Fix animation issue when activating second app window from shelf

Changes:
When an active window exists, clicking on shelf item to activate another
window should not run slide down animation.

Bug: 896908
Change-Id: Ifd037b139da44bac3d05c3c88dd5c7f044f7d898
Reviewed-on: https://chromium-review.googlesource.com/c/1292050
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601287}

ash/app_list/home_launcher_gesture_handler.cc

@@ -593,12 +593,21 @@ bool HomeLauncherGestureHandler::SetUpWindows(Mode mode, aura::Window* window) {
   const bool overview_active =
       Shell::Get()->window_selector_controller()->IsSelecting();
   const bool split_view_active = split_view_controller->IsSplitViewModeActive();
+  auto windows = Shell::Get()->mru_window_tracker()->BuildWindowForCycleList();
   if (window && (mode != Mode::kSlideDownToHide || overview_active ||
                  split_view_active)) {
     window_ = nullptr;
     return false;
   }
 
+  if (window && !windows.empty() && windows[0] != window &&
+      windows[0]->IsVisible()) {
+    // Do not run slide down animation for the |window| if another active window
+    // in mru list exists.
+    window_ = nullptr;
+    return false;
+  }
+
   if (Shell::Get()
           ->app_list_controller()
           ->IsHomeLauncherEnabledInTabletMode() &&
@@ -611,7 +620,6 @@ bool HomeLauncherGestureHandler::SetUpWindows(Mode mode, aura::Window* window) {
   // Always hide split view windows if they exist. Otherwise, hide the specified
   // window if it is not null. If non of above is true, we want the first window
   // in the mru list, if it exists and is usable.
-  auto windows = Shell::Get()->mru_window_tracker()->BuildWindowForCycleList();
   window_ = split_view_active
                 ? split_view_controller->GetDefaultSnappedWindow()
                 : (window ? window : (windows.empty() ? nullptr : windows[0]));

ash/wm/window_animations.cc

@@ -231,7 +231,7 @@ void AnimateHideWindow_BrightnessGrayscale(aura::Window* window) {
   AnimateShowHideWindowCommon_BrightnessGrayscale(window, false);
 }
 
-void AnimateShowWindow_SlideDown(aura::Window* window) {
+bool AnimateShowWindow_SlideDown(aura::Window* window) {
   AppListControllerImpl* app_list_controller =
       Shell::Get()->app_list_controller();
 
@@ -249,18 +249,18 @@ void AnimateShowWindow_SlideDown(aura::Window* window) {
       // style to default so that normal animation applies.
       ::wm::SetWindowVisibilityAnimationType(
           window, ::wm::WINDOW_VISIBILITY_ANIMATION_TYPE_DEFAULT);
-      return;
+      return true;
     }
   }
 
-  // Fallback to use minimize animation.
-  AnimateShowWindow_Minimize(window);
+  // Fallback to no animation.
+  return false;
 }
 
-void AnimateHideWindow_SlideDown(aura::Window* window) {
+bool AnimateHideWindow_SlideDown(aura::Window* window) {
   // The hide animation should be handled in HomeLauncherGestureHandler, so
-  // fallback to use minimize animation here.
-  AnimateHideWindow_Minimize(window);
+  // fallback to no animation.
+  return false;
 }
 
 bool AnimateShowWindow(aura::Window* window) {
@@ -277,8 +277,7 @@ bool AnimateShowWindow(aura::Window* window) {
       AnimateShowWindow_BrightnessGrayscale(window);
       return true;
     case wm::WINDOW_VISIBILITY_ANIMATION_TYPE_SLIDE_DOWN:
-      AnimateShowWindow_SlideDown(window);
-      return true;
+      return AnimateShowWindow_SlideDown(window);
     default:
       NOTREACHED();
       return false;
@@ -299,8 +298,7 @@ bool AnimateHideWindow(aura::Window* window) {
       AnimateHideWindow_BrightnessGrayscale(window);
       return true;
     case wm::WINDOW_VISIBILITY_ANIMATION_TYPE_SLIDE_DOWN:
-      AnimateHideWindow_SlideDown(window);
-      return true;
+      return AnimateHideWindow_SlideDown(window);
     default:
       NOTREACHED();
       return false;