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 3000 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;
-  }
-
   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 {
+    DCHECK(total_scroll_offset.x() <= max_scroll_offset.x());
+    DCHECK(total_scroll_offset.y() <= max_scroll_offset.y());
+    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;
-  }
-
   gfx::Vector2dF last_set_scroll_offset() {
     return last_set_scroll_offset_;
   }
 
   void set_getter_return_value(const gfx::Vector2dF& value) {
     getter_return_value_ = value;
   }
 
   gfx::Vector2dF max_scroll_offset() const {
     return max_scroll_offset_;
@@ skipping 56 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 3433 matching lines @@
   FakePictureLayerImpl* active_mask_content =
       static_cast<FakePictureLayerImpl*>(
           host_impl_->active_tree()->root_layer()->children()[0]->mask_layer());
   gfx::Rect r2 = active_mask_content->visible_rect_for_tile_priority();
 
   ASSERT_TRUE(!r2.IsEmpty());
 }
 
 }  // namespace
 }  // namespace cc