Pinch/Zoom Infrastructure & Plumbing CL

cc/trees/layer_tree_host.h

 // Copyright 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.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <list>
 #include <set>
@@ skipping 173 matching lines @@
                           base::Time wall_clock_time);
 
   void SetRootLayer(scoped_refptr<Layer> root_layer);
   Layer* root_layer() { return root_layer_.get(); }
   const Layer* root_layer() const { return root_layer_.get(); }
   const Layer* page_scale_layer() const { return page_scale_layer_.get(); }
   void RegisterViewportLayers(
       scoped_refptr<Layer> page_scale_layer,
       scoped_refptr<Layer> inner_viewport_scroll_layer,
       scoped_refptr<Layer> outer_viewport_scroll_layer);
+  Layer* inner_viewport_scroll_layer() const {
+    return inner_viewport_scroll_layer_.get();
+  }
+  Layer* outer_viewport_scroll_layer() const {
+    return outer_viewport_scroll_layer_.get();
+  }
 
   const LayerTreeSettings& settings() const { return settings_; }
 
   void SetDebugState(const LayerTreeDebugState& debug_state);
   const LayerTreeDebugState& debug_state() const { return debug_state_; }
 
   void SetViewportSize(gfx::Size device_viewport_size);
   void SetOverdrawBottomHeight(float overdraw_bottom_height);
 
   gfx::Size device_viewport_size() const { return device_viewport_size_; }
@@ skipping 20 matching lines @@
 
   void SetVisible(bool visible);
   bool visible() const { return visible_; }
 
   void StartPageScaleAnimation(gfx::Vector2d target_offset,
                                bool use_anchor,
                                float scale,
                                base::TimeDelta duration);
 
   void ApplyScrollAndScale(const ScrollAndScaleSet& info);
+  gfx::Vector2d DistributeScrollOffsetToViewports(const gfx::Vector2d offset,
+                                                  Layer* layer);
+  gfx::Vector2d BlinkScrollOffset(const Layer* layer) const;

[enne (OOO), 2014/01/02 19:28:17]

What does BlinkScrollOffset mean? What about TotalViewportScrollOffset?

Also, is this necessary? Scrolls go to Blink in two ways. 
LayerTreeHostClient::ApplyScrollAndScale sets the total scroll for the main
frame (which should include the viewports) and WebLayerScrollClient::didScroll
(the callback called via Layer::SetScrollOffsetFromImplSide) sets offsets per
layer for non-root (I think) layers (which shouldn't include viewports).

I'm trying to say that I think that WebLayerImpl should just ask the layer for
its scroll offset and that the total scroll offset should just get set via
ApplyScrollAndScale, and this function should only get called in that instance,
not in the WebLayerImpl::scrollPosition() function.

[wjmaclean, 2014/01/03 21:57:12]

This was code I experimented with to fix a failing unit test. It seems that
since I added it the test has either disappeared, or it's behaviour has been
accommodated by some other change I've made, since I can now remove this code
and the tests seem to run fine.

Removed.

 
   void SetImplTransform(const gfx::Transform& transform);
 
   // Virtual for tests.
   virtual void StartRateLimiter();
   virtual void StopRateLimiter();
 
   void RateLimit();
 
   bool AlwaysUsePartialTextureUpdates();
@@ skipping 204 matching lines @@
 
   ScopedPtrVector<SwapPromise> swap_promise_list_;
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_