I'm trying to build an application where my application runs in the background and detects when the user launches another application so that I can control the flow from thereon.
To illustrate my query, I'd like to specify an example.
My application is running in the background (say as a Service), and the user has just clicked on application 'XYZ'. Is it possible for my app to detect that app 'XYZ' has been launched?
More than just detecting whether 'XYZ's Activity has come to the foreground,I want to detect whther 'XYZ' has been launched or not. Say someone launches 'Whatsapp Messenger', I want to know if my app can know that 'Whatsapp Messenger' has been launched.
EDIT : A lot of people think I'm trying to build malware, but I'm not. I'm trying to build an app for a high school project. I want a stat to see how often I use my camera as part of a psych project. :/
Thanks in advance,
Sumit.
Yes, You can find the which application is launched, by Tracking the Logcat. Just Track on ActivityManager tag with info -I log.
From adb shell Command is,
adb logcat ActivityManager:I *:S
From your application code,
logcat ActivityManager:I *:S
And in Logcat you can find a line something like,
I/ActivityManager( 585): Starting activity: Intent { action=android.intent.action...}
When any application will launched.
It is logcat output that shows that the message relates to priority level "I" and tag "ActivityManager":
Update:
Just add permission in your Application's manifest file,
android.permission.READ_LOGS
I guess you should have a look at "app protector" applications in the Google Play. They detect that user launched another application. That is done by reading system logs. Try opening LogCat and reading logs after you launched any application on device. You'll be surprised.
And where should you go from there? I guess you should try aLogCat app. It's freen and open-source. That will help you to actually read logs.
All this is considered to be a security breach in Android by some developers, though.
I have made a service which can detect if other application launches. I have made it for dialer. similarly that can be replaced by any package name.
#Override
public int onStartCommand(Intent intent, int flags, int startId){
Toast.makeText(this,"Service Started", Toast.LENGTH_LONG).show();
final String str = "";
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
int phonelaunched = 0,phoneclosed =0;
int phonelaunches = 1;
#Override
public void run() {
ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> runningAppProcessInfo = am.getRunningAppProcesses();
for ( ActivityManager.RunningAppProcessInfo appProcess: runningAppProcessInfo ) {
Log.d(appProcess.processName.toString(),"is running");
if (appProcess.processName.equals("com.android.dialer")) {
if ( appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND /*isForeground(getApplicationContext(),runningAppProcessInfo.get(i).processName)*/){
if (phonelaunched == 0 ){
phonelaunched = 1;
Log.d(str,"dude phone has been launched");
}
else if (phoneclosed == 1){
phonelaunches++;
phoneclosed = 0;
Log.d(String.valueOf(phonelaunches),"dude that was counter");
}
}
else {
phoneclosed = 1;
Log.d(str,"dude phone has been closed");
}
}
}
}
},2000,3000);
return START_STICKY;
}
Here I go through all the running tasks and check if it is our intended application. If so I check if the application is foreground and application is never launched using 'phonelaunched' variable. phoneclosed is used when intended application is in background and variable is set accordingly.
All this is implemented in Service class
In my book, by the way you posed the question, that sounds like hi-jacking an app in a certain way for your service to control, bordering on malware jinx. But it will not work in Android - plain and simple due to the permissions of each application is different. Thereby, each app are isolated from one another. So to answer your question bluntly, its No.
As the other answer suggested - you can monitor the logcat but.. then again... why?
Related
I'm trying to develop an android app for the SDK version 30 that (when a button is clicked) starts listening to what apps are opened on the phone. If it detects the user opening Whatsapp, it is supposed to show a LockScreen activity over Whatsapp that makes you answer a math question before being able to use Whatsapp.
I know this can be done as their are apps like QualityTime or Forest that have similar features to restrict you from using certain apps, but I am a newbie when it comes to programming (probably obvious from my code) and feel totally stuck.
I have already figured out how to detect what app the user opened in the last second with code from stack overflow:
public String getCurrentApp() {
String topPackageName = "None";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
UsageStatsManager mUsageStatsManager = (UsageStatsManager) getSystemService("usagestats");
long time = System.currentTimeMillis();
List<UsageStats> stats = mUsageStatsManager.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, time - 1000 * 1, time);
// Sort the stats by the last time used
if (stats != null) {
SortedMap<Long, UsageStats> mySortedMap = new TreeMap<Long, UsageStats>();
for (UsageStats usageStats : stats) {
mySortedMap.put(usageStats.getLastTimeUsed(), usageStats);
}
if (!mySortedMap.isEmpty())
{
topPackageName = mySortedMap.get(mySortedMap.lastKey()).getPackageName();
}
}
}
return topPackageName;
}
I have another function that is started when the user clicks the button in my app to "activate" the listening process. This function keeps checking if the user opens Whatsapp and is then supposed to display the Lockscreen activity on top:
public void startListening(View view)
{
System.out.println("Lock activated.");
while (activated) {
String currentlyRunningApp;
currentlyRunningApp = getCurrentApp();
if (currentlyRunningApp.equals("com.whatsapp"))
{
System.out.println("Whatsapp detected. Showing Lockscreen...");
Intent i = new Intent(this,LockScreen.class);
startActivity(i);
}
try {
Thread.sleep(800);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
(All of the code I have shown is in my MainActivity btw.)
