Develop Reference

getAccessibilityButtonController Android Accessibility Service

I have been looking at the new methods available for Accessibility in Android O. I ran across this new method called getAccessibilityButtonController, I am unsure precisely what it does and an intended use. I know that in Android O there is a navigation button that can be used for an accessibility service. Does this accessibility button only launch the accessibility service, or could it have other functionality within the service such as to do specific tasks? I am curious possible uses for the accessibility and the getAccessibilityButtonController methods. Thank you for your time.

It can do pretty much anything you want it to. From the android accessibility doc, the button allows you to register a callback that has an onClicked method. If you enable the button and provide said callback you can execute whatever you'd like in the context of that callback.
Edit: The android documentation has been updated so the following should no longer be necessary.
Note that if you read the doc there's currently an example that has a call to getAccessibilityButtonController() within onCreate(). This is incorrect because the controller isn't valid until onServiceConnected is called. I've modified the example below to show something that should work.
private AccessibilityButtonController mAccessibilityButtonController;
private AccessibilityButtonController
.AccessibilityButtonCallback mAccessibilityButtonCallback;
private boolean mIsAccessibilityButtonAvailable;
#Override
protected void onServiceConnected() {
mAccessibilityButtonController = getAccessibilityButtonController();
mIsAccessibilityButtonAvailable =
mAccessibilityButtonController.isAccessibilityButtonAvailable();
if (!mIsAccessibilityButtonAvailable) {
return;
}
AccessibilityServiceInfo serviceInfo = getServiceInfo();
serviceInfo.flags
|= AccessibilityServiceInfo.FLAG_REQUEST_ACCESSIBILITY_BUTTON;
setServiceInfo(serviceInfo);
mAccessibilityButtonCallback =
new AccessibilityButtonController.AccessibilityButtonCallback() {
#Override
public void onClicked(AccessibilityButtonController controller) {
Log.d("MY_APP_TAG", "Accessibility button pressed!");
// Add custom logic for a service to react to the
// accessibility button being pressed.
}
#Override
public void onAvailabilityChanged(
AccessibilityButtonController controller, boolean available) {
if (controller.equals(mAccessibilityButtonController)) {
mIsAccessibilityButtonAvailable = available;
}
}
};
if (mAccessibilityButtonCallback != null) {
mAccessibilityButtonController.registerAccessibilityButtonCallback(
mAccessibilityButtonCallback, null);
}
}

Android support v7 MediaRouter sometimes doesn't work properly

I use v7 support library MediaRouter for switching routes between phone's speaker and bluetooth device.
And sometimes it works strange, for example, when I turn off the bluetooth, corresponding route seems to be removed (playback switches to the speaker), but my application doesn't receive any callback about it. And moreover, when I manually get all the routes via MediaRouter.getRoutes(), it returns that bluetooth route, but when I try to switch to it, it seems to be selected, but actually playback still goes through the speaker.
I tried all the flags CALLBACK_FLAG_FORCE_DISCOVERY, CALLBACK_FLAG_REQUEST_DISCOVERY etc, without result. Only phone reboot helps. Any suggestions?
I used Android 4.2, 4.4.
UPDATE, code sample:
....
private MediaRouter mMediaRouter;
private MediaRouter.Callback mMediaRouterCallback = new MediaRouter.Callback(){
#Override
public void onRouteAdded(MediaRouter router, MediaRouter.RouteInfo route) {
super.onRouteAdded(router, route);
refreshRoutes();
Log.i(TAG, "Route added ==> " + route.getName());
}
#Override
public void onRouteRemoved(MediaRouter router, MediaRouter.RouteInfo route) {
super.onRouteRemoved(router, route);
refreshRoutes();
Log.i(TAG, "Route removed ==> " + route.getName());
}
#Override
public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo route) {
super.onRouteSelected(router, route);
Log.i(TAG, "Route selected ==> " + route.getName());
refreshRoutes();
}
#Override
public void onRouteUnselected(MediaRouter router, MediaRouter.RouteInfo route) {
super.onRouteUnselected(router, route);
Log.i(TAG, "Route UNselected ==> " + route.getName());
refreshRoutes();
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRoutesList = (ListView) findViewById(R.id.routesList);
mRoutesList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String routeName = mRoutesAdapter.getItem(i);
List<MediaRouter.RouteInfo> routes = mMediaRouter.getRoutes();
for (MediaRouter.RouteInfo rout : routes){
if (rout.getName().equals(routeName)){
mMediaRouter.selectRoute(rout);
}
}
}
});
mMediaRouter = MediaRouter.getInstance(this);
mMediaRouter.addCallback(
new MediaRouteSelector.Builder()
.addControlCategory(MediaControlIntent.CATEGORY_LIVE_AUDIO)
.addControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK)
.build(),
mMediaRouterCallback,
MediaRouter.CALLBACK_FLAG_REQUEST_DISCOVERY);
mRoutesAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, 0);
mRoutesList.setAdapter(mRoutesAdapter);
refreshUi();
}
#Override
protected void onDestroy() {
mMediaRouter.removeCallback(mMediaRouterCallback);
super.onDestroy();
}
private void refreshRoutes(){
mRoutesAdapter.clear();
MediaRouter.RouteInfo selectedRoute = mMediaRouter.getSelectedRoute();
List<MediaRouter.RouteInfo> routes = mMediaRouter.getRoutes();
for (MediaRouter.RouteInfo rout : routes){
if (rout == selectedRoute)
mRoutesAdapter.add(rout.getName() + " [selected]");
else
mRoutesAdapter.add(rout.getName());
}
mRoutesAdapter.notifyDataSetChanged();
}

