Normalize top controls offset to (0, 1), Chromium-side.

cc/trees/layer_tree_impl.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_impl.h"
 
+#include <algorithm>
 #include <limits>
 #include <set>
 
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/animation/scrollbar_animation_controller_linear_fade.h"
 #include "cc/animation/scrollbar_animation_controller_thinning.h"
 #include "cc/base/math_util.h"
@@ skipping 52 matching lines @@
  private:
   LayerImpl* layer_;
   LayerScrollOffsetDelegate* delegate_;
   LayerTreeImpl* layer_tree_impl_;
   gfx::ScrollOffset last_set_scroll_offset_;
 };
 
 LayerTreeImpl::LayerTreeImpl(
     LayerTreeHostImpl* layer_tree_host_impl,
     scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
+    scoped_refptr<SyncedTopControls> top_controls_shown_ratio,
     scoped_refptr<SyncedElasticOverscroll> elastic_overscroll)
     : layer_tree_host_impl_(layer_tree_host_impl),
       source_frame_number_(-1),
       hud_layer_(0),
       currently_scrolling_layer_(NULL),
       root_layer_scroll_offset_delegate_(NULL),
       background_color_(0),
       has_transparent_background_(false),
       overscroll_elasticity_layer_(NULL),
       page_scale_layer_(NULL),
       inner_viewport_scroll_layer_(NULL),
       outer_viewport_scroll_layer_(NULL),
       page_scale_factor_(page_scale_factor),
       min_page_scale_factor_(0),
       max_page_scale_factor_(0),
       elastic_overscroll_(elastic_overscroll),
       scrolling_layer_id_from_previous_tree_(0),
       contents_textures_purged_(false),
       viewport_size_invalid_(false),
       needs_update_draw_properties_(true),
       needs_full_tree_sync_(true),
       next_activation_forces_redraw_(false),
       has_ever_been_drawn_(false),
       render_surface_layer_list_id_(0),
       top_controls_shrink_blink_size_(false),
       top_controls_height_(0),
-      top_controls_content_offset_(0),
-      top_controls_delta_(0),
-      sent_top_controls_delta_(0) {
+      top_controls_shown_ratio_(top_controls_shown_ratio) {
 }
 
 LayerTreeImpl::~LayerTreeImpl() {
   BreakSwapPromises(SwapPromise::SWAP_FAILS);
 
   // Need to explicitly clear the tree prior to destroying this so that
   // the LayerTreeImpl pointer is still valid in the LayerImpl dtor.
   DCHECK(!root_layer_);
   DCHECK(layers_with_copy_output_request_.empty());
 }
@@ skipping 85 matching lines @@
   // The request queue should have been processed and does not require a push.
   DCHECK_EQ(ui_resource_request_queue_.size(), 0u);
 
   if (next_activation_forces_redraw_) {
     target_tree->ForceRedrawNextActivation();
     next_activation_forces_redraw_ = false;
   }
 
   target_tree->PassSwapPromises(&swap_promise_list_);
 
-  // Track the change in top controls height to offset the top_controls_delta
-  // properly.  This is so that the top controls offset will be maintained
-  // across height changes.
-  float top_controls_height_delta =
-      target_tree->top_controls_height_ - top_controls_height_;
-
-  target_tree->top_controls_shrink_blink_size_ =
-      top_controls_shrink_blink_size_;
-  target_tree->top_controls_height_ = top_controls_height_;
-  target_tree->top_controls_content_offset_ = top_controls_content_offset_;
-  target_tree->top_controls_delta_ = target_tree->top_controls_delta_ -
-                                     target_tree->sent_top_controls_delta_ -
-                                     top_controls_height_delta;
-  target_tree->sent_top_controls_delta_ = 0.f;
+  target_tree->set_top_controls_shrink_blink_size(
+      top_controls_shrink_blink_size_);
+  target_tree->set_top_controls_height(top_controls_height_);
+  target_tree->PushTopControls(nullptr);
 
   // Active tree already shares the page_scale_factor object with pending
   // tree so only the limits need to be provided.
   target_tree->PushPageScaleFactorAndLimits(nullptr, min_page_scale_factor(),
                                             max_page_scale_factor());
   target_tree->elastic_overscroll()->PushPendingToActive();
 
   target_tree->pending_page_scale_animation_ =
       pending_page_scale_animation_.Pass();
 
