[ash-md] Hides frame headers in overview mode not using a mask

ash/common/wm/overview/scoped_transform_overview_window.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 "ash/common/wm/overview/scoped_transform_overview_window.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/common/material_design/material_design_controller.h"
@@ skipping 162 matching lines @@
       TransientDescendantIterator(GetTransientRoot(window)));
 }
 
 }  // namespace
 
 // Mask layer that clips the window's original header in overview mode.
 // Only used with Material Design.
 class ScopedTransformOverviewWindow::OverviewContentMask
     : public ui::LayerDelegate {
  public:
-  OverviewContentMask(int inset, int radius);
+  explicit OverviewContentMask(float radius);
   ~OverviewContentMask() override;
 
   ui::Layer* layer() { return &layer_; }
 
   // Overridden from LayerDelegate.
   void OnPaintLayer(const ui::PaintContext& context) override;
   void OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) override {}
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   base::Closure PrepareForLayerBoundsChange() override;
 
  private:
   ui::Layer layer_;
-  int inset_;
-  int radius_;
+  float radius_;
 
   DISALLOW_COPY_AND_ASSIGN(OverviewContentMask);
 };
 
 ScopedTransformOverviewWindow::OverviewContentMask::OverviewContentMask(
-    int inset,
-    int radius)
-    : layer_(ui::LAYER_TEXTURED), inset_(inset), radius_(radius) {
+    float radius)
+    : layer_(ui::LAYER_TEXTURED), radius_(radius) {
   layer_.set_delegate(this);
 }
 
 ScopedTransformOverviewWindow::OverviewContentMask::~OverviewContentMask() {
   layer_.set_delegate(nullptr);
 }
 
 void ScopedTransformOverviewWindow::OverviewContentMask::OnPaintLayer(
     const ui::PaintContext& context) {
   ui::PaintRecorder recorder(context, layer()->size());
   gfx::Rect bounds(layer()->bounds().size());
-  bounds.Inset(0, inset_, 0, 0);
 
   // Tile a window into an area, rounding the bottom corners.
   const SkRect rect = gfx::RectToSkRect(bounds);
   const SkScalar corner_radius_scalar = SkIntToScalar(radius_);
   SkScalar radii[8] = {0,
                        0,  // top-left
                        0,
                        0,  // top-right
                        corner_radius_scalar,
                        corner_radius_scalar,  // bottom-right
@@ skipping 25 matching lines @@
       minimized_(window->GetShowState() == ui::SHOW_STATE_MINIMIZED),
       ignored_by_shelf_(window->GetWindowState()->ignored_by_shelf()),
       overview_started_(false),
       original_transform_(window->GetTargetTransform()),
       original_opacity_(window->GetTargetOpacity()),
       weak_ptr_factory_(this) {}
 
 ScopedTransformOverviewWindow::~ScopedTransformOverviewWindow() {}
 
 void ScopedTransformOverviewWindow::RestoreWindow() {
-  if (ash::MaterialDesignController::IsOverviewMaterial()) {
-    window()->GetLayer()->SetMaskLayer(nullptr);
-    mask_.reset();
-  }
-
   ScopedAnimationSettings animation_settings_list;
   BeginScopedAnimation(OverviewAnimationType::OVERVIEW_ANIMATION_RESTORE_WINDOW,
                        &animation_settings_list);
   SetTransform(window()->GetRootWindow(), original_transform_, 0);
 
