Capture Mode: a11y chromevox announcements for selecting

CL #1 of 2 for chromevox announcements (second part is for tab
navigation).

Add the following announcements:
-Entering capture mode
-Exiting capture mode
-Selecting the type (image/video)
-Selecting the source (window/region/fullscreen)
-Screenshot captured
-Recording starting
-Recording stopped

Bug: 1140597
Test: manual
Change-Id: I17c8d62de27507dfd4a9711201525fbd76b993cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2598056
Commit-Queue: Richard Chui <richui@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843917}

ash/ash_strings.grd

@@ -3323,6 +3323,51 @@ Here are some things you can try to get started.
       <message name="IDS_ASH_SCREEN_CAPTURE_SETTING_OFF_STATE" desc="Description for a setting toggle off state.">
         off
       </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_OPEN" desc="Alert spoken by screen readers on entering capture mode.">
+        Capture Mode, default is <ph name="SOURCE">$1<ex>partial</ex></ph> <ph name="TYPE">$2<ex>screenshot</ex></ph>.
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_SOURCE_FULLSCREEN" desc="Spoken by screen readers for the open alert with the source as full screen.">
+        full screen
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_SOURCE_PARTIAL" desc="Spoken by screen readers for the open alert with the source as partial.">
+        partial
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_SOURCE_WINDOW" desc="Spoken by screen readers for the open alert with the source as window.">
+        window
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_TYPE_SCREENSHOT" desc="Spoken by screen readers for the open alert with the type as screenshot.">
+        screenshot
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_TYPE_SCREEN_RECORDING" desc="Spoken by screen readers for the open alert with the type as screen recording.">
+        screen recording
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_CLOSE" desc="Alert spoken by screen readers when exiting capture mode.">
+        Exit capture mode
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_IMAGE" desc="Alert spoken by screen readers on selecting screenshot mode.">
+        Screenshot mode selected
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_VIDEO" desc="Alert spoken by screen readers on selecting screen recording mode.">
+        Screen recording mode selected
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_FULLSCREEN" desc="Alert spoken by screen readers on selecting full screen as source.">
+        Selection area set to full screen
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_REGION" desc="Alert spoken by screen readers on selecting partial screen as source.">
+        Partial screenshot selected
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_WINDOW" desc="Alert spoken by screen readers on selecting window as source.">
+        Selection area set to window
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SCREENSHOT_CAPTURED" desc="Alert spoken by screen readers when screenshot captured.">
+        Screenshot captured
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STARTING" desc="Alert spoken by screen readers when recording starts.">
+        Recording starting in 3, 2, 1
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STOPPED" desc="Alert spoken by screen readers when recording stops.">
+        Screen recording completed
+      </message>
 
       <!-- Switch Between TABLET/LAPTOP MODE-->
       <message name="IDS_ASH_SWITCH_TO_TABLET_MODE" desc="Alert of switching to tablet mode.">

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_CLOSE.png.sha1

+b579f2fd0620061f426650f31ae0c917f8dd89d7
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_OPEN.png.sha1

+f9f2851b5d3913fafe28fbbadd2c8a1522396ecc
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STARTING.png.sha1

+32627ca6008b88cca148d7289ff2f67503976b83
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STOPPED.png.sha1

+80bb8009c74103c155e3fbec35452f391d459a64
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SCREENSHOT_CAPTURED.png.sha1

+2352bfd8f6fe06a2facebd9591ddc59b0e090f8e
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_FULLSCREEN.png.sha1

+f95a2a78824a8e773a1d824d2b1dc4960a718065
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_REGION.png.sha1

+f593832fe7ecff335da8e567418d01826fe9d995
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_WINDOW.png.sha1

+e4c2b9fd39522b27b0db03d35ae28a59e2ed4fc7
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_IMAGE.png.sha1

+b899ae55a980819614baa38ed42cf1f8aad414d0
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_VIDEO.png.sha1

+1ca3ac5e681b4bef5320ec2787e0c697f49d0142
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_SOURCE_FULLSCREEN.png.sha1

+28c64da72bd4769cf94b800981ef13f2fadc4eca
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_SOURCE_PARTIAL.png.sha1

+6fde7de7ebbe279265bd4348ece7ecbbe6762e98
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_SOURCE_WINDOW.png.sha1

+6d4784959f506b95e1139ff9848c245014d187ff
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_TYPE_SCREENSHOT.png.sha1

+28c64da72bd4769cf94b800981ef13f2fadc4eca
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_TYPE_SCREEN_RECORDING.png.sha1

