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POKnow when to show a passcode lock
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copied!<p>I am developing an application that needs to display a passcode screen whenever a user leaves the app and comes back (be it through a screen lock, or going back to the home screen through the back or home button). I had it working using the following:</p> <p>The starting activity would call for the passcode check on startup, and each activity added the following functionality to their onPause method:</p> <pre><code>@Override public void onPause() { super.onPause(); if (!isFinishing()) { new PasscodeCheckTask(this.getApplicationContext(),this).execute(); } } </code></pre> <p>The PassocdeCheckTask looks like the following. It checks to see if the screen is off or the app is no longer in the background</p> <pre><code>public class PasscodeCheckTask extends AsyncTask<Void, Void, Boolean> { public static final int CHECK_PASSCODE = 0; private Context mActivityApplicationContext; private Context mActivityContext; public PasscodeCheckTask(Context applicationContext, Context activityContext){ mActivityApplicationContext = applicationContext; mActivityContext = activityContext; } @Override protected Boolean doInBackground(Void... params) { Boolean result = false; if (!((PowerManager)mActivityApplicationContext.getSystemService(android.content.Context.POWER_SERVICE)).isScreenOn() || !isAppOnForeground(mActivityApplicationContext)) { result = true; } return result; } @Override protected void onPostExecute(Boolean result) { if (result) { // Start passcode activity to check for passcode /* CODE HERE */ ((Activity)mActivityContext).startActivityForResult(intent, CHECK_PASSCODE); } } protected boolean isAppOnForeground(final Context context) { List<RunningAppProcessInfo> appProcesses = ((ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE)).getRunningAppProcesses(); if (appProcesses == null) { return false; } final String packageName = context.getPackageName(); for (RunningAppProcessInfo appProcess : appProcesses) { if ((appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND) && appProcess.processName.equals(packageName)) { return true; } } return false; } } </code></pre> <p>The Passcode activity would finish when done, and the calling activity would moveTaskToBackground(true) if the passcode didn't pass. This system worked beautifully until I tried it on an HTC Evo with mikg ROM. For some reason, the appProcess.importance never showed up as IMPORTANCE_FOREGROUND. It was always IMPORTANCE_BACKGROUND. Thus, the passcode would ALWAYS be brought up, even though the app never went into the background.</p> <p>I tried DropBox on that phone (which has a passcode lock as well), and it worked beautifully. I can't seem to find a different way to know when an app has gone to the background, or if it is being brought back from the background. Any ideas on how to make this work?</p>

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