[Remoting Host] Handle text event characters that are not presented on the keyboard

remoting/host/linux/keyboard_interface.h

+// Copyright 2016 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_HOST_LINUX_KEYBOARD_INTERFACE_H_
+#define REMOTING_HOST_LINUX_KEYBOARD_INTERFACE_H_
+
+#include <stdint.h>
+
+#include <vector>
+
+#include "base/macros.h"
+
+namespace remoting {
+
+// An interface for accessing the keyboard and changing the keyboard layout.
+// An implementation is allowed to delay processing a request until Flush() or
+// Sync() is called.
+class KeyboardInterface {

[Yuwei, 2016/09/21 03:47:40]

This interface is basically for unit test. There will probably be another
interface for XServerKeyMapper.

[Sergey Ulanov, 2016/09/21 19:59:23]

We don't use Interface suffix for interfaces. Also this class is specific to
X11. Call it X11Keyboard?

[Yuwei, 2016/09/21 20:35:32]

"Interface" here actually means it is an interface to talk to the keyboard
If the interface takes "X11" as part of the name then how should we call the
actual X11 implementation?

Maybe just remove this interface and mark all functions of X11Keyboard virtual.

[Sergey Ulanov, 2016/09/21 20:55:23]

X11KeyboardImpl
This would work as well.
Potentially this code can be tested without mocking X11.

[Yuwei, 2016/09/23 01:40:37]

Done.

[Yuwei, 2016/09/23 01:40:37]

Done.

+ public:
+  virtual ~KeyboardInterface() {}
+
+  // Returns a vector of key codes that are not being mapped to a code point.
+  virtual std::vector<uint32_t> GetUnusedKeycodes() = 0;
+
+  // Simulates a key press with the given |keycode| and |modifiers|. Note that
+  // the application receiving the key press can decide whether or how the key
+  // press is interpreted into a character.
+  virtual void PressKey(uint32_t keycode, uint32_t modifiers) = 0;
+
+  // Finds a keycode and set of modifiers that generate character with the
+  // specified |code_point|. Returns true if the key code is successfully found.
+  virtual bool FindKeycode(uint32_t code_point,
+                           uint32_t* keycode,
+                           uint32_t* modifiers) = 0;
+
+  // Change the key mapping such that pressing |keycode| will output the
+  // character of |lower_case_code_point| or |upper_case_code_point| determined
+  // by the modifier.
+  virtual bool ChangeKeyMapping(uint32_t keycode,
+                                uint32_t lower_case_code_point,
+                                uint32_t upper_case_code_point) = 0;
+
+  // Flushes all requests but don't wait for processing the requests.
+  virtual void Flush() = 0;
+
+  // Flushes all requests and wait until all requests are processed.
+  virtual void Sync() = 0;
+
+ protected:
+  KeyboardInterface() {}
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_LINUX_KEYBOARD_INTERFACE_H_