Add initial CC support for scroll-blocks-on

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 "base/json/json_reader.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 36 matching lines @@
       mask_layer_id_(-1),
       replica_layer_id_(-1),
       layer_id_(id),
       layer_tree_impl_(tree_impl),
       scroll_offset_(scroll_offset),
       scroll_offset_delegate_(nullptr),
       scroll_clip_layer_(nullptr),
       should_scroll_on_main_thread_(false),
       have_wheel_event_handlers_(false),
       have_scroll_event_handlers_(false),
+      scroll_blocks_on_(ScrollBlocksOnNone),
       user_scrollable_horizontal_(true),
       user_scrollable_vertical_(true),
       stacking_order_changed_(false),
       double_sided_(true),
       should_flatten_transform_(true),
       layer_property_changed_(false),
       masks_to_bounds_(false),
       contents_opaque_(false),
       is_root_for_isolated_group_(false),
       use_parent_backface_visibility_(false),
@@ skipping 318 matching lines @@
                                      : 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::ScrollInputType type,
+    ScrollBlocksOn effective_block_mode) const {
   if (should_scroll_on_main_thread()) {
     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Failed ShouldScrollOnMainThread");
     return InputHandler::ScrollOnMainThread;
   }
 
   if (!screen_space_transform().IsInvertible()) {
     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Ignored NonInvertibleTransform");
     return InputHandler::ScrollIgnored;
   }
 
@@ skipping 17 matching lines @@
                         1.f / contents_scale_y());
     if (!clipped &&
         non_fast_scrollable_region().Contains(
             gfx::ToRoundedPoint(hit_test_point_in_layer_space))) {
       TRACE_EVENT0("cc",
                    "LayerImpl::tryScroll: Failed NonFastScrollableRegion");
       return InputHandler::ScrollOnMainThread;
     }
   }
 
-  if (type == InputHandler::Wheel && have_wheel_event_handlers()) {
+  if (have_scroll_event_handlers() &&
+      effective_block_mode & ScrollBlocksOnScrollEvent) {
+    TRACE_EVENT0("cc", "LayerImpl::tryScroll: Failed ScrollEventHandlers");
+    return InputHandler::ScrollOnMainThread;
+  }
+
+  if (type == InputHandler::Wheel && have_wheel_event_handlers() &&
+      effective_block_mode & ScrollBlocksOnWheelEvent) {
     TRACE_EVENT0("cc", "LayerImpl::tryScroll: Failed WheelEventHandlers");
     return InputHandler::ScrollOnMainThread;
   }
 
   if (!scrollable()) {
     TRACE_EVENT0("cc", "LayerImpl::tryScroll: Ignored not scrollable");
     return InputHandler::ScrollIgnored;
   }
 
   gfx::ScrollOffset max_scroll_offset = MaxScrollOffset();
@@ skipping 36 matching lines @@
       draw_checkerboard_for_missing_tiles_);
   layer->SetDrawsContent(DrawsContent());
   layer->SetHideLayerAndSubtree(hide_layer_and_subtree_);
   layer->SetHasRenderSurface(!!render_surface());
   layer->SetFilters(filters());
   layer->SetBackgroundFilters(background_filters());
   layer->SetMasksToBounds(masks_to_bounds_);
   layer->SetShouldScrollOnMainThread(should_scroll_on_main_thread_);
   layer->SetHaveWheelEventHandlers(have_wheel_event_handlers_);
   layer->SetHaveScrollEventHandlers(have_scroll_event_handlers_);
+  layer->SetScrollBlocksOn(scroll_blocks_on_);
   layer->SetNonFastScrollableRegion(non_fast_scrollable_region_);
   layer->SetTouchEventHandlerRegion(touch_event_handler_region_);
   layer->SetContentsOpaque(contents_opaque_);
   layer->SetOpacity(opacity_);
   layer->SetBlendMode(blend_mode_);
   layer->SetIsRootForIsolatedGroup(is_root_for_isolated_group_);
   layer->SetPosition(position_);
   layer->SetIsContainerForFixedPositionLayers(
       is_container_for_fixed_position_layers_);
   layer->SetPositionConstraint(position_constraint_);
@@ skipping 142 matching lines @@
 
   if (have_wheel_event_handlers_)
     result->SetBoolean("WheelHandler", have_wheel_event_handlers_);
   if (have_scroll_event_handlers_)
     result->SetBoolean("ScrollHandler", have_scroll_event_handlers_);
   if (!touch_event_handler_region_.IsEmpty()) {
     scoped_ptr<base::Value> region = touch_event_handler_region_.AsValue();
     result->Set("TouchRegion", region.release());
   }
 
+  if (scroll_blocks_on_) {
+    list = new base::ListValue;
+    if (scroll_blocks_on_ & ScrollBlocksOnStartTouch)
+      list->AppendString("StartTouch");
+    if (scroll_blocks_on_ & ScrollBlocksOnWheelEvent)
+      list->AppendString("WheelEvent");
+    if (scroll_blocks_on_ & ScrollBlocksOnScrollEvent)
+      list->AppendString("ScrollEvent");
+    result->Set("ScrollBlocksOn", list);
+  }
+
   list = new base::ListValue;
   for (size_t i = 0; i < children_.size(); ++i)
     list->Append(children_[i]->LayerTreeAsJson());
   result->Set("Children", list);
 
   return result;
 }
 
 void LayerImpl::SetStackingOrderChanged(bool stacking_order_changed) {
   if (stacking_order_changed) {
@@ skipping 771 matching lines @@
     Region scroll_region(scroll_rect);
     state->BeginArray("scroll_event_handler_region");
     scroll_region.AsValueInto(state);
     state->EndArray();
   }
   if (!non_fast_scrollable_region_.IsEmpty()) {
     state->BeginArray("non_fast_scrollable_region");
     non_fast_scrollable_region_.AsValueInto(state);
     state->EndArray();
   }
+  if (scroll_blocks_on_) {
+    state->SetInteger("scroll_blocks_on", scroll_blocks_on_);
+  }
 
   state->BeginArray("children");
   for (size_t i = 0; i < children_.size(); ++i) {
     state->BeginDictionary();
     children_[i]->AsValueInto(state);
     state->EndDictionary();
   }
   state->EndArray();
   if (mask_layer_) {
     state->BeginDictionary("mask_layer");
@@ skipping 85 matching lines @@
   SetNeedsPushProperties();
   layer_tree_impl()->set_needs_update_draw_properties();
   if (should_have_render_surface) {
     render_surface_ = make_scoped_ptr(new RenderSurfaceImpl(this));
     return;
   }
   render_surface_.reset();
 }
 
 }  // namespace cc