Virtual Desks 5: Implement desk switch animations.

When a desk is activated, this CL adds a horizontal
movement from the starting (current) desk to the
ending (to be activated) desk on all displays, since
a desk spans all displays.

Demos: https://bugs.chromium.org/p/chromium/issues/detail?id=866622#c24

BUG=866622
TEST=Manual, added tests to increase code coverage in
     the case of multi displays.

Change-Id: I901b000a6ff89173d70e3ab07cbb7656c34d8357
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1591000
Commit-Queue: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657376}

ash/BUILD.gn

@@ -1084,6 +1084,8 @@ component("ash") {
     "wm/desks/desks_util.h",
     "wm/desks/new_desk_button.cc",
     "wm/desks/new_desk_button.h",
+    "wm/desks/root_window_desk_switch_animator.cc",
+    "wm/desks/root_window_desk_switch_animator.h",
     "wm/drag_details.cc",
     "wm/drag_details.h",
     "wm/drag_window_controller.cc",

ash/wm/desks/desks_bar_view.cc

@@ -152,7 +152,6 @@ void DesksBarView::ButtonPressed(views::Button* sender,
   for (auto& mini_view : mini_views_) {
     if (mini_view.get() == sender) {
       controller->ActivateDesk(mini_view->desk());
-      Shell::Get()->overview_controller()->OnSelectionEnded();
       return;
     }
   }
@@ -205,6 +204,8 @@ void DesksBarView::OnDeskActivationChanged(const Desk* activated,
   }
 }
 
+void DesksBarView::OnDeskSwitchAnimationFinished() {}
+
 void DesksBarView::UpdateNewDeskButtonState() {
   new_desk_button_->SetEnabled(DesksController::Get()->CanCreateDesks());
 }

ash/wm/desks/desks_bar_view.h

@@ -63,6 +63,7 @@ class ASH_EXPORT DesksBarView : public views::View,
   void OnDeskRemoved(const Desk* desk) override;
   void OnDeskActivationChanged(const Desk* activated,
                                const Desk* deactivated) override;
+  void OnDeskSwitchAnimationFinished() override;
 
  private:
   // This is called on initialization or when a new desk is created to create

ash/wm/desks/desks_controller.cc

@@ -10,11 +10,14 @@
 #include "ash/shell.h"
 #include "ash/wm/desks/desk.h"
 #include "ash/wm/desks/desks_util.h"
+#include "ash/wm/desks/root_window_desk_switch_animator.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/overview/overview_controller.h"
 #include "ash/wm/window_util.h"
 #include "base/auto_reset.h"
 #include "base/logging.h"
+#include "ui/aura/window_tree_host.h"
+#include "ui/compositor/compositor.h"
 
 namespace ash {
 
@@ -79,6 +82,10 @@ void DesksController::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
+bool DesksController::AreDesksBeingModified() const {
+  return are_desks_being_modified_ || !desk_switch_animators_.empty();
+}
+
 bool DesksController::CanCreateDesks() const {
   // TODO(afakhry): Disable creating new desks in tablet mode.
   return desks_.size() < desks_util::kMaxNumberOfDesks;
@@ -176,7 +183,27 @@ void DesksController::RemoveDesk(const Desk* desk) {
 }
 
 void DesksController::ActivateDesk(const Desk* desk) {
-  ActivateDeskInternal(desk, /*update_window_activation=*/true);
+  DCHECK(HasDesk(desk));
+
+  if (desk == active_desk_)
+    return;
+
+  // New desks are always added at the end of the list to the right of existing
+  // desks. Therefore, desks at lower indices are located on the left of desks
+  // with higher indices.
+  const bool move_left = GetDeskIndex(active_desk_) < GetDeskIndex(desk);
+  for (auto* root : Shell::GetAllRootWindows()) {
+    desk_switch_animators_.emplace_back(
+        std::make_unique<RootWindowDeskSwitchAnimator>(root, desk, this,
+                                                       move_left));
+  }
+
+  // Once all animators are created, start them all by taking the starting desk
+  // screenshots. This is to avoid any potential race conditions that might
+  // happen if one animator finished phase (1) of the animation while other
+  // animators are still being constructed.
+  for (auto& animator : desk_switch_animators_)
+    animator->TakeStartingDeskScreenshot();
 }
 
 void DesksController::OnRootWindowAdded(aura::Window* root_window) {
@@ -189,6 +216,76 @@ void DesksController::OnRootWindowClosing(aura::Window* root_window) {
     desk->OnRootWindowClosing(root_window);
 }
 
