Improving the user transition to add special cases for maximized windows and make the transition "m…

chrome/browser/ui/ash/multi_user/user_switch_animator_chromeos.h

+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_UI_ASH_MULTI_USER_USER_SWITCH_ANIMATOR_CHROMEOS_H_
+#define CHROME_BROWSER_UI_ASH_MULTI_USER_USER_SWITCH_ANIMATOR_CHROMEOS_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/timer/timer.h"
+
+namespace aura {
+class Window;
+}  // namespace aura
+
+namespace chrome {
+
+class MultiUserWindowManagerChromeOS;
+
+// A class which performs transitions animations between users. Upon creation,
+// the animation gets started and upon destruction the animation gets finished
+// if not done yet.
+// Specifying |animation_disabled| upon creation will perform the transition
+// without visible animations.
+class UserSwichAnimatorChromeOS {
+ public:
+  // The animation step for the user change animation.
+  enum AnimationStep {
+    ANIMATION_STEP_HIDE_OLD_USER,  // Hiding the old user (and shelf).
+    ANIMATION_STEP_SHOW_NEW_USER,  // Show the shelf of the new user.
+    ANIMATION_STEP_FINALIZE,       // All animations are done - final cleanup.
+    ANIMATION_STEP_ENDED           // The animation has ended.
+  };
+
+  UserSwichAnimatorChromeOS(MultiUserWindowManagerChromeOS* owner,
+                            const std::string& new_user_id,
+                            bool animation_disabled);
+  ~UserSwichAnimatorChromeOS();
+
+  // Check if a window is covering the entire work area of the screen it is on.
+  static bool CoversScreen(aura::Window* window);
+
+  bool IsAnimationFinished() {
+    return animation_step_ == ANIMATION_STEP_ENDED;
+  }
+
+  // Returns the user id for which the wallpaper is currently shown.
+  // If a wallpaper is transitioning to B it will be returned as "->B".
+  const std::string& wallpaper_user_id_for_test() { return wallpaper_user_id_; }
+
+  // Advances the user switch animation to the next step. It reads the current
+  // step from |animation_step_| and increments it thereafter. When
+  // |ANIMATION_STEP_FINALIZE| gets executed, the animation is finished and the
+  // timer (if one exists) will get destroyed.
+  void AdvanceUserTransitionAnimation();
+
+ private:
+  // The window configuration of screen covering windows before an animation.
+  enum TransitioningScreenCover {
+    NO_USER_COVERS_SCREEN,   // No window covers the entire screen.
+    OLD_USER_COVERS_SCREEN,  // The current user has at least one window
+                             // covering the entire screen.
+    NEW_USER_COVERS_SCREEN,  // The user which becomes active has at least one
+                             // window covering the entire screen.
+    BOTH_USERS_COVER_SCREEN  // Both users have at least one window each
+                             // covering the entire screen.
+  };
+
+  // Finalizes the animation and ends the timer (if there is one).
+  void FinalizeAnimation();
+
+  // Execute the user wallpaper animations for |animation_step|.
+  void TransitionWallpaper(AnimationStep animtion_step);
+
+  // Execute the user shelf animations for |animation_step|.
+  void TransitionUserShelf(AnimationStep animtion_step);
+
+  // Execute the window animations for |animation_step|.
+  void TransitionWindows(AnimationStep animation_step);
+
+  // Check if a window is maximized / fullscreen / covering the entire screen.
+  // TODO(skuhne): We might want to do this on a per screen basis.
+  TransitioningScreenCover GetScreenCover();
+
+  // The owning window manager.
+  MultiUserWindowManagerChromeOS* owner_;
+
+  // The new user to set.
+  std::string new_user_id_;
+
+  // If true, all animations will be suppressed.
+  bool animation_disabled_;
+
+  // The next animation step for AdvanceUserTransitionAnimation().
+  AnimationStep animation_step_;
+
+  // The screen cover status before the animation has started.
+  TransitioningScreenCover screen_cover_;
+
+  // A timer which watches to executes the second part of a "user changed"
+  // animation. Note that this timer exists only during such an animation.
+  scoped_ptr<base::Timer> user_changed_animation_timer_;
+
+  // For unit tests: Check which wallpaper was set.
+  std::string wallpaper_user_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserSwichAnimatorChromeOS);
+};
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_UI_ASH_MULTI_USER_USER_SWITCH_ANIMATOR_CHROMEOS_H_