Add alert for entering/exiting tablet mode

Bug: 1010200
Change-Id: Ie3d552b6108c491e12510fb32f544a0d0f938453
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2353548Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Min Chen <minch@chromium.org>
Commit-Queue: Xiaodan Zhu <zxdan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799345}

ash/accessibility/test_accessibility_controller_client.cc

@@ -26,7 +26,9 @@ void TestAccessibilityControllerClient::TriggerAccessibilityAlert(
 }
 
 void TestAccessibilityControllerClient::TriggerAccessibilityAlertWithMessage(
-    const std::string& message) {}
+    const std::string& message) {
+  last_alert_message_ = message;
+}
 
 void TestAccessibilityControllerClient::PlayEarcon(int32_t sound_key) {
   sound_key_ = sound_key;

ash/accessibility/test_accessibility_controller_client.h

@@ -49,10 +49,11 @@ class TestAccessibilityControllerClient : public AccessibilityControllerClient {
   int select_to_speak_change_change_requests() const {
     return select_to_speak_state_change_requests_;
   }
+  const std::string& last_alert_message() const { return last_alert_message_; }
 
  private:
   AccessibilityAlert last_a11y_alert_ = AccessibilityAlert::NONE;
-
+  std::string last_alert_message_;
   int32_t sound_key_ = -1;
   bool is_dictation_active_ = false;
 

ash/ash_strings.grd

@@ -2660,6 +2660,13 @@ Here are some things you can try to get started.
       <message name="IDS_ASH_SCREEN_CAPTURE_BUTTON_DELETE" desc="The delete button label for the screen capture notificaiton.">
         Delete
       </message>
+      <!-- Switch Between TABLET/LAPTOP MODE-->
+      <message name="IDS_ASH_SWITCH_TO_TABLET_MODE" desc="Alert of switching to tablet mode.">
+        Switch to tablet mode
+      </message>
+      <message name="IDS_ASH_SWITCH_TO_LAPTOP_MODE" desc="Alert of switching to laptop mode.">
+        Switch to laptop mode
+      </message>
     </messages>
   </release>
 </grit>

ash/ash_strings_grd/IDS_ASH_SWITCH_TO_LAPTOP_MODE.png.sha1

+f80e905aa5f4885c58b0194719c231045d4b4b74
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SWITCH_TO_TABLET_MODE.png.sha1

+e88fae42cb9817f6de8b9ff7c52aa898e8f6f57b
\ No newline at end of file

ash/wm/tablet_mode/tablet_mode_controller.cc

@@ -8,6 +8,7 @@
 #include <string>
 #include <utility>
 
+#include "ash/accessibility/accessibility_controller_impl.h"
 #include "ash/public/cpp/ash_switches.h"
 #include "ash/public/cpp/metrics_util.h"
 #include "ash/public/cpp/shelf_config.h"
@@ -18,6 +19,7 @@
 #include "ash/shelf/shelf.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
+#include "ash/strings/grit/ash_strings.h"
 #include "ash/wm/overview/overview_controller.h"
 #include "ash/wm/splitview/split_view_utils.h"
 #include "ash/wm/tablet_mode/internal_input_devices_event_blocker.h"
@@ -42,6 +44,7 @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/accelerators/accelerator.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/display/display.h"
 #include "ui/display/manager/display_manager.h"
@@ -1329,6 +1332,11 @@ bool TabletModeController::UpdateUiTabletState() {
     return false;
 
   SetTabletModeEnabledInternal(should_be_in_tablet_mode);
+  Shell::Get()
+      ->accessibility_controller()
+      ->TriggerAccessibilityAlertWithMessage(l10n_util::GetStringUTF8(
+          should_be_in_tablet_mode ? IDS_ASH_SWITCH_TO_TABLET_MODE
+                                   : IDS_ASH_SWITCH_TO_LAPTOP_MODE));
   return true;
 }
 

ash/wm/tablet_mode/tablet_mode_controller_unittest.cc

@@ -11,10 +11,13 @@
 
 #include "ash/accelerometer/accelerometer_reader.h"
 #include "ash/accelerometer/accelerometer_types.h"
+#include "ash/accessibility/accessibility_controller_impl.h"
+#include "ash/accessibility/test_accessibility_controller_client.h"
 #include "ash/app_list/app_list_controller_impl.h"
 #include "ash/app_list/test/app_list_test_helper.h"
 #include "ash/app_list/views/app_list_view.h"
 #include "ash/display/screen_orientation_controller.h"
+#include "ash/public/cpp/accessibility_controller.h"
 #include "ash/public/cpp/app_types.h"
 #include "ash/public/cpp/ash_features.h"
 #include "ash/public/cpp/ash_switches.h"
@@ -24,6 +27,7 @@
 #include "ash/public/cpp/window_properties.h"
 #include "ash/screen_util.h"
 #include "ash/shell.h"
+#include "ash/strings/grit/ash_strings.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/overview/overview_controller.h"
 #include "ash/wm/overview/overview_wallpaper_controller.h"
@@ -46,6 +50,7 @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/test/test_window_delegate.h"
 #include "ui/base/hit_test.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/compositor/test/test_utils.h"
@@ -723,6 +728,20 @@ TEST_P(TabletModeControllerTest, VerticalHingeUnstableAnglesTest) {
   }
 }
 
+// Verify that the Alert Message will be triggered when switching between tablet
+// mode and laptop mode.
+TEST_P(TabletModeControllerTest, AlertInAndOutTabletMode) {
+  TestAccessibilityControllerClient client;
+
+  SetTabletMode(true);
+  EXPECT_TRUE(l10n_util::GetStringUTF8(IDS_ASH_SWITCH_TO_TABLET_MODE) ==
+              client.last_alert_message());
+
+  SetTabletMode(false);
+  EXPECT_TRUE(l10n_util::GetStringUTF8(IDS_ASH_SWITCH_TO_LAPTOP_MODE) ==
+              client.last_alert_message());
+}
+
 // Tests that when a TabletModeController is created that cached tablet mode
 // state will trigger a mode update.
 class TabletModeControllerInitedFromPowerManagerClientTest