Allow View to have a layer whose texture is updated externally.

This will be used to display texture produced by the GPU process for the RWHVV via the browser compositor.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/7231012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@90362 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 42 insertions, 0 deletions

diff --git a/views/view.cc b/views/view.cc
index 0994639..84bb6ea 100644
--- a/views/view.cc
+++ b/views/view.cc
@@ -108,6 +108,7 @@ View::View()
       needs_layout_(true),
       flip_canvas_on_paint_for_rtl_ui_(false),
       layer_needs_updating_(true),
+      layer_updated_externally_(false),
       paint_to_layer_(false),
       accelerator_registration_delayed_(false),
       accelerator_focus_manager_(NULL),
@@ -1218,6 +1219,31 @@ void View::PaintToLayer(const gfx::Rect& dirty_region) {
 void View::OnWillCompositeLayer() {
 }
 
+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);
+
+  bool use_external = (texture != NULL);
+  if (use_external != paint_to_layer_)
+    SetPaintToLayer(use_external);
+  else if (use_external && !layer_.get())
+    CreateLayer();
+
+  if (use_external && !layer_.get())
+    return false;
+
+  layer_updated_externally_ = use_external;
+  layer_needs_updating_ = !use_external;
+  if (layer_.get())
+    layer_->SetTexture(texture);
+
+  if (IsVisible())
+    SchedulePaintInternal(GetLocalBounds());
+
+  return true;
+}
+
 const ui::Compositor* View::GetCompositor() const {
   return parent_ ? parent_->GetCompositor() : NULL;
 }
@@ -1617,6 +1643,8 @@ bool View::ShouldPaintToLayer() const {
 }
 
 void View::MarkLayerDirty() {
+  if (layer_updated_externally_)
+    return;
   View* owner = this;
   while (!((owner->transform_.get() && owner->transform_->HasChange()) ||
            owner->paint_to_layer_) && owner->parent_)
diff --git a/views/view.h b/views/view.h
index 24f9ca7..e510d53 100644
--- a/views/view.h
+++ b/views/view.h
@@ -34,6 +34,7 @@ namespace ui {
 struct AccessibleViewState;
 class Compositor;
 class Layer;
+class Texture;
 class ThemeProvider;
 class Transform;
 #if defined(TOUCH_UI)
@@ -965,6 +966,15 @@ class View : public AcceleratorTarget {
   // layer is rendered by the compositor.
   virtual void OnWillCompositeLayer();
 
+  // This creates a layer for the view, if one does not exist. It then
+  // passes the texture to a layer associated with the view. While an external
+  // texture is set, the view will not update the layer contents.
+  //
+  // Passing NULL resets to default behavior.
+  //
+  // Returns false if it cannot create a layer to which to assign the texture.
+  bool SetExternalTexture(ui::Texture* texture);
+
   // Returns the Compositor.
   virtual const ui::Compositor* GetCompositor() const;
   virtual ui::Compositor* GetCompositor();
@@ -1370,6 +1380,10 @@ class View : public AcceleratorTarget {
   // Is the layer out of date?
   bool layer_needs_updating_;
 
+  // Is the texture backing the layer being updated externally?
+  // (i.e. by the GPU process when rendering 3D CSS)
+  bool layer_updated_externally_;
+
   // Should we paint to a layer? See description above setter for details.
   bool paint_to_layer_;