+6fde7de7ebbe279265bd4348ece7ecbbe6762e98
\ No newline at end of file

ash/capture_mode/capture_mode_controller.cc

@@ -747,6 +747,9 @@ void CaptureModeController::TerminateRecordingUiElements() {
       video_recording_watcher_->window_being_recorded()->GetRootWindow(),
       false);
   video_recording_watcher_.reset();
+
+  capture_mode_util::TriggerAccessibilityAlert(
+      IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STOPPED);
 }
 
 void CaptureModeController::CaptureImage(const CaptureParams& capture_params,
@@ -771,6 +774,9 @@ void CaptureModeController::CaptureImage(const CaptureParams& capture_params,
 
   ++num_consecutive_screenshots_;
   num_consecutive_screenshots_scheduler_.Reset();
+
+  capture_mode_util::TriggerAccessibilityAlert(
+      IDS_ASH_SCREEN_CAPTURE_ALERT_SCREENSHOT_CAPTURED);
 }
 
 void CaptureModeController::CaptureVideo(const CaptureParams& capture_params) {
@@ -786,6 +792,9 @@ void CaptureModeController::CaptureVideo(const CaptureParams& capture_params) {
   capture_mode_session_->StartCountDown(
       base::BindOnce(&CaptureModeController::OnVideoRecordCountDownFinished,
                      weak_ptr_factory_.GetWeakPtr()));
+
+  capture_mode_util::TriggerAccessibilityAlert(
+      IDS_ASH_SCREEN_CAPTURE_ALERT_RECORDING_STARTING);
 }
 
 void CaptureModeController::OnImageCaptured(
@@ -988,6 +997,10 @@ void CaptureModeController::OnVideoRecordCountDownFinished() {
   if (!IsActive())
     return;
 
+  // Do not trigger an alert when exiting the session, since we end the session
+  // to start recording.
+  capture_mode_session_->set_a11y_alert_on_session_exit(false);
+
   const base::Optional<CaptureParams> capture_params = GetCaptureParams();
   // Stop the capture session now, so the bar doesn't show up in the captured
   // video.

ash/capture_mode/capture_mode_session.cc

@@ -16,6 +16,7 @@
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/shell.h"
+#include "ash/strings/grit/ash_strings.h"
 #include "ash/style/ash_color_provider.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
@@ -27,6 +28,7 @@
 #include "ui/aura/window.h"
 #include "ui/base/cursor/cursor_factory.h"
 #include "ui/base/cursor/cursor_util.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_type.h"
 #include "ui/compositor/paint_recorder.h"
@@ -285,6 +287,27 @@ void ClipRectToFit(gfx::Rect* out_bounds, const gfx::Rect& rect) {
                           std::min(rect.bottom(), out_bounds->bottom()));
 }
 
+// Returns the appropriate |message_id| for a chromevox alert.
+// |for_toggle_alert| helps differentiate between the session start and when a
+// user toggles the source.
+int GetMessageIdForCaptureSource(CaptureModeSource source,
+                                 bool for_toggle_alert) {
+  switch (source) {
+    case CaptureModeSource::kFullscreen:
+      return for_toggle_alert
+                 ? IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_FULLSCREEN
+                 : IDS_ASH_SCREEN_CAPTURE_SOURCE_FULLSCREEN;
+    case CaptureModeSource::kRegion:
+      return for_toggle_alert
+                 ? IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_REGION
+                 : IDS_ASH_SCREEN_CAPTURE_SOURCE_PARTIAL;
+    default:
+      return for_toggle_alert
+                 ? IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_SOURCE_WINDOW
+                 : IDS_ASH_SCREEN_CAPTURE_SOURCE_WINDOW;
+  }
+}
+
 }  // namespace
 
 class CaptureModeSession::CursorSetter {
@@ -460,6 +483,15 @@ CaptureModeSession::CaptureModeSession(CaptureModeController* controller)
   TabletModeController::Get()->AddObserver(this);
   current_root_->AddObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
+
+  capture_mode_util::TriggerAccessibilityAlert(l10n_util::GetStringFUTF8(
+      IDS_ASH_SCREEN_CAPTURE_ALERT_OPEN,
+      l10n_util::GetStringUTF16(GetMessageIdForCaptureSource(
+          controller_->source(), /*for_toggle_alert=*/false)),
+      l10n_util::GetStringUTF16(
+          controller_->type() == CaptureModeType::kImage
+              ? IDS_ASH_SCREEN_CAPTURE_TYPE_SCREENSHOT
+              : IDS_ASH_SCREEN_CAPTURE_TYPE_SCREEN_RECORDING)));
 }
 
