phase based wheel scroll latching for mac

content/browser/renderer_host/render_widget_host_view_mac.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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurface.h>
 #include <stddef.h>
@@ skipping 469 matching lines @@
 
   // Returns the TextSelection information for the active widget. If
   // |is_guest_view_hack_| is true, then it will return the TextSelection
   // information for this RenderWidgetHostViewMac (which is serving as a
   // platform view for a guest).
   const TextInputManager::TextSelection* GetTextSelection();
 
   // Get the focused view that should be used for retrieving the text selection.
   RenderWidgetHostViewBase* GetFocusedViewForTextSelection();
 
+  bool WheelScrollLatchingEnabled() { return wheel_scroll_latching_enabled_; }

[tdresser, 2017/05/25 15:18:36]

Is this needed? It appears redundant with
https://cs.chromium.org/chromium/src/content/browser/renderer_host/render_wid...

[sahel, 2017/05/25 16:00:04]

Done.

+
+  base::OneShotTimer mouse_wheel_end_dispatch_timer_;

[tdresser, 2017/05/25 15:18:36]

Make private.

[sahel, 2017/05/25 16:00:04]

This is Stopped in RenderWidgetHostViewCocoa, should I make it private and add a
public function that stops this timer?

[tdresser, 2017/05/25 19:34:48]

Yup. The fact that this is implemented via a timer is arguably an implementation
detail that shouldn't be exposed, so you might want to name it more
semantically.

Maybe we need two methods, like "DispatchPendingWheelEndEvent" and
"IgnorePendingWheelEndEvent"?

+
+  void SendSyntheticWheelEventWithPhaseEnded(
+      blink::WebMouseWheelEvent wheel_event,
+      bool should_route_event);

[tdresser, 2017/05/25 15:18:36]

Can this be private?

[sahel, 2017/05/25 16:00:04]

This is called in RenderWidgetHostViewCocoa, cannot be private. 

[tdresser, 2017/05/25 19:34:48]

It is? Isn't it only called in
RenderWidgetHostViewMac::StartMouseWheelEndDispatchTimer?

[sahel, 2017/05/26 18:03:25]

Done.

+  void StartMouseWheelEndDispatchTimer(blink::WebMouseWheelEvent wheel_event,
+                                       bool should_route_event);

[tdresser, 2017/05/25 15:18:36]

Can this be private?

[sahel, 2017/05/25 16:00:04]

This is called in RenderWidgetHostViewCocoa, cannot be private.

[tdresser, 2017/05/25 19:34:47]

Acknowledged.

+
   // Returns the RenderWidgetHostDelegate corresponding to the currently focused
   // RenderWidgetHost. It is different from |render_widget_host_->delegate()|
   // when there are focused inner WebContentses on the page. Also, this method
   // can return nullptr; for instance when |render_widget_host_| becomes nullptr
   // in the destruction path of the WebContentsImpl.
   RenderWidgetHostDelegate* GetFocusedRenderWidgetHostDelegate();
 
  private:
   friend class RenderWidgetHostViewMacTest;
 
@@ skipping 67 matching lines @@
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_