Introduce bottom controls to CC and let it respond to scrolling

cc/input/top_controls_manager_unittest.cc

 // Copyright 2013 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/input/top_controls_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 15 matching lines @@
 class MockTopControlsManagerClient : public TopControlsManagerClient {
  public:
   MockTopControlsManagerClient(float top_controls_height,
                                float top_controls_show_threshold,
                                float top_controls_hide_threshold)
       : host_impl_(&task_runner_provider_,
                    &shared_bitmap_manager_,
                    &task_graph_runner_),
         redraw_needed_(false),
         update_draw_properties_needed_(false),
+        bottom_controls_height_(0.f),
         top_controls_shown_ratio_(1.f),
         top_controls_height_(top_controls_height),
         top_controls_show_threshold_(top_controls_show_threshold),
         top_controls_hide_threshold_(top_controls_hide_threshold) {
     active_tree_ = base::MakeUnique<LayerTreeImpl>(
         &host_impl_, new SyncedProperty<ScaleGroup>, new SyncedTopControls,
         new SyncedElasticOverscroll);
     root_scroll_layer_ = LayerImpl::Create(active_tree_.get(), 1);
   }
 
   ~MockTopControlsManagerClient() override {}
 
   void DidChangeTopControlsPosition() override {
     redraw_needed_ = true;
     update_draw_properties_needed_ = true;
   }
 
   bool HaveRootScrollLayer() const override { return true; }
 
+  float BottomControlsHeight() const override {
+    return bottom_controls_height_;
+  }
+
   float TopControlsHeight() const override { return top_controls_height_; }
 
   void SetCurrentTopControlsShownRatio(float ratio) override {
     ASSERT_FALSE(std::isnan(ratio));
     ASSERT_FALSE(ratio == std::numeric_limits<float>::infinity());
     ASSERT_FALSE(ratio == -std::numeric_limits<float>::infinity());
     ratio = std::max(ratio, 0.f);
     ratio = std::min(ratio, 1.f);
     top_controls_shown_ratio_ = ratio;
   }
@@ skipping 10 matching lines @@
     if (!manager_) {
       manager_ = TopControlsManager::Create(this,
                                             top_controls_show_threshold_,
                                             top_controls_hide_threshold_);
     }
     return manager_.get();
   }
 
   void SetTopControlsHeight(float height) { top_controls_height_ = height; }
 
+  void SetBottomControlsHeight(float height) {
+    bottom_controls_height_ = height;
+  }
+
  private:
   FakeImplTaskRunnerProvider task_runner_provider_;
   TestSharedBitmapManager shared_bitmap_manager_;
   TestTaskGraphRunner task_graph_runner_;
   FakeLayerTreeHostImpl host_impl_;
   std::unique_ptr<LayerTreeImpl> active_tree_;
   std::unique_ptr<LayerImpl> root_scroll_layer_;
   std::unique_ptr<TopControlsManager> manager_;
   bool redraw_needed_;
   bool update_draw_properties_needed_;
 
+  float bottom_controls_height_;
   float top_controls_shown_ratio_;
   float top_controls_height_;
   float top_controls_show_threshold_;
   float top_controls_hide_threshold_;
 };
 
 TEST(TopControlsManagerTest, EnsureScrollThresholdApplied) {
   MockTopControlsManagerClient client(100.f, 0.5f, 0.5f);
   TopControlsManager* manager = client.manager();
 
@@ skipping 355 matching lines @@
 
   manager->ScrollBegin();
   gfx::Vector2dF pending = manager->ScrollBy(gfx::Vector2dF(0.f, 20.f));
   EXPECT_FLOAT_EQ(20.f, pending.y());
   EXPECT_FLOAT_EQ(0.f, manager->ControlsTopOffset());
   EXPECT_FLOAT_EQ(0.f, manager->ContentTopOffset());
   EXPECT_FLOAT_EQ(1.f, client.CurrentTopControlsShownRatio());
   manager->ScrollEnd();
 }
 
+TEST(TopControlsManagerTest, ScrollThenRestoreBottomControls) {
+  MockTopControlsManagerClient client(100.f, 0.5f, 0.5f);
+  client.SetBottomControlsHeight(100.f);
+  TopControlsManager* manager = client.manager();
+  manager->ScrollBegin();
+  manager->ScrollBy(gfx::Vector2dF(0.f, 20.f));
+  EXPECT_FLOAT_EQ(80.f, manager->ContentBottomOffset());
+  EXPECT_FLOAT_EQ(0.8f, manager->BottomControlsShownRatio());
+  manager->ScrollEnd();
+
+  manager->ScrollBegin();
+  manager->ScrollBy(gfx::Vector2dF(0.f, -200.f));
+  EXPECT_FLOAT_EQ(100.f, manager->ContentBottomOffset());
+  EXPECT_FLOAT_EQ(1.f, manager->BottomControlsShownRatio());
+  manager->ScrollEnd();
+}
+
+TEST(TopControlsManagerTest, HideAndPeekBottomControls) {
+  MockTopControlsManagerClient client(100.f, 0.5f, 0.5f);
+  client.SetBottomControlsHeight(100.f);
+  TopControlsManager* manager = client.manager();
+  manager->ScrollBegin();
+  manager->ScrollBy(gfx::Vector2dF(0.f, 300.f));
+  EXPECT_FLOAT_EQ(0.f, manager->ContentBottomOffset());
+  EXPECT_FLOAT_EQ(0.f, manager->BottomControlsShownRatio());
+  manager->ScrollEnd();
+
+  manager->ScrollBegin();
+  manager->ScrollBy(gfx::Vector2dF(0.f, -15.f));
+  EXPECT_FLOAT_EQ(15.f, manager->ContentBottomOffset());
+  EXPECT_FLOAT_EQ(0.15f, manager->BottomControlsShownRatio());
+  manager->ScrollEnd();
+}
 
 }  // namespace
 }  // namespace cc