Update scrollbar parameters when it is associated to layer

Otherwise the scrollbar will be in invalid state (max=0, pos=0)
until the next time scrollbar parameters change.

BUG=388152
TEST=LayerImplScrollTest.SetNewScrollbarParameters

Review URL: https://codereview.chromium.org/358693007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@280233 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 51 insertions, 31 deletions

diff --git a/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc b/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
index c503335..e5801d6 100644
--- a/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
+++ b/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
@@ -50,8 +50,8 @@ class ScrollbarAnimationControllerLinearFadeTest
     LayerImpl* scroll_layer_ptr = scroll_layer.get();
     clip_layer_->AddChild(scroll_layer.Pass());
 
-    scrollbar_layer_->SetClipLayerById(clip_layer_->id());
-    scrollbar_layer_->SetScrollLayerById(scroll_layer_ptr->id());
+    scrollbar_layer_->SetScrollLayerAndClipLayerByIds(scroll_layer_ptr->id(),
+                                                      clip_layer_->id());
     clip_layer_->SetBounds(gfx::Size(100, 100));
     scroll_layer_ptr->SetBounds(gfx::Size(50, 50));
 
diff --git a/cc/animation/scrollbar_animation_controller_thinning_unittest.cc b/cc/animation/scrollbar_animation_controller_thinning_unittest.cc
index c0ab515..6dad5b0 100644
--- a/cc/animation/scrollbar_animation_controller_thinning_unittest.cc
+++ b/cc/animation/scrollbar_animation_controller_thinning_unittest.cc
@@ -49,8 +49,8 @@ class ScrollbarAnimationControllerThinningTest
                                              kIsLeftSideVerticalScrollbar,
                                              kIsOverlayScrollbar);
 
-    scrollbar_layer_->SetClipLayerById(clip_layer_->id());
-    scrollbar_layer_->SetScrollLayerById(scroll_layer_ptr->id());
+    scrollbar_layer_->SetScrollLayerAndClipLayerByIds(scroll_layer_ptr->id(),
+                                                      clip_layer_->id());
     clip_layer_->SetBounds(gfx::Size(100, 100));
     scroll_layer_ptr->SetBounds(gfx::Size(50, 50));
 
diff --git a/cc/layers/layer_impl_unittest.cc b/cc/layers/layer_impl_unittest.cc
index 281a3f1..39469c1 100644
--- a/cc/layers/layer_impl_unittest.cc
+++ b/cc/layers/layer_impl_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "cc/layers/layer_impl.h"
 
+#include "cc/layers/painted_scrollbar_layer_impl.h"
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
 #include "cc/test/fake_impl_proxy.h"
@@ -433,6 +434,8 @@ class LayerImplScrollTest : public testing::Test {
     return host_impl_.active_tree()->root_layer()->children()[0];
   }
 
+  LayerTreeImpl* tree() { return host_impl_.active_tree(); }
+
  private:
   FakeImplProxy proxy_;
   TestSharedBitmapManager shared_bitmap_manager_;
@@ -659,5 +662,30 @@ TEST_F(LayerImplScrollTest, DISABLED_ScrollUserUnscrollableLayer) {
   EXPECT_VECTOR_EQ(gfx::Vector2dF(30.5f, 5), layer()->TotalScrollOffset());
 }
 