   std::unique_ptr<ScopedOverviewAnimationSettings> animation_settings =
       CreateScopedOverviewAnimationSettings(
           OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS,
           window_);
   gfx::Transform transform;
   if (minimized_ && window_->GetShowState() != ui::SHOW_STATE_MINIMIZED) {
     // Setting opacity 0 and visible false ensures that the property change
     // to SHOW_STATE_MINIMIZED will not animate the window from its original
     // bounds to the minimized position.
     // Hiding the window needs to be done before the target opacity is 0,
     // otherwise the layer's visibility will not be updated
     // (See VisibilityController::UpdateLayerVisibility).
     window_->Hide();
     window_->SetOpacity(0);
     window_->SetShowState(ui::SHOW_STATE_MINIMIZED);
   }
   window_->GetWindowState()->set_ignored_by_shelf(ignored_by_shelf_);
   SetOpacity(original_opacity_);
+
+  if (ash::MaterialDesignController::IsOverviewMaterial()) {
+    ui::Layer* layer = window()->GetLayer();
+    layer->SetMaskLayer(nullptr);
+    mask_.reset();
+
+    if (original_window_shape_) {
+      layer->SetAlphaShape(
+          base::WrapUnique(new SkRegion(*original_window_shape_.get())));
+    } else {
+      layer->SetAlphaShape(nullptr);
+    }
+    window()->SetMasksToBounds(false);
+  }
 }
 
 void ScopedTransformOverviewWindow::BeginScopedAnimation(
     OverviewAnimationType animation_type,
     ScopedAnimationSettings* animation_settings) {
   for (auto* window : GetTransientTreeIterator(window_)) {
     animation_settings->push_back(
         CreateScopedOverviewAnimationSettings(animation_type, window));
   }
 }
@@ skipping 86 matching lines @@
   gfx::Transform transform;
   transform.Translate(dst_rect.x() - src_rect.x(), dst_rect.y() - src_rect.y());
   transform.Scale(static_cast<float>(dst_rect.width()) / src_rect.width(),
                   static_cast<float>(dst_rect.height()) / src_rect.height());
   return transform;
 }
 
 void ScopedTransformOverviewWindow::SetTransform(
     WmWindow* root_window,
     const gfx::Transform& transform,
-    int radius) {
+    float radius) {
   DCHECK(overview_started_);
 
-  if (ash::MaterialDesignController::IsOverviewMaterial() && !mask_) {
-    mask_.reset(new OverviewContentMask(
-        window()->GetIntProperty(WmWindowProperty::TOP_VIEW_INSET), radius));
-    mask_->layer()->SetBounds(GetTargetBoundsInScreen());
+  if (ash::MaterialDesignController::IsOverviewMaterial() &&
+      &transform != &original_transform_) {
+    gfx::Rect bounds(GetTargetBoundsInScreen().size());
+    mask_.reset(new OverviewContentMask(radius));
+    mask_->layer()->SetFillsBoundsOpaquely(false);
+    mask_->layer()->SetBounds(bounds);
     window()->GetLayer()->SetMaskLayer(mask_->layer());
+
+    SkRegion* window_shape = window()->GetLayer()->alpha_shape();
+    if (!original_window_shape_ && window_shape)
+      original_window_shape_.reset(new SkRegion(*window_shape));
+    const int inset =
+        window()->GetIntProperty(WmWindowProperty::TOP_VIEW_INSET);
+    if (inset > 0) {
+      bounds.Inset(0, inset, 0, 0);
+      SkRegion* region = new SkRegion;
+      region->setRect(RectToSkIRect(bounds));
+      if (original_window_shape_)
+        region->op(*original_window_shape_, SkRegion::kIntersect_Op);
+      window()->GetLayer()->SetAlphaShape(base::WrapUnique(region));
+      window()->SetMasksToBounds(true);
+    }
   }
 
   gfx::Point target_origin(GetTargetBoundsInScreen().origin());
 
   for (auto* window : GetTransientTreeIterator(window_)) {
     WmWindow* parent_window = window->GetParent();
     gfx::Point original_origin =
         parent_window->ConvertRectToScreen(window->GetTargetBounds()).origin();
     gfx::Transform new_transform =
         TransformAboutPivot(gfx::Point(target_origin.x() - original_origin.x(),
@@ skipping 33 matching lines @@
   if (parent_window)
     parent_window->CloseWidget();
 }
 
 // static
 void ScopedTransformOverviewWindow::SetImmediateCloseForTests() {
   immediate_close_for_tests = true;
 }
 
 }  // namespace ash