Make scroll offset type of float in cc

cc/layers/layer_impl.cc

 // Copyright 2012 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/layers/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/json/json_reader.h"
 #include "base/strings/stringprintf.h"
@@ skipping 336 matching lines @@
 
 RenderPassId LayerImpl::NextContributingRenderPassId(RenderPassId id) const {
   return RenderPassId(0, 0);
 }
 
 ResourceProvider::ResourceId LayerImpl::ContentsResourceId() const {
   NOTREACHED();
   return 0;
 }
 
-void LayerImpl::SetSentScrollDelta(const gfx::Vector2d& sent_scroll_delta) {
+void LayerImpl::SetSentScrollDelta(const gfx::ScrollOffset& sent_scroll_delta) {
   // Pending tree never has sent scroll deltas
   DCHECK(layer_tree_impl()->IsActiveTree());
 
   if (sent_scroll_delta_ == sent_scroll_delta)
     return;
 
   sent_scroll_delta_ = sent_scroll_delta;
 }
 
 gfx::Vector2dF LayerImpl::ScrollBy(const gfx::Vector2dF& scroll) {
   DCHECK(scrollable());
-  gfx::Vector2dF min_delta = -scroll_offset_;
-  gfx::Vector2dF max_delta = MaxScrollOffset() - scroll_offset_;
+  gfx::Vector2dF min_delta = -ToVector2dF(scroll_offset_);
+  gfx::Vector2dF max_delta = MaxScrollOffset() - ToVector2dF(scroll_offset_);

[danakj, 2014/09/25 15:13:30]

to ToVector2dF after the subtraction - MaxScrollOffset should be a ScrollOffset
type..

[Yufeng Shen (Slow to review), 2014/09/25 20:06:23]

Done.

   // Clamp new_delta so that position + delta stays within scroll bounds.
   gfx::Vector2dF new_delta = (ScrollDelta() + scroll);
   new_delta.SetToMax(min_delta);
   new_delta.SetToMin(max_delta);
   gfx::Vector2dF unscrolled =
       ScrollDelta() + scroll - new_delta;
   SetScrollDelta(new_delta);
 
   return unscrolled;
 }
@@ skipping 11 matching lines @@
   //
   // This function should not change the total scroll offset; it just shifts
   // some of the scroll delta to the scroll offset.  Therefore, adjust these
   // variables directly rather than calling the scroll offset delegate to
   // avoid sending it multiple spurious calls.
   //
   // Because of the way scroll delta is calculated with a delegate, this will
   // leave the total scroll offset unchanged on this layer regardless of
   // whether a delegate is being used.
   scroll_offset_ += sent_scroll_delta_;
-  scroll_delta_ -= sent_scroll_delta_;
-  sent_scroll_delta_ = gfx::Vector2d();
+  scroll_delta_ -= ToVector2dF(sent_scroll_delta_);
+  sent_scroll_delta_ = gfx::ScrollOffset();
 }
 
 void LayerImpl::ApplyScrollDeltasSinceBeginMainFrame() {
   // Only the pending tree can have missing scrolls.
   DCHECK(layer_tree_impl()->IsPendingTree());
   if (!scrollable())
     return;
 
   // Pending tree should never have sent scroll deltas.
   DCHECK(sent_scroll_delta().IsZero());
 
   LayerImpl* active_twin = layer_tree_impl()->FindActiveTreeLayerById(id());
   if (active_twin) {
     // Scrolls that happens after begin frame (where the sent scroll delta
     // comes from) and commit need to be applied to the pending tree
     // so that it is up to date with the total scroll.
     SetScrollDelta(active_twin->ScrollDelta() -
-                   active_twin->sent_scroll_delta());
+                   ToVector2dF(active_twin->sent_scroll_delta()));
   }
 }
 
