views: add layout delegates

ui/views/view.cc

 // Copyright (c) 2012 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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 550 matching lines @@
 
 void View::SetLayoutManager(LayoutManager* layout_manager) {
   if (layout_manager == layout_manager_.get())
     return;
 
   layout_manager_.reset(layout_manager);
   if (layout_manager_)
     layout_manager_->Installed(this);
 }
 
+static LayoutDelegate default_layout_delegate_;
+
+LayoutDelegate* View::GetLayoutDelegate() const {
+  if (layout_delegate_)
+    return layout_delegate_;
+  if (!parent_)
+    return &default_layout_delegate_;
+  return parent_->GetLayoutDelegate();
+}
+
+void View::SetLayoutDelegate(LayoutDelegate* delegate) {
+  layout_delegate_ = delegate;
+}
+
 void View::SnapLayerToPixelBoundary() {
   if (!layer())
     return;
 
   if (snap_layer_to_pixel_boundary_ && layer()->parent() &&
       layer()->GetCompositor()) {
     ui::SnapLayerToPhysicalPixelBoundary(layer()->parent(), layer());
   } else {
     // Reset the offset.
     layer()->SetSubpixelPositionOffset(gfx::Vector2dF());
@@ skipping 1841 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views