Long press menu (shift+f6) to toggle spoken feedback.

ash/accelerators/spoken_feedback_toggler.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 "ash/accelerators/spoken_feedback_toggler.h"
+
+#include "ash/accelerators/key_hold_detector.h"
+#include "ash/accessibility_delegate.h"
+#include "ash/shell.h"
+
+namespace ash {
+namespace {
+bool speech_feedback_toggler_enabled = false;
+}
+
+// static
+bool SpokenFeedbackToggler::IsEnabled() {
+  return speech_feedback_toggler_enabled;
+}
+
+// static
+void SpokenFeedbackToggler::SetEnabled(bool enabled) {
+  speech_feedback_toggler_enabled = enabled;
+}
+
+// static
+scoped_ptr<ui::EventHandler> SpokenFeedbackToggler::CreateHandler() {
+  scoped_ptr<KeyHoldDetector::Delegate> delegate(new SpokenFeedbackToggler());
+  return scoped_ptr<ui::EventHandler>(new KeyHoldDetector(delegate.Pass()));
+}
+
+bool SpokenFeedbackToggler::ShouldProcessEvent(
+    const ui::KeyEvent* event) const {
+  return IsEnabled() && event->key_code() == ui::VKEY_F6;
+}
+
+bool SpokenFeedbackToggler::IsStartEvent(const ui::KeyEvent* event) const {
+  return event->type() == ui::ET_KEY_PRESSED &&
+      event->flags() & ui::EF_SHIFT_DOWN;
+}
+
+void SpokenFeedbackToggler::OnKeyHold(const ui::KeyEvent* event) {
+  if (!toggled_) {
+    toggled_ = true;
+    Shell::GetInstance()->accessibility_delegate()->
+        ToggleSpokenFeedback(A11Y_NOTIFICATION_SHOW);
+  }
+}
+
+void SpokenFeedbackToggler::OnKeyUnhold(const ui::KeyEvent* event) {
+  toggled_ = false;
+}
+
+SpokenFeedbackToggler::SpokenFeedbackToggler() : toggled_(false) {}
+
+SpokenFeedbackToggler::~SpokenFeedbackToggler() {}
+
+}  // namespace ash