Automatically remap Command key on an Apple keyboard to Control [part 1 of 2 - Ash part]

Add key_rewriter_event_filter.h which allows its delegate to rewrite or delete an aura::KeyEvent. The new interface will be used for implementing the following three features:

* crosbug.com/25097: Remap keys on external keyboards (R19)
* crosbug.com/27167: Consider adding a way to send function keys to web pages (R20)
* crbug.com/115112: Move modifier remapping code from X to Chrome (M20)

Part 2 of 2: http://codereview.chromium.org/9854025/

BUG=chromium-os:25097
BUG=chromium-os:27167
BUG=115112
TEST=try

Review URL: https://chromiumcodereview.appspot.com/9838010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@129076 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 33 insertions, 0 deletions

diff --git a/ash/key_rewriter_delegate.h b/ash/key_rewriter_delegate.h
new file mode 100644
index 0000000..16fcad9
--- /dev/null
+++ b/ash/key_rewriter_delegate.h
@@ -0,0 +1,33 @@
+// 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 ASH_KEY_REWRITER_DELEGATE_H_
+#define ASH_KEY_REWRITER_DELEGATE_H_
+#pragma once
+
+namespace aura {
+class KeyEvent;
+}  // namespace aura
+
+namespace ash {
+
+// Delegate for rewriting or filtering a key event.
+class KeyRewriterDelegate {
+ public:
+  enum Action {
+    ACTION_REWRITE_EVENT,
+    ACTION_DROP_EVENT,
+  };
+
+  virtual ~KeyRewriterDelegate() {}
+
+  // A derived class can do either of the following:
+  // 1) Just return ACTION_DROP_EVENT to drop the |event|.
+  // 2) Rewrite the |event| and return ACTION_REWRITE_EVENT.
+  virtual Action RewriteOrFilterKeyEvent(aura::KeyEvent* event) = 0;
+};
+
+}  // namespace ash
+
+#endif  // ASH_KEY_REWRITER_DELEGATE_H_