Make LayerScrollOffsetDelegate updates consistent.

cc/trees/layer_tree_host_impl_unittest.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_host_impl.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 3012 matching lines @@
 
 class TestScrollOffsetDelegate : public LayerScrollOffsetDelegate {
  public:
   TestScrollOffsetDelegate()
       : page_scale_factor_(0.f),
         min_page_scale_factor_(-1.f),
         max_page_scale_factor_(-1.f) {}
 
   virtual ~TestScrollOffsetDelegate() {}
 
-  virtual void SetMaxScrollOffset(
-      const gfx::Vector2dF& max_scroll_offset) OVERRIDE {
-    max_scroll_offset_ = max_scroll_offset;
-  }
-
   virtual void SetTotalScrollOffset(const gfx::Vector2dF& new_value) OVERRIDE {
     last_set_scroll_offset_ = new_value;
+    CheckScrollOffsetWithinBounds();
   }
 
   virtual gfx::Vector2dF GetTotalScrollOffset() OVERRIDE {
     return getter_return_value_;
   }
 
   virtual bool IsExternalFlingActive() const OVERRIDE { return false; }
 
-  virtual void SetTotalPageScaleFactorAndLimits(
-      float page_scale_factor,
-      float min_page_scale_factor,
-      float max_page_scale_factor) OVERRIDE {
+  virtual void UpdateRootLayerState(const gfx::Vector2dF& total_scroll_offset,
+                                    const gfx::Vector2dF& max_scroll_offset,
+                                    const gfx::SizeF& scrollable_size,
+                                    float page_scale_factor,
+                                    float min_page_scale_factor,
+                                    float max_page_scale_factor) OVERRIDE {
+    last_set_scroll_offset_ = total_scroll_offset;
+    max_scroll_offset_ = max_scroll_offset;
+    scrollable_size_ = scrollable_size;
     page_scale_factor_ = page_scale_factor;
     min_page_scale_factor_ = min_page_scale_factor;
     max_page_scale_factor_ = max_page_scale_factor;
-  }
-
-  virtual void SetScrollableSize(const gfx::SizeF& scrollable_size) OVERRIDE {
-    scrollable_size_ = scrollable_size;
+    CheckScrollOffsetWithinBounds();
   }
 
   gfx::Vector2dF last_set_scroll_offset() {
     return last_set_scroll_offset_;
   }
 
   void set_getter_return_value(const gfx::Vector2dF& value) {
     getter_return_value_ = value;
   }
 
@@ skipping 11 matching lines @@
 
   float min_page_scale_factor() const {
     return min_page_scale_factor_;
   }
 
   float max_page_scale_factor() const {
     return max_page_scale_factor_;
   }
 
  private:
+  void CheckScrollOffsetWithinBounds() {
+    DCHECK(last_set_scroll_offset_.x() <= max_scroll_offset_.x());
+    DCHECK(last_set_scroll_offset_.y() <= max_scroll_offset_.y());
+  }
+
   gfx::Vector2dF last_set_scroll_offset_;
   gfx::Vector2dF getter_return_value_;
   gfx::Vector2dF max_scroll_offset_;
   gfx::SizeF scrollable_size_;
   float page_scale_factor_;
   float min_page_scale_factor_;
   float max_page_scale_factor_;
 };
 
 TEST_F(LayerTreeHostImplTest, RootLayerScrollOffsetDelegation) {
@@ skipping 27 matching lines @@
   host_impl_->active_tree()->SetPageScaleDelta(1.5f);
   EXPECT_EQ(3.f, scroll_delegate.page_scale_factor());
   EXPECT_EQ(0.5f, scroll_delegate.min_page_scale_factor());
   EXPECT_EQ(4.f, scroll_delegate.max_page_scale_factor());
   host_impl_->active_tree()->SetPageScaleDelta(1.f);
   host_impl_->active_tree()->SetPageScaleFactorAndLimits(1.f, 0.5f, 4.f);
   EXPECT_EQ(1.f, scroll_delegate.page_scale_factor());
   EXPECT_EQ(0.5f, scroll_delegate.min_page_scale_factor());
   EXPECT_EQ(4.f, scroll_delegate.max_page_scale_factor());
 
+  // The pinch gesture doesn't put the delegate into a state where the scroll
+  // offset is outside of the scroll range.  (this is verified by DCHECKs in the
+  // delegate).
+  host_impl_->ScrollBegin(gfx::Point(), InputHandler::Gesture);
+  host_impl_->PinchGestureBegin();
+  host_impl_->PinchGestureUpdate(2.f, gfx::Point());
+  host_impl_->PinchGestureUpdate(.5f, gfx::Point());
+  host_impl_->PinchGestureEnd();
+  host_impl_->ScrollEnd();
+
   // Scrolling should be relative to the offset as returned by the delegate.
   gfx::Vector2dF scroll_delta(0.f, 10.f);
   gfx::Vector2dF current_offset(7.f, 8.f);
 
   scroll_delegate.set_getter_return_value(current_offset);
   EXPECT_EQ(InputHandler::ScrollStarted,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::Gesture));
 
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
   EXPECT_EQ(current_offset + scroll_delta,
             scroll_delegate.last_set_scroll_offset());
 
   current_offset = gfx::Vector2dF(42.f, 41.f);
   scroll_delegate.set_getter_return_value(current_offset);
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
   EXPECT_EQ(current_offset + scroll_delta,
             scroll_delegate.last_set_scroll_offset());
   host_impl_->ScrollEnd();
+  scroll_delegate.set_getter_return_value(gfx::Vector2dF());
 
   // Forces a full tree synchronization and ensures that the scroll delegate
   // sees the correct size of the new tree.
   gfx::Size new_size(42, 24);
   host_impl_->CreatePendingTree();
   CreateScrollAndContentsLayers(host_impl_->pending_tree(), new_size);
   host_impl_->ActivatePendingTree();
   EXPECT_EQ(new_size, scroll_delegate.scrollable_size());
 
   // Un-setting the delegate should propagate the delegate's current offset to
@@ skipping 3322 matching lines @@
   // Verify implicit limits are calculated correctly with no overflows
   host_impl_->SetMemoryPolicy(mem_policy);
   EXPECT_EQ(host_impl_->global_tile_state().hard_memory_limit_in_bytes,
             300u * 1024u * 1024u);
   EXPECT_EQ(host_impl_->global_tile_state().soft_memory_limit_in_bytes,
             150u * 1024u * 1024u);
 }
 
 }  // namespace
 }  // namespace cc