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

ash/wm/key_rewriter_event_filter.cc

Index: ash/wm/key_rewriter_event_filter.cc
diff --git a/ash/wm/key_rewriter_event_filter.cc b/ash/wm/key_rewriter_event_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..30ba84da34db0b3bda5e4d74da55a37547909a5d
--- /dev/null
+++ b/ash/wm/key_rewriter_event_filter.cc
@@ -0,0 +1,61 @@
+// 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.
+
+#include "ash/wm/key_rewriter_event_filter.h"
+
+#include "base/logging.h"
+#include "ash/key_rewriter_delegate.h"
+#include "ui/aura/event.h"
+
+namespace ash {
+namespace internal {
+
+KeyRewriterEventFilter::KeyRewriterEventFilter() {}
+
+KeyRewriterEventFilter::~KeyRewriterEventFilter() {}
+
+void KeyRewriterEventFilter::SetKeyRewriterDelegate(
+    scoped_ptr<KeyRewriterDelegate> delegate) {
+  delegate_.swap(delegate);
+}
+
+bool KeyRewriterEventFilter::PreHandleKeyEvent(
+    aura::Window* target, aura::KeyEvent* event) {
+  if (!delegate_.get())
+    return false;
+
+  // Do not consume a translated key event which is generated by an IME.
+  if (event->type() == ui::ET_TRANSLATED_KEY_PRESS ||
+      event->type() == ui::ET_TRANSLATED_KEY_RELEASE) {
+    return false;
+  }
+
+  switch (delegate_->RewriteOrFilterKeyEvent(event)) {
+    case KeyRewriterDelegate::ACTION_REWRITE_EVENT:
+      return false;
+    case KeyRewriterDelegate::ACTION_DROP_EVENT:
+      return true;
+  }
+
+  NOTREACHED();
+  return false;
+}
+
+bool KeyRewriterEventFilter::PreHandleMouseEvent(
+    aura::Window* target, aura::MouseEvent* event) {
+  return false;  // Not handled.
+}
+
+ui::TouchStatus KeyRewriterEventFilter::PreHandleTouchEvent(
+    aura::Window* target, aura::TouchEvent* event) {
+  return ui::TOUCH_STATUS_UNKNOWN;  // Not handled.
+}
+
+ui::GestureStatus KeyRewriterEventFilter::PreHandleGestureEvent(
+    aura::Window* target, aura::GestureEvent* event) {
+  return ui::GESTURE_STATUS_UNKNOWN;  // Not handled.
+}
+
+}  // namespace internal
+}  // namespace ash