 InputHandler::ScrollStatus LayerImpl::TryScroll(
     const gfx::PointF& screen_space_point,
     InputHandler::ScrollInputType type) const {
   if (should_scroll_on_main_thread()) {
     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Failed ShouldScrollOnMainThread");
     return InputHandler::ScrollOnMainThread;
   }
@@ skipping 99 matching lines @@
   layer->SetPositionConstraint(position_constraint_);
   layer->SetShouldFlattenTransform(should_flatten_transform_);
   layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
   layer->SetTransformAndInvertibility(transform_, transform_is_invertible_);
 
   layer->SetScrollClipLayer(scroll_clip_layer_ ? scroll_clip_layer_->id()
                                                : Layer::INVALID_ID);
   layer->set_user_scrollable_horizontal(user_scrollable_horizontal_);
   layer->set_user_scrollable_vertical(user_scrollable_vertical_);
   layer->SetScrollOffsetAndDelta(
-      scroll_offset_, layer->ScrollDelta() - layer->sent_scroll_delta());
-  layer->SetSentScrollDelta(gfx::Vector2d());
+      scroll_offset_,
+      layer->ScrollDelta() - ToVector2dF(layer->sent_scroll_delta()));
+  layer->SetSentScrollDelta(gfx::ScrollOffset());
   layer->Set3dSortingContextId(sorting_context_id_);
   layer->SetNumDescendantsThatDrawContent(num_descendants_that_draw_content_);
 
   LayerImpl* scroll_parent = NULL;
   if (scroll_parent_) {
     scroll_parent = layer->layer_tree_impl()->LayerById(scroll_parent_->id());
     DCHECK(scroll_parent);
   }
 
   layer->SetScrollParent(scroll_parent);
@@ skipping 199 matching lines @@
   SetTransform(transform);
 }
 
 void LayerImpl::OnScrollOffsetAnimated(const gfx::Vector2dF& scroll_offset) {
   // Only layers in the active tree should need to do anything here, since
   // layers in the pending tree will find out about these changes as a
   // result of the call to SetScrollDelta.
   if (!IsActive())
     return;
 
-  SetScrollDelta(scroll_offset - scroll_offset_);
+  SetScrollDelta(scroll_offset - ToVector2dF(scroll_offset_));
 
   layer_tree_impl_->DidAnimateScrollOffset();
 }
 
 void LayerImpl::OnAnimationWaitingForDeletion() {}
 
 bool LayerImpl::IsActive() const {
   return layer_tree_impl_->IsActiveTree();
 }
 
@@ skipping 284 matching lines @@
   draw_properties_.contents_scale_x = contents_scale_x;
   draw_properties_.contents_scale_y = contents_scale_y;
   NoteLayerPropertyChanged();
 }
 
 void LayerImpl::SetScrollOffsetDelegate(
     ScrollOffsetDelegate* scroll_offset_delegate) {
   // Having both a scroll parent and a scroll offset delegate is unsupported.
   DCHECK(!scroll_parent_);
   if (!scroll_offset_delegate && scroll_offset_delegate_) {
-    scroll_delta_ =
-        scroll_offset_delegate_->GetTotalScrollOffset() - scroll_offset_;
+    scroll_delta_ = scroll_offset_delegate_->GetTotalScrollOffset() -
+                    ToVector2dF(scroll_offset_);
   }
   gfx::Vector2dF total_offset = TotalScrollOffset();
   scroll_offset_delegate_ = scroll_offset_delegate;
   if (scroll_offset_delegate_)
     scroll_offset_delegate_->SetTotalScrollOffset(total_offset);
 }
 
 bool LayerImpl::IsExternalFlingActive() const {
   return scroll_offset_delegate_ &&
          scroll_offset_delegate_->IsExternalFlingActive();
 }
 
-void LayerImpl::SetScrollOffset(const gfx::Vector2d& scroll_offset) {
+void LayerImpl::SetScrollOffset(const gfx::ScrollOffset& scroll_offset) {
   SetScrollOffsetAndDelta(scroll_offset, ScrollDelta());
 }
 
-void LayerImpl::SetScrollOffsetAndDelta(const gfx::Vector2d& scroll_offset,
+void LayerImpl::SetScrollOffsetAndDelta(const gfx::ScrollOffset& scroll_offset,
                                         const gfx::Vector2dF& scroll_delta) {
   bool changed = false;
 
