content/renderer/input/synchronous_input_handler_proxy.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_INPUT_SYNCHRONOUS_INPUT_HANDLER_PROXY_H_
   6 #define CONTENT_RENDERER_INPUT_SYNCHRONOUS_INPUT_HANDLER_PROXY_H_
   7
   8 #include "base/time/time.h"
   9
  10 namespace content {
  11
  12 class CONTENT_EXPORT SynchronousInputHandler {
  13  public:
  14   // Informs the Android WebView embedder that a fling animation is running, and
  15   // that it should call SynchronouslyAnimate() if it wants to execute that
  16   // animation. The embedder/app may choose to override and ignore the
  17   // request for animation.
  18   virtual void SetNeedsSynchronousAnimateInput() = 0;
  19 };
  20
  21 // Android WebView requires synchronous scrolling from the WebView application.
  22 // This interface provides support for that behaviour. The WebView embedder will
  23 // act as the InputHandler for controlling the timing of input (fling)
  24 // animations.
  25 class CONTENT_EXPORT SynchronousInputHandlerProxy {
  26  public:
  27   // Tell the proxy that we will control the timing of root fling animations
  28   // from the SynchronousInputHandler. Once this is set, the InputHandler is
  29   // not requested to Animate() the InputHandlerProxy for root layer flings.
  30   // Instead, requests for animation will go to the SynchronousInputHandler and
  31   // animation ticks will only come back through SynchronouslyAnimate().
  32   // Non-root flings are not affected.
  33   virtual void SetOnlySynchronouslyAnimateRootFlings(
  34       SynchronousInputHandler* synchronous_input_handler) = 0;
  35
  36   // Tick input (fling) animations. This may happen out of phase with the frame
  37   // timing, or not at all, as it is controlled by the WebView application. When
  38   // it returns, it expects the animation scroll offsets to be visible to the
  39   // application.
  40   virtual void SynchronouslyAnimate(base::TimeTicks time) = 0;
  41 };
  42
  43 }  // namespace content
  44
  45 #endif  // CONTENT_RENDERER_INPUT_SYNCHRONOUS_INPUT_HANDLER_PROXY_H_