Dictation JS can toggle Dictation and listen for toggles.

Adds AccessibilityCommon API listener onToggleDictation
which is called when Dictation is toggled.

Dictation C++ is no longer activated on toggle, instead
Dictation JS listens for onToggleDictation and, as a
placeholder, turns Dictation off again once it is turned on.
This behavior only occurs when Chrome is run with the flag
--enable-experimental-accessibility-dictation-extension.

Bug: 1216111
Change-Id: I0ba8b295de0d209c19d84a177057cfe98fc3ad03
AX-Relnotes: N/A
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2936124
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#889521}

ash/public/cpp/accessibility_controller_enums.h

@@ -68,7 +68,10 @@ enum class DictationToggleSource {
   // Chromevox chrome extension.
   kChromevox,
 
-  kMaxValue = kChromevox
+  // Accessibility Common chrome extension.
+  kAccessibilityCommon,
+
+  kMaxValue = kAccessibilityCommon
 };
 
 enum class SelectToSpeakState {

chrome/browser/accessibility/accessibility_extension_api.cc

@@ -494,6 +494,8 @@ AccessibilityPrivateToggleDictationFunction::Run() {
     source = ash::DictationToggleSource::kSwitchAccess;
   else if (extension()->id() == extension_misc::kChromeVoxExtensionId)
     source = ash::DictationToggleSource::kChromevox;
+  else if (extension()->id() == extension_misc::kAccessibilityCommonExtensionId)
+    source = ash::DictationToggleSource::kAccessibilityCommon;
   else
     NOTREACHED();
 

chrome/browser/ash/accessibility/accessibility_manager.cc

@@ -1584,10 +1584,29 @@ bool AccessibilityManager::ToggleDictation() {
   if (!profile_)
     return false;
 
-  if (!dictation_.get())
-    dictation_ = std::make_unique<Dictation>(profile_);
+  if (!::switches::IsExperimentalAccessibilityDictationExtensionEnabled()) {
+    if (!dictation_.get())
+      dictation_ = std::make_unique<Dictation>(profile_);
 
-  return dictation_->OnToggleDictation();
+    return dictation_->OnToggleDictation();
+  }
+
+  // We are using AccessibilityCommon extension instead of Dictation C++,
+  // so track Dictation state and simply send a notification to the
+  // AccessibilityPrivate API.
+  dictation_active_ = !dictation_active_;
+  extensions::EventRouter* event_router =
+      extensions::EventRouter::Get(profile_);
+  auto event_args = std::vector<base::Value>();
+  event_args.emplace_back(dictation_active_);
+  auto event = std::make_unique<extensions::Event>(
+      extensions::events::ACCESSIBILITY_PRIVATE_ON_TOGGLE_DICTATION,
+      extensions::api::accessibility_private::OnToggleDictation::kEventName,
+      std::move(event_args));
+  event_router->DispatchEventWithLazyListener(
+      extension_misc::kAccessibilityCommonExtensionId, std::move(event));
+
+  return dictation_active_;
 }
 
 const std::string AccessibilityManager::GetFocusRingId(

chrome/browser/ash/accessibility/accessibility_manager.h

@@ -497,6 +497,7 @@ class AccessibilityManager
   bool app_terminating_ = false;
 
   std::unique_ptr<Dictation> dictation_;
+  bool dictation_active_ = false;
 
   base::RepeatingCallback<void()> focus_ring_observer_for_test_;
   base::RepeatingCallback<void()> select_to_speak_state_observer_for_test_;

chrome/browser/resources/chromeos/accessibility/accessibility_common/dictation/dictation.js

