg: CloseHook.c,v 1.4 2001/02/09 02:03:51 xorgcvs Exp $ */
+
+/*
+Copyright 1989, 1998 The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+*/
+/* $XFree86: xc/lib/Xmu/CloseHook.c,v 3.5 2001/07/25 15:04:50 dawes Exp $ */
+
+/*
+ * CloseDisplayHook package - provide callback on XCloseDisplay
+ *
+ * *
+ * Author: Jim Fulton, MIT X Consortium
+ *
+ *
+ * Public Entry Points
+ *
+ * CloseHook XmuAddCloseDisplayHook (dpy, func, arg)
+ * Display *dpy;
+ * XmuCloseHookProc func;
+ * XPointer arg;
+ *
+ * Bool XmuRemoveCloseDisplayHook (dpy, hook, func, arg)
+ * Display *dpy;
+ * CloseHook hook;
+ * XmuCloseHookProc func;
+ * XPointer arg;
+ *
+ * Bool XmuLookupCloseDisplayHook (dpy, hook, func, arg)
+ * Display *dpy;
+ * CloseHook hook;
+ * XmuCloseHookProc func;
+ * XPointer arg;
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h> /* for NULL */
+#include <X11/Xos.h>
+#include <X11/Xlib.h>
+#include <X11/Xmu/CloseHook.h>
+#include <stdlib.h>
+
+/*
+ * Private data
+ *
+ * This is a list of display entries, each of which contains a list of callback
+ * records.
+ */
+
+typedef struct _CallbackRec {
+ struct _CallbackRec *next; /* next link in chain */
+ XmuCloseHookProc func; /* function to call */
+ XPointer arg; /* argument to pass with function */
+} CallbackRec;
+
+
+typedef struct _DisplayEntry {
+ struct _DisplayEntry *next; /* next link in chain */
+ Display *dpy; /* the display this represents */
+ int extension; /* from XAddExtension */
+ struct _CallbackRec *start, *end; /* linked list of callbacks */
+ struct _CallbackRec *calling; /* currently being called back */
+} DisplayEntry;
+
+/*
+ * Prototypes
+ */
+static DisplayEntry *_FindDisplayEntry(Display*, DisplayEntry**);
+static Bool _MakeExtension(Display*, int*);
+
+static DisplayEntry *elist = NULL;
+
+
+/*
+ *****************************************************************************
+ * Public Entry Points *
+ *****************************************************************************
+ */
+
+/*
+ * Add - add a callback for the given display. When the display is closed,
+ * the given function will be called as:
+ *
+ * (*func) (dpy, arg)
+ *
+ * This function is declared to return an int even though the value is ignored
+ * because some compilers have problems with functions returning void.
+ *
+ * This routine returns NULL if it was unable to add the callback, otherwise
+ * it returns an untyped pointer that can be used with Remove or Lookup, but
+ * not dereferenced.
+ */
+CloseHook
+XmuAddCloseDisplayHook(Display *dpy, XmuCloseHookProc func, XPointer arg)
+{
+ DisplayEntry *de;
+ CallbackRec *cb;
+
+ /* allocate ahead of time so that we can fail atomically */
+ cb = (CallbackRec *) malloc (sizeof (CallbackRec));
+ if (!cb) return ((XPointer) NULL);
+
+ de = _FindDisplayEntry (dpy, NULL);
+ if (!de) {
+ if ((de = (DisplayEntry *) malloc (sizeof (DisplayEntry))) == NULL ||
+ !_MakeExtension (dpy, &de->extension)) {
+ free ((char *) cb);
+ if (de) free ((char *) de);
+ return ((CloseHook) NULL);
+ }
+ de->dpy = dpy;
+ de->start = de->end = NULL;
+ de->calling = NULL;
+ de->next = elist;
+ elist = de;
+ }
+
+ /* add to end of list of callback recordss */
+ cb->func = func;
+ cb->arg = arg;
+ cb->next = NULL;
+ if (de->end) {
+ de->end->next = cb;
+ } else {
+ de->start = cb;
+ }
+ de->end = cb;
+
+ return ((CloseHook) cb);
+}
+
+
+/*
+ * Remove - get rid of a callback. If handle is non-null, use that to compare
+ * entries. Otherwise, remove first instance of the function/argument pair.
