how do i to make a window(osx) always hover on top of screen

Question

i trying to make a osx application that just have one window and it will always on the top of screen. anyone knows how to achieve it? thanks.

Answer 1

You can change the window's windowLevel (via -setLevel:) to NSFloatingWindowLevel.

[window setLevel:NSFloatingWindowLevel]; 

Documentation is here: Window_Levels

Answer 2

By "on the top", do you mean you do not want your window to be obscured, even if a different app is active? In that case, one way is to start with the NSPanel template in Interface Builder, check the "Utility" option, and uncheck "Hide on Deactivate".