text: // Copyright (c) 2012 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_KEY_EVENT_MAPPER_H_
  #define REMOTING_CLIENT_INPUT_KEY_EVENT_MAPPER_H_
  
  #include <stdint.h>
  
  #include <map>
  #include <set>
  
  #include "base/callback.h"
  #include "base/compiler_specific.h"
  #include "base/macros.h"
  #include "remoting/protocol/input_filter.h"
  
  namespace remoting {
  
  // Filtering InputStub which can be used to re-map the USB keycodes of events
  // before they are passed on to the next InputStub in the chain, or to trap
  // events with specific USB keycodes for special handling.
  class KeyEventMapper : public protocol::InputFilter {
   public:
    KeyEventMapper();
    explicit KeyEventMapper(InputStub* input_stub);
    ~KeyEventMapper() override;
  
    // Callback type for use with SetTrapCallback(), below.
    typedef base::Callback<void(const protocol::KeyEvent&)> KeyTrapCallback;
  
    // Sets the callback to which trapped keys will be delivered.
    void SetTrapCallback(KeyTrapCallback callback);
  
    // Causes events matching |usb_keycode| to be delivered to the trap callback.
    // Trapped events are not dispatched to the next InputStub in the chain.
    void TrapKey(uint32_t usb_keycode, bool trap_key);
  
    // Causes events matching |in_usb_keycode| to be mapped to |out_usb_keycode|.
    // Keys are remapped at most once. Traps are processed before remapping.
    void RemapKey(uint32_t in_usb_keycode, uint32_t out_usb_keycode);
  
    // InputFilter overrides.
    void InjectKeyEvent(const protocol::KeyEvent& event) override;
  
   private:
    std::map<uint32_t, uint32_t> mapped_keys;
    std::set<uint32_t> trapped_keys;
    KeyTrapCallback trap_callback;
  
    DISALLOW_COPY_AND_ASSIGN(KeyEventMapper);
  };
  
  }  // namespace remoting
  
  #endif  // REMOTING_CLIENT_INPUT_KEY_EVENT_MAPPER_H_
  