In interface Builder, in the attributes inspector, set the window by disabling:
- title bar
Thank you Claude31 I mean programmatically. Sorry, my fault. I have updated my question
if you want to make changes in code, consider tweaking the styleMask when you create a window. check the documentation in NSWindow for
init(contentRect: NSRect, styleMask style: NSWindow.StyleMask, backing backingStoreType: NSWindow.BackingStoreType, defer flag: Bool)
the NSWindow.StyleMask struct then gives you access to the parameters you want, such as titled, closable, miniaturizable, resizable, and so on. however, it appears you can only do this when defining the window; i don't see right away that you can change them on an exisiting window.
hope that helps,