Linux app with Header Bar (GTKLib)

[Adam_Charlton]

I’m working on a Gnome (GTK) Linux app at the moment, and am looking to add a GTK Header Bar and Buttons within it, as per standard Gnome applications, eg: Text Editor (see below).

I’ve found GTKLib by @Ulrich_Bogun which seems to have the basics and seems like it should do what I need, but the header bar buttons seem to be full height by default, as below. I found the BorderWidth property which lowers the height but makes the spacing between buttons too large.

Any advice anyone can provide would be great to make the header buttons ‘normal’ that would be very appreciated!

[Adam_Charlton]

Adding an example with BorderWidth = 8 for context/further example.

[Adam_Charlton]

In case anyone has similar issues in the future, the issue was dragging the GTKLib into a brand new project created with Xojo 2021 R3, which changed the GTKLibWindow super to DesktopWindow instead of Window as per the original/example project. With the example project, where the super is Window all works as expected.