Reland: Initial support for Spoken Feedback tablet toggle

TBR=derat@chromium.org

Change-Id: I5b31bee43dfca9de4d4aa188642a1f1ff9cfbca5
Reviewed-on: https://chromium-review.googlesource.com/1044289Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556145}

ash/BUILD.gn

@@ -71,6 +71,10 @@ component("ash") {
     "accessibility/focus_ring_controller.h",
     "accessibility/focus_ring_layer.cc",
     "accessibility/focus_ring_layer.h",
+    "accessibility/key_accessibility_enabler.cc",
+    "accessibility/key_accessibility_enabler.h",
+    "accessibility/spoken_feedback_enabler.cc",
+    "accessibility/spoken_feedback_enabler.h",
     "accessibility/touch_accessibility_enabler.cc",
     "accessibility/touch_accessibility_enabler.h",
     "accessibility/touch_exploration_controller.cc",
@@ -1541,6 +1545,7 @@ test("ash_unittests") {
     "accessibility/accessibility_focus_ring_controller_unittest.cc",
     "accessibility/accessibility_highlight_controller_unittest.cc",
     "accessibility/accessibility_panel_layout_manager_unittest.cc",
+    "accessibility/key_accessibility_enabler_unittest.cc",
     "accessibility/touch_accessibility_enabler_unittest.cc",
     "accessibility/touch_exploration_controller_unittest.cc",
     "accessibility/touch_exploration_manager_unittest.cc",

ash/accessibility/accessibility_controller.cc

@@ -25,6 +25,7 @@
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/system/power/backlights_forced_off_setter.h"
 #include "ash/system/power/scoped_backlights_forced_off.h"
+#include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "base/strings/string16.h"
 #include "chromeos/audio/cras_audio_handler.h"
 #include "components/pref_registry/pref_registry_syncable.h"
@@ -173,19 +174,21 @@ void ShowAccessibilityNotification(A11yNotificationType type) {
 
   base::string16 text;
   base::string16 title;
-  if (type == A11yNotificationType::kSpokenFeedbackBrailleEnabled) {
-    text =
-        l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED);
-    title = l10n_util::GetStringUTF16(
-        IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_BRAILLE_ENABLED_TITLE);
-  } else if (type == A11yNotificationType::kBrailleDisplayConnected) {
+  if (type == A11yNotificationType::kBrailleDisplayConnected) {
     text = l10n_util::GetStringUTF16(
         IDS_ASH_STATUS_TRAY_BRAILLE_DISPLAY_CONNECTED);
   } else {
+    bool is_tablet = Shell::Get()
+                         ->tablet_mode_controller()
+                         ->IsTabletModeWindowManagerEnabled();
+
     title = l10n_util::GetStringUTF16(
-        IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED_TITLE);
-    text =
-        l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED);
+        type == A11yNotificationType::kSpokenFeedbackBrailleEnabled
+            ? IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_BRAILLE_ENABLED_TITLE
+            : IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED_TITLE);
+    text = l10n_util::GetStringUTF16(
+        is_tablet ? IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED_TABLET
+                  : IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED);
   }
   message_center::RichNotificationData options;
   options.should_make_spoken_feedback_for_popup_updates = false;

