A little while ago I installed Kate, the KDE text editor. I've been using vim a lot and while it's nice, I still don't know most of the keyboard shortcuts. I can select text, cut, copy, paste, and that's about it. :) So I thought, perhaps, trying out a graphical text editor would be nice. I like Notepad++ a lot so I was hoping to find something similar, and it looks like I have with Kate.
It's easy to change the colour scheme in Kate, both for the editor text and the surrounding window. In the main menu I can select Settings, and the first two options are Window Colour Scheme and Editor Colour Scheme. The options I have for the window are all named Krita blender, Krita bright, etc. Does this mean they're only available because I have Krita installed? There are many options for the editor, with names like Breeze and Solarized that I recognise as widely available colour schemes.
It's also easy to change the editor font. That's done in Settings -> Configure Kate..., under the Appearance section and the General tab. There's an Editor font: property that you can click on, and it opens a font picker window where you can choose font, style, and size. Easy!
What's had me stuck for a fair while is the font for the rest of the window. By default it was way too small, and I had to lean in to be able to read it without straining my eyes. It turns out that despite using its own window colour scheme, Kate relies on the global Qt6 theme for its window font.
I understand that usually the global Qt6 theme is controlled through KDE's settings menu, but I am not using KDE. I am using i3. After much more hunting around than I feel it should have taken, I found a program called qt6ct, for "qt6 configuration tool", which I could install through the Arch repositories.
On first running qt6ct I was greeted by a banner warning me that I needed to set an environmnent variable, QT_QPA_PLATFORMTHEME=qt6ct, so I added an export line for that to my .profile file. I restarted my computer, and the warning went away.
With that sorted I can go to the Fonts tab and change the General: setting to something more visible. I went with Comic Sans MS 16 :) . I also changed the Fixed width: font while I was here, in case it came up somewhere.
There are buttons on this tab to create and remove a fonts.conf file. I'm not sure what its purpose is but this is a red herring. It is not necessary to create this file.
I click OK to close qt6ct, and I open Kate, and my new font has been applied. I can now read the menus! Huzzah.
There is one problem in Kate that remains - clicking the button to open the Terminal will crash Kate. I'm guessing it's trying to open Konsole, which I don't have installed. And yes! Now I've installed Konsole as well, there it is. It doesn't seem like there's a way to change the terminal emulator that Kate uses.