Animate the OverviewButtonTray

ash/system/tray/tray_background_view.cc

 // Copyright (c) 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 "ash/system/tray/tray_background_view.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf_layout_manager.h"
@@ skipping 20 matching lines @@
 #include "ui/views/background.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace {
 
 const int kTrayBackgroundAlpha = 100;
 const int kTrayBackgroundHoverAlpha = 150;
 const SkColor kTrayBackgroundPressedColor = SkColorSetRGB(66, 129, 244);
 
 const int kAnimationDurationForPopupMS = 200;
+const int kAnimationDurationForVisibility = 200;
 
+// Animations can be disabled for tests.
+bool animations_enabled = true;

[flackr, 2014/04/29 14:18:22]

nit: newline before end of namespace.

[jonross, 2014/04/30 14:09:31]

Done.

 }  // namespace
 
 using views::TrayBubbleView;
 
 namespace ash {
 
 // static
 const char TrayBackgroundView::kViewClassName[] = "tray/TrayBackgroundView";
 
 // Used to track when the anchor widget changes position on screen so that the
@@ skipping 248 matching lines @@
 
   // Initially we want to paint the background, but without the hover effect.
   hide_background_animator_.SetPaintsBackground(
       true, BACKGROUND_CHANGE_IMMEDIATE);
   hover_background_animator_.SetPaintsBackground(
       false, BACKGROUND_CHANGE_IMMEDIATE);
 
   tray_container_ = new TrayContainer(shelf_alignment_);
   SetContents(tray_container_);
   tray_event_filter_.reset(new TrayEventFilter);
+
+  SetPaintToLayer(true);
+  SetFillsBoundsOpaquely(false);
 }
 
 TrayBackgroundView::~TrayBackgroundView() {
   if (GetWidget())
     GetWidget()->RemoveObserver(widget_observer_.get());
 }
 
 void TrayBackgroundView::Initialize() {
   GetWidget()->AddObserver(widget_observer_.get());
   SetTrayBorder();
 }
 
+void TrayBackgroundView::SetVisible(bool set_visible) {
+  if (!GetWidget() || !animations_enabled) {
+    views::View::SetVisible(set_visible);
+    return;
+  }
+
+  if (!animation_) {
+    animation_.reset(new gfx::SlideAnimation(this));
+    animation_->SetSlideDuration(kAnimationDurationForVisibility);
+    animation_->SetTweenType(gfx::Tween::LINEAR);
+    animation_->Reset(visible() ? 1.0 : 0.0);
+  }
+
+  if (!set_visible) {
+    animation_->Hide();
+    AnimationProgressed(animation_.get());

[flackr, 2014/04/29 14:18:22]

Isn't AnimationProgressed supposed to be called automatically from the
animation?

+  } else {
+    animation_->Show();
+    AnimationProgressed(animation_.get());
+    views::View::SetVisible(true);
+  }
+}
+
+gfx::Size TrayBackgroundView::GetPreferredSize() {
+  gfx::Size size = views::View::GetPreferredSize();
+  if (!animation_.get() || !animation_->is_animating())
+    return size;
+  if (shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM ||
+      shelf_alignment_ == SHELF_ALIGNMENT_TOP) {
+    size.set_width(std::max(1,
+        static_cast<int>(size.width() * animation_->GetCurrentValue())));
+  } else {
+    size.set_height(std::max(1,
+        static_cast<int>(size.height() * animation_->GetCurrentValue())));
+  }
+  return size;
+}
+
+int TrayBackgroundView::GetHeightForWidth(int width) {
+  return GetPreferredSize().height();
+}
+
 const char* TrayBackgroundView::GetClassName() const {
   return kViewClassName;
 }
 
 void TrayBackgroundView::OnMouseEntered(const ui::MouseEvent& event) {
   hovered_ = true;
 }
 
 void TrayBackgroundView::OnMouseExited(const ui::MouseEvent& event) {
   hovered_ = false;
@@ skipping 81 matching lines @@
     top_edge = 0;
     left_edge = ShelfLayoutManager::kShelfItemInset;
     bottom_edge = on_edge ? kPaddingFromEdgeOfShelf : 0;
     right_edge = kShelfSize -
         ShelfLayoutManager::kShelfItemInset - kShelfItemHeight;
   }
   SetBorder(views::Border::CreateEmptyBorder(
       top_edge, left_edge, bottom_edge, right_edge));
 }
 
+void TrayBackgroundView::DisableAnimationsForTest() {
+  animations_enabled = false;

[flackr, 2014/04/29 14:18:22]

I realize this pattern is copied from elsewhere, but long-term we should
probably have a single global for all animations similar to (or perhaps making
more generic) this:
https://code.google.com/p/chromium/codesearch#chromium/src/ui/compositor/scop....
Maybe a TODO? The idea being that this code wouldn't have to have a special case
for no animations, it would just be the case that gfx::Animations complete
instantly in tests unless otherwise requested.

+}
+
+void TrayBackgroundView::AnimationProgressed(const gfx::Animation* animation) {
+  gfx::Transform transform;
+  if (shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM ||
+      shelf_alignment_ == SHELF_ALIGNMENT_TOP) {
+    transform.Translate(0, animation->CurrentValueBetween(
+        static_cast<double>(height()) / 2, 0.));

[flackr, 2014/04/29 14:18:22]

nit: The static_cast is unnecessary for this sort of thing, the implicit cast
from height() * 0.5 is fine.

+  } else {
+    transform.Translate(animation->CurrentValueBetween(
+        static_cast<double>(width() / 2), 0.), 0);

[flackr, 2014/04/29 14:18:22]

ditto.

+  }
+  transform.Scale(animation->GetCurrentValue(),
+                  animation->GetCurrentValue());
+  layer()->SetTransform(transform);

[flackr, 2014/04/29 14:18:22]

The animation is done as a layer transform? Would it work to do all of the
animations as ScopedLayerAnimations? I.e. just use
https://code.google.com/p/chromium/codesearch#chromium/src/ui/compositor/scop....

+  PreferredSizeChanged();
+}
+
+void TrayBackgroundView::AnimationEnded(const gfx::Animation* animation) {
+  if (animation->GetCurrentValue() < 0.1)
+    views::View::SetVisible(false);
+}
+
+void TrayBackgroundView::AnimationCanceled(const gfx::Animation* animation) {
+  AnimationEnded(animation);

[flackr, 2014/04/29 14:18:22]

Isn't this not guaranteed to give the correct result since in AnimationEnded you
base whether or not to hide on the current value. Presumably a canceled
animation should immediately update to end state?

+}
+
 void TrayBackgroundView::InitializeBubbleAnimations(
     views::Widget* bubble_widget) {
   wm::SetWindowVisibilityAnimationType(
       bubble_widget->GetNativeWindow(),
       wm::WINDOW_VISIBILITY_ANIMATION_TYPE_FADE);
   wm::SetWindowVisibilityAnimationTransition(
       bubble_widget->GetNativeWindow(),
       wm::ANIMATE_HIDE);
   wm::SetWindowVisibilityAnimationDuration(
       bubble_widget->GetNativeWindow(),
@@ skipping 86 matching lines @@
     background_->set_alpha(kTrayBackgroundAlpha);
   SchedulePaint();
 }
 
 void TrayBackgroundView::UpdateBubbleViewArrow(
     views::TrayBubbleView* bubble_view) {
   // Nothing to do here.
 }
 
 }  // namespace ash