I have a scenario in which I have to move to app settings screen from my current app activity. There is a dialog that does this. When I put the dialog open and goes to settings screen explicitly and change something, the button of the dialog that has to take me to app settings does not work. Any help please ?
If you don't want the history, can you try:
Intent.FLAG_ACTIVITY_NO_HISTORY
Intent.FLAG_ACTIVITY_CLEAR_TOP
Intent.FLAG_ACTIVITY_CLEAR_TASK
I'm trying to start an activity from a service I had already acquired the lock for as follows:
Intent i = new Intent(context, MyActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_NO_USER_ACTION);
startActivity(i);
The activity manifest is declared as follows:
<activity
android:name=".MyActivity"
android:configChanges="orientation|screenSize|keyboardHidden|keyboard|navigation"
android:excludeFromRecents="true"
android:launchMode="singleInstance"
android:screenOrientation="nosensor"
android:showOnLockScreen="true"
android:taskAffinity=""
android:theme="#style/MyTheme" />
And finally, on onCreate() or on onAttachedToWindow() (I tried on both), I add the following flags:
final Window win = getWindow();
win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
| WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
| WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON);
The problem is that the first time I call startActivity() from my service, the screen turns on but the activity itself does not show up. It shows the lock screen instead. Every subsequent call of startActivity() works properly but I can't find a reason for this odd behavior.
I tried already suggestions to get a full wakelock instead of partial, change the flags and values in the manifest according to the following SO answers:
Android Activity Not Showing When Screen is Woken Up and Lock Screen Not Disabling
how to unlock the screen when BroadcastReceiver is called?
Programmatically turn screen on in android
Android Galaxy S4 -- Activity that is visible over lock screen
Note that my theme is not a dialog but a fullscreen activity.
Any other ideas?
I'm facing the same problem, after a lot of searching here and google, found this which unlocked the screen and popped my activity but it only works for me when the app is running (foreground/background).
import android.view.Window;
import android.view.WindowManager.LayoutParams;
Window window = this.getWindow();
window.addFlags(LayoutParams.FLAG_DISMISS_KEYGUARD);
window.addFlags(LayoutParams.FLAG_SHOW_WHEN_LOCKED);
window.addFlags(LayoutParams.FLAG_TURN_SCREEN_ON);
i'm trying to start an activty when app is closed... (using broadcast receiver)
in the docs (for example here) and most of the answers on SO the flags are added this way:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
but when i tried the way it is like in the example it unlocked the screen instead of just turning on the screen.
hope this help . it still didn't solve my problem completely.
EDIT:
found this post which solved my problem.
there is a comment there on NOT using a dialog theme which solved it for me
Step 1: Add below code in your activity before
setContentView(R.layout.activity_about_us);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON|
WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD|
WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED|
WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
Step 2: Lock your mobile than you will see activity in which you have added this code.
You can implement this if you want to open particular screen by notification occurrence like skype call.
Since my application already includes a Service, this is what I do: if the screen is locked, I register a broadcast receiver (a bit simpler than this one, since it reacts only on unlocking) that starts the Activity as soon as the screen gets unlocked.
I'm working on an Android application. I've implemented a timer which redirects the user to the login actvity after a timeout period has expired. This part works well.
The only trouble I'm having is that if the user presses 'back' on the login activity without entering and validating his credentials, he is able to go back to the previous activity.
Which flags should I start the login activity with so that the user is not able to back press to the previous activity. These are the flags i'm using right now:
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
I know that an alternative is to override the behaviour of onBackPresed() but that does not sound like good practice to me.
Thanks!
Your approach sounds good except that it is the Timer's intent that needs to get flagged with Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK I believe and not the login activity.
Also, it is considered bad practise to use flags actually, at least moreso than overriding callbacks.
Im not saying you shouldnt use them tho =P
<<<<< EDIT: >>>>>
Actually I think i've misread, try this set of flags instead: FLAG_ACTIVITY_CLEAR_TASK
| Intent.FLAG_ACTIVITY_NEW_TASK
A few years ago, I wrote an alarm app that worked on Android 2, and I'm now trying to upgrade it to work on Android 4. Specifically, on the Samsung Galaxy S4.
On Android 2, if the phone was sleeping, it would wake the phone up and display a "Snooze or Dismiss" screen over the lock screen.
On Android 4, it wakes the phone up, but you have to unlock it, then open the notifications area, then click the alarm's notification, before you can hit "Dismiss."
I have always been using this code to do the waking:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
| WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
| WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
I have read 8 different stackoverflow questions on this matter. Most of them give the code above, which worked for me years ago in Android 2 but doesn't work in Android 4. But none of them have helped me solve this problem. Here are the questions that I read and tried:
Android: remove or disable programmatically the Lock Screen on Samsung Galaxy S2 device
How to display a fullscreen TYPE_SYSTEM_ALERT window?
How do I create an Activity that is visible on top of the lock screen
How to start a dialog (like alarm dimiss /snooze) that can be clicked without unlocking the screen
Android activity over default lock screen
android device locked, yet want alarm to sound and dialog to appear
Android dialog over lock screen
Show dialog with touch events over lockscreen in Android 2.3
Does anyone have any ideas about what's changed in Android 4 that may have caused this?