-  last_scroll_offset_ = scroll_offset;
+  last_scroll_offset_ = ToVector2dF(scroll_offset);
 
   if (scroll_offset_ != scroll_offset) {
     changed = true;
     scroll_offset_ = scroll_offset;
 
     if (scroll_offset_delegate_)
       scroll_offset_delegate_->SetTotalScrollOffset(TotalScrollOffset());
   }
 
   if (ScrollDelta() != scroll_delta) {
     changed = true;
     if (layer_tree_impl()->IsActiveTree()) {
       LayerImpl* pending_twin =
           layer_tree_impl()->FindPendingTreeLayerById(id());
       if (pending_twin) {
         // The pending twin can't mirror the scroll delta of the active
         // layer.  Although the delta - sent scroll delta difference is
         // identical for both twins, the sent scroll delta for the pending
         // layer is zero, as anything that has been sent has been baked
         // into the layer's position/scroll offset as a part of commit.
         DCHECK(pending_twin->sent_scroll_delta().IsZero());
-        pending_twin->SetScrollDelta(scroll_delta - sent_scroll_delta());
+        pending_twin->SetScrollDelta(scroll_delta -
+                                     ToVector2dF(sent_scroll_delta()));
       }
     }
 
     if (scroll_offset_delegate_) {
-      scroll_offset_delegate_->SetTotalScrollOffset(scroll_offset_ +
-                                                    scroll_delta);
+      scroll_offset_delegate_->SetTotalScrollOffset(
+          ToVector2dF(scroll_offset_) + scroll_delta);
     } else {
       scroll_delta_ = scroll_delta;
     }
   }
 
   if (changed) {
     NoteLayerPropertyChangedForSubtree();
     ScrollbarParametersDidChange();
   }
 }
 
 gfx::Vector2dF LayerImpl::ScrollDelta() const {
-  if (scroll_offset_delegate_)
-    return scroll_offset_delegate_->GetTotalScrollOffset() - scroll_offset_;
+  if (scroll_offset_delegate_) {
+    return scroll_offset_delegate_->GetTotalScrollOffset() -
+           ToVector2dF(scroll_offset_);
+  }
   return scroll_delta_;
 }
 
 void LayerImpl::SetScrollDelta(const gfx::Vector2dF& scroll_delta) {
   SetScrollOffsetAndDelta(scroll_offset_, scroll_delta);
 }
 
 gfx::Vector2dF LayerImpl::TotalScrollOffset() const {
-  return scroll_offset_ + ScrollDelta();
+  return ToVector2dF(scroll_offset_) + ScrollDelta();
 }
 
 void LayerImpl::SetDoubleSided(bool double_sided) {
   if (double_sided_ == double_sided)
     return;
 
   double_sided_ = double_sided;
   NoteLayerPropertyChangedForSubtree();
 }
 
@@ skipping 102 matching lines @@
     const gfx::Transform& layer_transform = current_layer->transform();
     if (current_layer == page_scale_layer) {
       DCHECK(layer_transform.IsIdentity());
       float scale_factor = layer_tree_impl()->total_page_scale_factor();
       current_offset.Scale(scale_factor);
       scroll_rect.Scale(scale_factor);
     } else {
       DCHECK(layer_transform.IsScale2d());
       gfx::Vector2dF layer_scale = layer_transform.Scale2d();
       DCHECK(layer_scale.x() == layer_scale.y());
-      gfx::Vector2dF new_offset =
-          current_layer->scroll_offset() + current_layer->ScrollDelta();
+      gfx::Vector2dF new_offset = ToVector2dF(current_layer->scroll_offset()) +
+                                  current_layer->ScrollDelta();
       new_offset.Scale(layer_scale.x(), layer_scale.y());
       current_offset += new_offset;
     }
   }
   // TODO(wjmaclean) Once we move to a model where the two-viewport model is
   // turned on in all builds, remove the next two lines. For now however, the
   // page scale layer may coincide with the clip layer, and so this is
   // necessary.
   if (page_scale_layer == scrollbar_clip_layer) {
     scroll_rect.Scale(layer_tree_impl()->total_page_scale_factor());
@@ skipping 273 matching lines @@
 }
 
 void LayerImpl::NotifyAnimationFinished(
     base::TimeTicks monotonic_time,
     Animation::TargetProperty target_property) {
   if (target_property == Animation::ScrollOffset)
     layer_tree_impl_->InputScrollAnimationFinished();
 }
 
 }  // namespace cc