Using #Xaver's suggestion in the question comments, I put all of the MediaRouting in a Service. I got everything working how it was before the service but the same error was occurring. When I returned to an activity, after one switch from the wired to the BlueTooth speaker, the MediaRouter would get stuck on the wired speaker despite saying that the current route was the Bluetooth speaker.
Switching from android.support.v7.media.MediaRouter to the android.media.MediaRouter and refactoring my code a little everything worked perfectly. Hard to say if moving the routing to a service was part of the combination but I got it working (after ~50 hours of tinkering with everything)
The unfortunate thing with android.media.MediaRouter is it doesn't have a getRoutes method, but nothing a little Googleing couldn't handle! Since I found it a pain to figure this out from the docs, since everything is referencing the v7 library, below is how to get the MediaRouter and select a route.
MediaRouter mr = (MediaRouter)this.getSystemService(this.MEDIA_ROUTER_SERVICE);
mr.selectRoute(mr.ROUTE_TYPE_LIVE_AUDIO, mr.getRouteAt(0));
Hopefully this helps someone!

Google Game Services onPeersDisconnected/onP2PDisconnected not being called

As in the title I've been able to connect to Google Game Services, exchange data between two devices and everything is running fine, except one thing: disconnection callbacks.
I tried to intercept both onPeersDisconnected and onP2PDisconnected without any success. The onP2PDisconnected method is being called in the device that get disconnected from Internet but not into device that is still online (so there is no way to tell the player that the other one got disconnected).
After the match is started it seems that the second device is never notified of the accidental disconnection. If the user close the game properly the onPeersLeft method is being called thought.
Is a ping between the two devices really necessary to overcome this "bug"? Am I doing something wrong?
Here is the code I use:
void startQuickGame() {
// quick-start a game with 1 randomly selected opponent
final int MIN_OPPONENTS = 1, MAX_OPPONENTS = 1;
Bundle autoMatchCriteria = RoomConfig.createAutoMatchCriteria(MIN_OPPONENTS,
MAX_OPPONENTS, 0);
RoomConfig.Builder rtmConfigBuilder = RoomConfig.builder(this);
rtmConfigBuilder.setMessageReceivedListener(this);
rtmConfigBuilder.setRoomStatusUpdateListener(this);
rtmConfigBuilder.setAutoMatchCriteria(autoMatchCriteria);
mListener.switchToScreen(R.id.screen_wait);
keepScreenOn();
resetGameVars();
getGamesClient().createRoom(rtmConfigBuilder.build());
}
And here the simple listeners:
#Override
public void onPeersDisconnected(Room room, List<String> peers) {
Log.d(TAG, "onPeersDisconnected");
updateRoom(room);
}
void updateRoom(Room room) {
Log.d(TAG, "UpdateRoom: "+room.getParticipants().size());
mParticipants = room.getParticipants();
}
#Override
public void onP2PDisconnected(String participantId) {
Log.d(TAG, "onP2PDisconnected");
}
public int getPartecipantsInRooom(){
if(mRoom != null)
return mRoom.getParticipants().size();
else
return -123456;
}
Note that calling getPartecipantsInRooom() after one of the two devices disconnects always return 2, and updateRoom never get called.

