How to make app lock app in android?

Question

I have to develop an app locker for Android where the user can block apps and other users can not access these apps without an access key.

I have installed an app but I don't know how to lock this app.

Please suggest me something.

Slue

Answer 1

For the most basic version of your app, you need to perform three functions.

Step 1: Get a list of all the installed apps on device and show them in a ListView with check box. If the user checks any app, add the app to a different list say BlockedAppsList(which will be the list of apps which user wants to block). You can get all the apps installed using the following code.

^{(Source How to get a list of installed android applications and pick one to run, credits to Nelson Ramirez)}

    final PackageManager pm = getPackageManager();
    //get a list of installed apps.
    List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);

    for (ApplicationInfo packageInfo : packages) {
    Log.d(TAG, "Installed package :" + packageInfo.packageName);
    Log.d(TAG, "Source dir : " + packageInfo.sourceDir);
    Log.d(TAG, "Launch Activity :" + pm.getLaunchIntentForPackage(packageInfo.packageName)); 
    }

Step 2: Check the which is the current opened app. You can check by using this code.

^{(Source Android get package name of current opened application, credits to Ravindra Kushwaha)}

    ActivityManager am = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
    List l = am.getRecentTasks(1, ActivityManager.RECENT_WITH_EXCLUDED);
    Iterator i = l.iterator();
    PackageManager pm = this.getPackageManager();
    while (i.hasNext()) {
    ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo)(i.next());
    try {
    CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(
    info.processName, PackageManager.GET_META_DATA));
    Log.w("LABEL", c.toString());
    } catch (Exception e) {
    // Name Not FOund Exception
        }
       }

Step 3: Now check if the current app is present in the BlockedAppsList, if it is there, you can show any screen with a block message.

Arhat

Answer 2

Assuming that you store the package names of locked apps in a table called:

locks

and you want to call an activity named

PasswordActivity

when ever the users launch a locked app, you can implement a polling mechanism like below:

public class CheckAppLaunchThread extends Thread {

private Context context;
private Handler handler;
private ActivityManager actMan;
private int timer = 100;
public static final String TAG = "App Thread";
public static String lastUnlocked;

// private String lastUnlocked;

public CheckAppLaunchThread(Handler mainHandler, Context context) {
    this.context = context;
    this.handler = mainHandler;
    actMan = (ActivityManager) context
            .getSystemService(Context.ACTIVITY_SERVICE);
    this.setPriority(MAX_PRIORITY);
}

@Override
public void run() {
    context.startService(new Intent(context, AppLockService.class));
    Looper.prepare();
    String prevTasks;
    String recentTasks = "";

    prevTasks = recentTasks;
    Log.d("Thread", "Inside Thread");
    while (true) {
        try {
            String topPackageName = "";
            if(Build.VERSION.SDK_INT >= 21) {
                UsageStatsManager mUsageStatsManager = (UsageStatsManager) context.getSystemService("usagestats");                       
                long time = System.currentTimeMillis(); 
                // We get usage stats for the last 10 seconds
                List<UsageStats> stats = mUsageStatsManager.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, time - 1000*5, time);                                    
                if(stats != null) {
                    SortedMap<Long,UsageStats> mySortedMap = new TreeMap<Long,UsageStats>();
                    for (UsageStats usageStats : stats) {
                        mySortedMap.put(usageStats.getLastTimeUsed(),usageStats);
                    }                    
                    if(mySortedMap != null && !mySortedMap.isEmpty()) {
                        topPackageName =  mySortedMap.get(mySortedMap.lastKey()).getPackageName();                                   
                    }                                       
                }
            }
            else {
                topPackageName = actMan.getRunningAppProcesses().get(0).processName;
            }
            recentTasks = topPackageName;
            Thread.sleep(timer);
            if (recentTasks.length()==0 || recentTasks.equals(
                    prevTasks)) {
            } else {
                if (isAppLocked(recentTasks)) {
                    Log.d(TAG, "Locked " + recentTasks);
                    handler.post(new RequestPassword(context, recentTasks));
                }
            }

        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        prevTasks = recentTasks;

    }

}

class ToastRunnable implements Runnable {

    String message;

    public ToastRunnable(String text) {
        message = text;
    }

    @Override
    public void run() {
        Toast.makeText(context, message, Toast.LENGTH_SHORT).show();

    }
}

class RequestPassword implements Runnable {

    private Context mContext;
    private String pkgName;

    public RequestPassword(Context mContext, String pkgName) {
        this.mContext = mContext;
        this.pkgName = pkgName;
    }

    @Override
    public void run() {

        Intent passwordAct = new Intent(context, PasswordActivity.class);
        passwordAct.putExtra("PACKAGE_NAME", pkgName);
        passwordAct.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_SINGLE_TOP);
        this.mContext.startActivity(passwordAct);

    }

}

private boolean isAppLocked(String packageName) {
    if (packageName.equals(PasswordActivity.lastUnlocked)) {
        return false;
    }
    PasswordActivity.lastUnlocked = null;
    DatabaseHelper dbHelper = new DatabaseHelper(context);
    SQLiteDatabase db = dbHelper.getReadableDatabase();
    Cursor cursor = db.rawQuery("SELECT * FROM locks WHERE package_name=\'"
            + packageName + "\'", null);
    boolean isLocked = false;
    if (cursor.moveToNext()) {
        isLocked = true;
    }

    cursor.close();
    db.close();
    dbHelper.close();
    return isLocked;
}

}

Now you must call the above code from your service like this:

@Override
public void onCreate() {
    handler = new Handler(getMainLooper());
    context = getApplicationContext();
    launchChecker = new CheckAppLaunchThread(handler, context);
    super.onCreate();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    while (true) {
        if (!launchChecker.isAlive())
            launchChecker.start();
        return START_STICKY;

    }
}

Warning: Since Oreo, google has restricted background services and you must figure out a way to always keep your service alive. (that is not the scope of this question) for a clue on this, consider scheduling a JobService and a broadcast receiver that would reschedule your service when ever the android kills it.

Curative

Password activity is only open for my package. Other things are working fine like toast before other app opening but activity is not opening – Dumbbell