Add support for composited child windows. (#412882, Ryan Lortie)

2007-06-01  Matthias Clasen  <mclasen@redhat.com>

        Add support for composited child windows.  (#412882, Ryan Lortie)

        * gdk/gdk.symbols:
        * gdk/gdkdisplay.h:
        * gdk/gdkinternals.h:
        * gdk/gdkwindow.[hc]: Add gdk_display_supports_composite() and
        gdk_window_set_composited().

        * gdk/x11/gdkevents-x11.c:
        * gdk/x11/gdkdisplay-x11.[hc]:
        * gdk/x11/gdkwindow-x11.[hc]: X11 implementation.

        * gdk/win32/gdkdisplay-win32.c:
        * gdk/win32/gdkwindow-win32.c: Dummy win32 implementration.

        * gdk/quartz/gdkdisplay-quartz.c:
        * gdk/quartz/gdkwindow-quartz.c: Dummy Quartz implementation.

        * gdk/directfb/gdkdisplay-directfb.c:
        * gdk/directfb/gdkwindow-directfb.c: Dummy DirectFB implementation.

        * tests/testgtk.c: Add a "composited window" test.


svn path=/trunk/; revision=18004

16 files changed, 295 insertions, 3 deletions

diff --git a/gdk/directfb/gdkdisplay-directfb.c b/gdk/directfb/gdkdisplay-directfb.c
index 9cf7a2fdb1..04275fee27 100644
--- a/gdk/directfb/gdkdisplay-directfb.c
+++ b/gdk/directfb/gdkdisplay-directfb.c
@@ -511,6 +511,13 @@ gdk_notify_startup_complete_with_id (const gchar* startup_id)
 {
 }
 
+
+gboolean
+gdk_display_supports_composite (GdkDisplay *display)
+{
+    return FALSE;
+}
+
 #define __GDK_DISPLAY_X11_C__
 #include "gdkaliasdef.c"
 
diff --git a/gdk/directfb/gdkwindow-directfb.c b/gdk/directfb/gdkwindow-directfb.c
index 59e28b7393..7fe3911852 100644
--- a/gdk/directfb/gdkwindow-directfb.c
+++ b/gdk/directfb/gdkwindow-directfb.c
@@ -3038,6 +3038,14 @@ gdk_window_set_opacity (GdkWindow *window,
   cardinal = opacity * 0xff;
   gdk_directfb_window_set_opacity(window,cardinal);
 }
+
+void
+_gdk_windowing_window_set_composited (GdkWindow *window,
+                                      gboolean   composited)
+{
+}
+
+
 #define __GDK_WINDOW_X11_C__
 #include "gdkaliasdef.c"
 
diff --git a/gdk/gdk.symbols b/gdk/gdk.symbols
index 56722e7cb6..8757324fcc 100644
--- a/gdk/gdk.symbols
+++ b/gdk/gdk.symbols
@@ -466,6 +466,7 @@ gdk_display_supports_clipboard_persistence
 gdk_display_supports_selection_notification
 gdk_display_supports_shapes
 gdk_display_supports_input_shapes
+gdk_display_supports_composite
 #endif
 #endif
 
@@ -673,6 +674,7 @@ gdk_window_remove_filter
 gdk_window_set_debug_updates
 gdk_window_set_user_data
 gdk_window_thaw_updates
+gdk_window_set_composited
 #endif
 #endif
 
diff --git a/gdk/gdkdisplay.h b/gdk/gdkdisplay.h
index c627a08581..b55b312257 100644
--- a/gdk/gdkdisplay.h
+++ b/gdk/gdkdisplay.h
@@ -181,6 +181,7 @@ void     gdk_display_store_clipboard                (GdkDisplay *display,
 
 gboolean gdk_display_supports_shapes           (GdkDisplay    *display);
 gboolean gdk_display_supports_input_shapes     (GdkDisplay    *display);
+gboolean gdk_display_supports_composite        (GdkDisplay    *display);
 
 G_END_DECLS
 
diff --git a/gdk/gdkinternals.h b/gdk/gdkinternals.h
index 1c279f4ec3..f97b97be04 100644
--- a/gdk/gdkinternals.h
+++ b/gdk/gdkinternals.h
@@ -337,6 +337,9 @@ void _gdk_windowing_window_destroy_foreign (GdkWindow *window);
 void _gdk_windowing_display_set_sm_client_id (GdkDisplay  *display,
 					      const gchar *sm_client_id);
 
