views: Force child views to paint into their own texture when the parent has an external texture.

views/view.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "views/view.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 1198 matching lines @@
   if (!layer_helper_.get())
     layer_helper_.reset(new internal::LayerHelper());
 
   layer_helper_->set_fills_bounds_opaquely(fills_bounds_opaquely);
 
   if (layer())
     layer()->SetFillsBoundsOpaquely(fills_bounds_opaquely);
 }
 
 bool View::SetExternalTexture(ui::Texture* texture) {
-  // A little heavy-handed -- it should be that each child has it's own layer.
-  // The desired use case is where there are no children.
-  DCHECK_EQ(child_count(), 0);
-
   if (!texture && !layer_helper_.get())
     return true;
 
   if (!layer_helper_.get())
     layer_helper_.reset(new internal::LayerHelper());
   bool use_external = (texture != NULL);
   if (use_external != layer_helper_->paint_to_layer())
     SetPaintToLayer(use_external);
   else if (use_external && !layer())
     CreateLayer();
 
   if (use_external && !layer())
     return false;
 
+  // Child views must not paint into the external texture. So make sure each
+  // child view has its own layer to paint into.
+  if (use_external) {
+    for (Views::iterator i = children_.begin(); i != children_.end(); ++i)
+      (*i)->SetPaintToLayer(true);

[rjkroege, 2011/08/10 14:29:53]

this is not recursive right? It's only the immediate children?

[sadrul, 2011/08/10 14:33:05]

Yes, that is correct (i.e. not recursive).

+  }
+
   layer_helper_->set_layer_updated_externally(use_external);
   layer_helper_->set_bitmap_needs_updating(!use_external);
   if (layer())
     layer()->SetTexture(texture);
 
   if (IsVisible())
     SchedulePaintInternal(GetLocalBounds());
 
   return true;
 }
@@ skipping 466 matching lines @@
   gfx::Point3f p(*point);
   trans.TransformPointReverse(p);
   *point = p.AsPoint();
   return result;
 }
 
 // Accelerated painting --------------------------------------------------------
 
 bool View::ShouldPaintToLayer() const {
   return use_acceleration_when_possible &&
-      layer_helper_.get() && layer_helper_->ShouldPaintToLayer();
+      ((layer_helper_.get() && layer_helper_->ShouldPaintToLayer()) ||
+       (parent_ && parent_->layer_helper_.get() &&
+        parent_->layer_helper_->layer_updated_externally()));
 }
 
 void View::CreateLayer() {
   if (!ShouldPaintToLayer() || layer())
     return;
 
   ui::Compositor* compositor = GetCompositor();
   if (!compositor)
     return;
 
@@ skipping 307 matching lines @@
     result.append(child_at(i)->PrintViewGraph(false));
 
   if (first)
     result.append("}\n");
 
   return result;
 }
 #endif
 
 }  // namespace views