 CaptureModeSession::~CaptureModeSession() {
@@ -485,6 +517,11 @@ CaptureModeSession::~CaptureModeSession() {
     dimensions_label_widget_->CloseNow();
   DCHECK(capture_mode_bar_widget_);
   capture_mode_bar_widget_->CloseNow();
+
+  if (a11y_alert_on_session_exit_) {
+    capture_mode_util::TriggerAccessibilityAlert(
+        IDS_ASH_SCREEN_CAPTURE_ALERT_CLOSE);
+  }
 }
 
 aura::Window* CaptureModeSession::GetSelectedWindow() const {
@@ -509,6 +546,9 @@ void CaptureModeSession::OnCaptureSourceChanged(CaptureModeSource new_source) {
   UpdateCaptureLabelWidget();
   UpdateCursor(display::Screen::GetScreen()->GetCursorScreenPoint(),
                /*is_touch=*/false);
+
+  capture_mode_util::TriggerAccessibilityAlert(
+      GetMessageIdForCaptureSource(new_source, /*for_toggle_alert=*/true));
 }
 
 void CaptureModeSession::OnCaptureTypeChanged(CaptureModeType new_type) {
@@ -516,6 +556,11 @@ void CaptureModeSession::OnCaptureTypeChanged(CaptureModeType new_type) {
   UpdateCaptureLabelWidget();
   UpdateCursor(display::Screen::GetScreen()->GetCursorScreenPoint(),
                /*is_touch=*/false);
+
+  capture_mode_util::TriggerAccessibilityAlert(
+      new_type == CaptureModeType::kImage
+          ? IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_IMAGE
+          : IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_VIDEO);
 }
 
 void CaptureModeSession::ReportSessionHistograms() {

ash/capture_mode/capture_mode_session.h

@@ -64,6 +64,9 @@ class ASH_EXPORT CaptureModeSession : public ui::LayerOwner,
   aura::Window* current_root() const { return current_root_; }
   bool is_selecting_region() const { return is_selecting_region_; }
   bool is_drag_in_progress() const { return is_drag_in_progress_; }
+  void set_a11y_alert_on_session_exit(bool value) {
+    a11y_alert_on_session_exit_ = value;
+  }
 
   // Gets the current window selected for |kWindow| capture source. Returns
   // nullptr if no window is available for selection.
@@ -309,6 +312,9 @@ class ASH_EXPORT CaptureModeSession : public ui::LayerOwner,
   // The window which had input capture prior to entering the session. It may be
   // null if no such window existed.
   aura::Window* input_capture_window_ = nullptr;
+
+  // False only when we end the session to start recording.
+  bool a11y_alert_on_session_exit_ = true;
 };
 
 }  // namespace ash

ash/capture_mode/capture_mode_util.cc

@@ -4,10 +4,13 @@
 
 #include "ash/capture_mode/capture_mode_util.h"
 
+#include "ash/accessibility/accessibility_controller_impl.h"
 #include "ash/capture_mode/stop_recording_button_tray.h"
 #include "ash/root_window_controller.h"
+#include "ash/shell.h"
 #include "base/check.h"
 #include "base/notreached.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 
@@ -84,6 +87,16 @@ void SetStopRecordingButtonVisibility(aura::Window* root, bool visible) {
   stop_recording_button->SetVisiblePreferred(visible);
 }
 
+void TriggerAccessibilityAlert(const std::string& message) {
+  Shell::Get()
+      ->accessibility_controller()
+      ->TriggerAccessibilityAlertWithMessage(message);
+}
+
+void TriggerAccessibilityAlert(int message_id) {
+  TriggerAccessibilityAlert(l10n_util::GetStringUTF8(message_id));
+}
+
 }  // namespace capture_mode_util
 
 }  // namespace ash

ash/capture_mode/capture_mode_util.h

@@ -5,6 +5,8 @@
 #ifndef ASH_CAPTURE_MODE_CAPTURE_MODE_UTIL_H_
 #define ASH_CAPTURE_MODE_CAPTURE_MODE_UTIL_H_
 
+#include <string>
+
 #include "ash/ash_export.h"
 #include "ash/capture_mode/capture_mode_types.h"
 
@@ -35,6 +37,10 @@ bool ShouldHideDragAffordance(FineTunePosition position);
 // widget of the given |root| window.
 void SetStopRecordingButtonVisibility(aura::Window* root, bool visible);
 
+// Triggers an accessibility alert to give the user feedback.
+void TriggerAccessibilityAlert(const std::string& message);
+void TriggerAccessibilityAlert(int message_id);
+
 }  // namespace capture_mode_util
 
 }  // namespace ash