cc: Move TryScroll from LayerImpl to LayerTreeHostImpl

cc/layers/layer_impl.cc

 // Copyright 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 "cc/layers/layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
@@ skipping 474 matching lines @@
 bool LayerImpl::user_scrollable(ScrollbarOrientation orientation) const {
   return (orientation == HORIZONTAL) ? user_scrollable_horizontal_
                                      : user_scrollable_vertical_;
 }
 
 void LayerImpl::ApplySentScrollDeltasFromAbortedCommit() {
   DCHECK(layer_tree_impl()->IsActiveTree());
   scroll_offset_->AbortCommit();
 }
 
-InputHandler::ScrollStatus LayerImpl::TryScroll(
-    const gfx::PointF& screen_space_point,
-    InputHandler::ScrollInputType type) const {
-  InputHandler::ScrollStatus scroll_status;
-  scroll_status.main_thread_scrolling_reasons =
-      MainThreadScrollingReason::kNotScrollingOnMain;
-  if (should_scroll_on_main_thread()) {
-    TRACE_EVENT0("cc", "LayerImpl::TryScroll: Failed ShouldScrollOnMainThread");
-    scroll_status.thread = InputHandler::SCROLL_ON_MAIN_THREAD;
-    scroll_status.main_thread_scrolling_reasons =
-        main_thread_scrolling_reasons_;
-    return scroll_status;
-  }
-
-  gfx::Transform screen_space_transform = ScreenSpaceTransform();
-  if (!screen_space_transform.IsInvertible()) {
-    TRACE_EVENT0("cc", "LayerImpl::TryScroll: Ignored NonInvertibleTransform");
-    scroll_status.thread = InputHandler::SCROLL_IGNORED;
-    scroll_status.main_thread_scrolling_reasons =
-        MainThreadScrollingReason::kNonInvertibleTransform;
-    return scroll_status;
-  }
-
-  if (!non_fast_scrollable_region().IsEmpty()) {
-    bool clipped = false;
-    gfx::Transform inverse_screen_space_transform(
-        gfx::Transform::kSkipInitialization);
-    if (!screen_space_transform.GetInverse(&inverse_screen_space_transform)) {
-      // TODO(shawnsingh): We shouldn't be applying a projection if screen space
-      // transform is uninvertible here. Perhaps we should be returning
-      // SCROLL_ON_MAIN_THREAD in this case?
-    }
-
-    gfx::PointF hit_test_point_in_layer_space = MathUtil::ProjectPoint(
-        inverse_screen_space_transform, screen_space_point, &clipped);
-    if (!clipped &&
-        non_fast_scrollable_region().Contains(
-            gfx::ToRoundedPoint(hit_test_point_in_layer_space))) {
-      TRACE_EVENT0("cc",
-                   "LayerImpl::tryScroll: Failed NonFastScrollableRegion");
-      scroll_status.thread = InputHandler::SCROLL_ON_MAIN_THREAD;
-      scroll_status.main_thread_scrolling_reasons =
-          MainThreadScrollingReason::kNonFastScrollableRegion;
-      return scroll_status;
-    }
-  }
-
-  if (type == InputHandler::WHEEL || type == InputHandler::ANIMATED_WHEEL) {
-    EventListenerProperties event_properties =
-        layer_tree_impl_->event_listener_properties(
-            EventListenerClass::kMouseWheel);
-    if (event_properties == EventListenerProperties::kBlocking ||
-        event_properties == EventListenerProperties::kBlockingAndPassive ||
-        (!layer_tree_impl_->settings().use_mouse_wheel_gestures &&
-         event_properties == EventListenerProperties::kPassive)) {
-      TRACE_EVENT0("cc", "LayerImpl::tryScroll: Failed WheelEventHandlers");
-      scroll_status.thread = InputHandler::SCROLL_ON_MAIN_THREAD;
-      scroll_status.main_thread_scrolling_reasons =
-          MainThreadScrollingReason::kEventHandlers;
-      return scroll_status;
-    }
-  }
-
-  if (!scrollable()) {
-    TRACE_EVENT0("cc", "LayerImpl::tryScroll: Ignored not scrollable");
-    scroll_status.thread = InputHandler::SCROLL_IGNORED;
-    scroll_status.main_thread_scrolling_reasons =
-        MainThreadScrollingReason::kNotScrollable;
-    return scroll_status;
-  }
-
-  gfx::ScrollOffset max_scroll_offset = MaxScrollOffset();
-  if (max_scroll_offset.x() <= 0 && max_scroll_offset.y() <= 0) {
-    TRACE_EVENT0("cc",
-                 "LayerImpl::tryScroll: Ignored. Technically scrollable,"
-                 " but has no affordance in either direction.");
-    scroll_status.thread = InputHandler::SCROLL_IGNORED;
-    scroll_status.main_thread_scrolling_reasons =
-        MainThreadScrollingReason::kNotScrollable;
-    return scroll_status;
-  }
-
-  scroll_status.thread = InputHandler::SCROLL_ON_IMPL_THREAD;
-  return scroll_status;
-}
-
 skia::RefPtr<SkPicture> LayerImpl::GetPicture() {
   return skia::RefPtr<SkPicture>();
 }
 
 scoped_ptr<LayerImpl> LayerImpl::CreateLayerImpl(LayerTreeImpl* tree_impl) {
   return LayerImpl::Create(tree_impl, layer_id_, scroll_offset_);
 }
 
 void LayerImpl::PushPropertiesTo(LayerImpl* layer) {
   layer->SetTransformOrigin(transform_origin_);
@@ skipping 1281 matching lines @@
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       DrawTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc