API proposal for chrome.app.window to intercept all keys.

chrome/browser/ui/views/apps/desktop_keyboard_capture.cc

+// Copyright 2014 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 "chrome/browser/ui/views/apps/desktop_keyboard_capture.h"
+#include "chrome/browser/ui/views/apps/keyboard_hook_handler.h"
+
+DesktopKeyboardCapture::DesktopKeyboardCapture(views::Widget* widget)
+    : widget_(widget), is_registered_(false) {
+  widget_->AddObserver(this);
+
+  if (widget_->IsActive())
+    RegisterKeyboardHooks();
+}
+
+DesktopKeyboardCapture::~DesktopKeyboardCapture() {
+  if (is_registered_)
+    DeregisterKeyboardHooks();
+
+  widget_->RemoveObserver(this);
+}
+
+void DesktopKeyboardCapture::RegisterKeyboardHooks() {
+  KeyboardHookHandler::GetInstance()->Register(widget_);
+  is_registered_ = true;
+}
+
+void DesktopKeyboardCapture::DeregisterKeyboardHooks() {
+  KeyboardHookHandler::GetInstance()->Deregister(widget_);
+  is_registered_ = false;
+}
+
+void DesktopKeyboardCapture::OnWidgetActivationChanged(views::Widget* widget,
+                                                       bool active) {
+  if (active) {
+    RegisterKeyboardHooks();
+  } else {
+    DeregisterKeyboardHooks();
+  }
+}