I am looking for a way to launch another app from within my app but so that the focus is not changed from my app to the app launched.
I.e currently I have the new app launched via a intent, however when this is carried out the new app is launched and becomes the app in view, I need it to be kept in the background with my app still in view.
The reason for this?
I am developing an application for internal use that will act like a lock-screen to the device so although things must happen in the background the 'lock-screen' must always be on top.
I have done some research into intents and launching other apps but can not find anything about what I need.
Hope you can help thank you!
Currently the terminal is called like this:
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setComponent(new ComponentName("jackpal.androidterm", "jackpal.androidterm.RemoteInterface"));
intent.setAction("jackpal.androidterm.RUN_SCRIPT");
intent.putExtra("jackpal.androidterm.iInitialCommand", cmdString);
The reason it needs to be running in the background is so that the app can run commands in terminal without the user having access, but then they 'unlock' the screen they need to then be able to view the terminal and what commands are being run etc
You can not startActivity in Background.Instead start the activity and minimise the activity(in your case this activity is of different application) using moveTaskToBack(true);
In your case, put a condition based on your intent and its params and use moveTaskToBack(true); so that activity will be minimised only when your application launches.
This won't be possible, you will have to start a background Service that does the actual work and only launch the Activity you want to navigate to once your foreground Activity is finished. Depending on your architecture, you can store the Activity to call when your foreground Activity is finished and change it from the service. That way you will have your desire behaviour without having to actually call the Activity.
In addition to the answer from #Meher, in the intent for your current starting activity, you can add the flag FLAG_FROM_BACKGROUND.
With this you get rid of the "blinking" effect (the one where your activity shows for one fraction of second while it discovers wether to go to background)
Related
I have a basic Activity which mainly allows the user to change settings and save them. I also have a BroadcastReceiver which is launched on SMS_RECEIVED.
The main point of the app is to vibrate whenever a certain message is received until the user taps a button to make it stop. The activity is only there to allow the user to change settings and press the "Stop" button.
In my onReceive method (BroadcastReceiver), I get the content of the last message received and make the phone vibrate if the message is equal to a certain string. All of that is working perfectly, the problem is when I want to make it stop. Right now, I'm trying to make a "Stop" button appear in the Activity when the phone starts vibrating.
I understand that UI elements should remain in the Activity and so what I'm trying to do is communicate between the Activity and my BroadcastReceiver. I've found here how to do that with an Observer. The problem though is that I want the app to function at any time, even at boot time. It's very easy with a BroadcastReceiver but since it requires the Activity to be shown to allow the user to stop the vibration, I have to start the activity if it isn't started already.
So what I do is this:
Intent i = new Intent(context, MainActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.putExtra("SMSReceived", true);
context.startActivity(i);
ObservableObject.getInstance().updateValue(true);
The problem is, when there is no instance launched, it creates a new one and sends the extra boolean correctly but the updateValue method doesn't seem to get called at all (due to the previous instance I suppose?) and inversely, when there is an instance launched (in the background) the extra boolean doesn't get passed and the updateValue method gets called correctly.
I suppose I could just launch the Activity on boot and immediately put it in the background but it could cause problems if the user closes the application, at which point it would simply stop working until the user started it again since the Observer would have no instance to send data to.
Do you guys have any idea of what I could do to solve my problem?
If it's not clear I can try to explain further.
My app, running in background, at some point displays activity to purposefully interrupt user's flow. My activity starts a new task, which appears in "Recent Tasks" lists while being in foreground. Is there any way it could be prevented? Setting android:excludeFromRecents does not work - activity is not presented anymore in "Recent Tasks" only after is has been paused.
Manifest looks like:
<activity
android:name="com.example.recenttasks.MainActivity"
android:excludeFromRecents="true">
</activity>
and activity is started this way:
#Override
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, MainActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
The key thing you mentioned is
appears in "Recent Tasks" lists while being in foreground
I think you can't change that behavior. I just tested on my app and the same thing happens. If I press the "recent tasks" button while having my activity in the foreground, it appears listed there. The moment I move out of it to another activity or to my phone's main screen, the activity is not listed anymore.
I also tested this on the built-in DeskClock app that comes with recent Android versions and the same behavior is present there when a new alarm is triggered. Note that the AlarmAlertFullscreen activity of that app has the same parameters you mentioned in your question.
I'm not sure you can circumvent this or why you would need to in the first place since the activity is not listed anymore once it loses the focus.
you are defined it in manifest that is enough but it is not coming..
ok..try add this flag also to your Intnet and start the Activity..
intnet.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
Should the user be able to return to it? (Meaning if it shows and user clicks recents, have they lost their chance to see the hidden activity or should it still be there?)
If they cannot return to it anyway then the best action would be to finish() the activity onPause(). This will mean that as long as you have used android:excludeFromRecents and android:noHistory="true", there will be no item in recents.
If however you do wish to return to the 'interruption' activity (but do not want a recents entry) you could consider still finishing the activity onPause - but also recording a preference flag (something like IS_INTERSTITIAL). Your other activities can then check this preference in onResume and, if it is true, send an Intent to restart the Interstitial instead - To the user it will just appear they are resuming the app in the same state as they left it (interstitial)
Edit: If the screen needs to stay (rather than be re-instantiated) it may be possible to use a DialogFragment, although then you must worry about configuration changes. There is one hack you could try (explained in this answer) -
Set your label empty By using android:label="" your recent task is excluded. however this is a definite hack which may produce inconsistent results (as I haven't tested it to be sure)
I am implementing oauth login in Android, and I'm stuck on one point. I am required to redirect to the native browser to initiate the login (rather than use an embedded WebView of my own), but that is causing issues with the back stack. My goal is simple: return to my activity after the redirect with no trace of the native browser in the back stack. Here is the closest I've come so far:
To initiate the login from my activity I use:
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY
| Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
context.startActivity(intent);
I have a separate activity to receive the return redirect and handle the rest of the login process. I don't really care whether it's a separate activity or not, it is just my current solution. In its manifest I set android:noHistory="true". Once it finishes the login process, I attempt to return to the first activity using code like this:
Intent intent = new Intent(context, OrigActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
context.startActivity(intent);
However, this ends up creating a second copy of the original activity, and when I press back it returns me to the first copy. In other words, it does not seem to respect FLAG_ACTIVITY_CLEAR_TOP. Did I miss something simple to make it work, despite all my searching? Or is there some other way I should go about all of this?
