GdkFrameClock: add freeze/thaw

Add the ability to freeze a frame clock, which pauses its operation,
then thaw it again later to resume.

Initially this is used to implement freezing updates when we are
waiting for ConfigureNotify in response to changing the size of
a toplevel.

We need a per-window clock for this to work properly, so add that
for the X11 backend.

https://bugzilla.gnome.org/show_bug.cgi?id=685460

5 files changed, 110 insertions, 14 deletions

diff --git a/gdk/gdkframeclock.c b/gdk/gdkframeclock.c
index 9fcf642c36..d385123842 100644
--- a/gdk/gdkframeclock.c
+++ b/gdk/gdkframeclock.c
@@ -226,6 +226,23 @@ gdk_frame_clock_request_phase (GdkFrameClock      *clock,
 }
 
 
+void
+gdk_frame_clock_freeze (GdkFrameClock *clock)
+{
+  g_return_if_fail (GDK_IS_FRAME_CLOCK (clock));
+
+  GDK_FRAME_CLOCK_GET_IFACE (clock)->freeze (clock);
+}
+
+
+void
+gdk_frame_clock_thaw (GdkFrameClock *clock)
+{
+  g_return_if_fail (GDK_IS_FRAME_CLOCK (clock));
+
+  GDK_FRAME_CLOCK_GET_IFACE (clock)->thaw (clock);
+}
+
 /**
  * gdk_frame_clock_get_requested:
  * @clock: the clock
diff --git a/gdk/gdkframeclock.h b/gdk/gdkframeclock.h
index fe0ea58b60..a733b558a9 100644
--- a/gdk/gdkframeclock.h
+++ b/gdk/gdkframeclock.h
@@ -61,6 +61,9 @@ struct _GdkFrameClockInterface
                                         GdkFrameClockPhase  phase);
   GdkFrameClockPhase (* get_requested) (GdkFrameClock      *clock);
 
+  void     (* freeze)              (GdkFrameClock *clock);
+  void     (* thaw)                (GdkFrameClock *clock);
+
   /* signals */
   /* void (* frame_requested)    (GdkFrameClock *clock); */
   /* void (* before_paint)       (GdkFrameClock *clock); */
@@ -77,6 +80,9 @@ void               gdk_frame_clock_request_phase (GdkFrameClock      *clock,
                                                   GdkFrameClockPhase  phase);
 GdkFrameClockPhase gdk_frame_clock_get_requested (GdkFrameClock      *clock);
 
+void     gdk_frame_clock_freeze              (GdkFrameClock *clock);
+void     gdk_frame_clock_thaw                (GdkFrameClock *clock);
+
 /* Convenience API */
 void  gdk_frame_clock_get_frame_time_val (GdkFrameClock  *clock,
                                           GTimeVal       *timeval);
diff --git a/gdk/gdkframeclockidle.c b/gdk/gdkframeclockidle.c
index bdcb16a08a..2911237687 100644
--- a/gdk/gdkframeclockidle.c
+++ b/gdk/gdkframeclockidle.c
@@ -37,6 +37,7 @@ struct _GdkFrameClockIdlePrivate
   guint64 frame_time;
 
   guint idle_id;
+  guint freeze_count;
 
   GdkFrameClockPhase requested;
   GdkFrameClockPhase phase;
@@ -72,6 +73,7 @@ gdk_frame_clock_idle_init (GdkFrameClockIdle *frame_clock_idle)
   priv = frame_clock_idle->priv;
 
   priv->timer = g_timer_new ();
+  priv->freeze_count = 0;
 }
 
 static void
@@ -138,7 +140,7 @@ maybe_start_idle (GdkFrameClockIdle *clock_idle)
 {
   GdkFrameClockIdlePrivate *priv = clock_idle->priv;
 
-  if (priv->idle_id == 0 && priv->requested != 0)
+  if (priv->idle_id == 0 && priv->freeze_count == 0 && priv->requested != 0)
     {
       priv->idle_id = gdk_threads_add_idle_full (GDK_PRIORITY_REDRAW,
                                                  gdk_frame_clock_paint_idle,
@@ -160,19 +162,51 @@ gdk_frame_clock_paint_idle (void *data)
 
   priv->frame_time = compute_frame_time (clock_idle);
 