+TEST_F(LayerImplScrollTest, SetNewScrollbarParameters) {
+  gfx::Vector2d scroll_offset(10, 5);
+  layer()->SetScrollOffset(scroll_offset);
+
+  scoped_ptr<PaintedScrollbarLayerImpl> vertical_scrollbar(
+      PaintedScrollbarLayerImpl::Create(tree(), 100, VERTICAL));
+  vertical_scrollbar->SetScrollLayerAndClipLayerByIds(
+      layer()->id(), tree()->root_layer()->id());
+
+  int expected_vertical_maximum =
+      layer()->bounds().height() - tree()->root_layer()->bounds().height();
+  EXPECT_EQ(expected_vertical_maximum, vertical_scrollbar->maximum());
+  EXPECT_EQ(scroll_offset.y(), vertical_scrollbar->current_pos());
+
+  scoped_ptr<PaintedScrollbarLayerImpl> horizontal_scrollbar(
+      PaintedScrollbarLayerImpl::Create(tree(), 101, HORIZONTAL));
+  horizontal_scrollbar->SetScrollLayerAndClipLayerByIds(
+      layer()->id(), tree()->root_layer()->id());
+
+  int expected_horizontal_maximum =
+      layer()->bounds().width() - tree()->root_layer()->bounds().width();
+  EXPECT_EQ(expected_horizontal_maximum, horizontal_scrollbar->maximum());
+  EXPECT_EQ(scroll_offset.x(), horizontal_scrollbar->current_pos());
+}
+
 }  // namespace
 }  // namespace cc
diff --git a/cc/layers/painted_scrollbar_layer.cc b/cc/layers/painted_scrollbar_layer.cc
index 9c5ab88..3764689 100644
--- a/cc/layers/painted_scrollbar_layer.cc
+++ b/cc/layers/painted_scrollbar_layer.cc
@@ -152,8 +152,8 @@ void PaintedScrollbarLayer::PushScrollClipPropertiesTo(LayerImpl* layer) {
   PaintedScrollbarLayerImpl* scrollbar_layer =
       static_cast<PaintedScrollbarLayerImpl*>(layer);
 
-  scrollbar_layer->SetScrollLayerById(scroll_layer_id_);
-  scrollbar_layer->SetClipLayerById(clip_layer_id_);
+  scrollbar_layer->SetScrollLayerAndClipLayerByIds(scroll_layer_id_,
+                                                   clip_layer_id_);
 }
 
 void PaintedScrollbarLayer::SetLayerTreeHost(LayerTreeHost* host) {
diff --git a/cc/layers/scrollbar_layer_impl_base.cc b/cc/layers/scrollbar_layer_impl_base.cc
index 9db0254..956f617 100644
--- a/cc/layers/scrollbar_layer_impl_base.cc
+++ b/cc/layers/scrollbar_layer_impl_base.cc
@@ -41,8 +41,8 @@ void ScrollbarLayerImplBase::PushPropertiesTo(LayerImpl* layer) {
 
 void ScrollbarLayerImplBase::PushScrollClipPropertiesTo(LayerImpl* layer) {
   DCHECK(layer->ToScrollbarLayer());
-  layer->ToScrollbarLayer()->SetScrollLayerById(ScrollLayerId());
-  layer->ToScrollbarLayer()->SetClipLayerById(ClipLayerId());
+  layer->ToScrollbarLayer()->SetScrollLayerAndClipLayerByIds(ScrollLayerId(),
+                                                             ClipLayerId());
 }
 
 ScrollbarLayerImplBase* ScrollbarLayerImplBase::ToScrollbarLayer() {
@@ -77,28 +77,22 @@ void RegisterScrollbarWithLayers(ScrollbarLayerImplBase* scrollbar,
 }
 }  // namespace
 
-void ScrollbarLayerImplBase::SetScrollLayerById(int id) {
-  LayerImpl* scroll_layer = layer_tree_impl()->LayerById(id);
-  if (scroll_layer_ == scroll_layer)
+void ScrollbarLayerImplBase::SetScrollLayerAndClipLayerByIds(
+    int scroll_layer_id,
+    int clip_layer_id) {
+  LayerImpl* scroll_layer = layer_tree_impl()->LayerById(scroll_layer_id);
+  LayerImpl* clip_layer = layer_tree_impl()->LayerById(clip_layer_id);
+  if (scroll_layer_ == scroll_layer && clip_layer_ == clip_layer)
     return;
 
   RegisterScrollbarWithLayers(
       this, clip_layer_, scroll_layer_, &LayerImpl::RemoveScrollbar);
   scroll_layer_ = scroll_layer;
-  RegisterScrollbarWithLayers(
-      this, clip_layer_, scroll_layer_, &LayerImpl::AddScrollbar);
-}
-
-void ScrollbarLayerImplBase::SetClipLayerById(int id) {
-  LayerImpl* clip_layer = layer_tree_impl()->LayerById(id);
-  if (clip_layer_ == clip_layer)
-    return;
-
-  RegisterScrollbarWithLayers(
-      this, clip_layer_, scroll_layer_, &LayerImpl::RemoveScrollbar);
   clip_layer_ = clip_layer;
   RegisterScrollbarWithLayers(
       this, clip_layer_, scroll_layer_, &LayerImpl::AddScrollbar);
+
+  ScrollbarParametersDidChange();
 }
 