Just to be sure this might not work for you, for my applications I use this to let me know when another Participant has left the Room, and it is called immediately :
#Override
public void onPeerLeft(Room room, final List<String> participantIds) {
this.mRoomCurrent = room;
this.mRoomId = this.mRoomCurrent.getRoomId();
this.mParticipants = this.mRoomCurrent.getParticipants();
int connected = 0;
for (Participant p : room.getParticipants()) {
if(p.getStatus() == Participant.STATUS_JOINED) {
connected += 1;
}
}
final int fconnected = connected;
for (String s : listIgnoreTheseIDs) {
//checkint to see if we care anymore about this ID.. if out of game already.. nope
if(s.equals(participantIds.get(0))){
return;
}
}
Gdx.app.postRunnable(new Runnable() {
#Override
public void run() {
mGHInterface.onPeerLeft(fconnected, participantIds.size());
}
});
}
No idea why there are two items, but like you, I realized the onPeersDisconnected() isn't that reliable, but onPeerLeft() normally gets back to the other devices in under 1 second.

onPeerDisconnected() handles disconnects. So if somebody is still in the application but the network connection is lost, this is called for him.
onPeerLeft() handles participants who leave a room. This is called when somebody explizit leaves the room in the application or the application is minimized, and the room is left on the androids onStop() or onDestroy() callback.

I'm making two player game. So I use this approach
#Override
public void onPeerLeft(Room room, List<String> peersWhoLeft) {
updateRoom(room);
Toast.makeText(MyLauncherActivity.this, "Other player left the game", Toast.LENGTH_LONG).show();
quitGame();
}

Unable to both start and discover a specific service with Wifi Direct

I'm pretty new with Android programming. But I have been working on this for over a week now, and it starts to get booooring.
My idea is that I want to connect two devices using Wifi Direct. But I only want to connect to those which are running my application. Besides, I want the users to be able to see some information of the other devices (such as user name), not just the MAC or the Android_XXXX name included in the WifiP2pDevice. That's why I decided that a device looking for other devices, should both start the application service and search for peers which are also broadcasting this service.
The problem (I'm testing with two real devices) is that, even though they are running exactly the same code, only one of them is getting the service discovery callbacks (the onDnsSd... listeners below). So, one side acts in the proper way, but not the other. Moreover I'm getting "old" services, meaning that apparently each time I start de service (even though I cancel previously started services), that service seems to be still broadcast during at least some minutes.
I include a shortened version of my code:
public class MoveFlufietsDialogFragment extends DialogFragment implements ChannelListener, DeviceActionListener {
public final HashMap<String, FlufietsPeer> mBuddies = new HashMap<String, FlufietsPeer>();
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
...
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
mManager = (WifiP2pManager) getActivity().getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mManager.initialize(getActivity(), getActivity().getMainLooper(), null);
...
startRegistration();
discoverFlufietsService();
...
}
public void discoverFlufietsService() {
DnsSdTxtRecordListener txtListener = new DnsSdTxtRecordListener() {
#Override
public void onDnsSdTxtRecordAvailable(String fullDomain, Map record, WifiP2pDevice device) {
// This and the next listener are only called in one of the devices.
String serviceName = (String) record.get("serviceName");
if ((serviceName != null) && (serviceName.equals("flufiets")) {
// I put the record data in the mBuddies HashMap.
...
mBuddies.put(device.deviceAddress, myPeerDataStructure);
}
}
};
DnsSdServiceResponseListener servListener = new DnsSdServiceResponseListener() {
#Override
public void onDnsSdServiceAvailable(String instanceName, String registrationType, WifiP2pDevice resourceType) {
if (mBuddies.containsKey(resourceType.deviceAddress)) {
FlufietsPeer flufietsPeer = mBuddies.get(resourceType.deviceAddress);
WiFiPeerListAdapter adapter = ((WiFiPeerListAdapter) mFragmentList.getListAdapter());
adapter.add(flufietsPeer);
adapter.notifyDataSetChanged();
}
}
};
mManager.setDnsSdResponseListeners(mChannel, servListener, txtListener);
WifiP2pDnsSdServiceRequest serviceRequest = WifiP2pDnsSdServiceRequest.newInstance();
mManager.addServiceRequest(mChannel, serviceRequest, new ActionListener() {
// onSuccess/onFailure toasts.
});
mManager.discoverServices(mChannel, new WifiP2pManager.ActionListener() {
// onSuccess/onFailure toasts.
});
}
public void startRegistration() {
mManager.clearLocalServices(mChannel, new ActionListener() {
// onSuccess/onFailure toasts.
});
Map record = new HashMap();
record.put("serviceName", "flufiets");
...
WifiP2pDnsSdServiceInfo serviceInfo = WifiP2pDnsSdServiceInfo.newInstance(flufietsService, "_tcp", record);
mManager.addLocalService(mChannel, serviceInfo, new ActionListener() {
// onSuccess/onFailure toasts.
});
}
#Override
public void onResume() {
super.onResume();
mReceiver = new WiFiDirectBroadcastReceiver(mManager, mChannel, this);
getActivity().registerReceiver(mReceiver, mIntentFilter);
}
#Override
public void onPause() {
super.onPause();
getActivity().unregisterReceiver(mReceiver);
}
#Override
public void onStop() {
super.onStop();
mManager.clearLocalServices(mChannel, new ActionListener() {
// onSuccess/onFailure toasts.
});
}
...
}
The problem doesn't seem to be related with the device itself (sometimes it works, sometimes it doesn't, but always only in one of them). I suspect it has to do with either trying to discover a service that we ourselves are broadcasting, or having the same service being offered by two devices. I have tried changing the names of the service, so each device would offer either a "send" or "receive" service, but it doesn't work. I only get the callbacks called (onDnsSd...) in one of the devices.
And that thing about getting old services, when I always clear them, is weird (I do include a timestamp in the service record data, and I could always discard all but the last, but doesn't seem to be logical).
Any ideas? ANY help would be VERY appreciated, because writing the application is not funny any more (:-)=
Thanks a lot!

