How to show layout over all screens?

Question

In some cases my app should show block screen. This screen pop up over alll screens, cover all UI elements and doesn't react on presses on back and home button, but should have ability to input password into.

Could you please suggest me a way how I can do that?

Sounds to me like he wants to do a passcode Activity for his own app, what's the problem with that? — dmon, Dec 25 '12 at 16:33
As a user I would like to be able to navigate away from that, perhaps even related to this! For example launching or switching to my email/browser/talk/skype application where my passcode can be found. And then return to this screen. — Mattias Isegran Bergander, Dec 25 '12 at 16:40
You will have a chance to turn off this functionality from settings. — I was Born bad, Dec 25 '12 at 16:43

Mattias Isegran Bergander · Answer 1 · 2012-12-25T20:14:14.853

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You really shouldn't even try that. The user should be in control of his own phone. If I want to check my email, see my notifications, swap to another app or whatever I should be able to do so whenever I can.

Having said that: blocking the back button can be done by overriding this method in your activity (to do nothing for example)

public void onBackPressed() {
}

edited Dec 25 '12 at 20:14

answered Dec 25 '12 at 16:17

Mattias Isegran Bergander

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score 1 · Answer 2 · answered Dec 25 '12 at 16:20

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Create fullscreen Activity with transparent background, put your "input password info" logic, override "Home" and "BackButton" actions in that Activity.

But this is not the best Android practice.

answered Dec 25 '12 at 16:20

Veaceslav Gaidarji

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Thank you for your answer, but as I know it is bossible to override back button not there is no way to do it for Home button – I was Born bad Dec 25 '12 at 16:41
it is possible too to override the event click on HomeButton – Houcine Dec 25 '12 at 16:42
Could you please provide an example how to do that? – I was Born bad Dec 25 '12 at 16:44
Overriding Home button is dangerous for security reasons, but your can read this post http://stackoverflow.com/questions/2079691/overriding-the-home-button-how-do-i-get-rid-of-the-choice – Veaceslav Gaidarji Dec 25 '12 at 16:57

score 0 · Accepted Answer · answered Dec 25 '12 at 18:03

I'll ignore the question of why you would want to do this, and just focus on the how. If you want to display UI full screen over all other screens, you will need to use an system alert window. You will need permissions SYSTEM_ALERT_WINDOW, and set your window type to

WindowManager.LayoutParams.TYPE_SYSTEM_ALERT

How to show layout over all screens?

3 Answers3