How to overlay views in other apps

Question

Where do I start?

I don\'t know what functions or permissions will I use to make this. No root required.

The view look like this, the camera button on the ri

Answer 1

Try this:

    if(!isSystemAlertPermissionGranted(MainActivity.this)){
        requestSystemAlertPermission(MainActivity.this,1);
    }

    startService(new Intent(getApplicationContext(), Overlay.class));

And:

public static void requestSystemAlertPermission(Activity context, int requestCode) {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
        return;
    final String packageName = context == null ? context.getPackageName() : context.getPackageName();
    final Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + packageName));
    if (context != null)
        context.startActivityForResult(intent, requestCode);
    else
        context.startActivityForResult(intent, requestCode);
}
@TargetApi(23)
public static boolean isSystemAlertPermissionGranted(Context context) {
    final boolean result = Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP || Settings.canDrawOverlays(context);
    return result;
}