Thank you for information, I somehow missed this information, and works mouse on Android 7 exactly like on pc? Or only black cursor can be hidden. Will try explain. There are two issues with physical mouse on android :
1. Black cursor could not be hidden
2. That how android sends mouse coordinates. On desktop pc if you move cursor to border of screen and you still move mouse, then system still sends new and new coordinates. You dont have any problem with physical mouse. But android stops sending new cootdinates if you reach border with black cursor. This means that mouse cursor wont move anymore to the side where black cursor reached border.
Currently mDosbox uses Android Api 21 (android 5.1). To get higher (to android 7.0) must be fixed issues with new storage policies introduced in android 6.0. It must be done, but I was not hurry, because newer android version dont offer nothing interesting – only problems.
But if android fixed problems with physical mouse then there is good reason to go higher. But only “hiding” feature is not so hot reason, second point is interesting
EDIT : Ok I found it
They change image to transparent. People did it on rooted phones. Unfortunately seems they still didn’t fix functionality how android sends coordinates 🙁