+void _gdk_windowing_window_set_composited (GdkWindow *window,
+					   gboolean composited);
+
 #define GDK_TYPE_PAINTABLE            (_gdk_paintable_get_type ())
 #define GDK_PAINTABLE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GDK_TYPE_PAINTABLE, GdkPaintable))
 #define GDK_IS_PAINTABLE(obj)	      (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GDK_TYPE_PAINTABLE))
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index d0d1573a6e..5e1d830698 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -1042,6 +1042,7 @@ gdk_window_end_paint (GdkWindow *window)
 {
 #ifdef USE_BACKING_STORE
   GdkWindowObject *private = (GdkWindowObject *)window;
+  GdkWindowObject *composited;
   GdkWindowPaint *paint;
   GdkGC *tmp_gc;
   GdkRectangle clip_box;
@@ -1094,6 +1095,34 @@ gdk_window_end_paint (GdkWindow *window)
   g_object_unref (paint->pixmap);
   gdk_region_destroy (paint->region);
   g_free (paint);
+
+  /* find a composited window in our hierarchy to signal its
+   * parent to redraw, calculating the clip box as we go...
+   *
+   * stop if parent becomes NULL since then we'd have nowhere
+   * to draw (ie: 'composited' will always be non-NULL here).
+   */
+  for (composited = private;
+       composited->parent;
+       composited = composited->parent)
+    {
+      int width, height;
+
+      gdk_drawable_get_size (GDK_DRAWABLE (composited->parent),
+			     &width, &height);
+
+      clip_box.x += composited->x;
+      clip_box.y += composited->y;
+      clip_box.width = MIN (clip_box.width, width - clip_box.x);
+      clip_box.height = MIN (clip_box.height, height - clip_box.y);
+
+      if (composited->composited)
+	{
+	  gdk_window_invalidate_rect (GDK_WINDOW (composited->parent),
+				      &clip_box, FALSE);
+	  break;
+	}
+    }
 #endif /* USE_BACKING_STORE */
 }
 
@@ -2601,7 +2630,8 @@ gdk_window_invalidate_maybe_recurse (GdkWindow *window,
 	  child_region = gdk_region_rectangle (&child_rect);
 	  
 	  /* remove child area from the invalid area of the parent */
-	  if (GDK_WINDOW_IS_MAPPED (child) && !child->shaped)
+	  if (GDK_WINDOW_IS_MAPPED (child) && !child->shaped &&
+	      !child->composited)
 	    gdk_region_subtract (visible_region, child_region);
 	  
 	  if (child_func && (*child_func) ((GdkWindow *)child, user_data))
@@ -3056,5 +3086,64 @@ gdk_window_foreign_new (GdkNativeWindow anid)
   return gdk_window_foreign_new_for_display (gdk_display_get_default (), anid);
 }
 
+/**
+ * gdk_window_set_composited:
+ * @window: a #GdkWindow
+ *
+ * Sets a #GdkWindow as composited. Composited windows do
+ * not automatically have their contents drawn to the screen.
+ * Drawing is redirected to an offscreen buffer and an expose
+ * event is emitted on the parent of the composited window.
+ * It is the responsibility of the parent's expose handler to
+ * manually merge the off-screen content onto the screen in
+ * whatever way it sees fit. See <xref linkend="composited-window-example"/>
+ * for an example.
+ *
+ * It only makes sense for child windows to be composited; see
+ * gdk_window_set_opacity() if you need translucent toplevel
+ * windows.
+ *
+ * An additional effect of this call is that the area of this
+ * window is no longer clipped from regions marked for
+ * invalidation on its parent. Draws done on the parent
+ * window are also no longer clipped by the child.
+ *
+ * This call is only supported on some systems (currently,
+ * only X11 with new enough Xcomposite and Xdamage extensions). 
+ * You must call gdk_display_supports_composite() to check if
+ * setting a window as composited is supported before
+ * attempting to do so.
+ *
+ * Since: 2.12
+ */
+void
+gdk_window_set_composited (GdkWindow *window,
+                           gboolean   composited)
+{
+  GdkWindowObject *private = (GdkWindowObject *)window;
+  GdkDisplay *display;
+
+  g_return_if_fail (window != NULL);
+  g_return_if_fail (GDK_IS_WINDOW (window));
+
+  composited = composited != FALSE;
+
+  if (private->composited == composited)
+    return;
+
+  display = gdk_drawable_get_display (GDK_DRAWABLE (window));
+
+  if (!gdk_display_supports_composite (display) && composited)
+    {
+      g_warning ("gdk_window_set_composited called but "
+		 "compositing is not supported");
+      return;
+    }
+
+  _gdk_windowing_window_set_composited (window, composited);
+
+  private->composited = composited;
+}
+
 #define __GDK_WINDOW_C__
 #include "gdkaliasdef.c"
diff --git a/gdk/gdkwindow.h b/gdk/gdkwindow.h
index 9ff3a09fca..d50d3e6c9a 100644
--- a/gdk/gdkwindow.h
+++ b/gdk/gdkwindow.h
@@ -289,6 +289,7 @@ struct _GdkWindowObject
   guint guffaw_gravity : 1;
   guint input_only : 1;
   guint modal_hint : 1;
+  guint composited : 1;
   
