Is there any way in android to determine when the user clicked the app icon to launch the app ? I mean say a user was using my app. Then he presses the home key as a result of which the app goes to the background. After sometime he clicks the app icon again. My question is do I get a call-back for this ?
Just to inform, I used the flag android:clearTaskOnLaunch="true" in my launcher activity. As a result, its onResume method was called and I could identify that the launcher icon was clicked
It will call the onResume() method if the app is already in the stack. And if the app not in the stack then it will call the onCreate() method.
This mechanism is based on the launchMode specified for the activity.
please read http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
How many activities your application has, you will get a callback onResume() for the last open activity.
If an app comes from the background, you can check it by getting intent flags
intent.getFlags() & Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) == 0
it will be true if your app comes from the background. If you click on the app icon to open it, the above logic will not be true.
Related
So my scenario is as such.
Let's say there is a MainActivity, which only job is to start, call installSplashScreen().setKeepOnScreenCondition { true } to show the Splash screen using the new backward compatible APIs, and then after checking some state it does startActivity(SomeActivity); finish()
Now we're on the SomeActivity and if we press the home button, the app is gone on the background. Then if we click on the launched icon, the SomeActivity is launched correctly, and the MainActivity's onCreate is never called, therefore the splash screen does not show again, and the SomeActivity shows instantly.
But if instead of pressing the home button, we press the back button, and the app is backgrounded that way, then when we click on the launcher icon, the MainActivity's oncreate is called again, and the splash screen icon flashes for a tiny fraction too making it look jarring.
My question is, does this sound like it's some wrong configuration on my part, or am I stuck with this behavior as long as I am not on a single activity architecture?
You are confused. Pressing the BACK button does not "send the app to the background". The default behaviour of the BACK button (assuming that you don't override this and provide your own behaviour) is to finish the current Activity. Normally this will take the user to the previous Activity in the current task. In your case, there is no other Activity in the task stack, so the current task is empty. This may appear to the user as "the app is sent to the background", but in reality there is nothing in the background. Your app's task is empty and so it is gone.
When the user then taps the app icon on the HOME screen or taps on the app's task in the list of recent tasks, there is no existing task to bring to the foreground, so the app is started again by creating a new task and launching the root Activity (in your case MainActivity) into the newly created task.
If you want the BACK button to just put your app into the background (instead of calling finish() on SomeActivity, which is the default behaviour) then just override onBackPressed() in SomeActivity and do this instead:
moveTaskToBack(true);
It seems like there is no solution to what I am facing as long as the Activity I want to resume to is not the Launcher activity.
From the the docs:
"Root launcher activities are activities that declare an Intent filter with both ACTION_MAIN and CATEGORY_LAUNCHER. These activities are unique because they act as entry points into your app from the app launcher and are used to start a task.
System behavior on Android 12 and higher
The system moves the activity and its task to the background instead of finishing the activity. This behavior matches the default system behavior when navigating out of an app using the Home button or gesture."
Reading the docs about the new back behavior on Android 12 and onwards tells us that pressing back when you got nothing else on the stack will act as if you pressed the home button.
There's a big exception here, and that is that when you re-open the application, if the one you just popped was not the launcher activity, it will then still need to launch that launcher activity and can't resume from where you left off in a hot state, exactly the reason why I am seeing the splash screen again.
So I think my best bet is to either ignore this for now, or fix my app to be a single-activity app, or at least keep the launcher activity be the top-level one that you exit the app from by pressing back
To indicate a couple of examples, if one wants to experience what I mean, the reproduction steps are to:
Open the app
Press the back button which will send you out of the app to the home screen
Click on the app icon again
As of today, apps like Google Photos, and Google Podcasts don't show the splash again. In contrast, apps like Google Maps, Twitter, Spotify do show the splash again for a brief second.
to call the launcher activity every time you have to clear the stack that means you have to use a flag in your manifest to tell your app not to keep activity in background try android:launchMode="singleTask" inside your activity tag in manifest the activity that you want to be killed everytime you go to background, and as far as how much time splash should be showing you can use timer for that after the timer is finished then your someActivity will be called.
I am calling one activity on click of status bar notification which is having a Complete button. on click of btn. i have folllowing code -
public void completeTask(){
taskDBAdapter.deleteReminder(rowId);
taskDBAdapter.close();
Intent intent = new Intent(this, TaskManagerActivity.class);
startActivity(intent);
finish();
}
whhen i click complete btn new activity (TaskManagerActivity) gets opened properly.But if i reopen my application it still tries to open this activity and not my default landing activity. Any help on this.??
