gtk: add option for numeric icons on tabs

[jcollie]

[tristan957]

I don't love this particular solution, but would be interested in unlocking this feature for people. I think templating in the window (surface) title would make more sense.

[jcollie]

I don't love this particular solution, but would be interested in unlocking this feature for people. I think templating in the window (surface) title would make more sense.

The big reason that I switched to an icon was that I had better control over the looks of the icon. I initially tried using unicode chars like "①" but they were a little small and didn't look very good in the default Cantarell font. By using an icon we can have much better control over it's appearance, maybe even dynamically generating it since we do have the machinery for that.

[tristan957]

But why not just use ascii numbers? Imagine a config like:

tab-title-prefix = {tab-index} {emdash}

Something stupid like that.

[jcollie]

But why not just use ascii numbers? Imagine a config like:

tab-title-prefix = {tab-index} {emdash}

Something stupid like that.

Because I wanted something that would be visually distinct from the tab title. If it's just text in the same font as the tab title that's much harder to do.

Also, there's the possibility of dynamically generating the icons. Some possible uses are spinners/beachballs/progress meters for the ConEmu OSC 9;4 codes. Probably a lot of other creative uses we can come up with.