Bottom row alignment or "fixing" the padding below statusbars

[dmun]

I have been experimenting with trying to 'fix' the padding below statusbars when using neovim for example. So far terminals use a resize in steps option to do this, but I personally don't like windows not being full sized.

I was wondering if this is also wanted by others, and if it even is the right approach.

Screen.Recording.2025-01-03.at.11.07.17.AM.mov

Approach

Currently, if all the cells in the bottom row are 'opaque', the bottom row is aligned to the bottom. Then I just offset the last 1 row by the amount of bottom padding and decide the color of that new padding based on the same neverExtendBg heuristics.

This however assumes that there is a max of one statusbar, and that the background color of the terminal application is the same as Ghostty's background color, otherwise it would always consider the last row a status bar.

Considerations

I've been thinking of better heuristics for determining whether a row is a statusbar and how many there are, but they all seem too complex and too specific. Here are some considerations:

Should we handle multiple status bars? The only situation I can think of with multiple status bars is using tmux + vim. How do we determine the amount of statusbars?

Something to consider is that cursorline rows in neovim for example can be completely opaque which makes it hard to decide anything based on just the color.

Or can we just assume that a status bar always has a powerline icon? That would make everything much easier. I personally don't use those icons, but I feel like the majority of users do.

Or should we let users tweak their own heuristics by letting them provide their own characters/words that they know will be in the status bar?

Alternatives

Other ways to get rid of the excess padding beneath the last row:

1. Distributing the excess bottom padding along all rows: I think this would work but personally don't like inconsistent line heights between resizes.
2. Increasing the line height of the bottom row by the bottom padding: I this this looks nice, but this also feels inconsistent and we still need to determine whether its a statusbar.