views: add layout delegates

ui/views/view.h

 // 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.
 
 #ifndef UI_VIEWS_VIEW_H_
 #define UI_VIEWS_VIEW_H_
 
 #include <stddef.h>
 
 #include <algorithm>
@@ skipping 18 matching lines @@
 #include "ui/compositor/layer_owner.h"
 #include "ui/compositor/paint_cache.h"
 #include "ui/events/event.h"
 #include "ui/events/event_target.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/path.h"
+#include "ui/views/layout/layout_delegate.h"
 #include "ui/views/view_targeter.h"
 #include "ui/views/views_export.h"
 
 #if defined(OS_WIN)
 #include "base/win/scoped_comptr.h"
 #endif
 
 using ui::OSExchangeData;
 
 namespace gfx {
@@ skipping 17 matching lines @@
 }
 
 namespace views {
 
 class Background;
 class Border;
 class ContextMenuController;
 class DragController;
 class FocusManager;
 class FocusTraversable;
+class LayoutDelegate;
 class LayoutManager;
 class NativeViewAccessibility;
 class ScrollView;
 class Widget;
 class WordLookupClient;
 
 namespace internal {
 class PreEventDispatchHandler;
 class PostEventDispatchHandler;
 class RootView;
@@ skipping 303 matching lines @@
   // parent views do not change.
   void InvalidateLayout();
 
   // Gets/Sets the Layout Manager used by this view to size and place its
   // children.
   // The LayoutManager is owned by the View and is deleted when the view is
   // deleted, or when a new LayoutManager is installed.
   LayoutManager* GetLayoutManager() const;
   void SetLayoutManager(LayoutManager* layout);
 
+  // Gets/Sets the Layout Delegate used by this view and its children / related
+  // views to compute spacing between and around elements. The LayoutDelegate is
+  // not owned by the View and should not be deleted.
+  LayoutDelegate* GetLayoutDelegate() const;
+  void SetLayoutDelegate(LayoutDelegate* delegate);
+
   // Adjust the layer's offset so that it snaps to the physical pixel boundary.
   // This has no effect if the view does not have an associated layer.
   void SnapLayerToPixelBoundary();
 
   // Attributes ----------------------------------------------------------------
 
   // The view class name.
   static const char kViewClassName[];
 
   // Return the receiving view's class name. A view class is a string which
@@ skipping 1095 matching lines @@
 
   // Layout --------------------------------------------------------------------
 
   // Whether the view needs to be laid out.
   bool needs_layout_;
 
   // The View's LayoutManager defines the sizing heuristics applied to child
   // Views. The default is absolute positioning according to bounds_.
   std::unique_ptr<LayoutManager> layout_manager_;
 
+  // The View's LayoutDelegate, if it has one.
+  LayoutDelegate* layout_delegate_ = nullptr;
+
   // Whether this View's layer should be snapped to the pixel boundary.
   bool snap_layer_to_pixel_boundary_;
 
   // Painting ------------------------------------------------------------------
 
   // Background
   std::unique_ptr<Background> background_;
 
   // Border.
   std::unique_ptr<Border> border_;
@@ skipping 52 matching lines @@
   // Belongs to this view, but it's reference-counted on some platforms
   // so we can't use a scoped_ptr. It's dereferenced in the destructor.
   NativeViewAccessibility* native_view_accessibility_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_