// Copyright (c) 2013 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 UI_KEYBOARD_KEYBOARD_CONTROLLER_H_
#define UI_KEYBOARD_KEYBOARD_CONTROLLER_H_

#include "base/basictypes.h"
#include "base/event_types.h"
#include "base/memory/scoped_ptr.h"
#include "base/observer_list.h"
#include "ui/aura/window_observer.h"
#include "ui/base/ime/input_method_observer.h"
#include "ui/base/ime/text_input_type.h"
#include "ui/gfx/rect.h"
#include "ui/keyboard/keyboard_export.h"
#include "url/gurl.h"

namespace aura {
class Window;
}
namespace ui {
class InputMethod;
class TextInputClient;
}

namespace keyboard {

class CallbackAnimationObserver;
class WindowBoundsChangeObserver;
class KeyboardControllerObserver;
class KeyboardControllerProxy;

// Animation distance.
const int kAnimationDistance = 30;

// Provides control of the virtual keyboard, including providing a container
// and controlling visibility.
class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
                                           public aura::WindowObserver {
 public:
  // Different ways to hide the keyboard.
  enum HideReason {
    // System initiated.
    HIDE_REASON_AUTOMATIC,
    // User initiated.
    HIDE_REASON_MANUAL,
  };

  // Takes ownership of |proxy|.
  explicit KeyboardController(KeyboardControllerProxy* proxy);
  virtual ~KeyboardController();

  // Returns the container for the keyboard, which is owned by
  // KeyboardController.
  aura::Window* GetContainerWindow();

  // Whether the container window for the keyboard has been initialized.
  bool keyboard_container_initialized() const {
    return container_.get() != NULL;
  }

  // Reloads the content of the keyboard. No-op if the keyboard content is not
  // loaded yet.
  void Reload();

  // Hides virtual keyboard and notifies observer bounds change.
  // This function should be called with a delay to avoid layout flicker
  // when the focus of input field quickly change. |automatic| is true when the
  // call is made by the system rather than initiated by the user.
  void HideKeyboard(HideReason reason);

  // Notifies the keyboard observer for keyboard bounds changed.
  void NotifyKeyboardBoundsChanging(const gfx::Rect& new_bounds);

  // Management of the observer list.
  virtual void AddObserver(KeyboardControllerObserver* observer);
  virtual void RemoveObserver(KeyboardControllerObserver* observer);

  KeyboardControllerProxy* proxy() { return proxy_.get(); }

  void set_lock_keyboard(bool lock) { lock_keyboard_ = lock; }

  // Force the keyboard to show up if not showing and lock the keyboard if
  // |lock| is true.
  void ShowKeyboard(bool lock);

  // Sets the active keyboard controller. KeyboardController takes ownership of
  // the instance. Calling ResetIntance with a new instance destroys the
  // previous one. May be called with NULL to clear the instance.
  static void ResetInstance(KeyboardController* controller);

  // Retrieve the active keyboard controller.
  static KeyboardController* GetInstance();

  // Returns true if keyboard is currently visible.
  bool keyboard_visible() { return keyboard_visible_; }

  bool show_on_resize() { return show_on_resize_; }

  // Returns the current keyboard bounds. When the keyboard is not shown,
  // an empty rectangle will get returned.
  const gfx::Rect& current_keyboard_bounds() {
    return current_keyboard_bounds_;
  }

  // Determines whether a particular window should have insets for overscroll.
  bool ShouldEnableInsets(aura::Window* window);

  // Updates insets on web content window
  void UpdateWindowInsets(aura::Window* window);

 private:
  // For access to Observer methods for simulation.
  friend class KeyboardControllerTest;

  // aura::WindowObserver overrides
  virtual void OnWindowHierarchyChanged(
      const HierarchyChangeParams& params) override;

  // InputMethodObserver overrides
  virtual void OnTextInputTypeChanged(
      const ui::TextInputClient* client) override {}
  virtual void OnFocus() override {}
  virtual void OnBlur() override {}
  virtual void OnCaretBoundsChanged(
      const ui::TextInputClient* client) override {}
  virtual void OnTextInputStateChanged(
      const ui::TextInputClient* client) override;
  virtual void OnInputMethodDestroyed(
      const ui::InputMethod* input_method) override;
  virtual void OnShowImeIfNeeded() override;

  // Show virtual keyboard immediately with animation.
  void ShowKeyboardInternal();

  // Clears any insets on web content windows.
  void ResetWindowInsets();

  // Returns true if keyboard is scheduled to hide.
  bool WillHideKeyboard() const;

  // Called when show and hide animation finished successfully. If the animation
  // is aborted, it won't be called.
  void ShowAnimationFinished();
  void HideAnimationFinished();

  // Adds an observer for tracking changes to a window size or
  // position while the keyboard is displayed. Any window repositioning
  // invalidates insets for overscrolling.
  void AddBoundsChangedObserver(aura::Window* window);

  scoped_ptr<KeyboardControllerProxy> proxy_;
  scoped_ptr<aura::Window> container_;
  // CallbackAnimationObserver should destructed before container_ because it
  // uses container_'s animator.
  scoped_ptr<CallbackAnimationObserver> animation_observer_;

  scoped_ptr<WindowBoundsChangeObserver> window_bounds_observer_;

  ui::InputMethod* input_method_;
  bool keyboard_visible_;
  bool show_on_resize_;
  bool lock_keyboard_;
  ui::TextInputType type_;

  ObserverList<KeyboardControllerObserver> observer_list_;

  // The currently used keyboard position.
  gfx::Rect current_keyboard_bounds_;

  static KeyboardController* instance_;

  base::WeakPtrFactory<KeyboardController> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(KeyboardController);
};

}  // namespace keyboard

#endif  // UI_KEYBOARD_KEYBOARD_CONTROLLER_H_