@@ skipping 120 matching lines @@
   }
   if (IsActiveTree())
     changed_page_scale |= page_scale_factor_->PushPendingToActive();
   changed_page_scale |=
       SetPageScaleFactorLimits(min_page_scale_factor, max_page_scale_factor);
 
   if (changed_page_scale)
     DidUpdatePageScale();
 }
 
+void LayerTreeImpl::set_top_controls_shrink_blink_size(bool shrink) {
+  if (top_controls_shrink_blink_size_ == shrink)
+    return;
+
+  top_controls_shrink_blink_size_ = shrink;
+  if (IsActiveTree())
+    layer_tree_host_impl_->UpdateViewportContainerSizes();
+}
+
+void LayerTreeImpl::set_top_controls_height(float top_controls_height) {
+  if (top_controls_height_ == top_controls_height)
+    return;
+
+  top_controls_height_ = top_controls_height;
+  if (IsActiveTree())
+    layer_tree_host_impl_->UpdateViewportContainerSizes();
+}
+
+bool LayerTreeImpl::SetCurrentTopControlsShownRatio(float ratio) {
+  ratio = std::max(ratio, 0.f);
+  ratio = std::min(ratio, 1.f);
+  return top_controls_shown_ratio_->SetCurrent(ratio);
+}
+
+void LayerTreeImpl::PushTopControlsFromMainThread(
+    float top_controls_shown_ratio) {
+  PushTopControls(&top_controls_shown_ratio);
+}
+
+void LayerTreeImpl::PushTopControls(const float* top_controls_shown_ratio) {
+  DCHECK(top_controls_shown_ratio || IsActiveTree());
+
+  if (top_controls_shown_ratio) {
+    DCHECK(!IsActiveTree() || !layer_tree_host_impl_->pending_tree());
+    top_controls_shown_ratio_->PushFromMainThread(*top_controls_shown_ratio);
+  }
+  if (IsActiveTree()) {
+    if (top_controls_shown_ratio_->PushPendingToActive())
+      layer_tree_host_impl_->DidChangeTopControlsPosition();
+  }
+}
+
 bool LayerTreeImpl::SetPageScaleFactorLimits(float min_page_scale_factor,
                                              float max_page_scale_factor) {
   if (min_page_scale_factor == min_page_scale_factor_ &&
       max_page_scale_factor == max_page_scale_factor_)
     return false;
 
   min_page_scale_factor_ = min_page_scale_factor;
   max_page_scale_factor_ = max_page_scale_factor;
 
   return true;
@@ skipping 67 matching lines @@
 }
 
 static void ApplySentScrollDeltasFromAbortedCommitTo(LayerImpl* layer) {
   layer->ApplySentScrollDeltasFromAbortedCommit();
 }
 
 void LayerTreeImpl::ApplySentScrollAndScaleDeltasFromAbortedCommit() {
   DCHECK(IsActiveTree());
 
   page_scale_factor()->AbortCommit();
+  top_controls_shown_ratio()->AbortCommit();
   elastic_overscroll()->AbortCommit();
 
-  top_controls_content_offset_ += sent_top_controls_delta_;
-  top_controls_delta_ -= sent_top_controls_delta_;
-  sent_top_controls_delta_ = 0.f;
-
   if (!root_layer())
     return;
 
   LayerTreeHostCommon::CallFunctionForSubtree(
       root_layer(), base::Bind(&ApplySentScrollDeltasFromAbortedCommitTo));
 }
 
 void LayerTreeImpl::SetViewportLayersFromIds(
     int overscroll_elasticity_layer_id,
     int page_scale_layer_id,
@@ skipping 1086 matching lines @@
     scoped_ptr<PendingPageScaleAnimation> pending_animation) {
   pending_page_scale_animation_ = pending_animation.Pass();
 }
 
 scoped_ptr<PendingPageScaleAnimation>
     LayerTreeImpl::TakePendingPageScaleAnimation() {
   return pending_page_scale_animation_.Pass();
 }
 
 }  // namespace cc