ash: Improved window maximize/restore animations

ash/wm/base_layout_manager.cc

Index: ash/wm/base_layout_manager.cc
diff --git a/ash/wm/base_layout_manager.cc b/ash/wm/base_layout_manager.cc
index 4f27115e81e160c7d72b3e301e51e1f00858583a..1cabafa7c2241a25863cd81037c038f0596ec11b 100644
--- a/ash/wm/base_layout_manager.cc
+++ b/ash/wm/base_layout_manager.cc
@@ -4,12 +4,14 @@
 
 #include "ash/wm/base_layout_manager.h"
 
+#include "ash/ash_switches.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/shelf_layout_manager.h"
 #include "ash/wm/window_animations.h"
 #include "ash/wm/window_properties.h"
 #include "ash/wm/window_util.h"
+#include "base/command_line.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
@@ -75,7 +77,7 @@ void BaseLayoutManager::OnWindowAddedToLayout(aura::Window* child) {
   // Only update the bounds if the window has a show state that depends on the
   // workspace area.
   if (wm::IsWindowMaximized(child) || wm::IsWindowFullscreen(child))
-    UpdateBoundsFromShowState(child);
+    UpdateBoundsFromShowState(child, false);
 }
 
 void BaseLayoutManager::OnWillRemoveWindowFromLayout(aura::Window* child) {
@@ -98,14 +100,9 @@ void BaseLayoutManager::OnChildWindowVisibilityChanged(aura::Window* child,
 
 void BaseLayoutManager::SetChildBounds(aura::Window* child,
                                        const gfx::Rect& requested_bounds) {
-  gfx::Rect child_bounds(requested_bounds);
-  // Avoid a janky resize on startup by ensuring the initial bounds fill the
-  // screen.
-  if (wm::IsWindowMaximized(child))
-    child_bounds = ScreenAsh::GetMaximizedWindowBounds(child);
-  else if (wm::IsWindowFullscreen(child))
-    child_bounds = gfx::Screen::GetMonitorNearestWindow(child).bounds();
-  SetChildBoundsDirect(child, child_bounds);
+  // Just set the bounds immediately.  We fix up maximized and fullscreen
+  // bounds in OnWindowAddedToLayout() above.
+  SetChildBoundsDirect(child, requested_bounds);
 }
 
 /////////////////////////////////////////////////////////////////////////////
@@ -130,7 +127,7 @@ void BaseLayoutManager::OnWindowPropertyChanged(aura::Window* window,
                                                 const void* key,
                                                 intptr_t old) {
   if (key == aura::client::kShowStateKey) {
-    UpdateBoundsFromShowState(window);
+    UpdateBoundsFromShowState(window, true);
     ShowStateChanged(window, static_cast<ui::WindowShowState>(old));
   }
 }
@@ -167,13 +164,15 @@ void BaseLayoutManager::ShowStateChanged(aura::Window* window,
   }
 }
 
-void BaseLayoutManager::UpdateBoundsFromShowState(aura::Window* window) {
+void BaseLayoutManager::UpdateBoundsFromShowState(aura::Window* window,
+                                                  bool animate) {
   switch (window->GetProperty(aura::client::kShowStateKey)) {
     case ui::SHOW_STATE_DEFAULT:
     case ui::SHOW_STATE_NORMAL: {
       const gfx::Rect* restore = GetRestoreBounds(window);
       if (restore) {
-        SetChildBoundsDirect(window,
+        MaybeAnimateToBounds(window,
+                             animate,
                              BoundsWithScreenEdgeVisible(window, *restore));
       }
       window->ClearProperty(aura::client::kRestoreBoundsKey);
@@ -182,13 +181,17 @@ void BaseLayoutManager::UpdateBoundsFromShowState(aura::Window* window) {
 
     case ui::SHOW_STATE_MAXIMIZED:
       SetRestoreBoundsIfNotSet(window);
-      SetChildBoundsDirect(window, ScreenAsh::GetMaximizedWindowBounds(window));
+      MaybeAnimateToBounds(window,
+                           animate,
+                           ScreenAsh::GetMaximizedWindowBounds(window));
       break;
 
     case ui::SHOW_STATE_FULLSCREEN:
       SetRestoreBoundsIfNotSet(window);
-      SetChildBoundsDirect(
-          window, gfx::Screen::GetMonitorNearestWindow(window).bounds());
+      MaybeAnimateToBounds(
+          window,
+          animate,
+          gfx::Screen::GetMonitorNearestWindow(window).bounds());
       break;
 
     default:
@@ -196,6 +199,20 @@ void BaseLayoutManager::UpdateBoundsFromShowState(aura::Window* window) {
   }
 }
 
+void BaseLayoutManager::MaybeAnimateToBounds(aura::Window* window,
+                                             bool animate,
+                                             const gfx::Rect& new_bounds) {
+  // Only animate visible windows.
+  if (animate &&
+      window->TargetVisibility() &&
+      !CommandLine::ForCurrentProcess()->HasSwitch(
+          ash::switches::kAuraWindowAnimationsDisabled)) {
+    CrossFadeToBounds(window, new_bounds);
+    return;
+  }
+  SetChildBoundsDirect(window, new_bounds);
+}
+
 void BaseLayoutManager::AdjustWindowSizesForScreenChange() {
   // If a user plugs an external monitor into a laptop running Aura the
   // monitor size will change.  Maximized windows need to resize to match.