Linux has always been kind of an odd duck when it comes to Xojo. If you create Linux applications with the IDE running in Linux the default sizes for controls is 26 which is different than MacOS or Windows since their default control height is 22. See the initial screenshot: the controls in Linux just don’t look right at the default Mac/Win control height.
The standard answer for many years was to subclass your controls and modify the height of the controls in Linux. This was okay but it hard to make your UI look good on all three target platforms.
Xojo 2017 R2 changed the drawing system it uses. The switch to GTK3 made it possible to modify the CSS of your application theoretically making it possible to make all platforms look and behave the same.
Just because you can modify the CSS means it’s a trivial task. Several long time Xojo community members Jim McKay and Jürg Otter stepped up to the plate and put in the time to figure it out. The result is at https://bitbucket.org/pidog/modgtk3/src/master/.
In this screenshot you can see that everything looks as you’d expect.
Implementing this in your own project is simple. Download the BitBucket repository, open the project in Xojo and copy the GTK3 folder into your own project. Then in the App.Open event put these three lines in:
modGTK3.initGtkEntryFix
modGTK3.initGtkWidgetHeightFix
modGTK3.InitGlobalGTK3Style
That’s it. Voila! Now your app looks better in Linux and there’s no need to subclass your controls. I realize this isn’t magic but it sure seems like it.