ash/accessibility/key_accessibility_enabler.cc

+// Copyright 2018 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/accessibility/key_accessibility_enabler.h"
+
+#include "ash/accessibility/spoken_feedback_enabler.h"
+#include "ash/shell.h"
+#include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "ui/events/event.h"
+
+namespace ash {
+
+KeyAccessibilityEnabler::KeyAccessibilityEnabler() {
+  Shell::Get()->AddPreTargetHandler(this, ui::EventTarget::Priority::kSystem);
+}
+
+KeyAccessibilityEnabler::~KeyAccessibilityEnabler() {
+  Shell::Get()->RemovePreTargetHandler(this);
+}
+
+void KeyAccessibilityEnabler::OnKeyEvent(ui::KeyEvent* event) {
+  if ((event->type() != ui::ET_KEY_PRESSED &&
+       event->type() != ui::ET_KEY_RELEASED) ||
+      !Shell::Get()
+           ->tablet_mode_controller()
+           ->IsTabletModeWindowManagerEnabled())
+    return;
+
+  if (event->key_code() == ui::VKEY_VOLUME_DOWN)
+    vol_down_pressed_ = event->type() == ui::ET_KEY_PRESSED;
+  else if (event->key_code() == ui::VKEY_VOLUME_UP)
+    vol_up_pressed_ = event->type() == ui::ET_KEY_PRESSED;
+
+  if (vol_down_pressed_ && vol_up_pressed_) {
+    event->StopPropagation();
+    if (!spoken_feedback_enabler_.get())
+      spoken_feedback_enabler_ = std::make_unique<SpokenFeedbackEnabler>();
+  } else if (spoken_feedback_enabler_.get()) {
+    spoken_feedback_enabler_.reset();
+  }
+}
+
+}  // namespace ash

ash/accessibility/key_accessibility_enabler.h

+// Copyright 2018 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_ACCESSIBILITY_KEY_ACCESSIBILITY_ENABLER_H_
+#define ASH_ACCESSIBILITY_KEY_ACCESSIBILITY_ENABLER_H_
+
+#include "ash/ash_export.h"
+#include "base/macros.h"
+#include "ui/events/event_handler.h"
+
+namespace ui {
+class KeyEvent;
+}  // namespace ui
+
+namespace ash {
+class SpokenFeedbackEnabler;
+
+// Toggles spoken feedback when the volume up and volume down keys are held for
+// at least 5 seconds.
+class ASH_EXPORT KeyAccessibilityEnabler : public ui::EventHandler {
+ public:
+  KeyAccessibilityEnabler();
+  ~KeyAccessibilityEnabler() override;
+
+ private:
+  friend class KeyAccessibilityEnablerTest;
+
+  // Overridden from ui::EventHandler
+  void OnKeyEvent(ui::KeyEvent* event) override;
+
+  std::unique_ptr<SpokenFeedbackEnabler> spoken_feedback_enabler_;
+  bool vol_down_pressed_ = false;
+  bool vol_up_pressed_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(KeyAccessibilityEnabler);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCESSIBILITY_KEY_ACCESSIBILITY_ENABLER_H_