You need to wait until the clearLocalService call succeeds before adding the local service later. So put the addLocalService call into the onSuccess callback of the clearLocalServices.

My app gets "Force close" on several devices

I have people complaining my application gets FC when they launch it (meanwhile others never had a single problem). Here is my full activity source. Since it happens on devices I don't own I can not fix it. From what they tell me it doesn't work on: Motorola Blackflip, Motorola Dext, Motorola CLIQ XT. Guess Motorola doesn't like my app after all...
Could it be that I allow a minSdkVersion="3"? I tested 1.5 on the emulator and worked fine...
Thank you in advance for your responses.
public class workit extends Activity implements OnClickListener {
Button yay;
Button yay0;
Button yay1;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
yay = (Button) findViewById(R.id.gostart);
yay.setOnClickListener(this);
yay0 = (Button) findViewById(R.id.dontstart);
yay0.setOnClickListener(this);
yay1 = (Button) findViewById(R.id.exit);
yay1.setVisibility(ImageView.GONE);
ImageView inizio = (ImageView)findViewById(R.id.start);
inizio.setVisibility(ImageView.VISIBLE);
inizio.setBackgroundResource(R.drawable.start);
}
public void onClick(View v) {
// TODO Auto-generated method stub
if (v == yay0) {
finish();
}
if (v == yay) {
ImageView inizio = (ImageView)findViewById(R.id.start);
inizio.setVisibility(ImageView.GONE);
WebView work = new WebView(this);
setContentView(work);
work.loadUrl("file:///android_asset/index1.html");
work.setWebViewClient( new work());
work.setBackgroundColor(0);
work.getSettings().setBuiltInZoomControls(true);
work.getSettings().setDefaultZoom(ZoomDensity.FAR);
}
if (v == yay1) {
finish();
}
}
private class work extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.contains("exit.html")) {
// TODO: do what you have to do
finish();
}
view.loadUrl(url);
return true;
}
}
}

Your best bet is to ask somebody to send you the LogCollector output (in my experience, users are very happy to provide you information to debug problems. There are some really cool people out there). That should give you a callstack, and information on what kind of exception you triggered (NullPointerException, etc).
Next up - what are you building your app against? There should be an "Android x.x" entry in your project structure somewhere. If you're building something that is supposed to run on Android 1.5, then make sure you actually build against 1.5. You CAN build against 2.0 if you want, but if you need to use 2.0-specific functions, you'll have to encapsulate them properly. (This has been explained in detail on stackoverflow several times.)
On an unrelated note - I recommend more informative variable names. "yay0" doesn't mean anything to anyone who hasn't been working intimately with the code for a while.