// 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 <memory>

#include "base/event_types.h"
#include "base/macros.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/geometry/rect.h"
#include "ui/keyboard/keyboard_export.h"

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

namespace keyboard {

class CallbackAnimationObserver;
class KeyboardControllerObserver;
class KeyboardUI;

// Animation distance.
const int kAnimationDistance = 30;

enum KeyboardMode {
  // Invalid mode.
  NONE,
  // Full width virtual keyboard. The virtual keyboard window has the same width
  // as the display.
  FULL_WIDTH,
  // Floating virtual keyboard. The virtual keyboard window has customizable
  // width and is draggable.
  FLOATING,
};

// 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 |ui|.
  explicit KeyboardController(KeyboardUI* ui);
  ~KeyboardController() override;

  // 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_ != nullptr; }

  // 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);

  KeyboardUI* ui() { return ui_.get(); }

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

  bool get_lock_keyboard() const { return lock_keyboard_; }

  KeyboardMode keyboard_mode() const { return keyboard_mode_; }

  void SetKeyboardMode(KeyboardMode mode);

  // 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. An empty rectangle will get returned
  // when the keyboard is not shown or in FLOATING mode.
  const gfx::Rect& current_keyboard_bounds() {
    return current_keyboard_bounds_;
  }

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

  // aura::WindowObserver overrides
  void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
  void OnWindowAddedToRootWindow(aura::Window* window) override;
  void OnWindowRemovingFromRootWindow(aura::Window* window,
                                      aura::Window* new_root) override;
  void OnWindowBoundsChanged(aura::Window* window,
                             const gfx::Rect& old_bounds,
                             const gfx::Rect& new_bounds) override;

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

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

  // 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();

  std::unique_ptr<KeyboardUI> ui_;
  std::unique_ptr<aura::Window> container_;
  // CallbackAnimationObserver should destructed before container_ because it
  // uses container_'s animator.
  std::unique_ptr<CallbackAnimationObserver> animation_observer_;

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

  base::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_