ash/accessibility/key_accessibility_enabler_unittest.cc

+// Copyright 2018 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/accessibility/key_accessibility_enabler.h"
+
+#include "ash/accessibility/accessibility_controller.h"
+#include "ash/accessibility/accessibility_observer.h"
+#include "ash/shell.h"
+#include "ash/system/web_notification/web_notification_tray.h"
+#include "ash/test/ash_test_base.h"
+#include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "base/run_loop.h"
+#include "base/test/simple_test_tick_clock.h"
+#include "ui/events/base_event_utils.h"
+#include "ui/events/event.h"
+
+namespace ash {
+
+class KeyAccessibilityEnablerTest : public AshTestBase,
+                                    public AccessibilityObserver {
+ public:
+  KeyAccessibilityEnablerTest() {}
+
+  void SetUp() override {
+    WebNotificationTray::DisableAnimationsForTest(true);
+    ui::SetEventTickClockForTesting(&clock_);
+    AshTestBase::SetUp();
+    Shell::Get()->accessibility_controller()->AddObserver(this);
+    key_accessibility_enabler_ = Shell::Get()->key_accessibility_enabler();
+  }
+
+  void TearDown() override {
+    ui::SetEventTickClockForTesting(nullptr);
+    AshTestBase::TearDown();
+  }
+
+  void SendKeyEvent(ui::KeyEvent* event) {
+    // Tablet mode gets exited elsewhere, so we must force it enabled before
+    // each key event.
+    Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+    key_accessibility_enabler_->OnKeyEvent(event);
+  }
+
+  void WaitForAccessibilityStatusChanged() {
+    run_loop_ = std::make_unique<base::RunLoop>();
+    clock_.Advance(base::TimeDelta::FromMilliseconds(5000));
+    run_loop_->Run();
+  }
+
+ private:
+  // AccessibilityObserver:
+  void OnAccessibilityStatusChanged() override { run_loop_->Quit(); }
+
+  std::unique_ptr<base::RunLoop> run_loop_;
+  KeyAccessibilityEnabler* key_accessibility_enabler_;
+  base::SimpleTestTickClock clock_;
+};
+
+TEST_F(KeyAccessibilityEnablerTest, TwoVolumeKeyDown) {
+  ui::KeyEvent vol_down_press(ui::ET_KEY_PRESSED, ui::VKEY_VOLUME_DOWN,
+                              ui::EF_NONE);
+  ui::KeyEvent vol_up_press(ui::ET_KEY_PRESSED, ui::VKEY_VOLUME_UP,
+                            ui::EF_NONE);
+  ui::KeyEvent vol_down_release(ui::ET_KEY_RELEASED, ui::VKEY_VOLUME_DOWN,
+                                ui::EF_NONE);
+  ui::KeyEvent vol_up_release(ui::ET_KEY_RELEASED, ui::VKEY_VOLUME_UP,
+                              ui::EF_NONE);
+
+  AccessibilityController* controller =
+      Shell::Get()->accessibility_controller();
+
+  ASSERT_FALSE(controller->IsSpokenFeedbackEnabled());
+  SendKeyEvent(&vol_down_press);
+  SendKeyEvent(&vol_up_press);
+  WaitForAccessibilityStatusChanged();
+  ASSERT_TRUE(controller->IsSpokenFeedbackEnabled());
+  SendKeyEvent(&vol_down_release);
+  SendKeyEvent(&vol_up_release);
+
+  SendKeyEvent(&vol_down_press);
+  SendKeyEvent(&vol_up_press);
+  WaitForAccessibilityStatusChanged();
+  ASSERT_FALSE(controller->IsSpokenFeedbackEnabled());
+}
+
+}  // namespace ash

ash/accessibility/spoken_feedback_enabler.cc

+// Copyright 2018 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/accessibility/spoken_feedback_enabler.h"
+
+#include "ash/accessibility/accessibility_controller.h"
+#include "ash/shell.h"
+#include "ui/events/base_event_utils.h"
+
+namespace ash {
+
+namespace {
+
+// Delay between timer callbacks. Each one plays a tick sound.
+constexpr base::TimeDelta kTimerDelay = base::TimeDelta::FromMilliseconds(500);
+
+// The number of ticks of the timer before the first sound is generated.
+constexpr int kTimerTicksOfFirstSoundFeedback = 6;
+
+// The number of ticks of the timer before toggling spoken feedback.
+constexpr int kTimerTicksToToggleSpokenFeedback = 10;
+
+}  // namespace
+
+SpokenFeedbackEnabler::SpokenFeedbackEnabler() {
+  start_time_ = ui::EventTimeForNow();
+  timer_.Start(FROM_HERE, kTimerDelay, this, &SpokenFeedbackEnabler::OnTimer);
+}
+
+SpokenFeedbackEnabler::~SpokenFeedbackEnabler() {}
+
+void SpokenFeedbackEnabler::OnTimer() {
+  base::TimeTicks now = ui::EventTimeForNow();
+  double tick_count_f = (now - start_time_) / kTimerDelay;
+  int tick_count = roundf(tick_count_f);
+
+  AccessibilityController* delegate = Shell::Get()->accessibility_controller();
+  CHECK(delegate);
+  if (tick_count >= kTimerTicksOfFirstSoundFeedback &&
+      tick_count < kTimerTicksToToggleSpokenFeedback) {
+    delegate->PlaySpokenFeedbackToggleCountdown(tick_count);
+  } else if (tick_count == kTimerTicksToToggleSpokenFeedback) {
+    delegate->SetSpokenFeedbackEnabled(!delegate->IsSpokenFeedbackEnabled(),
+                                       A11Y_NOTIFICATION_SHOW);
+    timer_.Stop();
+  }
+}
+
+}  // namespace ash