   guint destroyed : 2;
 
@@ -394,6 +395,9 @@ void gdk_window_shape_combine_region (GdkWindow	    *window,
  */
 void gdk_window_set_child_shapes (GdkWindow *window);
 
+void gdk_window_set_composited   (GdkWindow *window,
+                                  gboolean composited);
+
 /*
  * This routine allows you to merge (ie ADD) child shapes to your
  * own window's shape keeping its current shape and ADDING the child
diff --git a/gdk/quartz/gdkdisplay-quartz.c b/gdk/quartz/gdkdisplay-quartz.c
index b34567eaf7..3f9a01f254 100644
--- a/gdk/quartz/gdkdisplay-quartz.c
+++ b/gdk/quartz/gdkdisplay-quartz.c
@@ -169,3 +169,11 @@ gdk_display_store_clipboard (GdkDisplay *display,
 {
   /* FIXME: Implement */
 }
+
+
+gboolean
+gdk_display_supports_composite (GdkDisplay *display)
+{
+  /* FIXME: Implement */
+  return FALSE;
+}
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index 31f2b01a39..51f253ecf2 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -2155,3 +2155,8 @@ gdk_window_set_opacity (GdkWindow *window,
 
   [impl->toplevel setAlphaValue: opacity];
 }
+
+void
+_gdk_windowing_window_set_composited (GdkWindow *window, gboolean composited)
+{
+}
diff --git a/gdk/win32/gdkdisplay-win32.c b/gdk/win32/gdkdisplay-win32.c
index 5b77fb11bb..78c26bf779 100644
--- a/gdk/win32/gdkdisplay-win32.c
+++ b/gdk/win32/gdkdisplay-win32.c
@@ -389,3 +389,9 @@ gdk_display_supports_input_shapes (GdkDisplay *display)
 
   return FALSE;
 }
+
+gboolean
+gdk_display_supports_composite (GdkDisplay *display)
+{
+  return FALSE;
+}
diff --git a/gdk/win32/gdkwindow-win32.c b/gdk/win32/gdkwindow-win32.c
index 631d4200d1..fad5644a3b 100644
--- a/gdk/win32/gdkwindow-win32.c
+++ b/gdk/win32/gdkwindow-win32.c
@@ -3571,3 +3571,8 @@ gdk_window_set_opacity (GdkWindow *window,
 					 opacity * 0xff,
 					 LWA_ALPHA));
 }
+
+void
+_gdk_windowing_window_set_composited (GdkWindow *window, gboolean composited)
+{
+}
diff --git a/gdk/x11/gdkdisplay-x11.c b/gdk/x11/gdkdisplay-x11.c
index c57ef2e833..de7c1f2f83 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -54,6 +54,14 @@
 #include <X11/extensions/shape.h>
 #endif
 
+#ifdef HAVE_XCOMPOSITE
+#include <X11/extensions/Xcomposite.h>
+#endif
+
+#ifdef HAVE_XDAMAGE
+#include <X11/extensions/Xdamage.h>
+#endif
+
 
 static void   gdk_display_x11_dispose            (GObject            *object);
 static void   gdk_display_x11_finalize           (GObject            *object);
@@ -206,6 +214,29 @@ gdk_display_open (const gchar *display_name)
 #endif
     display_x11->have_xfixes = FALSE;
 
