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I am developing Lock screen where i want to disable Home button in ice cream sandwich and in Jelly bean , i can block it using following methods in android 2.2 , 2.3

  @Override
public void onAttachedToWindow() {
    // TODO Auto-generate method stub
    this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);
    super.onAttachedToWindow();
}

also tried this 

   getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);

Here i am also not getting event info via onPause Method or onKeyDown

But these methods done't work for me in ICS,Jelly bean if is there any method that can replace it then let me know

Swayam
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Ronak Mehta
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3 Answers3

14

Post ICS i.e. Android 4+, the overriding of the HomeButton has been removed for security reasons, to enable the user exit in case the application turns out to be a malware.

Plus, it is not a really good practice to not let the user navigate away from the application. But, since you are making a lock screen application, what you can do is declare the activity as a Launcher , so that when the HomeButton is pressed it will simply restart your application and remain there itself (the users would notice nothing but a slight flicker in the screen).

EDIT #1 : Here is another workaround, more suited to your needs.

EDIT #2 : Just came across this. Haven't tested it. But looks kinda promising. Not sure if it would work, but you could give it a try.

Community
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Swayam
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    @Swayam, declaring the activity as launcher will prompt the user to choose default launcher, and next it will also mess up the launcher configurations. – Rachit Mishra Oct 29 '13 at 14:58
  • I agree with you that the user would be prompted to choose. But, he just needs to make the choice once and it is saved as his preference. That is some assumption we would need to make, especially given the fact that the user would want the lock screen app to work as intended. And, as far as * "messing up the launcher configurations" * is concerned, could you please elaborate, because I have never come across any such issue ? – Swayam Oct 29 '13 at 15:56
9

There are few things that you can try:

  • You can set your activity single top, and start it over with clear to top flag when onPause() method is called, this will block the home button and opening other activities.

  • Listen to BOOT_COMPLETED broadcast to start your activity - this will protect you from users who will take the battery out of the device in order to reboot it.

  • Add Alarmmanager that will test every second if your app is alive and if it is not, then start it - This will protect you from userers that some how managed to close your app(may be with external tools).

Do this and no one be able to exit your app.

Ilya Gazman
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  • Those are some wonderful points there mate! I had used the Boot_completed broadcast in one of my applications, but to use the `AlarmManager` is pure genius! +1 !! – Swayam Feb 28 '13 at 16:52
1

I think it is impossible to detect and/or intercept the HOME button from within an Android app. This is built into the system to prevent malicious apps that cannot be exited.

Ketan
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