Clean up PointIsClippedBySurfaceOrClipRect

This function made unnecessary use of the render
target and didn't walk its clipping ancestor
chain correctly. This CL refactors the function
and fixes that walk (and adds test to show that
the walk is correct).


R=danakj@chromium.org

Review URL: https://codereview.chromium.org/328753002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276799 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 138 insertions, 0 deletions

diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index 8db2b95..91bad3e 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -1117,6 +1117,144 @@ TEST_F(LayerTreeImplTest, HitTestingForMultipleLayersAtVaryingDepths) {
   EXPECT_EQ(4, result_layer->id());
 }
 
+TEST_F(LayerTreeImplTest, HitTestingRespectsClipParents) {
+  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
+  gfx::Transform identity_matrix;
+  gfx::Point3F transform_origin;
+  gfx::PointF position;
+  gfx::Size bounds(100, 100);
+  SetLayerPropertiesForTesting(root.get(),
+                               identity_matrix,
+                               transform_origin,
+                               position,
+                               bounds,
+                               true,
+                               false);
+  root->SetDrawsContent(true);
+  {
+    scoped_ptr<LayerImpl> child =
+        LayerImpl::Create(host_impl().active_tree(), 2);
+    scoped_ptr<LayerImpl> grand_child =
+        LayerImpl::Create(host_impl().active_tree(), 4);
+
+    position = gfx::PointF(10.f, 10.f);
+    bounds = gfx::Size(1, 1);
+    SetLayerPropertiesForTesting(child.get(),
+                                 identity_matrix,
+                                 transform_origin,
+                                 position,
+                                 bounds,
+                                 true,
+                                 false);
+    child->SetDrawsContent(true);
+    child->SetMasksToBounds(true);
+
+    position = gfx::PointF(0.f, 40.f);
+    bounds = gfx::Size(100, 50);
+    SetLayerPropertiesForTesting(grand_child.get(),
+                                 identity_matrix,
+                                 transform_origin,
+                                 position,
+                                 bounds,
+                                 true,
+                                 false);
+    grand_child->SetDrawsContent(true);
+    grand_child->SetForceRenderSurface(true);
+
+    // This should let |grand_child| "escape" |child|'s clip.
+    grand_child->SetClipParent(root.get());
+
+    child->AddChild(grand_child.Pass());
+    root->AddChild(child.Pass());
+  }
+
+  host_impl().SetViewportSize(root->bounds());
+  host_impl().active_tree()->SetRootLayer(root.Pass());
+  host_impl().active_tree()->UpdateDrawProperties();
+
+  gfx::Point test_point = gfx::Point(12, 52);
+  LayerImpl* result_layer =
+      host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
+  ASSERT_TRUE(result_layer);
+  EXPECT_EQ(4, result_layer->id());
+}
+
+TEST_F(LayerTreeImplTest, HitTestingRespectsScrollParents) {
+  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
+  gfx::Transform identity_matrix;
+  gfx::Point3F transform_origin;
+  gfx::PointF position;
+  gfx::Size bounds(100, 100);
+  SetLayerPropertiesForTesting(root.get(),
+                               identity_matrix,
+                               transform_origin,
+                               position,
+                               bounds,
+                               true,
+                               false);
+  root->SetDrawsContent(true);
+  {
+    scoped_ptr<LayerImpl> child =
+        LayerImpl::Create(host_impl().active_tree(), 2);
+    scoped_ptr<LayerImpl> scroll_child =
+        LayerImpl::Create(host_impl().active_tree(), 3);
+    scoped_ptr<LayerImpl> grand_child =
+        LayerImpl::Create(host_impl().active_tree(), 4);
+
+    position = gfx::PointF(10.f, 10.f);
+    bounds = gfx::Size(1, 1);
+    SetLayerPropertiesForTesting(child.get(),
+                                 identity_matrix,
+                                 transform_origin,
+                                 position,
+                                 bounds,
+                                 true,
+                                 false);
+    child->SetDrawsContent(true);
+    child->SetMasksToBounds(true);
+
+    position = gfx::PointF();
+    bounds = gfx::Size(200, 200);
+    SetLayerPropertiesForTesting(scroll_child.get(),
+                                 identity_matrix,
+                                 transform_origin,
+                                 position,
+                                 bounds,
+                                 true,
+                                 false);
+    scroll_child->SetDrawsContent(true);
+
+    // This should cause scroll child and its descendants to be affected by
+    // |child|'s clip.
+    scroll_child->SetScrollParent(child.get());
+
+    SetLayerPropertiesForTesting(grand_child.get(),
+                                 identity_matrix,
+                                 transform_origin,
+                                 position,
+                                 bounds,
+                                 true,
+                                 false);
+    grand_child->SetDrawsContent(true);
+    grand_child->SetForceRenderSurface(true);
+
+    scroll_child->AddChild(grand_child.Pass());
+    root->AddChild(scroll_child.Pass());
+    root->AddChild(child.Pass());
+  }
+
+  host_impl().SetViewportSize(root->bounds());
+  host_impl().active_tree()->SetRootLayer(root.Pass());
+  host_impl().active_tree()->UpdateDrawProperties();
+
+  gfx::Point test_point = gfx::Point(12, 52);
+  LayerImpl* result_layer =
+      host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
+  // The |test_point| should have been clipped away by |child|, the scroll
+  // parent, so the only thing that should be hit is |root|.
+  ASSERT_TRUE(result_layer);
+  ASSERT_EQ(1, result_layer->id());
+}
 TEST_F(LayerTreeImplTest, HitTestingForMultipleLayerLists) {
   //
   // The geometry is set up similarly to the previous case, but