EDIT -
I have tried repositioning my finish() statement . Still its not working.
EDIT 1.1 -
Ok I will provide some details here. Assume my app has two activities
Main Activity
Notification Activity
My app create some notification to display on Status bar. So as soon as i click on status bar Notification actvty will open. Now there is a button called Complete on click of which the code given will fire and main activity (in the code TaskManagerActivity.class) will open. But after I press back button in my app and again reopen it , it opens the notification activity when it should have fired the main activity (as it is launching activity).
Thanks,
Ray
That's the default way android functions. If you press the home button and then open your app again, it will restore the apps previous state (unless it has killed the apps processes and activities due to memory constraints). So you are not actually restarting your app but only restoring it.
If you wanna quit the app, then press the back button. Now when you re-open the app, the original activity will be launched.
Do not modify this behavior. It is the default system behavior and users expect it to work this way. Your app is fine :-)
- First of all the behavior which you are experiencing is the way Android is made to function, moreover when a user gets a call while this app is open, after finishing the app he will definitely want to get back to the state where he left the application.
Still if you want it that way, here it is.....
- Make sure your application has only single instance of it running, by using android:launchMode="singleTask", or android:launchMode="singleInstance"
- Then finish() your Activity at onPause().
#Override
void onPause()
{
super.onPause();
finish();
}
Our app has 2 Activities- A MainActivity (associated with Launcher icon) and an AuxActivity for handling URI events.
I'm seeing an issue with this scenario, with my app initially exited:
Open Browser, click on a URI to launch the AuxActivity.
AuxActivity exits (calls finish()), user returns to Browser.
User brings up recent Apps (long-press home), and selects my app.
Instead of starting MainActivity, I'm seeing AuxActivity being started with the same intent that represents a URI click (android.intent.action.VIEW).
Now instead of step 3, if the user were to open my app through its Home Screen icon, I get back to MainActivity, as expected.
How can I get step 3 to launch MainActivity instead?
Put this in AuxActivity's onCreate:
if ((getIntent().getFlags() & Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) > 0) {
// do something different e.g. launch MainActivity
}
Based on Tim's suggestion, what about adding
android:excludeFromRecents="true"
To the auxActivity listing in the Manifest? Does that help?
Not sure if this will work, but you might also try:
android:noHistory="true"
Whether or not the activity should be removed from
the activity stack and finished (its finish() method called) when the
user navigates away from it and it's no longer visible on screen —
"true" if it should be finished, and "false" if not. The default value
is "false". A value of "true" means that the activity will not leave a
historical trace. It will not remain in the activity stack for the
task, so the user will not be able to return to it. This attribute was
introduced in API Level 3.
how to check whether the activity was launched from notification or from the user click on home screen dashboard app icon in android. Is there any parameters that tells that this activity was launched due to user clicked on notification..
There already were several questions on this topic:
detecting application launch from
home or history
Determine if app was launched from
home screen?
As of the home screen part, as far as I know there is no way to detect that.
However, you can detect whether your activity is launched from the notification icon:
When setting up your notification, you put an extra into it's PendingIntent, say fromNotification: boolean.
In your main activity's onCreate method you check the intent's extras, and if (there are any and) the fromNotification is among them with the value true, than you know it has been invoked by clikcing on the notification icon.
You can use startActivityForResult() when launching Activity from your App and then check if getCallingActivity() returns null. If it does, your activity has been launched from notification.
I want the user to enter a password everytime he tries to enter the application. That is, the user must enter the password everytime the app comes to foreground from background, be it by pressing the launcher icon or long-pressing the home key
I sort-of achieved the first part because the launcher intent is fired and i get a callback in onRestart of that activity.
But by long-pressing home key and launching the does not provide callback to onRestart.
Also what if the user launches the app by pressing the notification from, the notification bar. How do I distinguish whether the app was originally in background or fore-ground before the user clicked the notification
In your onResume call, set a loginCounter += 1, in your onPause -= 1.
if loginCounter == 0 => show Login Dialog.
In the Notification Bar you set an Intent to call the Activity, correct? Simply add a parameter "isCalledByNotificationBar" as boolean in there.
If onResume doesn't work, how about onWindowFocusChanged(boolean)?
Perhaps what you should do is on re-entry into the application see if it's been less than 30 (?) seconds since a timestamp that you update when any activity of your application was last paused. If it's been less, don't ask for a password. Thinking being that this short time window might smooth over some transitions you don't want to log out on.