Fix WebView accessibility scripts. (df313699) · Commits · e / os / android_frameworks_base

core/java/android/webkit/AccessibilityInjector.java

+159 −11

Original line number	Diff line number	Diff line
		@@ -21,6 +21,10 @@ import android.os.Bundle;
		import android.os.SystemClock;
		import android.provider.Settings;
		import android.speech.tts.TextToSpeech;
		import android.speech.tts.TextToSpeech.Engine;
		import android.speech.tts.TextToSpeech.OnInitListener;
		import android.speech.tts.UtteranceProgressListener;
		import android.util.Log;
		import android.view.KeyEvent;
		import android.view.View;
		import android.view.accessibility.AccessibilityManager;
		@@ -44,6 +48,10 @@ import java.util.concurrent.atomic.AtomicInteger;
		* APIs.
		*/
		class AccessibilityInjector {
		private static final String TAG = AccessibilityInjector.class.getSimpleName();

		private static boolean DEBUG = false;

		// The WebViewClassic this injector is responsible for managing.
		private final WebViewClassic mWebViewClassic;

		@@ -90,6 +98,10 @@ class AccessibilityInjector {
		private static final String ACCESSIBILITY_ANDROIDVOX_TEMPLATE =
		"cvox.AndroidVox.performAction('%1s')";

		// JS code used to shut down an active AndroidVox instance.
		private static final String TOGGLE_CVOX_TEMPLATE =
		"javascript:(function() { cvox.ChromeVox.host.activateOrDeactivateChromeVox(%b); })();";

		/**
		* Creates an instance of the AccessibilityInjector based on
		* {@code webViewClassic}.
		@@ -117,6 +129,7 @@ class AccessibilityInjector {

		addTtsApis();
		addCallbackApis();
		toggleAndroidVox(true);
		}

		/**
		@@ -126,10 +139,20 @@ class AccessibilityInjector {
		* </p>
		*/
		public void removeAccessibilityApisIfNecessary() {
		toggleAndroidVox(false);
		removeTtsApis();
		removeCallbackApis();
		}

		private void toggleAndroidVox(boolean state) {
		if (!mAccessibilityScriptInjected) {
		return;
		}

		final String code = String.format(TOGGLE_CVOX_TEMPLATE, state);
		mWebView.loadUrl(code);
		}

		/**
		* Initializes an {@link AccessibilityNodeInfo} with the actions and
		* movement granularity levels supported by this
		@@ -262,6 +285,9 @@ class AccessibilityInjector {
		*/
		public void onPageStarted(String url) {
		mAccessibilityScriptInjected = false;
		if (DEBUG)
		Log.w(TAG, "[" + mWebView.hashCode() + "] Started loading new page");
		addAccessibilityApisIfNecessary();
		}

		/**
		@@ -282,15 +308,23 @@ class AccessibilityInjector {
		if (!shouldInjectJavaScript(url)) {
		mAccessibilityScriptInjected = false;
		toggleFallbackAccessibilityInjector(true);
		if (DEBUG)
		Log.d(TAG, "[" + mWebView.hashCode() + "] Using fallback accessibility support");
		return;
		}

		toggleFallbackAccessibilityInjector(false);

		if (!mAccessibilityScriptInjected) {
		mAccessibilityScriptInjected = true;
		final String injectionUrl = getScreenReaderInjectionUrl();
		mWebView.loadUrl(injectionUrl);

		mAccessibilityScriptInjected = true;
		if (DEBUG)
		Log.d(TAG, "[" + mWebView.hashCode() + "] Loading screen reader into WebView");
		} else {
		if (DEBUG)
		Log.w(TAG, "[" + mWebView.hashCode() + "] Attempted to inject screen reader twice");
		}
		}

		/**
		@@ -368,6 +402,8 @@ class AccessibilityInjector {
		if (mTextToSpeech != null) {
		return;
		}
		if (DEBUG)
		Log.d(TAG, "[" + mWebView.hashCode() + "] Adding TTS APIs into WebView");
		mTextToSpeech = new TextToSpeechWrapper(mContext);
		mWebView.addJavascriptInterface(mTextToSpeech, ALIAS_TTS_JS_INTERFACE);
		}
		@@ -381,6 +417,8 @@ class AccessibilityInjector {
		return;
		}

		if (DEBUG)
		Log.d(TAG, "[" + mWebView.hashCode() + "] Removing TTS APIs from WebView");
		mWebView.removeJavascriptInterface(ALIAS_TTS_JS_INTERFACE);
		mTextToSpeech.stop();
		mTextToSpeech.shutdown();
		@@ -527,37 +565,143 @@ class AccessibilityInjector {
		* Used to protect the TextToSpeech class, only exposing the methods we want to expose.
		*/
		private static class TextToSpeechWrapper {
		private TextToSpeech mTextToSpeech;
		private static final String WRAP_TAG = TextToSpeechWrapper.class.getSimpleName();

		private final HashMap<String, String> mTtsParams;
		private final TextToSpeech mTextToSpeech;

