// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_INPUT_KEYBOARD_EVENT_MANAGER_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_INPUT_KEYBOARD_EVENT_MANAGER_H_

#include "build/build_config.h"
#include "third_party/blink/public/common/input/web_input_event.h"
#include "third_party/blink/public/platform/web_input_event_result.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/scroll/scrollable_area.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "third_party/blink/renderer/platform/keyboard_codes.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"

namespace blink {

class KeyboardEvent;
class LocalFrame;
class Node;
class ScrollManager;
class WebKeyboardEvent;

enum class OverrideCapsLockState { kDefault, kOn, kOff };

class CORE_EXPORT KeyboardEventManager final
    : public GarbageCollected<KeyboardEventManager> {
 public:
  static const int kAccessKeyModifiers =
// TODO(crbug.com/618397): Add a settings to control this behavior.
#if BUILDFLAG(IS_MAC)
      WebInputEvent::kControlKey | WebInputEvent::kAltKey;
#else
      WebInputEvent::kAltKey;
#endif

  KeyboardEventManager(LocalFrame&, ScrollManager&);
  KeyboardEventManager(const KeyboardEventManager&) = delete;
  KeyboardEventManager& operator=(const KeyboardEventManager&) = delete;
  void Trace(Visitor*) const;

  bool HandleAccessKey(const WebKeyboardEvent&);
  WebInputEventResult KeyEvent(const WebKeyboardEvent&);
  void DefaultKeyboardEventHandler(KeyboardEvent*, Node*);

  void CapsLockStateMayHaveChanged();
  static WebInputEvent::Modifiers GetCurrentModifierState();
  static bool CurrentCapsLockState();
  void SetScrollendEventTarget(ScrollableArea* scrollable_area) {
    scrollend_event_target_ = scrollable_area;
  }
  bool HasPendingScrollendOnKeyUp() const {
    return has_pending_scrollend_on_key_up_;
  }

  bool is_handling_key_event() const { return is_handling_key_event_; }

  // Moves focus forwards or backwards given a KeyboardEvent for the tab key.
  // Returns true is focus was moved, otherwise false.
  bool DefaultTabEventHandler(KeyboardEvent*);

 private:
  friend class Internals;
  // Allows overriding the current caps lock state for testing purposes.
  static void SetCurrentCapsLockState(OverrideCapsLockState);

  void DefaultSpaceEventHandler(KeyboardEvent*, Node*);
  void DefaultEscapeEventHandler(KeyboardEvent*);
  void DefaultEnterEventHandler(KeyboardEvent*);
  void DefaultImeSubmitHandler(KeyboardEvent*);
  void DefaultNavigationKeyEventHandler(KeyboardEvent*, Node*);

  const Member<LocalFrame> frame_;

  Member<ScrollManager> scroll_manager_;
  WeakMember<ScrollableArea> scrollend_event_target_;

  bool is_handling_key_event_ = false;
  // If a ScrollManager::BubblingScroll or ScrollManager::LogicalScroll is
  // started by a keydown event, this records the keycode for that event so
  // that we can fire a "scrollend" event if necessary on the accompanying keyup
  // event.
  int last_scrolling_keycode_ = VKEY_UNKNOWN;
  bool has_pending_scrollend_on_key_up_ = false;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_INPUT_KEYBOARD_EVENT_MANAGER_H_