ash/accessibility/spoken_feedback_enabler.h

+// Copyright 2018 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_ACCESSIBILITY_SPOKEN_FEEDBACK_ENABLER_H_
+#define ASH_ACCESSIBILITY_SPOKEN_FEEDBACK_ENABLER_H_
+
+#include "ash/ash_export.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+
+namespace ash {
+
+// A class that enables ChromeVox based on a timer, providing progress
+// sound feedback.
+class ASH_EXPORT SpokenFeedbackEnabler {
+ public:
+  SpokenFeedbackEnabler();
+  ~SpokenFeedbackEnabler();
+
+ private:
+  // Handles ticks of the timer.
+  void OnTimer();
+
+  // The start time.
+  base::TimeTicks start_time_;
+
+  // A timer that triggers repeatedly until either cancel or the desired time
+  // elapsed.
+  base::RepeatingTimer timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SpokenFeedbackEnabler);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCESSIBILITY_SPOKEN_FEEDBACK_ENABLER_H_

ash/ash_strings.grd

@@ -208,6 +208,9 @@ This file contains the strings for ash.
       <message name="IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED" desc="The message shown on a notification when spoken feedback is enabled">
         Press Ctrl + Alt + Z to disable spoken feedback.
       </message>
+      <message name="IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED_TABLET" desc="The message shown on a notification when spoken feedback is enabled on a tablet">
+        Press and hold both volume keys for five seconds to disable spoken feedback.
+      </message>
       <message name="IDS_ASH_STATUS_TRAY_SPOKEN_FEEDBACK_ENABLED_TITLE" desc="The title message shown on a notification when spoken feedback is enabled">
         ChromeVox enabled
       </message>

ash/shell.cc

@@ -17,6 +17,7 @@
 #include "ash/accessibility/accessibility_controller.h"
 #include "ash/accessibility/accessibility_delegate.h"
 #include "ash/accessibility/accessibility_focus_ring_controller.h"
+#include "ash/accessibility/key_accessibility_enabler.h"
 #include "ash/app_list/app_list_controller_impl.h"
 #include "ash/ash_constants.h"
 #include "ash/assistant/ash_assistant_controller.h"
@@ -862,6 +863,7 @@ Shell::~Shell() {
   partial_magnification_controller_.reset();
   highlighter_controller_.reset();
   voice_interaction_controller_.reset();
+  key_accessibility_enabler_.reset();
 
   // This also deletes all RootWindows. Note that we invoke Shutdown() on
   // WindowTreeHostManager before resetting |window_tree_host_manager_|, since
@@ -1263,6 +1265,8 @@ void Shell::Init(ui::ContextFactory* context_factory,
 
   split_view_controller_.reset(new SplitViewController());
 
+  key_accessibility_enabler_ = std::make_unique<KeyAccessibilityEnabler>();
+
   // The compositor thread and main message loop have to be running in
   // order to create mirror window. Run it after the main message loop
   // is started.

ash/shell.h

@@ -116,6 +116,7 @@ class HighlighterController;
 class ImeController;
 class ImmersiveContextAsh;
 class ImmersiveHandlerFactoryAsh;
+class KeyAccessibilityEnabler;
 class KeyboardBrightnessControlDelegate;
 class KeyboardUI;
 class LaserPointerController;
@@ -410,6 +411,9 @@ class ASH_EXPORT Shell : public SessionObserver,
     return high_contrast_controller_.get();
   }
   ImeController* ime_controller() { return ime_controller_.get(); }
+  KeyAccessibilityEnabler* key_accessibility_enabler() {
+    return key_accessibility_enabler_.get();
+  }
   KeyboardBrightnessControlDelegate* keyboard_brightness_control_delegate() {
     return keyboard_brightness_control_delegate_.get();
   }
@@ -864,6 +868,10 @@ class ASH_EXPORT Shell : public SessionObserver,
   // hide the cursor on Windows.
   std::unique_ptr<::wm::CursorManager> cursor_manager_;
 
+  // Enables spoken feedback accessibility based on a press and hold of both
+  // volume keys.
+  std::unique_ptr<KeyAccessibilityEnabler> key_accessibility_enabler_;
+
   // For testing only: simulate that a modal window is open
   bool simulate_modal_window_open_for_test_ = false;