+void DesksController::OnStartingDeskScreenshotTaken(const Desk* ending_desk) {
+  DCHECK(!desk_switch_animators_.empty());
+
+  // Once all starting desk screenshots on all roots are taken and placed on the
+  // screens, do the actual desk activation logic.
+  for (const auto& animator : desk_switch_animators_) {
+    if (!animator->starting_desk_screenshot_taken())
+      return;
+  }
+
+  // Extend the compositors' timeouts in order to prevents any repaints until
+  // the desks are switched and overview mode exits.
+  const auto roots = Shell::GetAllRootWindows();
+  for (auto* root : roots)
+    root->GetHost()->compositor()->SetAllowLocksToExtendTimeout(true);
+
+  const bool is_selecting = Shell::Get()->overview_controller()->IsSelecting();
+
+  ActivateDeskInternal(ending_desk, /*update_window_activation=*/true);
+
+  // Activating a desk should not change the overview mode state.
+  DCHECK_EQ(is_selecting, Shell::Get()->overview_controller()->IsSelecting());
+
+  if (is_selecting) {
+    // Exit overview mode immediately without any animations before taking the
+    // ending desk screenshot. This makes sure that the ending desk
+    // screenshot will only show the windows in that desk, not overview stuff.
+    Shell::Get()->overview_controller()->ToggleOverview(
+        OverviewSession::EnterExitOverviewType::kImmediateExit);
+  }
+
+  for (auto* root : roots)
+    root->GetHost()->compositor()->SetAllowLocksToExtendTimeout(false);
+
+  // Continue the second phase of the animation by taking the ending desk
+  // screenshot and actually animating the layers.
+  for (auto& animator : desk_switch_animators_)
+    animator->TakeEndingDeskScreenshot();
+}
+
+void DesksController::OnEndingDeskScreenshotTaken() {
+  DCHECK(!desk_switch_animators_.empty());
+
+  // Once all ending desk screenshots on all roots are taken, start the
+  // animation on all roots at the same time, so that they look synchrnoized.
+  for (const auto& animator : desk_switch_animators_) {
+    if (!animator->ending_desk_screenshot_taken())
+      return;
+  }
+
+  for (auto& animator : desk_switch_animators_)
+    animator->StartAnimation();
+}
+
+void DesksController::OnDeskSwitchAnimationFinished() {
+  DCHECK(!desk_switch_animators_.empty());
+
+  // Once all desk switch animations on all roots finish, destroy all the
+  // animators.
+  for (const auto& animator : desk_switch_animators_) {
+    if (!animator->animation_finished())
+      return;
+  }
+
+  desk_switch_animators_.clear();
+
+  for (auto& observer : observers_)
+    observer.OnDeskSwitchAnimationFinished();
+}
+
 bool DesksController::HasDesk(const Desk* desk) const {
   auto iter = std::find_if(
       desks_.begin(), desks_.end(),
@@ -196,6 +293,16 @@ bool DesksController::HasDesk(const Desk* desk) const {
   return iter != desks_.end();
 }
 
+int DesksController::GetDeskIndex(const Desk* desk) const {
+  for (size_t i = 0; i < desks_.size(); ++i) {
+    if (desk == desks_[i].get())
+      return i;
+  }
+
+  NOTREACHED();
+  return -1;
+}
+
 void DesksController::ActivateDeskInternal(const Desk* desk,
                                            bool update_window_activation) {
   DCHECK(HasDesk(desk));
@@ -218,8 +325,6 @@ void DesksController::ActivateDeskInternal(const Desk* desk,
 
   for (auto& observer : observers_)
     observer.OnDeskActivationChanged(active_desk_, old_active);
-
-  // TODO(afakhry): Do desk activation animation.
 }
 
 }  // namespace ash

ash/wm/desks/desks_controller.h

@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "ash/ash_export.h"
+#include "ash/wm/desks/root_window_desk_switch_animator.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 
@@ -23,7 +24,8 @@ class Desk;
 
 // Defines a controller for creating, destroying and managing virtual desks and
 // their windows.
-class ASH_EXPORT DesksController {
+class ASH_EXPORT DesksController
+    : public RootWindowDeskSwitchAnimator::Delegate {
  public:
   class Observer {
    public:
@@ -41,12 +43,15 @@ class ASH_EXPORT DesksController {
     virtual void OnDeskActivationChanged(const Desk* activated,
                                          const Desk* deactivated) = 0;
 
+    // Called when the desk switch animations on all root windows finish.
+    virtual void OnDeskSwitchAnimationFinished() = 0;
+
    protected:
     virtual ~Observer() = default;
   };
 
   DesksController();
-  ~DesksController();
+  ~DesksController() override;
 
