Hide scrollbars when their dimensions are not scrollable.

cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc

Index: cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
diff --git a/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc b/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
index 99b45b35052a8eda18f025bb28b81e9e13435a4a..4ffb0b27b4f201f3734f8403c5177855e548e1f3 100644
--- a/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
+++ b/cc/animation/scrollbar_animation_controller_linear_fade_unittest.cc
@@ -7,7 +7,9 @@
 #include "cc/layers/solid_color_scrollbar_layer_impl.h"
 #include "cc/test/fake_impl_proxy.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
+#include "cc/test/geometry_test_utils.h"
 #include "cc/test/test_shared_bitmap_manager.h"
+#include "cc/trees/layer_tree_impl.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
@@ -41,7 +43,7 @@ class ScrollbarAnimationControllerLinearFadeTest
     scrollbar_layer_ =
         SolidColorScrollbarLayerImpl::Create(host_impl_.active_tree(),
                                              2,
-                                             HORIZONTAL,
+                                             orientation(),
                                              kThumbThickness,
                                              kTrackStart,
                                              kIsLeftSideVerticalScrollbar,
@@ -54,7 +56,7 @@ class ScrollbarAnimationControllerLinearFadeTest
     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));
+    scroll_layer_ptr->SetBounds(gfx::Size(200, 200));
 
     scrollbar_controller_ = ScrollbarAnimationControllerLinearFade::Create(
         scroll_layer_ptr,
@@ -64,6 +66,8 @@ class ScrollbarAnimationControllerLinearFadeTest
         base::TimeDelta::FromSeconds(3));
   }
 
+  virtual ScrollbarOrientation orientation() const { return HORIZONTAL; }
+
   FakeImplProxy proxy_;
   TestSharedBitmapManager shared_bitmap_manager_;
   FakeLayerTreeHostImpl host_impl_;
@@ -76,6 +80,12 @@ class ScrollbarAnimationControllerLinearFadeTest
   int needs_frame_count_;
 };
 
+class VerticalScrollbarAnimationControllerLinearFadeTest
+    : public ScrollbarAnimationControllerLinearFadeTest {
+ protected:
+  virtual ScrollbarOrientation orientation() const override { return VERTICAL; }
+};
+
 TEST_F(ScrollbarAnimationControllerLinearFadeTest, DelayAnimationOnResize) {
   scrollbar_layer_->SetOpacity(0.0f);
   scrollbar_controller_->DidScrollBegin();
@@ -119,6 +129,131 @@ TEST_F(ScrollbarAnimationControllerLinearFadeTest,
   EXPECT_EQ(0, needs_frame_count_);
 }
 
+TEST_F(ScrollbarAnimationControllerLinearFadeTest, HideOnResize) {
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  EXPECT_SIZE_EQ(gfx::Size(200, 200), scroll_layer->bounds());
+
+  EXPECT_EQ(HORIZONTAL, scrollbar_layer_->orientation());
+
+  // Shrink along X axis, horizontal scrollbar should appear.
+  clip_layer_->SetBounds(gfx::Size(100, 200));
+  EXPECT_SIZE_EQ(gfx::Size(100, 200), clip_layer_->bounds());
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+
+  // Shrink along Y axis and expand along X, horizontal scrollbar
+  // should disappear.
+  clip_layer_->SetBounds(gfx::Size(200, 100));
+  EXPECT_SIZE_EQ(gfx::Size(200, 100), clip_layer_->bounds());
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(0.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
+TEST_F(VerticalScrollbarAnimationControllerLinearFadeTest, HideOnResize) {
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  EXPECT_SIZE_EQ(gfx::Size(200, 200), scroll_layer->bounds());
+
+  EXPECT_EQ(VERTICAL, scrollbar_layer_->orientation());
+
+  // Shrink along X axis, vertical scrollbar should remain invisible.
+  clip_layer_->SetBounds(gfx::Size(100, 200));
+  EXPECT_SIZE_EQ(gfx::Size(100, 200), clip_layer_->bounds());
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(0.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+
+  // Shrink along Y axis and expand along X, vertical scrollbar should appear.
+  clip_layer_->SetBounds(gfx::Size(200, 100));
+  EXPECT_SIZE_EQ(gfx::Size(200, 100), clip_layer_->bounds());
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
+TEST_F(ScrollbarAnimationControllerLinearFadeTest,
+       HideOnUserNonScrollableHorz) {
+  EXPECT_EQ(HORIZONTAL, scrollbar_layer_->orientation());
+
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  scroll_layer->set_user_scrollable_horizontal(false);
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(0.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
+TEST_F(ScrollbarAnimationControllerLinearFadeTest,
+       ShowOnUserNonScrollableVert) {
+  EXPECT_EQ(HORIZONTAL, scrollbar_layer_->orientation());
+
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  scroll_layer->set_user_scrollable_vertical(false);
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
+TEST_F(VerticalScrollbarAnimationControllerLinearFadeTest,
+       HideOnUserNonScrollableVert) {
+  EXPECT_EQ(VERTICAL, scrollbar_layer_->orientation());
+
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  scroll_layer->set_user_scrollable_vertical(false);
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(0.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
+TEST_F(VerticalScrollbarAnimationControllerLinearFadeTest,
+       ShowOnUserNonScrollableHorz) {
+  EXPECT_EQ(VERTICAL, scrollbar_layer_->orientation());
+
+  LayerImpl* scroll_layer = host_impl_.active_tree()->LayerById(1);
+  ASSERT_TRUE(scroll_layer);
+  scroll_layer->set_user_scrollable_horizontal(false);
+
+  scrollbar_controller_->DidScrollBegin();
+
+  scrollbar_controller_->DidScrollUpdate(false);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->opacity());
+
+  scrollbar_controller_->DidScrollEnd();
+}
+
 TEST_F(ScrollbarAnimationControllerLinearFadeTest, AwakenByScrollingGesture) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);