@@ -8,5 +8,21 @@
  * --enable-experimental-accessibility-dictation-extension
  */
 export class Dictation {
-  constructor() {}
+  constructor() {
+    chrome.accessibilityPrivate.onToggleDictation.addListener(
+        this.onToggleDictation_.bind(this));
+  }
+
+  /**
+   * Called when Dictation is toggled.
+   * @param {boolean} activated Whether Dictation was just activated.
+   * @private
+   */
+  onToggleDictation_(activated) {
+    if (activated) {
+      // Dictation as a JS extension isn't actually implemented yet, so just
+      // turn off again.
+      chrome.accessibilityPrivate.toggleDictation();
+    }
+  }
 }

chrome/common/extensions/api/accessibility_private.json

@@ -789,6 +789,19 @@
         "description": "Fired when ChromeVox should show its tutorial.",
         "parameters": [],
         "platforms": ["chromeos"]
+      },
+      {
+        "name": "onToggleDictation",
+        "type": "function",
+        "description": "Fired when Dictation is activated or deactivated using a keyboard shortcut, the button in the tray, or after a call from accessibilityPrivate.toggleDictation",
+        "parameters": [
+          {
+            "name": "activated",
+            "type": "boolean",
+            "description": "True if Dictation was activated, false if it was deactivated."
+          }
+        ],
+        "platforms": ["chromeos"]
       }
     ]
   }

extensions/browser/extension_event_histogram_value.h

@@ -498,6 +498,7 @@ enum HistogramValue {
   TTS_ENGINE_ON_SPEAK_WITH_AUDIO_STREAM = 476,
   ACCESSIBILITY_PRIVATE_ON_SHOW_CHROMEVOX_TUTORIAL = 477,
   STORAGE_SESSION_ON_CHANGE = 478,
+  ACCESSIBILITY_PRIVATE_ON_TOGGLE_DICTATION = 479,
   // Last entry: Add new entries above, then run:
   // python tools/metrics/histograms/update_extension_histograms.py
   ENUM_BOUNDARY

third_party/closure_compiler/externs/accessibility_private.js

@@ -7,7 +7,7 @@
 // NOTE: The format of types has changed. 'FooType' is now
 //   'chrome.accessibilityPrivate.FooType'.
 // Please run the closure compiler before committing changes.
-// See https://chromium.googlesource.com/chromium/src/+/master/docs/closure_compilation.md
+// See https://chromium.googlesource.com/chromium/src/+/main/docs/closure_compilation.md
 
 /** @fileoverview Externs generated from namespace: accessibilityPrivate */
 
@@ -561,3 +561,11 @@ chrome.accessibilityPrivate.onCustomSpokenFeedbackToggled;
  * @type {!ChromeEvent}
  */
 chrome.accessibilityPrivate.onShowChromeVoxTutorial;
+
+/**
+ * Fired when Dictation is activated or deactivated using a keyboard shortcut,
+ * the button in the tray, or after a call from
+ * accessibilityPrivate.toggleDictation
+ * @type {!ChromeEvent}
+ */
+chrome.accessibilityPrivate.onToggleDictation;

tools/metrics/histograms/enums.xml

@@ -15618,6 +15618,7 @@ metrics consent we also won't be able to send UMA metrics. -->
   <int value="1" label="Click onscreen button"/>
   <int value="2" label="Select the button in the SwitchAccess context menu"/>
   <int value="3" label="ChromeVox gesture"/>
+  <int value="4" label="AccessibilityCommon extension"/>
 </enum>
 
 <enum name="CrosDisksArchiveType">
@@ -26043,6 +26044,7 @@ Called by update_extension_histograms.py.-->
   <int value="476" label="TTS_ENGINE_ON_SPEAK_WITH_AUDIO_STREAM"/>
   <int value="477" label="ACCESSIBILITY_PRIVATE_ON_SHOW_CHROMEVOX_TUTORIAL"/>
   <int value="478" label="STORAGE_SESSION_ON_CHANGE"/>
+  <int value="479" label="ACCESSIBILITY_PRIVATE_ON_TOGGLE_DICTATION"/>
 </enum>
 
 <enum name="ExtensionFileWriteResult">