[Android] Implementation of overscroll effect for Android L

content/browser/renderer_host/render_widget_host_view_android.cc

 // 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 
 #include <android/bitmap.h>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 111 matching lines @@
     const cc::CompositorFrameMetadata& frame_metadata) {
   const float scale_factor =
       frame_metadata.page_scale_factor * frame_metadata.device_scale_factor;
 
   // Compute the size and offsets for each edge, where each effect is sized to
   // the viewport and offset by the distance of each viewport edge to the
   // respective content edge.
   OverscrollGlow::DisplayParameters params;
   params.size = gfx::ScaleSize(
       frame_metadata.scrollable_viewport_size, scale_factor);
-  params.edge_offsets[EdgeEffect::EDGE_TOP] =
+  params.edge_offsets[OverscrollGlow::EDGE_TOP] =
       -frame_metadata.root_scroll_offset.y() * scale_factor;
-  params.edge_offsets[EdgeEffect::EDGE_LEFT] =
+  params.edge_offsets[OverscrollGlow::EDGE_LEFT] =
       -frame_metadata.root_scroll_offset.x() * scale_factor;
-  params.edge_offsets[EdgeEffect::EDGE_BOTTOM] =
+  params.edge_offsets[OverscrollGlow::EDGE_BOTTOM] =
       (frame_metadata.root_layer_size.height() -
        frame_metadata.root_scroll_offset.y() -
        frame_metadata.scrollable_viewport_size.height()) * scale_factor;
-  params.edge_offsets[EdgeEffect::EDGE_RIGHT] =
+  params.edge_offsets[OverscrollGlow::EDGE_RIGHT] =
       (frame_metadata.root_layer_size.width() -
        frame_metadata.root_scroll_offset.x() -
        frame_metadata.scrollable_viewport_size.width()) * scale_factor;
-  params.device_scale_factor = frame_metadata.device_scale_factor;
 
   return params;
 }
 
 ui::GestureProvider::Config CreateGestureProviderConfig() {
   ui::GestureProvider::Config config = ui::DefaultGestureProviderConfig();
   config.disable_click_delay =
       CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableClickDelay);
   return config;
 }
@@ skipping 949 matching lines @@
 
 void RenderWidgetHostViewAndroid::ProcessAckedTouchEvent(
     const TouchEventWithLatencyInfo& touch, InputEventAckState ack_result) {
   const bool event_consumed = ack_result == INPUT_EVENT_ACK_STATE_CONSUMED;
   gesture_provider_.OnTouchEventAck(event_consumed);
 }
 
 void RenderWidgetHostViewAndroid::GestureEventAck(
     const blink::WebGestureEvent& event,
     InputEventAckState ack_result) {
+  // The overscroll effect requires an explicit release signal that may not be
+  // sent from the renderer compositor.
+  if (event.type == blink::WebInputEvent::GestureScrollEnd ||
+      event.type == blink::WebInputEvent::GestureFlingStart) {
+    DidOverscroll(DidOverscrollParams());
+  }
+
   if (content_view_core_)
     content_view_core_->OnGestureEventAck(event, ack_result);
 }
 
 InputEventAckState RenderWidgetHostViewAndroid::FilterInputEvent(
     const blink::WebInputEvent& input_event) {
+  if (input_event.type == blink::WebInputEvent::GestureScrollUpdate) {
+    const blink::WebGestureEvent& gesture =
+        static_cast<const blink::WebGestureEvent&>(input_event);
+    last_scroll_update_position_ = gfx::PointF(gesture.x, gesture.y);
+  }
+
   if (content_view_core_ &&
       content_view_core_->FilterInputEvent(input_event))
     return INPUT_EVENT_ACK_STATE_CONSUMED;
 
   if (!host_)
     return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
 
   if (input_event.type == blink::WebInputEvent::GestureTapDown ||
       input_event.type == blink::WebInputEvent::TouchStart) {
     GpuDataManagerImpl* gpu_data = GpuDataManagerImpl::GetInstance();
@@ skipping 105 matching lines @@
 
   const float device_scale_factor = content_view_core_->GetDpiScale();
   if (overscroll_effect_->OnOverscrolled(
           content_view_core_->GetLayer(),
           base::TimeTicks::Now(),
           gfx::ScaleVector2d(params.accumulated_overscroll,
                              device_scale_factor),
           gfx::ScaleVector2d(params.latest_overscroll_delta,
                              device_scale_factor),
           gfx::ScaleVector2d(params.current_fling_velocity,
+                             device_scale_factor),
+          gfx::ScaleVector2d(last_scroll_update_position_.OffsetFromOrigin(),
                              device_scale_factor))) {
     SetNeedsAnimate();
   }
 }
 
 void RenderWidgetHostViewAndroid::DidStopFlinging() {
   if (content_view_core_)
     content_view_core_->DidStopFlinging();
 }
 
@@ skipping 228 matching lines @@
   results->orientationAngle = display.RotationAsDegree();
   results->orientationType =
       RenderWidgetHostViewBase::GetOrientationTypeForMobile(display);
   gfx::DeviceDisplayInfo info;
   results->depth = info.GetBitsPerPixel();
   results->depthPerComponent = info.GetBitsPerComponent();
   results->isMonochrome = (results->depthPerComponent == 0);
 }
 
 } // namespace content