		/**
		* Whether this wrapper is ready to speak. If this is {@code true} then
		* {@link #mShutdown} is guaranteed to be {@code false}.
		*/
		private volatile boolean mReady;

		/**
		* Whether this wrapper was shut down. If this is {@code true} then
		* {@link #mReady} is guaranteed to be {@code false}.
		*/
		private volatile boolean mShutdown;

		public TextToSpeechWrapper(Context context) {
		if (DEBUG)
		Log.d(WRAP_TAG, "[" + hashCode() + "] Initializing text-to-speech on thread "
		+ Thread.currentThread().getId() + "...");

		final String pkgName = context.getPackageName();
		mTextToSpeech = new TextToSpeech(context, null, null, pkgName + ".webview", true);

		mReady = false;
		mShutdown = false;

		mTtsParams = new HashMap<String, String>();
		mTtsParams.put(Engine.KEY_PARAM_UTTERANCE_ID, WRAP_TAG);

		mTextToSpeech = new TextToSpeech(
		context, mInitListener, null, pkgName + ".webview", true);
		mTextToSpeech.setOnUtteranceProgressListener(mErrorListener);
		}

		@JavascriptInterface
		@SuppressWarnings("unused")
		public boolean isSpeaking() {
		synchronized (mTextToSpeech) {
		if (!mReady) {
		return false;
		}

		return mTextToSpeech.isSpeaking();
		}
		}

		@JavascriptInterface
		@SuppressWarnings("unused")
		public int speak(String text, int queueMode, HashMap<String, String> params) {
		synchronized (mTextToSpeech) {
		if (!mReady) {
		if (DEBUG)
		Log.w(WRAP_TAG, "[" + hashCode() + "] Attempted to speak before TTS init");
		return TextToSpeech.ERROR;
		} else {
		if (DEBUG)
		Log.i(WRAP_TAG, "[" + hashCode() + "] Speak called from JS binder");
		}

		return mTextToSpeech.speak(text, queueMode, params);
		}
		}

		@JavascriptInterface
		@SuppressWarnings("unused")
		public int stop() {
		synchronized (mTextToSpeech) {
		if (!mReady) {
		if (DEBUG)
		Log.w(WRAP_TAG, "[" + hashCode() + "] Attempted to stop before initialize");
		return TextToSpeech.ERROR;
		} else {
		if (DEBUG)
		Log.i(WRAP_TAG, "[" + hashCode() + "] Stop called from JS binder");
		}

		return mTextToSpeech.stop();
		}
		}

		@SuppressWarnings("unused")
		protected void shutdown() {
		synchronized (mTextToSpeech) {
		if (!mReady) {
		if (DEBUG)
		Log.w(WRAP_TAG, "[" + hashCode() + "] Called shutdown before initialize");
		} else {
		if (DEBUG)
		Log.i(WRAP_TAG, "[" + hashCode() + "] Shutting down text-to-speech from "
		+ "thread " + Thread.currentThread().getId() + "...");
		}
		mShutdown = true;
		mReady = false;
		mTextToSpeech.shutdown();
		}
		}

		private final OnInitListener mInitListener = new OnInitListener() {
		@Override
		public void onInit(int status) {
		synchronized (mTextToSpeech) {
		if (!mShutdown && (status == TextToSpeech.SUCCESS)) {
		if (DEBUG)
		Log.d(WRAP_TAG, "[" + TextToSpeechWrapper.this.hashCode()
		+ "] Initialized successfully");
		mReady = true;
		} else {
		if (DEBUG)
		Log.w(WRAP_TAG, "[" + TextToSpeechWrapper.this.hashCode()
		+ "] Failed to initialize");
		mReady = false;
		}
		}
		}
		};

		private final UtteranceProgressListener mErrorListener = new UtteranceProgressListener() {
		@Override
		public void onStart(String utteranceId) {
		// Do nothing.
		}

		@Override
		public void onError(String utteranceId) {
		if (DEBUG)
		Log.w(WRAP_TAG, "[" + TextToSpeechWrapper.this.hashCode()
		+ "] Failed to speak utterance");
		}

		@Override
		public void onDone(String utteranceId) {
		// Do nothing.
		}
		};
		}

		/**
		* Exposes result interface to JavaScript.
		*/
		@@ -625,6 +769,8 @@ class AccessibilityInjector {
		* @return Whether the result was received.
		*/
		private boolean waitForResultTimedLocked(int resultId) {
		if (DEBUG)
		Log.d(TAG, "Waiting for CVOX result...");
		long waitTimeMillis = RESULT_TIMEOUT;
		final long startTimeMillis = SystemClock.uptimeMillis();
		while (true) {
		@@ -642,6 +788,8 @@ class AccessibilityInjector {
		}
		mResultLock.wait(waitTimeMillis);
		} catch (InterruptedException ie) {
		if (DEBUG)
		Log.w(TAG, "Timed out while waiting for CVOX result");
		/* ignore */
		}
		}