Develop Reference

How can I return an app to the foreground, considering the new security changes in API 29?

I have an app that makes an http request via the localhost to a separate, third-party app which I do not control, and waits for a response from that call before continuing. The workflow goes like this:
User is inside my app
User presses a button, which launches and calls out to the third-party application
User interacts with the third-party application
When the third-party application finishes its work, my app picks up the completed http response, and pulls itself back to the forefront via MoveTaskToFront for the user to continue working.
This functions properly in Android 9 and below, but the last step does not work in Android 10, I believe due to the new restrictions on launching activities from the background.
I have no control over the third-party app, so I cannot modify it to close itself when finished working, or request that the calling app be returned to the foreground when appropriate. Does anyone know of a workaround for this?
Edit: as requested, I've added the code snippet with the call out. This is a Xamarin project, so it's written in C#, but this particular code section is Android-platform-specific, so I am able to make Android system calls.
First I have to bring up the third-party app:
Intent intent = CrossCurrentActivity.Current.AppContext.PackageManager.GetLaunchIntentForPackage("com.bbpos.android.tsys");
if (intent != null)
{
// We found the activity now start the activity
intent.AddFlags(ActivityFlags.ClearTask);
CrossCurrentActivity.Current.AppContext.StartActivity(intent);
}
Then I call into it via the localhost, process the response, and want to switch back to my app.
using (var client = new HttpClient())
{
// by calling .Result we're forcing synchronicity
var response = client.GetAsync("http://127.0.0.1:8080/v2/pos?TransportKey=" + pTransportKey + "&Format=JSON").Result;
if (response.IsSuccessStatusCode)
{
var responseContent = response.Content;
// as above, forcing synchronicity
string responseString = responseContent.ReadAsStringAsync().Result;
var result = JsonConvert.DeserializeObject<GeniusTransactionResponse>(responseString);
var manager = (ActivityManager)Application.Context.GetSystemService(Context.ActivityService);
var test = manager.AppTasks.First().TaskInfo.Id;
manager.AppTasks.First().MoveToFront();
//manager.MoveTaskToFront(CrossCurrentActivity.Current.Activity.TaskId, 0);
return result;
}
else
{
return null;
}
}

Quick update in case anyone else has this same issue: I was able to work around this by adding an Accessibility Service to the project. Simply having an Accessibility Service registered and enabled by the user allows MoveTaskToFront to function as it did in APIs <29; the actual service doesn't need to do anything.

Android beacon library how to turn foreground service to background mode?

What I want to achieve is, when user enter geofencing, the beacons foreground service will start to run and after one beacon detected, I will kill this foreground service and start to run it on the background just like the sample code on android-beacon-library-reference library.
private fun monitorBeacons(startForegroundService: Boolean) {
var beaconManager = WolApp.appContext?.beaconManager
if (beaconManager == null) {
WolApp.appContext?.beaconManager = BeaconManager.getInstanceForApplication(WolApp.appContext!!)
beaconManager = WolApp.appContext?.beaconManager
beaconManager?.backgroundMode = true
beaconManager?.beaconParsers?.clear()
beaconManager?.beaconParsers?.add(BeaconParser().setBeaconLayout("m:2-3=0215,i:4-19,i:20-21,i:22-23,p:24-24"))
beaconManager?.removeAllMonitorNotifiers()
}
if (startForegroundService) {
setupForegroundNotificationService(WolApp.appContext!!)
} else {
WolApp.appContext?.regionBootstrap?.disable()
WolApp.appContext?.regionBootstrap = null
try {
WolApp.appContext?.beaconManager?.disableForegroundServiceScanning()
} catch (e: IllegalStateException) {}
if (beaconManager?.scheduledScanJobsEnabled == false) {
beaconManager.setEnableScheduledScanJobs(true)
beaconManager.backgroundBetweenScanPeriod = BeaconManager.DEFAULT_BACKGROUND_BETWEEN_SCAN_PERIOD
beaconManager.backgroundScanPeriod = BeaconManager.DEFAULT_BACKGROUND_SCAN_PERIOD
}
}
if (WolApp.appContext?.regionBootstrap == null) {
WolApp.appContext?.regionBootstrap = RegionBootstrap(WolApp.appContext!!, regions)//regions are some iBeacon regions
}
if (!startForegroundService) {
WolApp.appContext?.backgroundPowerSaver = BackgroundPowerSaver(WolApp.appContext!!)
}
}
For setupForegroundNotificationService method is same with android-beacon-library-reference library.
I'm not quite sure if I'm doing this right or wrong, can anyone help, please?

It is a little bit tricky to switch a foreground service on or off because you are trying to change the behavior of multiple threads of execution that are already running behind the scenes in existing services.
The key thing missing from the code shown is that you must also make sure you have stopped the library from scanning before you can switch. This is complex because it is asynchronous -- it takes time for the scanner to shut down its threads.
If using regionBootstrap, the call to regionBootstrap.disable() does this. (You can also use beaconManager.unbind(...) if not using regionBootstrap). But the problem is those APIs do not give you a callback when the scaning service is fully shut down. And restarting it again before it is shut down can cause problems. I do not have a great suggestion here , other than perhaps using a timer -- say one second between stop and start?
You might also want to look at this discussion of a similar setup:
https://github.com/AltBeacon/android-beacon-library/issues/845

Listener for Phone Events and Voice command

My app uses a microphone(AudioRecord) in a background mode,How to make the listener for phone events and voice commands (like google voice). It is necessary for me to release a microphone(AudioRecord) for use.
I found a solution to phone events: http://www.botskool.com/geeks/how-listen-phone-events-android.
to use: TelephonyManager , PhoneStateListener.
But not to voice commands. Help pls.