-  priv->phase = GDK_FRAME_CLOCK_PHASE_BEFORE_PAINT;
-  priv->requested &= ~GDK_FRAME_CLOCK_PHASE_BEFORE_PAINT;
-  g_signal_emit_by_name (G_OBJECT (clock), "before-paint");
-  priv->phase = GDK_FRAME_CLOCK_PHASE_LAYOUT;
-  priv->requested &= ~GDK_FRAME_CLOCK_PHASE_LAYOUT;
-  g_signal_emit_by_name (G_OBJECT (clock), "layout");
-  priv->phase = GDK_FRAME_CLOCK_PHASE_PAINT;
-  priv->requested &= ~GDK_FRAME_CLOCK_PHASE_PAINT;
-  g_signal_emit_by_name (G_OBJECT (clock), "paint");
-  priv->phase = GDK_FRAME_CLOCK_PHASE_AFTER_PAINT;
-  priv->requested &= ~GDK_FRAME_CLOCK_PHASE_AFTER_PAINT;
-  g_signal_emit_by_name (G_OBJECT (clock), "after-paint");
-  priv->phase = GDK_FRAME_CLOCK_PHASE_NONE;
+  switch (priv->phase)
+    {
+    case GDK_FRAME_CLOCK_PHASE_NONE:
+    case GDK_FRAME_CLOCK_PHASE_BEFORE_PAINT:
+      if (priv->freeze_count == 0)
+	{
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_BEFORE_PAINT;
+          priv->requested &= ~GDK_FRAME_CLOCK_PHASE_BEFORE_PAINT;
+          /* We always emit ::before-paint and ::after-paint even if
+           * not explicitly requested, and unlike other phases,
+           * they don't get repeated if you freeze/thaw while
+           * in them. */
+	  g_signal_emit_by_name (G_OBJECT (clock), "before-paint");
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_LAYOUT;
+	}
+    case GDK_FRAME_CLOCK_PHASE_LAYOUT:
+      if (priv->freeze_count == 0)
+	{
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_LAYOUT;
+          if (priv->requested & GDK_FRAME_CLOCK_PHASE_LAYOUT)
+            {
+              priv->requested &= ~GDK_FRAME_CLOCK_PHASE_LAYOUT;
+              g_signal_emit_by_name (G_OBJECT (clock), "layout");
+            }
+	}
+    case GDK_FRAME_CLOCK_PHASE_PAINT:
+      if (priv->freeze_count == 0)
+	{
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_PAINT;
+          if (priv->requested & GDK_FRAME_CLOCK_PHASE_PAINT)
+            {
+              priv->requested &= ~GDK_FRAME_CLOCK_PHASE_PAINT;
+              g_signal_emit_by_name (G_OBJECT (clock), "paint");
+            }
+	}
+    case GDK_FRAME_CLOCK_PHASE_AFTER_PAINT:
+      if (priv->freeze_count == 0)
+	{
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_AFTER_PAINT;
+          priv->requested &= ~GDK_FRAME_CLOCK_PHASE_AFTER_PAINT;
+	  g_signal_emit_by_name (G_OBJECT (clock), "after-paint");
+          /* the ::after-paint phase doesn't get repeated on freeze/thaw */
+	  priv->phase = GDK_FRAME_CLOCK_PHASE_NONE;
+	}
+    }
 
   maybe_start_idle (clock_idle);
 
@@ -199,11 +233,43 @@ gdk_frame_clock_idle_get_requested (GdkFrameClock *clock)
 }
 
 static void
+gdk_frame_clock_idle_freeze (GdkFrameClock *clock)
+{
+  GdkFrameClockIdlePrivate *priv = GDK_FRAME_CLOCK_IDLE (clock)->priv;
+
+  priv->freeze_count++;
+
+  if (priv->freeze_count == 1)
+    {
+      if (priv->idle_id)
+	{
+	  g_source_remove (priv->idle_id);
+	  priv->idle_id = 0;
+	}
+    }
+}
+
+static void
+gdk_frame_clock_idle_thaw (GdkFrameClock *clock)
+{
+  GdkFrameClockIdle *clock_idle = GDK_FRAME_CLOCK_IDLE (clock);
+  GdkFrameClockIdlePrivate *priv = clock_idle->priv;
+
+  g_return_if_fail (priv->freeze_count > 0);
+
+  priv->freeze_count--;
+  if (priv->freeze_count == 0)
+    maybe_start_idle (clock_idle);
+}
+
+static void
 gdk_frame_clock_idle_interface_init (GdkFrameClockInterface *iface)
 {
   iface->get_frame_time = gdk_frame_clock_idle_get_frame_time;
   iface->request_phase = gdk_frame_clock_idle_request_phase;
   iface->get_requested = gdk_frame_clock_idle_get_requested;
+  iface->freeze = gdk_frame_clock_idle_freeze;
+  iface->thaw = gdk_frame_clock_idle_thaw;
 }
 
 GdkFrameClock *
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index e3b5026c83..0505d3fb6e 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -4919,6 +4919,7 @@ gdk_window_freeze_toplevel_updates_libgtk_only (GdkWindow *window)
   g_return_if_fail (window->window_type != GDK_WINDOW_CHILD);
 
   window->update_and_descendants_freeze_count++;
+  gdk_frame_clock_freeze (gdk_window_get_frame_clock (window));
 }
 
 /**
@@ -4939,6 +4940,7 @@ gdk_window_thaw_toplevel_updates_libgtk_only (GdkWindow *window)
   g_return_if_fail (window->update_and_descendants_freeze_count > 0);
 
   window->update_and_descendants_freeze_count--;
+  gdk_frame_clock_thaw (gdk_window_get_frame_clock (window));
 
   gdk_window_schedule_update (window);
 }
diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index e86cf7d2c8..e86a73322c 100644
--- a/gdk/x11/gdkwindow-x11.c
+++ b/gdk/x11/gdkwindow-x11.c
@@ -35,6 +35,7 @@
 #include "gdkasync.h"
 #include "gdkeventsource.h"
 #include "gdkdisplay-x11.h"
+#include "gdkframeclockidle.h"
 #include "gdkprivate-x11.h"
 
 #include <stdlib.h>
@@ -712,6 +713,7 @@ _gdk_x11_display_create_window_impl (GdkDisplay    *display,
   GdkWindowImplX11 *impl;
   GdkX11Screen *x11_screen;
   GdkX11Display *display_x11;
+  GdkFrameClock *clock;
 
   Window xparent;
   Visual *xvisual;
@@ -856,6 +858,9 @@ _gdk_x11_display_create_window_impl (GdkDisplay    *display,
   gdk_x11_event_source_select_events ((GdkEventSource *) display_x11->event_source,
                                       GDK_WINDOW_XID (window), event_mask,
                                       StructureNotifyMask | PropertyChangeMask);
+
+  clock = g_object_new (GDK_TYPE_FRAME_CLOCK_IDLE, NULL);
+  gdk_window_set_frame_clock (window, clock);
 }
 
 static GdkEventMask