Edit: It turns out the problem stems from the fact that the browser is launched in a separate task. From some Android documentation:
... if your application issues an intent to open the Android Browser, its activity is not placed in the same task as your application. Instead, either a new task starts for the Browser or, if the Browser already has a task running in the background, that task is brought forward to handle the new intent.
If I set my original activity's launch mode to singleTask it properly brings it to the foreground instead of creating a new copy, but a new problem occurs. The browser is now in the back stack behind all of my activities, so now it seems FLAG_ACTIVITY_NO_HISTORY is not being respected. I'm not sure if that brings me any closer to a proper solution ...
Edit 2: Correction: if the browser was not running before I launched it, everything works perfectly. However, if it WAS already running FLAG_ACTIVITY_NO_HISTORY seems to have no effect on it.
What you're seeing makes sense because calling the browser with the FLAG_ACTIVITY_NO_HISTORY wouldn't remove back stack from PRIOR to the start of your application.
I want to start multiple instance of the same Activity class from a Service. The reason I'm doing this, is because I have a Service that runs a "scan" daily, and if it finds any malfunctions it should display a popup for each malfunction.
The Activity that I'm starting is more like a Dialog, has a Dialog theme to display info about the malfunction.
Manfiest:
<activity
android:name=".ui.dialogs.MalfunctionActivity"
android:theme="#style/MyDialog"
android:launchMode="standard">
Intent to start the activity from Service:
Intent displayMalf=new Intent(this, MalfunctionActivity.class);
displayMalf.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(displayMalf);
PROBLEM: to start the Activity from a Service I need the FLAG_ACTIVITY_NEW_TASK which somehow cancels the launchMode="standard" from the manifest, and gives me just one Activity even if I try to start multiple diffrent instances.
Is there anyway in which I can achieve this?
It was so simple. There is the flag FLAG_ACTIVITY_MULTIPLE_TASK which according to the documentation :
Used in conjunction with FLAG_ACTIVITY_NEW_TASK to disable the behavior of bringing an existing task to the foreground. When set, a new task is always started to host the Activity for the Intent, regardless of whether there is already an existing task running the same thing.
Was exactly what I need. Thanks and sorry for answering on my question. It is not a habit. :)
Service will take the flag FLAG_ACTIVITY_NEW_TASK to start the activity but here you can try like this:
Set the instance of the handler of the activity of which you want multiple instances, in the service.
When you want the new instance of the activity use handler.sendMessage(msg) and on receiving this msg in your activity, start this activity again.
I guess your app works in the background and will display the popups even if the app is not in the foreground at the moment, right?
Otherwise I would use normal popup's (AlertViews) instead of starting new activities all the time.
If the app works in the background, you could tell the user with the first popup that your app has found one or more malfunctions and that he should activate the app for more details
How to close an android app if more than one activity is in active state?
A blog post entitled Exiting Android Application will show how to exit an Android app:
When the user wishes to exit all open activities, they should press a button which loads the first Activity that runs when your app starts, in my case "LoginActivity".
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivity(intent);
The above code clears all the activities except for LoginActivity. LoginActivity is the first activity that is brought up when the user runs the program. Then put this code inside the LoginActivity's onCreate, to signal when it should self destruct when the 'Exit' message is passed.
if (getIntent().getBooleanExtra("EXIT", false)) {
finish();
}
I got an easy solution for this problem
From the activity you press the exit button go to the first activity using the following source code. Please read the documentation for FLAG_ACTIVITY_CLEAR_TOP also.
Intent intent = new Intent(ExitConfirmationActivity.this, FirstActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
Now overide onResume() of the first activity using finish()
The answer is simple: You really do not need to 'close' an Android application. If no activity is shown any more, the system will kill the process after some time. The users can close activities by pressing the 'back' button. Reto Meier explains it pretty well here:
http://blog.radioactiveyak.com/2010/05/when-to-include-exit-button-in-android.html
You might also want to read this thread; it is very helpful to say the least: Quitting an Android application - Is it frowned upon?
Well, you shouldn't close your applications, as the system manages that. Refer to the posts/topics in the other answers for more information.
However, if you really, really want to, you can still call System.exit (0); like in any other Java application.
EDIT
ActivityManager actmgr = (ActivityManager) this.getSystemService (Context.ACTIVITY_SERVICE);
actmgr.restartPackage ("com.android.your.package.name");
I remembered something. I was trying to use this code to restart my application, but it only managed to kill my app. You can try it and see if it works for you.
I asked a similar question a couple of weeks back. Do go through the answers and comments for more perspective and possible solutions.
IMO quitting an application depends on what your application does and the user expectations. While I understand the rationale on not having a quit button I also do believe that it's a choice that the application designer has to make based on the situation.
Once your last Activity looses focus, Android will unload your process according to the current system needs / free resources.
You shouldn't really care about that - just use the lifecycle onStart, OnStop etc... to manage your state.
If you want to exit from one Android activity, this will bring you back to the previous activity or another activity from a specific place in current activity.
finish();
System.exit(0);