This question asked how to know if Android Talkback is active; that worked until Jelly Bean. Starting from Android 4.1, that steps no longer work, because the mentioned cursor is empty.
Having this said, I want to ask is if there is a way to do the same checking in Jelly Bean.
EDIT I tried to search for TalkBack code and I found it here. For checking if TalkBack is active, I am using the following code:
Intent screenReaderIntent = new Intent("android.accessibilityservice.AccessibilityService");
screenReaderIntent.addCategory("android.accessibilityservice.category.FEEDBACK_SPOKEN");
List<ResolveInfo> screenReaders = getPackageManager().queryIntentServices(screenReaderIntent, 0);
Cursor cursor = null;
ContentResolver cr = getContentResolver();
for (ResolveInfo screenReader : screenReaders) {
cursor = cr.query(Uri.parse("content://" + screenReader.serviceInfo.packageName
+ ".providers.StatusProvider"), null, null, null, null);
//here, cursor is not null, but calling cursor.moveToFirst() returns false, which means the cursor is empty
}
Having this said, if the cursor is empty, how do we know if TalkBack is running?
EDIT 2 Following @JoxTraex suggestions, I am now sending a broadcast to query whether or not TalkBack is enabled:
Intent i = new Intent();
i.setAction("com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND");
sendBroadcast(i);
Now how should I receive the response?
I tried adding the following to manifest, but my receiver does not receive any response:
<receiver android:name="my.package.MyBroadcastReceiver"
android:permission="com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK">
<intent-filter>
<action android:name="com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND" />
</intent-filter>
This can be achieved much easier by using AccessibilityManager
.
AccessibilityManager am = (AccessibilityManager) getSystemService(ACCESSIBILITY_SERVICE);
boolean isAccessibilityEnabled = am.isEnabled();
boolean isExploreByTouchEnabled = am.isTouchExplorationEnabled();
While looking at TalkBackService.java, I found these code segments. These segments should provide some insight on how to query the status.
Code
/**
* {@link Intent} broadcast action for querying the state of TalkBack. </p>
* Note: Sending intent broadcast commands to TalkBack must be performed
* through {@link Context#sendBroadcast(Intent, String)}
*/
@Deprecated
// TODO(caseyburkhardt): Remove when we decide to no longer support intent broadcasts for
// querying the current state of TalkBack.
public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";
/**
* Result that TalkBack is enabled.
*
* @see #ACTION_QUERY_TALKBACK_ENABLED_COMMAND
*/
public static final int RESULT_TALKBACK_ENABLED = 0x00000001;
/**
* Result that TalkBack is disabled.
*
* @see #ACTION_QUERY_TALKBACK_ENABLED_COMMAND
*/
public static final int RESULT_TALKBACK_DISABLED = 0x00000002;
/**
* Permission to send {@link Intent} broadcast commands to TalkBack.
*/
public static final String PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK = "com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK";
/**
* Tag for logging.
*/
private static final String LOG_TAG = "TalkBackService";
public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";
..
} else if (ACTION_QUERY_TALKBACK_ENABLED_COMMAND.equals(intentAction)) {
// TODO(caseyburkhardt): Remove this block when we decide to no
// longer support
// intent broadcasts for determining the state of TalkBack in
// favor of the content
// provider method.
if (sInfrastructureInitialized) {
setResultCode(RESULT_TALKBACK_ENABLED);
} else {
setResultCode(RESULT_TALKBACK_DISABLED);
}
}
...
}
Explanation
You must send an Intent broadcast to the TalkBackService using the action of:
public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";
Then examine the contents of the Extras and process it accordingly.
ALSO insure that you have the right permission:
public static final String PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK = "com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK";
I'm not sure this is the best way of achieving what is proposed, but I managed to make this work by using the following code:
Intent screenReaderIntent = new Intent("android.accessibilityservice.AccessibilityService");
screenReaderIntent.addCategory("android.accessibilityservice.category.FEEDBACK_SPOKEN");
List<ResolveInfo> screenReaders = getPackageManager().queryIntentServices(screenReaderIntent, 0);
Cursor cursor = null;
int status = 0;
ContentResolver cr = getContentResolver();
List<String> runningServices = new ArrayList<String>();
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
runningServices.add(service.service.getPackageName());
}
for (ResolveInfo screenReader : screenReaders) {
cursor = cr.query(Uri.parse("content://" + screenReader.serviceInfo.packageName
+ ".providers.StatusProvider"), null, null, null, null);
if (cursor != null && cursor.moveToFirst()) { //this part works for Android <4.1
status = cursor.getInt(0);
cursor.close();
if (status == 1) {
//screen reader active!
} else {
//screen reader inactive
}
} else { //this part works for Android 4.1+
if (runningServices.contains(screenReader.serviceInfo.packageName)) {
//screen reader active!
} else {
//screen reader inactive
}
}
}
Probably this is not the best way but it is the only one I can think of that works in Jelly Bean and in previous Android versions
You can check the enabled spoken accessibility servers
fun Context.isScreenReaderEnabled(): Boolean {
val accessibilityManager = getSystemService(Context.ACCESSIBILITY_SERVICE) as AccessibilityManager
if (!accessibilityManager.isEnabled)
return false
val serviceInfoList = accessibilityManager.getEnabledAccessibilityServiceList(AccessibilityServiceInfo.FEEDBACK_SPOKEN)
if (serviceInfoList.isNullOrEmpty())
return false
return true
}
来源:https://stackoverflow.com/questions/11831666/how-to-check-if-talkback-is-active-in-jellybean