I experience some difference in the way windows are handled.
I have windows without title :
self.window!.titleVisibility = NSWindow.TitleVisibility.hidden
self.window!.titlebarAppearsTransparent = true
self.window!.styleMask.insert(NSWindow.StyleMask.fullSizeContentView)
I draw a textField with a coloured background at the place of the title, next to the control buttons.
In 10.12.6, I set the background color of the textField at windowDidLoad ; and it stays so all time (that helps user recognize what type of window it is).
When I run the same code in 10.13.1, the color of the textField changes when window is not frontmost ; just as if system was using the color defined in xib for textField when window is not frontmost.
I tried to force background color in all func:
windowDidBecomeMain
windowDidResignKey
windowDidBecomeKey
windowDidResignMain
No result.
However, another textField which is single character does not experience the problem.
(I noticed in XCode 9.2 release note a point about this :
Localization warnings are no longer reported for a UILabel with numberOfLines set to 0, or for any single-character text strings. (34767956)
Could there be a link ?)
I read this SO thread that seems to hint at a bug or change of behavior at least.
h ttps://stackoverflow.com/questions/44448448/frameless-browserwindow-in-macos-10-13-beta-still-displays-a-title-bar
Is this documented somewhere ?
Is there a way to avoid this behavior .
Is this a bug ?
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I also noticed that the dragging of objects in the window that was very smooth on 10.12 is now a bit jirky.
Here also, did anything change in 10.13 with porrer performance ?
EDITED : Problem was a intempestive cursor update. My error, nothing to do with OSX.