Can't get device real width when app create

[SteveYo]

Hi all,

When running app on Surface duo, is always create on one screen(1350x1800), not two screen(for me is full screen, 2784x1800).

I can't get device real width when app only on one screen, but user usually don't put app on two screen.

I use android api like

WindowManager wm = (WindowManager) MainActivity.this.getSystemService(Context.WINDOW_SERVICE);
Point size = new Point();
wm.getDefaultDisplay().getRealSize(size);

Still not get real device width.

So, is there any function can get real device width? or can app start on two screen(full screen)?

Thanks for any helpful tip!

[#2]

@SteveYo apps cannot start on two screens - it is always a user-choice to span. So it will always start on a single screen.

The app can only get the dimensions that it runs in, so Window Manager can only get the 1350x1800 dimensions when the app is one a single screen.

Can you share why you need two-screen width when your app is only running on one screen?

[#3]

@Craig_Dunn 

Hi Sir,
Thanks for your help.

I would use the screenshot function to take screenshots,
and do something on this screenshot.

for example, get icon from screenshot.

This screenshot is full screen(two-screen) but only 1350x1800 dimensions(one-screen).

I will get wrong position because wrong dimensions.

Now I know app can only get the dimensions that it runs in(1350x1800 dimensions).
And is there any function can get real device width(2700x1800 dimensions)?

Thanks for any helpful tip!

[#4]

@SteveYo I've learned that screen capture apps that use the MediaProjection API are a special case. You need to run a foreground service to capture and have the android:foregroundServiceType="mediaProjection" attribute in the manifest.

In the media projection foreground service, queries for the DisplayMetrics will get the full display metrics (both screens) - but only in the service, not in any query made from an activity.

Hope that helps.