[not for review - epic CL] Adding Elastic+Momentum+Layered scrolling to views::ScrollView

ui/views/controls/scroll_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_CONTROLS_SCROLL_VIEW_H_
 #define UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "ui/views/controls/scrollbar/scroll_bar.h"
 
+namespace gfx {
+class ScrollOffset;
+}
+
 namespace views {
+namespace test {
+class ScrollViewTestApi;
+}
 
 /////////////////////////////////////////////////////////////////////////////
 //
 // ScrollView class
 //
 // A ScrollView is used to make any View scrollable. The view is added to
 // a viewport which takes care of clipping.
 //
 // In this current implementation both horizontal and vertical scrollbars are
 // added as needed.
@@ skipping 51 matching lines @@
   void SetVerticalScrollBar(ScrollBar* vert_sb);
 
   // View overrides:
   gfx::Size GetPreferredSize() const override;
   int GetHeightForWidth(int width) const override;
   void Layout() override;
   bool OnKeyPressed(const ui::KeyEvent& event) override;
   bool OnMouseWheel(const ui::MouseWheelEvent& e) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseExited(const ui::MouseEvent& event) override;
+  void OnScrollEvent(ui::ScrollEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
   const char* GetClassName() const override;
+  ScrollView* EnclosingScrollView() override;
 
   // ScrollBarController overrides:
   void ScrollToPosition(ScrollBar* source, int position) override;
   int GetScrollIncrement(ScrollBar* source,
                          bool is_page,
                          bool is_positive) override;
 
  private:
-  FRIEND_TEST_ALL_PREFIXES(ScrollViewTest, CornerViewVisibility);
+  friend class test::ScrollViewTestApi;
+
   class Viewport;
 
   // Used internally by SetHeader() and SetContents() to reset the view.  Sets
   // |member| to |new_view|. If |new_view| is non-null it is added to |parent|.
   void SetHeaderOrContents(View* parent, View* new_view, View** member);
 
   // Scrolls the minimum amount necessary to make the specified rectangle
   // visible, in the coordinates of the contents view. The specified rectangle
   // is constrained by the bounds of the contents view. This has no effect if
   // the contents have not been set.
   void ScrollContentsRegionToBeVisible(const gfx::Rect& rect);
 
   // Computes the visibility of both scrollbars, taking in account the view port
   // and content sizes.
   void ComputeScrollBarsVisibility(const gfx::Size& viewport_size,
                                    const gfx::Size& content_size,
                                    bool* horiz_is_shown,
                                    bool* vert_is_shown) const;
 
   // Shows or hides the scrollbar/corner_view based on the value of
   // |should_show|.
   void SetControlVisibility(View* control, bool should_show);
 
   // Update the scrollbars positions given viewport and content sizes.
   void UpdateScrollBarPositions();
 
-  // The current contents and its viewport. |contents_| is contained in
-  // |contents_viewport_|.
+  // Gets and sets the current scroll offset.
+  gfx::ScrollOffset CurrentOffset() const;
+  void ScrollToOffset(const gfx::ScrollOffset& offset);
+
+  // Callback entrypoint when hosted layers are scrolled by the compositor.
+  void OnLayerScrolled();
+
+  // Horizontally scroll the header (if any) to match the contents.
+  void ScrollHeader();
+
+  // The current contents and its viewport. |contents_| is contained in the
+  // layer-backed |contents_container_| which guarantees it is at least as high
+  // and wide as the |contents_viewport_|, which does the clipping.
   View* contents_;
+  View* contents_container_;
   View* contents_viewport_;
 
   // The current header and its viewport. |header_| is contained in
   // |header_viewport_|.
   View* header_;
   View* header_viewport_;
 
   // Horizontal scrollbar.
   ScrollBar* horiz_sb_;
 
@@ skipping 81 matching lines @@
  private:
   int top_margin_;
   int row_height_;
 
   DISALLOW_COPY_AND_ASSIGN(FixedRowHeightScrollHelper);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_SCROLL_VIEW_H_