There is no specific way you can do this (unfortunately) and it will only be the application that attempts to use the mic resource that will get an error.
What you can do is monitor what the user is doing in the background and react accordingly. Here is the code to check if Google Now has become the foreground application:
public static boolean googleNowForeground(final Context ctx) {
final ActivityManager activityManager = (ActivityManager) ctx.getSystemService(Context.ACTIVITY_SERVICE);
if (activityManager.getRunningTasks(1).get(0) != null) {
final PackageManager pm = ctx.getPackageManager();
try {
final PackageInfo foregroundAppPackageInfo = pm.getPackageInfo(
activityManager.getRunningTasks(1).get(0).topActivity.getPackageName(), 0);
if (foregroundAppPackageInfo != null) {
if (foregroundAppPackageInfo.packageName.matches(Constants.GOOGLE_NOW_PACKAGE_NAME)) {
return true;
}
}
} catch (NameNotFoundException e) {
e.printStackTrace();
}
}
return false;
}
This is the least 'expensive' way I've found to perform such actions, but the method above is not guaranteed to be called in future OS versions, not to mention having to hard-code the package names you are concerned with....
The 'expense' of monitoring for foreground applications that you know will conflict with your application may be somewhat minimal in comparison to permanently recording audio, but you should code your implementation wisely to minimise the monitor within certain device condition parameters.
I've investigated other methods to monitor intent broadcasts that are associated with mic resources, but they've been less successful than the above.
Requesting that the user create an 'exclude list' for the conflicting applications will allow you to dynamically monitor if they become the foreground application and react accordingly.
Hope that helps....

clear missed calls and clear notification from android bar

Using this code I managed to mark all missed calls as read:
ContentValues values = new ContentValues();
values.put(Calls.NEW, 0);
if (android.os.Build.VERSION.SDK_INT >= 14) {
values.put(Calls.IS_READ, 1);
}
StringBuilder where = new StringBuilder();
where.append(Calls.NEW);
where.append(" = 1 AND ");
where.append(Calls.TYPE);
where.append(" = ?");
context.getContentResolver().update(Calls.CONTENT_URI, values, where.toString(),
new String[]{ Integer.toString(Calls.MISSED_TYPE) });
but in the android notification bar I still have a flag with missed calls. How can I also clear the notification bar for calls in android?

How can I also clear the notification bar for calls in android?
You don't. That Notification is put there by another app, and you have no means of controlling whether that Notification is displayed, short of building a ROM mod that changes the behavior of that other app.
UPDATE: Since this answer was originally written, NotificationListenerService was added and can clear notifications, but only on Android 4.3+.

The only "legal" but extremely ugly and usually useless way to achieve what you want is to show Call Log to user. And I mean literally show (becomes visual, gets focus). In case you want to do this, here's how:
public static boolean showCallLog(Context context)
{
try
{
Intent showCallLog = new Intent();
showCallLog.setAction(Intent.ACTION_VIEW);
showCallLog.setType(android.provider.CallLog.Calls.CONTENT_TYPE);
context.startActivity(showCallLog);
return true;
}
catch (Exception e)
{
Log.d("Couldn't show call log.", e.getMessage());
}
return false;
}
The reason behind this mess is the fact that apps authoritatively responsible for call logging and notifying users about missed calls (stock phone apps) use cached values. Why? Because of overall performance. You need to somehow notify those apps that Call Log has changed (seen means changed, as well) and that it should update it. It would be nice if all such apps on all devices would receive a broadcast in order to refresh, but as far as I know, it's not the case.
I hope someone will find a better way (without interrupting the user) to force refresh on stock phone apps.

Detect Hardware Acceleration at Runtime: Android

Is it possible to consistently detect if an Activity has hardware acceleration enabled when it is created? I'm worried that users of my library will enable it through the manifest when they shouldn't, by not specifically disabling it for my Activity (as I instruct them to do.)
The only solid information I can find (http://android-developers.blogspot.com/2011/03/android-30-hardware-acceleration.html) says that I can query View.isHardwareAccelerated() and Canvas.isHardwareAccelerated(). However, for my purposes, I would like to ensure it is off when my library's Activity is shown. So far, I can't get anything to report a consistent yes/no when it is on or off. I tried hacking in a dummy view, setting it to my activity and then testing it, but it always returns false. Also, I tried testing Window.getAttributes( ).flags, but they aren't showing it either.
I am testing this because the hardware accelerated draw path for my library doesn't function correctly, and there doesn't seem like there is any way to fix it.

Try FLAG_HARDWARE_ACCELERATED in flags in ActivityInfo for the activity, which you would get from PackageManager via getActivityInfo().

I'm new in Android so I was stuck even with the clues given in the answer above.. went to search around and found this code somewhere in the sea of Google. Hope it helps someone.
/**
* Returns true if the given Activity has hardware acceleration enabled
* in its manifest, or in its foreground window.
*
* TODO(husky): Remove when initialize() is refactored (see TODO there)
* TODO(dtrainor) This is still used by other classes. Make sure to pull some version of this
* out before removing it.
*/
public static boolean hasHardwareAcceleration(Activity activity) {
// Has HW acceleration been enabled manually in the current window?
Window window = activity.getWindow();
if (window != null) {
if ((window.getAttributes().flags
& WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED) != 0) {
return true;
}
}
// Has HW acceleration been enabled in the manifest?
try {
ActivityInfo info = activity.getPackageManager().getActivityInfo(
activity.getComponentName(), 0);
if ((info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0) {
return true;
}
} catch (PackageManager.NameNotFoundException e) {
Log.e("Chrome", "getActivityInfo(self) should not fail");
}
return false;
}