Add CompWalker interface.

2 files changed, 59 insertions, 0 deletions

diff --git a/include/compiz.h b/include/compiz.h
index 2e0808c..76f3f88 100644
--- a/include/compiz.h
+++ b/include/compiz.h
@@ -90,6 +90,7 @@ typedef struct _CompCursor	  CompCursor;
 typedef struct _CompMatch	  CompMatch;
 typedef struct _CompMetadata      CompMetadata;
 typedef struct _CompOutput        CompOutput;
+typedef struct _CompWalker        CompWalker;
 
 /* virtual modifiers */
 
@@ -1228,6 +1229,22 @@ typedef void (*ApplyScreenTransformProc) (CompScreen		  *screen,
 					  CompOutput		  *output,
 					  CompTransform	          *transform);
 
+typedef void (*WalkerFiniProc) (CompScreen *screen,
+				CompWalker *walker);
+
+typedef CompWindow *(*WalkInitProc) (CompScreen *screen);
+typedef CompWindow *(*WalkStepProc) (CompWindow *window);
+
+struct _CompWalker {
+    WalkerFiniProc fini;
+    CompPrivate	   priv;
+
+    WalkInitProc first;
+    WalkInitProc last;
+    WalkStepProc next;
+    WalkStepProc prev;
+};
+
 /*
   window paint flags
 
@@ -1703,6 +1720,9 @@ typedef void (*WindowAddNotifyProc) (CompWindow *window);
 
 typedef void (*OutputChangeNotifyProc) (CompScreen *screen);
 
+typedef void (*InitWindowWalkerProc) (CompScreen *screen,
+				      CompWalker *walker);
+
 #define COMP_SCREEN_DAMAGE_PENDING_MASK (1 << 0)
 #define COMP_SCREEN_DAMAGE_REGION_MASK  (1 << 1)
 #define COMP_SCREEN_DAMAGE_ALL_MASK     (1 << 2)
@@ -2015,6 +2035,8 @@ struct _CompScreen {
 
     OutputChangeNotifyProc outputChangeNotify;
 
+    InitWindowWalkerProc initWindowWalker;
+
     CompPrivate *privates;
 };
 
diff --git a/src/screen.c b/src/screen.c
index d3e0d48..a3d39a5 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -1359,6 +1359,41 @@ leaveShowDesktopMode (CompScreen *s,
 		     (unsigned char *) &data, 1);
 }
 
+static CompWindow *
+walkFirst (CompScreen *s)
+{
+    return s->windows;
+}
+
+static CompWindow *
+walkLast (CompScreen *s)
+{
+    return s->reverseWindows;
+}
+
+static CompWindow *
+walkNext (CompWindow *w)
+{
+    return w->next;
+}
+
+static CompWindow *
+walkPrev (CompWindow *w)
+{
+    return w->prev;
+}
+
+static void
+initWindowWalker (CompScreen *screen,
+		  CompWalker *walker)
+{
+    walker->fini  = NULL;
+    walker->first = walkFirst;
+    walker->last  = walkLast;
+    walker->next  = walkNext;
+    walker->prev  = walkPrev;
+}
+
 Bool
 addScreen (CompDisplay *display,
 	   int	       screenNum,
@@ -1554,6 +1589,8 @@ addScreen (CompDisplay *display,
 
     s->outputChangeNotify = outputChangeNotify;
 
+    s->initWindowWalker = initWindowWalker;
+
     s->getProcAddress = 0;
 
     if (!XGetWindowAttributes (dpy, s->root, &s->attrib))