remoting/client/input/normalizing_input_filter_cros.h

// Copyright 2015 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 REMOTING_CLIENT_INPUT_NORMALIZING_INPUT_FILTER_CROS_H_
#define REMOTING_CLIENT_INPUT_NORMALIZING_INPUT_FILTER_CROS_H_

#include <stdint.h>

#include "remoting/proto/event.pb.h"
#include "remoting/protocol/input_filter.h"

namespace remoting {

// NormalizingInputFilterCros addresses the problems generated by key rewritings
// such as Down->PageDown, 1->F1, etc, when keys are pressed in combination with
// the OSKey (aka Search). Rewriting OSKey+Down, for example, causes us to
// receive the following:
//
// keydown OSKey
// keydown PageDown
// keyup PageDown
// keyup OSKey
//
// The host system will therefore behave as if OSKey+PageDown were pressed,
// rather than PageDown alone.
class NormalizingInputFilterCros : public protocol::InputFilter {
 public:
  explicit NormalizingInputFilterCros(protocol::InputStub* input_stub);

  NormalizingInputFilterCros(const NormalizingInputFilterCros&) = delete;
  NormalizingInputFilterCros& operator=(const NormalizingInputFilterCros&) =
      delete;

  ~NormalizingInputFilterCros() override;

  // InputFilter overrides.
  void InjectKeyEvent(const protocol::KeyEvent& event) override;
  void InjectMouseEvent(const protocol::MouseEvent& event) override;

 private:
  void ProcessKeyDown(const protocol::KeyEvent& event);
  void ProcessKeyUp(const protocol::KeyEvent& event);

  void SwitchRewritingKeyToModifying();
  void UndoAltKeyMapping(protocol::KeyEvent* event);

  // Holds the keydown event for the most recent OSKey to have been pressed,
  // while it is Rewriting, or we are not yet sure whether it is Normal,
  // Rewriting or Modifying. The event is sent on if we switch to Modifying, or
  // discarded if the OSKey is released while in Rewriting mode.
  protocol::KeyEvent deferred_keydown_event_;

  // True while the |rewrite_keydown_event_| key is Rewriting, i.e. was followed
  // by one or more Rewritten key events, and not by any Modified events.
  bool deferred_key_is_rewriting_;

  // Stores the code of the OSKey while it is pressed for use as a Modifier.
  uint32_t modifying_key_;

  // True if the left or right Alt keys are pressed, respectively.
  bool left_alt_is_pressed_;
  bool right_alt_is_pressed_;

  // Previous mouse coordinates.
  int previous_mouse_x_;
  int previous_mouse_y_;
};

}  // namespace remoting

#endif  // REMOTING_CLIENT_INPUT_NORMALIZING_INPUT_FILTER_CROS_H_