Develop Reference

Open Apps Widgets screen Android

How to open the Apps | Widget screen?
I mean this screen

Got the issue, basically all you have to do is make an intent that chooses this.
Intent homeScreenIntent = new Intent(Intent.ACTION_MAIN);
homeScreenIntent.addCategory(Intent.CATEGORY_LAUNCHER);
homeScreenIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(homeScreenIntent);
Hope it helps.
Won't recommend but seems one of this will work but be careful:
moveTaskToBack(true) // Pushes the activity in stack to back.
and
finish() // Kills the app
Reference: Dev blog

Confusing behaviour with intents in Android

I call GooglePlay from my app through an intent and again after I kill my own app:
Intent intent = new Intent(Intent.ACTION_VIEW);
String sModule = "market://search?q=pub:mycompany";
intent.setData(Uri.parse(sModule));
startActivity(intent);
finish();
android.os.Process.killProcess(android.os.Process.myPid());
Task manager shows, that only GooglePlay is running. My app isn't there anymore.
So my focus is GooglePlay at the moment. When going to the Desktop through the Home-Button and calling my App again it directs me to GooglePlay again.
Why is that? How can I call GooglePlay from my app independently?
I expected that when starting my app again, which I had previously killed, it would start my app and not focus on google play.

keyword is "launchMode" and "task".
this type of problems are so annoying and much complicated in android.
but this time you can try this.
Intent intent = new Intent(Intent.ACTION_VIEW);
String sModule = "market://search?q=pub:mycompany";
intent.setData(Uri.parse(sModule));
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
finish();
if u cant solve, try combine another flags with FLAG_ACTIVITY_NEW_TASK.
cheers!

Create new intent in background

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)

Launch activity from background app

I have my app running in the background and I want the app to be shown on the top(launched) of the android phone when the code below is ran. (I know the code is ran for sure)
This seems like a simple thing but I spent a couple hours on this site and everyone seems to be suggesting something like this:
Intent intent = new Intent(myActivity.this, myActivity.class);
startActivity(intent);
However, it is not bringing the app to the front and launching it.
I got it to work from a PendingIntent launched from a notification. Which I done by the code below. But I want the app to launch by itself without the user clicking on the notification.
Intent intent = new Intent(myActivity.this, myActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(this, REQUEST_CODE, intent, 0);
notification.setLatestEventInfo(this, "title", "msg", contentIntent);
I also tried:
Intent intent = new Intent("android.intent.action.MAIN");
startActivity(intent);
and flagging the intent:
intent.setFlags(Intent.FLAG_FROM_BACKGROUND);
intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
But doesn't seem to do anything, any help appreciated.

You should be able to call your own application like this:
Intent intent = new Intent("android.intent.category.LAUNCHER");
intent.setClassName("com.your.package", "com.your.package.MainActivity");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Edit: Forgot to add intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

From what I understand, you want a service that is running in the background and on a certain event, you want your application's activity to come in front i.e. on the users current screen whatever he is doing. It is not advisable to let a background service launch an application without a user's action. The android developer website says
A status bar notification should be used for any case in which a
background service needs to alert the user about an event that
requires a response. A background service should never launch an
activity on its own in order to receive user interaction. The service
should instead create a status bar notification that will launch the
activity when selected by the user.
Hence, do not try to make it launch on its own.

I An not behind my laptop atm so I am nog sure, but I think you have toe pass a context object hand then do context.startactivity(intent);
Sorry for not wel formated I am at my phone atm
Hope It helps

I am clutching at straws here, but you wrote:
MyActivity is launched first, then I either navigate to another app or just hit the home screen to have my app running in the background.
So the situation is that your original Activity is NOT running in the background, when you pressed HOME it might well could have been stopped and destroyed. Your background task remained orphan and MyActivity.this is null at this point.
Try and test what does Log.i(TAG,MyActivity.this); print into LogCat.

I ended up using a pending intent and instead of stright up trying to use a intent.
Something like this: seems a lot more simple.
Intent.send(this, 0, intent);
Thanks.

Also, I’ve seen since compileSdkVersion 29 it's not possible, unless a few restrictions:
The activity started very recently.
The app called finish() very recently.
Through a PendingIntent, but only after a few seconds after the notification was sent.
The app has been granted the SYSTEM_ALERT_WINDOW permission by the user.
...
https://developer.android.com/guide/components/activities/background-starts

Exit an android app

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);