   // Convenience method for returning the DesksController instance. The actual
   // instance is created and owned by Shell.
@@ -56,11 +61,14 @@ class ASH_EXPORT DesksController {
 
   const Desk* active_desk() const { return active_desk_; }
 
-  bool are_desks_being_modified() const { return are_desks_being_modified_; }
-
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
+  // Returns true if desks are being modified due to desk creation, removal, or
+  // activation. It also returns true while the desk switch animation is in
+  // progress.
+  bool AreDesksBeingModified() const;
+
   // Returns true if we haven't reached the maximum allowed number of desks.
   bool CanCreateDesks() const;
 
@@ -75,10 +83,11 @@ class ASH_EXPORT DesksController {
   // CanRemoveDesks() must be checked before this.
   void RemoveDesk(const Desk* desk);
 
-  // Activates the given |desk| and deactivates the currently active one. |desk|
-  // has to be an existing desk. The active window on the currently active desk
-  // will be deactivated, and the most-recently used window from the
-  // newly-activated desk will be activated.
+  // Performs the desk switch animation on all root windows to activate the
+  // given |desk| and to deactivate the currently active one. |desk| has to be
+  // an existing desk. The active window on the currently active desk will be
+  // deactivated, and the most-recently used window from the newly-activated
+  // desk will be activated.
   void ActivateDesk(const Desk* desk);
 
   // Called explicitly by the RootWindowController when a root window has been
@@ -86,9 +95,16 @@ class ASH_EXPORT DesksController {
   void OnRootWindowAdded(aura::Window* root_window);
   void OnRootWindowClosing(aura::Window* root_window);
 
+  // RootWindowDeskSwitchAnimator::Delegate:
+  void OnStartingDeskScreenshotTaken(const Desk* ending_desk) override;
+  void OnEndingDeskScreenshotTaken() override;
+  void OnDeskSwitchAnimationFinished() override;
+
  private:
   bool HasDesk(const Desk* desk) const;
 
+  int GetDeskIndex(const Desk* desk) const;
+
   // Activates the given |desk| and deactivates the currently active one. |desk|
   // has to be an existing desk. If |update_window_activation| is true,
   // the active desk on the deactivated desk will be deactivated, and the most-
@@ -109,6 +125,11 @@ class ASH_EXPORT DesksController {
   // mode as a result of desks modifications.
   bool are_desks_being_modified_ = false;
 
+  // An animator object per each root. Once all the animations are complete,
+  // this list is cleared.
+  std::vector<std::unique_ptr<RootWindowDeskSwitchAnimator>>
+      desk_switch_animators_;
+
   // A free list of desk container IDs to be used for newly-created desks. New
   // desks pops from this queue and removed desks's associated container IDs are
   // re-pushed on this queue.

ash/wm/overview/overview_session.cc

@@ -304,7 +304,8 @@ void OverviewSession::Shutdown() {
   for (std::unique_ptr<OverviewGrid>& overview_grid : grid_list_) {
     // During shutdown, do not animate all windows in overview if we need to
     // animate the snapped window.
-    if (overview_grid->should_animate_when_exiting()) {
+    if (overview_grid->should_animate_when_exiting() &&
+        enter_exit_overview_type_ != EnterExitOverviewType::kImmediateExit) {
       overview_grid->CalculateWindowListAnimationStates(
           selected_item_ &&
                   selected_item_->overview_grid() == overview_grid.get()
@@ -704,7 +705,7 @@ void OverviewSession::OnWindowActivating(
     return;
 
   if (features::IsVirtualDesksEnabled() &&
-      DesksController::Get()->are_desks_being_modified()) {
+      DesksController::Get()->AreDesksBeingModified()) {
     // Activating a desk from its mini view will activate its most-recently used
     // window, but this should not result in ending overview mode now.
     // DesksBarView will end it explicitly. This will become significant when
@@ -807,7 +808,7 @@ void OverviewSession::OnWindowHierarchyChanged(
   // of that desk to the associated container of another desk. This is a window
   // hierarchy change that shouldn't result in exiting overview mode.
   if (features::IsVirtualDesksEnabled() &&
-      DesksController::Get()->are_desks_being_modified()) {
+      DesksController::Get()->AreDesksBeingModified()) {
     return;
   }
 

ash/wm/overview/overview_utils.cc

@@ -22,6 +22,7 @@
 #include "ash/wm/window_transient_descendant_iterator.h"
 #include "ash/wm/wm_event.h"
 #include "base/no_destructor.h"
+#include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/scoped_canvas.h"
@@ -120,7 +121,8 @@ void FadeOutWidgetAndMaybeSlideOnExit(std::unique_ptr<views::Widget> widget,
 }
 
 void ImmediatelyCloseWidgetOnExit(std::unique_ptr<views::Widget> widget) {
-  ScopedAnimationDisabler animation_disabler(widget->GetNativeWindow());
+  widget->GetNativeWindow()->SetProperty(aura::client::kAnimationsDisabledKey,
+                                         true);
   widget->Close();
   widget.reset();
 }