Hook ScrollElasticityController to InputHandlerProxy

cc/trees/layer_tree_scroll_elasticity_client.cc

Index: cc/trees/layer_tree_scroll_elasticity_client.cc
diff --git a/cc/trees/layer_tree_scroll_elasticity_client.cc b/cc/trees/layer_tree_scroll_elasticity_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fa9ccf2c0fe9519beb6a8e25a48d8a1ea3d2c850
--- /dev/null
+++ b/cc/trees/layer_tree_scroll_elasticity_client.cc
@@ -0,0 +1,118 @@
+// Copyright 2014 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 "cc/trees/layer_tree_scroll_elasticity_client.h"
+
+#include "cc/layers/layer_impl.h"
+#include "cc/trees/layer_tree_host_impl.h"
+
+namespace cc {
+
+LayerTreeScrollElasticityClient::LayerTreeScrollElasticityClient(
+    LayerTreeHostImpl* layer_tree)
+    : layer_tree_(layer_tree), controller_(NULL), timer_active_(false) {
+}
+
+LayerTreeScrollElasticityClient::~LayerTreeScrollElasticityClient() {
+  if (controller_)
+    controller_->WillShutdown();
+}
+
+void LayerTreeScrollElasticityClient::Animate(base::TimeTicks monotonic_time) {
+  if (!timer_active_)
+    return;
+
+  if (controller_)
+    controller_->Animate(monotonic_time);
+
+  // If the controller has not indicated that it is done animating, request
+  // another frame.
+  if (timer_active_)
+    layer_tree_->SetNeedsAnimate();
+}
+
+void LayerTreeScrollElasticityClient::BindToController(
+    ScrollElasticityController* controller) {
+  DCHECK(!controller_);
+  controller_ = controller;
+}
+
+bool LayerTreeScrollElasticityClient::AllowsHorizontalStretching() {
+  // TODO(ccameron): Get this information from the LayerTreeHostImpl.
+  return true;
+}
+
+bool LayerTreeScrollElasticityClient::AllowsVerticalStretching() {
+  // TODO(ccameron): Get this information from the LayerTreeHostImpl.
+  return true;
+}
+
+gfx::Vector2dF LayerTreeScrollElasticityClient::StretchAmount() {
+  return stretch_offset_;
+}
+
+bool LayerTreeScrollElasticityClient::PinnedInDirection(
+    const gfx::Vector2dF& direction) {
+  LayerImpl* layer = layer_tree_->InnerViewportScrollLayer();
+  bool result = false;
+  if (direction.x() < 0)
+    result |= layer->TotalScrollOffset().x() <= 0;
+  if (direction.x() > 0)
+    result |= layer->TotalScrollOffset().x() >= layer->MaxScrollOffset().x();
+  if (direction.y() < 0)
+    result |= layer->TotalScrollOffset().y() <= 0;
+  if (direction.y() > 0)
+    result |= layer->TotalScrollOffset().y() >= layer->MaxScrollOffset().y();
+  return result;
+}
+
+bool LayerTreeScrollElasticityClient::CanScrollHorizontally() {
+  // TODO(ccameron): This information is likely unnecessary, remove it or get
+  // the correct information from LayerTreeHostImpl.
+  return true;
+}
+
+bool LayerTreeScrollElasticityClient::CanScrollVertically() {
+  // TODO(ccameron): This information is likely unnecessary, remove it or get
+  // the correct information from LayerTreeHostImpl.
+  return true;
+}
+
+gfx::Vector2dF LayerTreeScrollElasticityClient::AbsoluteScrollPosition() {
+  // TODO(ccameron): This information is likely unnecessary, remove it or get
+  // the correct information from LayerTreeHostImpl.
+  return stretch_offset_;
+}
+
+void LayerTreeScrollElasticityClient::ImmediateScrollBy(
+    const gfx::Vector2dF& scroll) {
+  // TODO(ccameron): This is no longer necessary because elasticity is now
+  // decoupled from scrolling. Remove this.
+}
+
+void LayerTreeScrollElasticityClient::
+    ImmediateScrollByWithoutContentEdgeConstraints(
+        const gfx::Vector2dF& scroll) {
+  stretch_offset_ += scroll;
+  // TODO(ccameron): Update the transform of the appropriate layer in the
+  // LayerTreeHostImpl, and request that a frame be drawn.
+}
+
+void LayerTreeScrollElasticityClient::StartSnapRubberbandTimer() {
+  if (timer_active_)
+    return;
+  timer_active_ = true;
+  layer_tree_->SetNeedsAnimate();
+}
+
+void LayerTreeScrollElasticityClient::StopSnapRubberbandTimer() {
+  timer_active_ = false;
+}
+
+void LayerTreeScrollElasticityClient::
+    AdjustScrollPositionToBoundsIfNecessary() {
+  // TODO(ccameron): This function is likely unnecessary. Remove it.
+}
+
+}  // namespace cc