+#ifdef HAVE_XCOMPOSITE
+  if (XCompositeQueryExtension (display_x11->xdisplay,
+				&ignore, &ignore))
+      display_x11->have_xcomposite = TRUE;
+  else
+#endif
+    display_x11->have_xcomposite = FALSE;
+
+#ifdef HAVE_XDAMAGE
+  if (XDamageQueryExtension (display_x11->xdisplay,
+			     &display_x11->xdamage_event_base,
+			     &ignore))
+    {
+      display_x11->have_xdamage = TRUE;
+
+      gdk_x11_register_standard_event_type (display,
+					    display_x11->xdamage_event_base,
+					    XDamageNumberEvents);
+    }
+  else
+#endif
+    display_x11->have_xdamage = FALSE;
+
   display_x11->have_shapes = FALSE;
   display_x11->have_input_shapes = FALSE;
 #ifdef HAVE_SHAPE_EXT
@@ -1363,5 +1394,30 @@ gdk_x11_display_get_startup_notification_id (GdkDisplay *display)
   return GDK_DISPLAY_X11 (display)->startup_notification_id;
 }
 
+/**
+ * gdk_display_supports_composite:
+ * @display: a #GdkDisplay
+ *
+ * Returns %TRUE if gdk_window_set_composited() can be used
+ * to redirect drawing on the window using compositing.
+ *
+ * Currently this only works on X11 with XComposite and
+ * XDamage extensions available.
+ *
+ * Returns: %TRUE if windows may be composited.
+ *
+ * Since: 2.12
+ */
+gboolean
+gdk_display_supports_composite (GdkDisplay *display)
+{
+  GdkDisplayX11 *x11_display = GDK_DISPLAY_X11 (display);
+
+  return x11_display->have_xcomposite &&
+	 x11_display->have_xdamage &&
+	 x11_display->have_xfixes;
+}
+
+
 #define __GDK_DISPLAY_X11_C__
 #include "gdkaliasdef.c"
diff --git a/gdk/x11/gdkdisplay-x11.h b/gdk/x11/gdkdisplay-x11.h
index 14b8fd5b29..7b2654cd7c 100644
--- a/gdk/x11/gdkdisplay-x11.h
+++ b/gdk/x11/gdkdisplay-x11.h
@@ -81,6 +81,10 @@ struct _GdkDisplayX11
   gboolean have_xfixes;
   gint xfixes_event_base;
 
+  gboolean have_xcomposite;
+  gboolean have_xdamage;
+  gint xdamage_event_base;
+
   /* If the SECURITY extension is in place, whether this client holds 
    * a trusted authorization and so is allowed to make various requests 
    * (grabs, properties etc.) Otherwise always TRUE. */
diff --git a/gdk/x11/gdkevents-x11.c b/gdk/x11/gdkevents-x11.c
index 6df08bb3df..b9560d46ed 100644
--- a/gdk/x11/gdkevents-x11.c
+++ b/gdk/x11/gdkevents-x11.c
@@ -2101,6 +2101,34 @@ gdk_event_translate (GdkDisplay *display,
 	}
       else
 #endif
+#if defined(HAVE_XCOMPOSITE) && defined (HAVE_XDAMAGE) && defined (HAVE_XFIXES)
+      if (display_x11->have_xdamage && window_private->composited &&
+	  xevent->type == display_x11->xdamage_event_base + XDamageNotify)
+	{
+	  XDamageNotifyEvent *damage_event = (XDamageNotifyEvent *) xevent;
+	  XserverRegion repair;
+	  GdkRectangle rect;
+
+	  rect.x = window_private->x + damage_event->area.x;
+	  rect.y = window_private->y + damage_event->area.y;
+	  rect.width = damage_event->area.width;
+	  rect.height = damage_event->area.height;
+
+	  repair = XFixesCreateRegion (display_x11->xdisplay,
+				      &damage_event->area, 1);
+	  XDamageSubtract (display_x11->xdisplay,
+			   window_impl->damage,
+			   repair, None);
+	  XFixesDestroyRegion (display_x11->xdisplay, repair);
+
+	  if (window_private->parent != NULL)
+	    _gdk_window_process_expose (GDK_WINDOW (window_private->parent),
+					damage_event->serial, &rect);
+
+	  return_val = TRUE;
+	}
+      else
+#endif
 	{
 	  /* something else - (e.g., a Xinput event) */
 	  
diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index e3e84270d6..a58de4526d 100644
--- a/gdk/x11/gdkwindow-x11.c
+++ b/gdk/x11/gdkwindow-x11.c
@@ -59,6 +59,18 @@
 #include <X11/extensions/shape.h>
 #endif
 
