Route selection bounds updates through the compositor

cc/trees/layer_tree_impl.cc

 // Copyright 2011 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_impl.h"
 
 #include <limits>
 #include <set>
 
 #include "base/debug/trace_event.h"
@@ skipping 192 matching lines @@
 
   if (page_scale_layer_ && inner_viewport_scroll_layer_) {
     target_tree->SetViewportLayersFromIds(
         page_scale_layer_->id(),
         inner_viewport_scroll_layer_->id(),
         outer_viewport_scroll_layer_ ? outer_viewport_scroll_layer_->id()
                                      : Layer::INVALID_ID);
   } else {
     target_tree->ClearViewportLayers();
   }
+
+  target_tree->RegisterSelection(selection_anchor_, selection_focus_);
+
   // This should match the property synchronization in
   // LayerTreeHost::finishCommitOnImplThread().
   target_tree->set_source_frame_number(source_frame_number());
   target_tree->set_background_color(background_color());
   target_tree->set_has_transparent_background(has_transparent_background());
 
   if (ContentsTexturesPurged())
     target_tree->SetContentsTexturesPurged();
   else
     target_tree->ResetContentsTexturesPurged();
@@ skipping 892 matching lines @@
 
   // If ProjectPoint could not project to a valid value, then we assume that
   // this point doesn't hit this region.
   if (clipped)
     return false;
 
   return layer_space_region.Contains(
       gfx::ToRoundedPoint(hit_test_point_in_layer_space));
 }
 
-static LayerImpl* GetNextClippingLayer(LayerImpl* layer) {
+static const LayerImpl* GetNextClippingLayer(const LayerImpl* layer) {
   if (layer->scroll_parent())
     return layer->scroll_parent();
   if (layer->clip_parent())
     return layer->clip_parent();
   return layer->parent();
 }
 
 static bool PointIsClippedBySurfaceOrClipRect(
     const gfx::PointF& screen_space_point,
-    LayerImpl* layer) {
+    const LayerImpl* layer) {
   // Walk up the layer tree and hit-test any render_surfaces and any layer
   // clip rects that are active.
   for (; layer; layer = GetNextClippingLayer(layer)) {
     if (layer->render_surface() &&
         !PointHitsRect(screen_space_point,
                        layer->render_surface()->screen_space_transform(),
                        layer->render_surface()->content_rect(),
                        NULL))
       return true;
 
     if (LayerClipsSubtree(layer) &&
         !PointHitsRect(screen_space_point,
                        layer->screen_space_transform(),
                        gfx::Rect(layer->content_bounds()),
                        NULL))
       return true;
   }
 
   // If we have finished walking all ancestors without having already exited,
   // then the point is not clipped by any ancestors.
   return false;
 }
 
-static bool PointHitsLayer(LayerImpl* layer,
+static bool PointHitsLayer(const LayerImpl* layer,
                            const gfx::PointF& screen_space_point,
                            float* distance_to_intersection) {
   gfx::RectF content_rect(layer->content_bounds());
   if (!PointHitsRect(screen_space_point,
                      layer->screen_space_transform(),
                      content_rect,
                      distance_to_intersection))
     return false;
 
   // At this point, we think the point does hit the layer, but we need to walk
@@ skipping 131 matching lines @@
     return NULL;
   if (!UpdateDrawProperties())
     return NULL;
   FindTouchEventLayerFunctor func = {screen_space_point};
   FindClosestMatchingLayerDataForRecursion data_for_recursion;
   FindClosestMatchingLayer(
       screen_space_point, root_layer(), func, &data_for_recursion);
   return data_for_recursion.closest_match;
 }
 
+void LayerTreeImpl::RegisterSelection(const LayerSelectionBound& anchor,
+                                      const LayerSelectionBound& focus) {
+  selection_anchor_ = anchor;
+  selection_focus_ = focus;
+}
+
+static ViewportSelectionBound ComputeViewportSelection(
+    const LayerSelectionBound& bound,
+    LayerImpl* layer,
+    float device_scale_factor) {
+  ViewportSelectionBound result;
+  result.type = bound.type;
+
+  if (!layer || bound.type == SELECTION_BOUND_EMPTY)
+    return result;
+
+  gfx::RectF layer_scaled_rect = gfx::ScaleRect(
+      bound.layer_rect, layer->contents_scale_x(), layer->contents_scale_y());
+  gfx::RectF screen_rect = MathUtil::ProjectClippedRect(
+      layer->screen_space_transform(), layer_scaled_rect);
+
+  // The bottom left of the bound is used for visibility because 1) the bound
+  // edge rect is one-dimensional (no width), and 2) the bottom is the logical
+  // focal point for bound selection handles (this may change in the future).
+  const gfx::PointF& visibility_point = screen_rect.bottom_left();
+  float intersect_distance = 0.f;
+  result.visible = PointHitsLayer(layer, visibility_point, &intersect_distance);
+
+  screen_rect.Scale(1.f / device_scale_factor);
+  result.viewport_rect = screen_rect;
+
+  return result;
+}
+
+void LayerTreeImpl::GetViewportSelection(ViewportSelectionBound* anchor,
+                                         ViewportSelectionBound* focus) {
+  DCHECK(anchor);
+  DCHECK(focus);
+
+  *anchor = ComputeViewportSelection(
+      selection_anchor_,
+      selection_anchor_.layer_id ? LayerById(selection_anchor_.layer_id) : NULL,
+      device_scale_factor());
+  if (anchor->type == SELECTION_BOUND_CENTER ||
+      anchor->type == SELECTION_BOUND_EMPTY) {
+    *focus = *anchor;
+  } else {
+    *focus = ComputeViewportSelection(
+        selection_focus_,
+        selection_focus_.layer_id ? LayerById(selection_focus_.layer_id) : NULL,
+        device_scale_factor());
+  }
+}
+
 void LayerTreeImpl::RegisterPictureLayerImpl(PictureLayerImpl* layer) {
   layer_tree_host_impl_->RegisterPictureLayerImpl(layer);
 }
 
 void LayerTreeImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   layer_tree_host_impl_->UnregisterPictureLayerImpl(layer);
 }
 
 }  // namespace cc