 gfx::Rect ScrollbarLayerImplBase::ScrollbarLayerRectToContentRect(
diff --git a/cc/layers/scrollbar_layer_impl_base.h b/cc/layers/scrollbar_layer_impl_base.h
index e7a2fc7..435943d 100644
--- a/cc/layers/scrollbar_layer_impl_base.h
+++ b/cc/layers/scrollbar_layer_impl_base.h
@@ -19,13 +19,13 @@ class CC_EXPORT ScrollbarLayerImplBase : public LayerImpl {
   int ScrollLayerId() const {
     return scroll_layer_ ? scroll_layer_->id() : Layer::INVALID_ID;
   }
-  void ClearScrollLayer() { scroll_layer_ = NULL; }
-  void SetScrollLayerById(int id);
   int ClipLayerId() const {
     return clip_layer_ ? clip_layer_->id() : Layer::INVALID_ID;
   }
+
+  void SetScrollLayerAndClipLayerByIds(int scroll_layer_id, int clip_layer_id);
+  void ClearScrollLayer() { scroll_layer_ = NULL; }
   void ClearClipLayer() { clip_layer_ = NULL; }
-  void SetClipLayerById(int id);
 
   float current_pos() const { return current_pos_; }
   void SetCurrentPos(float current_pos);
diff --git a/cc/layers/solid_color_scrollbar_layer.cc b/cc/layers/solid_color_scrollbar_layer.cc
index 8749398..7ea7265 100644
--- a/cc/layers/solid_color_scrollbar_layer.cc
+++ b/cc/layers/solid_color_scrollbar_layer.cc
@@ -65,8 +65,8 @@ void SolidColorScrollbarLayer::PushScrollClipPropertiesTo(LayerImpl* layer) {
   SolidColorScrollbarLayerImpl* scrollbar_layer =
       static_cast<SolidColorScrollbarLayerImpl*>(layer);
 
-  scrollbar_layer->SetScrollLayerById(scroll_layer_id_);
-  scrollbar_layer->SetClipLayerById(clip_layer_id_);
+  scrollbar_layer->SetScrollLayerAndClipLayerByIds(scroll_layer_id_,
+                                                   clip_layer_id_);
 }
 
 void SolidColorScrollbarLayer::SetNeedsDisplayRect(const gfx::RectF&) {
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index bfe5938..ed38144 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -1360,11 +1360,10 @@ class LayerTreeHostImplOverridePhysicalTime : public LayerTreeHostImpl {
       SolidColorScrollbarLayerImpl::Create(                                   \
           host_impl_->active_tree(), 4, VERTICAL, 10, 0, false, true);        \
   EXPECT_FLOAT_EQ(0.f, scrollbar->opacity());                                 \
-  scrollbar->SetScrollLayerById(2);                                           \
-  scrollbar->SetClipLayerById(1);                                             \
                                                                               \
   scroll->AddChild(contents.Pass());                                          \
   root->AddChild(scroll.Pass());                                              \
+  scrollbar->SetScrollLayerAndClipLayerByIds(2, 1);                           \
   root->AddChild(scrollbar.PassAs<LayerImpl>());                              \
                                                                               \
   host_impl_->active_tree()->SetRootLayer(root.Pass());                       \
@@ -1523,11 +1522,10 @@ void LayerTreeHostImplTest::SetupMouseMoveAtWithDeviceScale(
   scrollbar->SetBounds(gfx::Size(15, viewport_size.height()));
   scrollbar->SetContentBounds(gfx::Size(15, viewport_size.height()));
   scrollbar->SetPosition(gfx::Point(285, 0));
-  scrollbar->SetClipLayerById(1);
-  scrollbar->SetScrollLayerById(2);
 
   scroll->AddChild(contents.Pass());
   root->AddChild(scroll.Pass());
+  scrollbar->SetScrollLayerAndClipLayerByIds(2, 1);
   root->AddChild(scrollbar.PassAs<LayerImpl>());
 
   host_impl_->active_tree()->SetRootLayer(root.Pass());