Tweaks workspace animation code per latest from Nicholas. Additionally

ash/wm/workspace/workspace_animations.cc

Index: ash/wm/workspace/workspace_animations.cc
diff --git a/ash/wm/workspace/workspace_animations.cc b/ash/wm/workspace/workspace_animations.cc
new file mode 100644
index 0000000000000000000000000000000000000000..745adf8f35bb394805125bf899784eb80fd998e2
--- /dev/null
+++ b/ash/wm/workspace/workspace_animations.cc
@@ -0,0 +1,161 @@
+// 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/wm/workspace/workspace_animations.h"
+
+#include "ash/ash_switches.h"
+#include "base/command_line.h"
+#include "ui/aura/window.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+
+namespace ash {
+namespace internal {
+
+const int kWorkspaceSwitchTimeMS = 200;
+
+namespace {
+
+// Tween type used when showing/hiding workspaces.
+const ui::Tween::Type kWorkspaceTweenType = ui::Tween::EASE_OUT;
+
+// Scales for workspaces above/below current workspace.
+const float kWorkspaceScaleAbove = 1.1f;
+const float kWorkspaceScaleBelow = .9f;
+
+enum WorkspaceScaleType {
+  WORKSPACE_SCALE_ABOVE,
+  WORKSPACE_SCALE_BELOW,
+};
+
+// Applies the specified WorkspaceScaleType.
+void ApplyWorkspaceScale(ui::Layer* layer, WorkspaceScaleType type) {
+  const float scale = type == WORKSPACE_SCALE_ABOVE ? kWorkspaceScaleAbove :
+      kWorkspaceScaleBelow;
+  ui::Transform transform;
+  transform.ConcatScale(scale, scale);
+  transform.ConcatTranslate(
+      -layer->bounds().width() * (scale - 1.0f) / 2,
+      -layer->bounds().height() * (scale - 1.0f) / 2);
+  layer->SetTransform(transform);
+}
+
+// If |details.duration| is not-empty it is returned, otherwise
+// |kWorkspaceSwitchTimeMS| is returned.
+base::TimeDelta DurationForWorkspaceShowOrHide(
+    const WorkspaceAnimationDetails& details) {
+  return details.duration == base::TimeDelta() ?
+      base::TimeDelta::FromMilliseconds(kWorkspaceSwitchTimeMS) :
+      details.duration;
+}
+
+}  // namespace
+
+WorkspaceAnimationDetails::WorkspaceAnimationDetails()
+    : direction(WORKSPACE_ANIMATE_UP),
+      animate(false),
+      animate_opacity(false),
+      animate_scale(false),
+      pause_time_ms(0) {
+}
+
+WorkspaceAnimationDetails::~WorkspaceAnimationDetails() {
+}
+
+void ShowWorkspace(aura::Window* window,
+                   const WorkspaceAnimationDetails& details) {
+  window->Show();
+
+  if (!details.animate || CommandLine::ForCurrentProcess()->HasSwitch(
+          ash::switches::kAshWindowAnimationsDisabled)) {
+    window->layer()->SetOpacity(1.0f);
+    window->layer()->SetTransform(ui::Transform());
+    return;
+  }
+
+  window->layer()->SetOpacity(details.animate_opacity ? 0.0f : 1.0f);
+  if (details.animate_scale) {
+    ApplyWorkspaceScale(window->layer(),
+                        details.direction == WORKSPACE_ANIMATE_UP ?
+                            WORKSPACE_SCALE_BELOW : WORKSPACE_SCALE_ABOVE);
+  } else {
+    window->layer()->SetTransform(ui::Transform());
+  }
+
+  // In order for pause to work we need to stop animations.
+  window->layer()->GetAnimator()->StopAnimating();
+
+  {
+    ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
+
+    if (details.pause_time_ms > 0) {
+      settings.SetPreemptionStrategy(ui::LayerAnimator::ENQUEUE_NEW_ANIMATION);
+      window->layer()->GetAnimator()->SchedulePauseForProperties(
+          base::TimeDelta::FromMilliseconds(details.pause_time_ms),
+          ui::LayerAnimationElement::TRANSFORM,
+          ui::LayerAnimationElement::OPACITY,
+          ui::LayerAnimationElement::BRIGHTNESS,
+          ui::LayerAnimationElement::VISIBILITY,
+          -1);
+    }
+
+    settings.SetTweenType(kWorkspaceTweenType);
+    settings.SetTransitionDuration(DurationForWorkspaceShowOrHide(details));
+    window->layer()->SetTransform(ui::Transform());
+    window->layer()->SetOpacity(1.0f);
+  }
+}
+
+void HideWorkspace(aura::Window* window,
+                   const WorkspaceAnimationDetails& details) {
+  window->layer()->SetTransform(ui::Transform());
+  window->layer()->SetOpacity(1.0f);
+  window->layer()->GetAnimator()->StopAnimating();
+
+  if (!details.animate || CommandLine::ForCurrentProcess()->HasSwitch(
+          ash::switches::kAshWindowAnimationsDisabled)) {
+    window->Hide();
+    return;
+  }
+
+  ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
+  if (details.pause_time_ms > 0) {
+    settings.SetPreemptionStrategy(ui::LayerAnimator::ENQUEUE_NEW_ANIMATION);
+    window->layer()->GetAnimator()->SchedulePauseForProperties(
+        base::TimeDelta::FromMilliseconds(details.pause_time_ms),
+        ui::LayerAnimationElement::TRANSFORM,
+        ui::LayerAnimationElement::OPACITY,
+        ui::LayerAnimationElement::BRIGHTNESS,
+        ui::LayerAnimationElement::VISIBILITY,
+        -1);
+  }
+
+  settings.SetTransitionDuration(DurationForWorkspaceShowOrHide(details));
+  settings.SetTweenType(kWorkspaceTweenType);
+  if (details.animate_scale) {
+    ApplyWorkspaceScale(window->layer(),
+                        details.direction == WORKSPACE_ANIMATE_UP ?
+                            WORKSPACE_SCALE_ABOVE : WORKSPACE_SCALE_BELOW);
+  } else {
+    window->layer()->SetTransform(ui::Transform());
+  }
+
+  // NOTE: Hide() must be before SetOpacity(), else
+  // VisibilityController::UpdateLayerVisibility doesn't pass the false to the
+  // layer so that the layer and window end up out of sync and confused.
+  window->Hide();
+
+  if (details.animate_opacity)
+    window->layer()->SetOpacity(0.0f);
+
+  // After the animation completes snap the transform back to the identity,
+  // otherwise any one that asks for screen bounds gets a slightly scaled
+  // version.
+  settings.SetPreemptionStrategy(ui::LayerAnimator::ENQUEUE_NEW_ANIMATION);
+  settings.SetTransitionDuration(base::TimeDelta());
+  window->layer()->SetTransform(ui::Transform());
+}
+
+}  // namespace internal
+}  // namespace ash