I have the following permissions granted to my app:
android.permission.PACKAGE_USAGE_STATS (for the getCurrentApp() function)
android.permission.SYSTEM_ALERT_WINDOW (as suggested here)
android.permission.ACTION_MANAGE_OVERLAY_PERMISSION (although I am not sure I even need this one)
My problem is, that instead of showing the Lockscreen activity I created, it only shows a blackscreen for the user. The Lockscreen activity itself works fine if I let the user open it through a button on the mainActivity, so the issue seems to really be that I can not properly show an activity if my app is running in the background and I want to display it on top of Whatsapp.
I have tried to look through similar questions, but all of the posts on here with similar use cases seem to be very old and outdated (i.e. this or this), as the newer versions seem to have way tighter security restrictions.
I also tried to do it with a screen overlay instead of an activity (using this source), but this doesn't even give me a blackscreen - just does nothing...
I am also aware that there are probably better ways to program the whole "listening and checking for whatsapp" part - i.e. with a service instead of a while-loop or something, but I only found out about services while researching this problem and I'd like to fix the blackscreen issue first.
After lots of trial and error I figured out that the issues was indeed caused by a missing permission, but one that I could not find on any stack overflow answer related to black screen problems. On top of that, I believe it's an issue that only occurred because I used a Xiaomi device for testing.
There are currently two separate permissions for displaying screens over other apps that you will need to grant:
Display over other apps, also called Display pop-up window. This is the android.permission.ACTION_MANAGE_OVERLAY_PERMISSION that I wasn't sure was even needed. So to emphasize, I definetly do need this permission.
Display pop-up windows while running in the background. This is the permission I was missing.
After I allowed them both (which you can do under Settings > Apps > Manage Apps > Your App > Other Permissions) everything worked fine.
To direct the user directly to the settings menu where they can allow these permissions, I used the code from this stack overflow answer. This is also where I got the info that it's a xiaomi-specific "issue".
On our application there's a service that is normally started during Application.OnCreate (directly calling context.startService) and also later on via AlarmManager (refactor is in progress to migrate some of its work to JobScheduler).
Our application also have a BroadcastReceiver that gets launched with its direct intent.
Given the new limitations in Android Oreo (https://developer.android.com/about/versions/oreo/android-8.0-changes.html) we're having an issue as follows:
app/process is in background/dead
BroadcastReceiver gets fired by the OS
Application.onCreate() executes before the BroadcastReceiver
Application.onCreate() code tries to run the Service
this leads to crash with "IllegalStateException: Not allowed to start service Intent".
I'm aware of the new recommended ways of launching a Service as answered by CommonsWare here https://stackoverflow.com/a/44505719/906362, but for this specific case, I simply want to have if(process in foreground) { startService }. I'm currently using the following method and it seems to work:
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static boolean isProcessInForeground_V21(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
List<ActivityManager.AppTask> tasks = am.getAppTasks();
return tasks.size() > 0;
}
But I can't find the exact checks Android Oreo is doing (I got as far as here https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/app/ContextImpl.java on the startServiceCommon method, but from there requireForeground flag seems to go to some native implementation)
So my question:
For the specific purpose of Android Oreo new limitations, how to check if my process is foreground before calling startService?
To continue your investigation: (TL;DR: see between horizontal lines at the bottom)
Disclaimer, I don't know too much about Android, I just like digging in the source code.
Note: you can also navigate the code in Android Studio if you jump to file instead of class:
or searching for text in Project and Libraries.
IActivityManager is defined by AIDL, that's why there are no sources for it:
https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/java/android/app/IActivityManager.aidl#145
Based on how AIDL needs to be implemented I found that ActivityManagerService extends IActivityManager.Stub (God bless Google indexing).
Note I also found this, which might be an interesting read if you're really interested how things work internally.
https://programmer.group/android-9.0-source-app-startup-process.html
ActivityManagerService sources reveal that in Oreo startService is forwarded to ActiveServices which is located in the same package.
Assuming we're looking for an exception like this:
java.lang.IllegalStateException: Not allowed to start service Intent {...}: app is in background uid UidRecord{af72e61 u0a229 CAC bg:+3m52s273ms idle procs:1 seq(0,0,0)}
we have to continue down the rabbit hole: requireForeground gets assigned to fgRequired parameter and the message is here. The condition to allow this depends on the start mode returned by ActivityManagerService.getAppStartModeLocked(packageTargetSdk = 26 or greater, disabledOnly = false, forcedStandby = false).
There are 4 start modes:
APP_START_MODE_NORMAL (needs to be different than this, i.e. !=)
APP_START_MODE_DELAYED (this is ok, i.e. return null)
APP_START_MODE_DELAYED_RIGID
APP_START_MODE_DISABLED
Ephemeral apps will immediately return APP_START_MODE_DISABLED, but assuming this is a normal app, we end up in appServicesRestrictedInBackgroundLocked.