EDIT: Here is one of the simplest examples I've seen of an alarm dialog that doesn't come up "minimized." It does not, as written, appear over the lockscreen, but you can fix that with WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
http://wptrafficanalyzer.in/blog/setting-up-alarm-using-alarmmanager-and-waking-up-screen-and-unlocking-keypad-on-alarm-goes-off-in-android/
It's written with a FragmentActivity and a DialogFragment, but it still works as an Activity. It uses an AlertDialog.Builder to make the dialog, and if you try to do it with an XML layout, it won't work. Why?
I figured it out, and the answer was very different from what I expected.
This piece of code was included in the alarm clock sample from Android 2, in the AlarmAlert.java Activity:
#Override
protected void onStop() {
super.onStop();
// Don't hang around.
finish();
}
For reference, you can see the file from the example code in Git's past right here, containing the above onStop function. It never caused a problem in Android 2.
But in Android 4, if the phone was off, this onStop would fire right before the phone woke up, effectively "minimizing" the Activity. Once I removed this function, it immediately worked again.
But I wonder, is this the problem that other people like #radley and #Guardanis are getting? It seems unlikely, but please let me know if this fixes your problems too.
If you're visiting this answer in the future, and you're getting this problem, what I would try is:
Take out any onStop functions.
Add this code to the Activity:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
| WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
| WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
Make sure you're using a full screen theme, and not a dialog theme.
This didn't make a difference for me, but you could try setting showOnLockScreen explicitly in the manifest: <activity android:name="com.example.MyActivity" android:showOnLockScreen="true"/>
A second thing that didn't make a difference for me but you might try is adding the flag WindowManager.LayoutParams.FLAG_FULLSCREEN
I hope this helps other people!
In Kotlin,
For Api level 28 or less, you can simply add below method in your activity that needs to be opened:
override fun onAttachedToWindow() {
super.onAttachedToWindow()
toBeShownOnLockScreen()
}
private fun toBeShownOnLockScreen() {
window.addFlags(
WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
or WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
setTurnScreenOn(true)
setShowWhenLocked(true)
} else {
window.addFlags(
WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
or WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
)
}
}
And to make it work on Android Pie and above, in additional to above step, we need to set in AndroidManifest as well:
<activity
android:name=".view.activity.LockScreenActivity"
android:showOnLockScreen="true"
android:showWhenLocked="true"
android:turnScreenOn="true" />
I have tested this code from Api level 21 to 29, and works like charm!
Not sure if this is the problem in all cases, but the documentation on ShowWhenLocked says it applies only to the top-most full-screen window. I had a window themed as a dialog which was not working, but it worked fine once I changed it to a regular full-screen window.
One of the questions you linked to has an answer that appeared to solve this issue for me.
This is the code I am using which appears to be working:
#Override
public void onAttachedToWindow() {
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
| WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
| WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
| WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onAttachedToWindow();
}
I'm also explicitly declaring this in the activity definition in the manifest:
<activity
android:name="com.example.MyActivity"
android:label="#string/app_name"
android:showOnLockScreen="true"
>
Android activity over default lock screen
Right - So I have been struggling with this one recently but with a 5.0.2 Galaxy Tab A. Unsurprisingly what works on every other device does not work on Samsung (this has been the case since the first Samsung Galaxy device, they break something new each release!)
The general solution for showing an Activity over the lock screen for most devices is
//wake up device and show even when on lock screen
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD |
WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON |
WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
WindowManager.LayoutParams.FLAG_FULLSCREEN);
However this does not work for samsung devices. Removing FLAG_DISMISS_KEYGUARD however does this trick.
Looking at the docs for this flag we have
Window flag: when set the window will cause the keyguard to be dismissed, only if it is not a secure lock keyguard. Because such a keyguard is not needed for security, it will never re-appear if the user navigates to another window (in contrast to FLAG_SHOW_WHEN_LOCKED, which will only temporarily hide both secure and non-secure keyguards but ensure they reappear when the user moves to another UI that doesn't hide them). If the keyguard is currently active and is secure (requires an unlock pattern) than the user will still need to confirm it before seeing this window, unless FLAG_SHOW_WHEN_LOCKED has also been set.
and for FLAG_SHOW_WHEN_LOCKED we have
Window flag: special flag to let windows be shown when the screen is
locked. This will let application windows take precedence over key
guard or any other lock screens. Can be used with FLAG_KEEP_SCREEN_ON
to turn screen on and display windows directly before showing the key
guard window. Can be used with FLAG_DISMISS_KEYGUARD to automatically
fully dismisss non-secure keyguards. This flag only applies to the
top-most full-screen window.
You can see they can be used together but it seems samsung will not bother with FLAG_SHOW_WHEN_LOCKED if the device is locked and FLAG_DISMISS_KEYGUARD is present. My app requires a lock screen to be setup so removing the dismiss keyguard flag actually allows me to show full screen Activities over the lock screen. Yay for me, nay for samsung.
I have an app widget on the home screen which includes a button that launches a basic settings Activity.
When the user presses the Back button, if the main application has some activities in it's stack, the back press takes you to the most recently viewed Activity in the app, rather than back to the homepage. I've tried the following flags for my intent:
settingsIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
settingsIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_TASK_ON_HOME);
settingsIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
But no luck with any. Is there any flag or combination of flags I can use to do this? Thanks.
You need to do the following:
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
You are currently using setFlags which overrides the flags you set previously when you need both of these flags for it to work correctly.
You can read abut this at http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_CLEAR_TOP
try next
settingsIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
settingsIntent.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
This flags run activity in new task and don't add it to history after exit.
So your settings activity don't cross with main app