+ */
+Bool
+XmuRemoveCloseDisplayHook(Display *dpy, CloseHook handle,
+ XmuCloseHookProc func, XPointer arg)
+{
+ DisplayEntry *de = _FindDisplayEntry (dpy, NULL);
+ register CallbackRec *h, *prev;
+
+ if (!de) return False;
+
+ /* look for handle or function/argument pair */
+ for (h = de->start, prev = NULL; h; h = h->next) {
+ if (handle) {
+ if (h == (CallbackRec *) handle) break;
+ } else {
+ if (h->func == func && h->arg == arg) break;
+ }
+ prev = h;
+ }
+ if (!h) return False;
+
+
+ /* remove from list, watch head and tail */
+ if (de->start == h) {
+ de->start = h->next;
+ } else {
+ prev->next = h->next;
+ }
+ if (de->end == h) de->end = prev;
+ if (de->calling != h) free ((char *) h);
+ return True;
+}
+
+
+/*
+ * Lookup - see whether or not a handle has been installed. If handle is
+ * non-NULL, look for an entry that matches it; otherwise look for an entry
+ * with the same function/argument pair.
+ */
+Bool
+XmuLookupCloseDisplayHook(Display *dpy, CloseHook handle,
+ XmuCloseHookProc func, XPointer arg)
+{
+ DisplayEntry *de = _FindDisplayEntry (dpy, NULL);
+ register CallbackRec *h;
+
+ if (!de) return False;
+
+ for (h = de->start; h; h = h->next) {
+ if (handle) {
+ if (h == (CallbackRec *) handle) break;
+ } else {
+ if (h->func == func && h->arg == arg) break;
+ }
+ }
+ return (h ? True : False);
+}
+
+
+/*
+ *****************************************************************************
+ * internal routines *
+ *****************************************************************************
+ */
+
+
+/*
+ * Find the specified display on the linked list of displays. Also return
+ * the preceeding link so that the display can be unlinked without having
+ * back pointers.
+ */
+static DisplayEntry *
+_FindDisplayEntry(register Display *dpy, DisplayEntry **prevp)
+{
+ register DisplayEntry *d, *prev;
+
+ for (d = elist, prev = NULL; d; d = d->next) {
+ if (d->dpy == dpy) {
+ if (prevp) *prevp = prev;
+ return d;
+ }
+ prev = d;
+ }
+ return NULL;
+}
+
+
+
+/*
+ * _DoCallbacks - process all of the callbacks for this display and free
+ * the associated callback data (callback records and display entries).
+ */
+/* ARGSUSED */
+static int
+_DoCallbacks(Display *dpy, XExtCodes *codes)
+{
+ register CallbackRec *h;
+ DisplayEntry *prev;
+ DisplayEntry *de = _FindDisplayEntry (dpy, &prev);
+
+ if (!de) return 0;
+
+ /* walk the list doing the callbacks and freeing callback record */
+ for (h = de->start; h;) {
+ register CallbackRec *nexth = h->next;
+ de->calling = h; /* let remove know we'll free it */
+ (*(h->func)) (dpy, h->arg);
+ de->calling = NULL;
+ free ((char *) h);
+ h = nexth;
+ }
+
+ /* unlink this display from chain */
+ if (elist == de) {
+ elist = de->next;
+ } else {
+ prev->next = de->next;
+ }
+ free ((char *) de);
+ return 1;
+}
+
+
+/*
+ * _MakeExtension - create an extension for this display; done once per display
+ */
+static Bool
+_MakeExtension(Display *dpy, int *extensionp)
+{
+ XExtCodes *codes;
+
+ codes = XAddExtension (dpy);
+ if (!codes) return False;
+
+ (void) XESetCloseDisplay (dpy, codes->extension, _DoCallbacks);
+
+ *extensionp = codes->extension;
+ return True;
+}
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