As per mentioned in https://stackoverflow.com/a/22442702/3286489, the below code would require
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
WindowManager.LayoutParams p = new WindowManager.LayoutParams(
// Shrink the window to wrap the content rather than filling the screen
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
// Display it on top of other application windows, but only for the current user
WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
// Don't let it grab the input focus
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
// Make the underlying application window visible through any transparent parts
PixelFormat.TRANSLUCENT);
// Define the position of the window within the screen
p.gravity = Gravity.TOP | Gravity.RIGHT;
p.x = 0;
p.y = 100;
WindowManager windowManager = (WindowManager)getSystemService(WINDOW_SERVICE);
windowManager.addView(myView, p);
However, when checking through the source code of WindowManager.java, it seems to me that only if we use TYPE_APPLICATION_OVERLAY, then the permission is required.
/**
* Window type: Application overlay windows are displayed above all activity windows
* (types between {@link #FIRST_APPLICATION_WINDOW} and {@link #LAST_APPLICATION_WINDOW})
* but below critical system windows like the status bar or IME.
* <p>
* The system may change the position, size, or visibility of these windows at anytime
* to reduce visual clutter to the user and also manage resources.
* <p>
* Requires {@link android.Manifest.permission#SYSTEM_ALERT_WINDOW} permission.
* <p>
* The system will adjust the importance of processes with this window type to reduce the
* chance of the low-memory-killer killing them.
* <p>
* In multi-user systems shows only on the owning user's screen.
*/
public static final int TYPE_APPLICATION_OVERLAY = FIRST_SYSTEM_WINDOW + 38;
The reason I ask is, I'm thinking of using windowManager.addView(myView, p); within my App only (to draw something over my app), and not on other app, or run in background service. I'm not using TYPE_APPLICATION_OVERLAY flag. I believe I don't need the request permission of
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
But I want to confirm, since the stackoverflow link I provide above seems to alluded that it need that permission.