+#ifdef HAVE_XCOMPOSITE
+#include <X11/extensions/Xcomposite.h>
+#endif
+
+#ifdef HAVE_XFIXES
+#include <X11/extensions/Xfixes.h>
+#endif
+
+#ifdef HAVE_XDAMAGE
+#include <X11/extensions/Xdamage.h>
+#endif
+
 const int _gdk_event_mask_table[21] =
 {
   ExposureMask,
@@ -185,6 +197,14 @@ gdk_window_impl_x11_finalize (GObject *object)
 
   _gdk_xgrab_check_destroy (GDK_WINDOW (wrapper));
 
+#if defined(HAVE_XCOMPOSITE) && defined(HAVE_XDAMAGE) && defined (HAVE_XFIXES)
+  if (window_impl->damage != None)
+  {
+    XDamageDestroy (GDK_WINDOW_XDISPLAY (object), window_impl->damage);
+    window_impl->damage = None;
+  }
+#endif
+
   if (!GDK_WINDOW_DESTROYED (wrapper))
     {
       GdkDisplay *display = GDK_WINDOW_DISPLAY (wrapper);
@@ -6413,10 +6433,14 @@ gdk_window_beep (GdkWindow *window)
  *
  * Request the windowing system to make @window partially transparent,
  * with opacity 0 being fully transparent and 1 fully opaque. (Values
- * of the opacity parameter are clamped to the [0,1] range.) On X11
- * this works only on X screens with a compositing manager running.
+ * of the opacity parameter are clamped to the [0,1] range.) 
+ *
+ * On X11, this works only on X screens with a compositing manager 
+ * running.
  *
  * For setting up per-pixel alpha, see gdk_screen_get_rgba_colormap().
+ * For making non-toplevel windows translucent, see 
+ * gdk_window_set_composited().
  *
  * Since: 2.12
  */
@@ -6455,5 +6479,39 @@ gdk_window_set_opacity (GdkWindow *window,
 		     (guchar *) cardinal, 1);
 }
 
+void
+_gdk_windowing_window_set_composited (GdkWindow *window,
+                                      gboolean   composited)
+{
+#if defined(HAVE_XCOMPOSITE) && defined(HAVE_XDAMAGE) && defined (HAVE_XFIXES)
+  GdkWindowObject *private = (GdkWindowObject *) window;
+  GdkDisplayX11 *x11_display;
+  GdkWindowImplX11 *impl;
+  GdkDisplay *display;
+  Display *dpy;
+  Window xid;
+
+  impl = GDK_WINDOW_IMPL_X11 (private->impl);
+
+  display = gdk_screen_get_display (GDK_DRAWABLE_IMPL_X11 (impl)->screen);
+  x11_display = GDK_DISPLAY_X11 (display);
+  dpy = GDK_DISPLAY_XDISPLAY (display);
+  xid = GDK_WINDOW_XWINDOW (private);
+
+  if (composited)
+    {
+      XCompositeRedirectWindow (dpy, xid, CompositeRedirectManual);
+      impl->damage = XDamageCreate (dpy, xid, XDamageReportBoundingBox);
+    }
+  else
+    {
+      XCompositeUnredirectWindow (dpy, xid, CompositeRedirectManual);
+      XDamageDestroy (dpy, impl->damage);
+      impl->damage = None;
+    }
+#endif
+}
+
+
 #define __GDK_WINDOW_X11_C__
 #include "gdkaliasdef.c"
diff --git a/gdk/x11/gdkwindow-x11.h b/gdk/x11/gdkwindow-x11.h
index 18fa23a057..3ab23d6003 100644
--- a/gdk/x11/gdkwindow-x11.h
+++ b/gdk/x11/gdkwindow-x11.h
@@ -29,6 +29,10 @@
 
 #include <gdk/x11/gdkdrawable-x11.h>
 
+#ifdef HAVE_XDAMAGE
+#include <X11/extensions/Xdamage.h>
+#endif
+
 #ifdef HAVE_XSYNC
 #include <X11/extensions/sync.h>
 #endif
@@ -79,6 +83,10 @@ struct _GdkWindowImplX11
   gint8 toplevel_window_type;
   guint override_redirect : 1;
   guint use_synchronized_configure : 1;
+
+#if defined (HAVE_XCOMPOSITE) && defined(HAVE_XDAMAGE) && defined (HAVE_XFIXES)
+  Damage damage;
+#endif
 };
  
 struct _GdkWindowImplX11Class