Note: this is where some of the whitelist mentioned in https://stackoverflow.com/a/46445436/253468 is decided.
Since all branches but last return APP_START_MODE_NORMAL, this redirects to appRestrictedInBackgroundLocked where we find our most likely suspect:
int appRestrictedInBackgroundLocked(int uid, String packageName, int packageTargetSdk) {
// Apps that target O+ are always subject to background check
if (packageTargetSdk >= Build.VERSION_CODES.O) {
return ActivityManager.APP_START_MODE_DELAYED_RIGID;
}
So the reason for denial is simply targeting O. I think the final answer to your question of how the OS decides if your app is foreground or background is this condition in getAppStartModeLocked
UidRecord uidRec = mActiveUids.get(uid);
if (uidRec == null || alwaysRestrict || uidRec.idle) {
My guess is that a missing record means it's not running (but then how is it starting a service?!), and idle means it's backgrounded. Notice that in my exception message the UidRecord is saying that it's idle and has been backgrounded for 3m52s.
I peeked into your getAppTasks and it's based on TaskRecord.effectiveUid, so I'm guessing that's quite close to listing UidRecords for your app.
Not sure if this helps, but I'll post it anyway, so if anyone wants to investigate more, they have more info.
I want to check if my app is running on a background mode.
The problem is that i have many activities(list activities, map activities etc.). Initially I have tried in the life cycle's resume and pause(or the onUserLeaveHint) methods to set a static boolean as true or false and work with this way. But this obviously can't work because when I move from one activity to another, the previous one get paused.
Also, I've read here on stackoverflow that the getRunningTasks() should be used only for debugging purposes. I did a huge research but I can't find a solution. All I want to do is to be able to detect if a the app is running on a background. Can anyone propose me a way, or express any thought on how can I do that?
You can try the same mechanism (a boolean attribute) but on application side rather than activity side. Create a class which extends Application, declare it in the manifest file under <application android:name=YourClassApp>.
EDIT: I assume you know that activities aren't intended for background processing, if not you should take a look at the Services.
I don't know if this will help but you can use
getApplicaton().registerActivityLifecycleCallbacks(yourClass);
To get a birds eye view of how your activities are displayed in the FG. (For older s/w you can use this)
If your Application has a Service you could have a static get/set which accesses a static variable. Do not do this in Activities though, it causes mem leaks.
But realistically speaking there is no tidy way of tracking if your application is running or not.
I had the same problemen when overwriting the Firebase push messaging default behavior (show notifications only when in the background) I checked how Firebase did this by looking in the .class file com.google.firebase.messaging.zzb:53 (firebase-messaging:19.0.1) which appears to us getRunningAppProcesses. Mind you FireBase is created by Google them self. So I'm assuming it's pretty save to use. Cleaned up version:
List<ActivityManager.RunningAppProcessInfo> runningApps;
boolean isInForeground =false;
if ((runningApps = ((ActivityManager)this.getApplication().getSystemService(Context.ACTIVITY_SERVICE)).getRunningAppProcesses()) != null) {
Iterator runningApp = runningApps.iterator();
int myPid = Process.myPid();
while(runningApp.hasNext()) {
ActivityManager.RunningAppProcessInfo processInfo;
if ((processInfo = (ActivityManager.RunningAppProcessInfo)runningApp.next()).pid == myPid) {
isInForeground = processInfo.importance == 100;
break;
}
}
}
There is an application and it needs system reboot after installation. I registrered boot receiver and write info to system log. And activity checks for this line. It works well, but there is one problem...
When user uninstall and install this app in one session(I mean user doesn't reboot phone) system log still has line "Phone restarted" and application runs with errors.
As I know I can't check uninstallation event on my app cause receiver stops before the application going to uninstall. So my question is could I check for my app installation? or maybe uninstallation any other way?
Thanks!
Maybe someone will be interested. I found the code that allows me to checked system reboot after installation/update:
public static boolean phone_rebooted(Context ctx) {
ApplicationInfo appInfo = ctx.getApplicationInfo();
String appFile = appInfo.sourceDir;
long installed = new File(appFile).lastModified();
long boot_time = System.currentTimeMillis() - SystemClock.elapsedRealtime();
if(boot_time < installed) {
return false;
} else {
return true;
}
}
My problem is make a function to set up themes in my application every 00:00 AM if there are new themes. As I know, to do this problem we must use a loop.
Here is my code:
private void updateThemes() {
Thread time = new Thread() {
public void run() {
int time = 0;
while(time > 86400000) {
//invoke method or start new activity
}
}
};
}
Please help me - Thanks.
Running a thread and waiting for a full day is not going to work. What if the phone is shutdown? What if the user switches to another app and your app is closed by Android because it needed the resources? Besides, it's not very battery friendly either.
You'd better use the Android AlarmManager to set the times at which you would like to check for updates. Also specify a BroadcastReceiver in your app that will receive and process the alarms. There's an example application that does this here or check this post for more info.