More views on gtk paint tweaks. My previous attempt resulted in the

ability to continually paint. I've tweaked it so that we only schedule
a paint if the paint is happening from Gtk and not views.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/251084

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27998 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 26 insertions, 9 deletions

diff --git a/views/widget/root_view_gtk.cc b/views/widget/root_view_gtk.cc
index 75f444e..e284313 100644
--- a/views/widget/root_view_gtk.cc
+++ b/views/widget/root_view_gtk.cc
@@ -13,13 +13,17 @@
 namespace views {
 
 void RootView::OnPaint(GdkEventExpose* event) {
+  WidgetGtk* widget = static_cast<WidgetGtk*>(GetWidget());
+  if (!widget) {
+    NOTREACHED();
+    return;
+  }
   gfx::Rect scheduled_dirty_rect = GetScheduledPaintRectConstrainedToSize();
   gfx::Rect expose_rect = gfx::Rect(event->area);
   gfx::CanvasPaint canvas(event);
   bool invoked_process_paint = false;
   if (!canvas.is_empty()) {
-    canvas.set_composite_alpha(
-        static_cast<WidgetGtk*>(GetWidget())->is_transparent());
+    canvas.set_composite_alpha(widget->is_transparent());
     SchedulePaint(gfx::Rect(canvas.rectangle()), false);
     if (NeedsPainting(false)) {
       ProcessPaint(&canvas);
@@ -28,12 +32,15 @@ void RootView::OnPaint(GdkEventExpose* event) {
   }
 
   if (invoked_process_paint && !scheduled_dirty_rect.IsEmpty() &&
-      !expose_rect.Contains(scheduled_dirty_rect)) {
-    // The region Views needs to paint (scheduled_dirty_rect) isn't contained
-    // within the region GTK wants us to paint. ProccessPaint clears out the
-    // dirty region, so that at this point views thinks everything has painted
-    // correctly, but we haven't. Invoke schedule paint again to make sure we
-    // paint everything we need to.
+      !expose_rect.Contains(scheduled_dirty_rect) && widget &&
+      !widget->in_paint_now()) {
+    // We're painting as the result of Gtk wanting us to paint (not from views)
+    // and there was a region scheduled by views to be painted that is not
+    // contained in the region gtk wants us to paint. As a result of the
+    // ProcessPaint call above views no longer thinks it needs to be painted.
+    // We have to invoke SchedulePaint here to be sure we end up painting the
+    // region views wants to paint, otherwise we'll drop the views paint region
+    // on the floor.
     //
     // NOTE: We don't expand the region to paint to include
     // scheduled_dirty_rect as that results in us drawing on top of any GTK
diff --git a/views/widget/widget_gtk.cc b/views/widget/widget_gtk.cc
index 8fcac89..734ea02 100644
--- a/views/widget/widget_gtk.cc
+++ b/views/widget/widget_gtk.cc
@@ -107,7 +107,8 @@ WidgetGtk::WidgetGtk(Type type)
       transparent_(false),
       ignore_drag_leave_(false),
       opacity_(255),
-      drag_data_(NULL) {
+      drag_data_(NULL),
+      in_paint_now_(false) {
   static bool installed_message_loop_observer = false;
   if (!installed_message_loop_observer) {
     installed_message_loop_observer = true;
@@ -394,7 +395,9 @@ void WidgetGtk::PaintNow(const gfx::Rect& update_rect) {
     gtk_widget_queue_draw_area(widget_, update_rect.x(), update_rect.y(),
                                update_rect.width(), update_rect.height());
     // Force the paint to occur now.
+    in_paint_now_ = true;
     gdk_window_process_updates(widget_->window, true);
+    in_paint_now_ = false;
   }
 }
 
diff --git a/views/widget/widget_gtk.h b/views/widget/widget_gtk.h
index 080c1a0..8009f89 100644
--- a/views/widget/widget_gtk.h
+++ b/views/widget/widget_gtk.h
@@ -84,6 +84,10 @@ class WidgetGtk
   // Starts a drag on this widget. This blocks until the drag is done.
   void DoDrag(const OSExchangeData& data, int operation);
 
+  // Are we in PaintNow? See use in root_view_gtk for details on what this is
+  // used for.
+  bool in_paint_now() const { return in_paint_now_; }
+
   // Overridden from Widget:
   virtual void Init(gfx::NativeView parent, const gfx::Rect& bounds);
   virtual void SetContentsView(View* view);
@@ -377,6 +381,9 @@ class WidgetGtk
   // for the drag.
   const OSExchangeDataProviderGtk* drag_data_;
 
+  // See description above getter for details.
+  bool in_paint_now_;
+
   DISALLOW_COPY_AND_ASSIGN(WidgetGtk);
 };