vi-mode: visual mode: no background for commands

[blueyed]

When using vi-keybindings and entering visual mode (v), the visual selection gets a background color / standout mode, but this does not work with some parts when using zsh-syntax-highlighting, e.g. commands and invalid command:

In the below screenshot, the whole line is visually selected, but it is not visible for ls and lss:

[rosshadden]

👍

[danielshahaf]

In your example, printing $region_highlight from a widget shows:

region_highlight=( '0 2 fg=green' '3 6 underline' '7 10 none' '11 12 none' '13 16 fg=red,bold' )

Combining that with your screenshot shows reverse video only applies to the portions that have an fg=… attribute.

I can reproduce this without zsh-syntax-highlighting:

$ zsh -f
% bindkey -v
% f() { region_highlight=('0 2 fg=green' '2 4 underline') }
% zle -N f
% bindkey -a ^T f
% abcdef<Esc>v0<^T>    # cdef in reverse video, ab in green on normal-background-color

Should zsh turn the fg=green to bg=green? Or should everyone who sets $region_highlight check MARK and CURSOR and swap bg and fg? I would guess zsh itself should take care of applying reverse video. @blueyed @rosshadden Do you know? Maybe check with zsh-users@?

[blueyed]

Should zsh turn the fg=green to bg=green?

Seems sensible in the case of reverse?!

[danielshahaf]

Seems sensible in the case of reverse?!

It seems both you and I expect $region_highlight to be applied first, and the MARK..CURSOR region's highlighting to be applied on top of that. (Yes, the names are confusing.) However, it would not be unreasonable of zle to do things the other way around: first to apply the MARK..CURSOR region's highlighting and then to apply $region_highlight on top of that, so widgets can override the MARK..CURSOR region's highlighting.

The MARK..CURSOR's region highlighting, which defaults to standout (i.e., reverse video), is specified by $zle_highlight.

The man page is silent on the interaction between $zle_highlight and $region_highlight. I think that should be clarified by upstream. Once it is clarified whose responsibility it is to reverse the video of the ls and lss (in your example), that party — either zle or zsh-syntax-highlighting — can implement a fix.

Makes sense?

[danielshahaf]

workers/29425 also discusses the interaction between $zle_highlight and $region_highlight.

[danielshahaf]

jimmijj@ece762e fixes this for the special case that $zle_highlight contains an explicit region:… element. Therefore, a workaround is:

1. Set the default explicitly: zle_highlight+=( region:standout )
2. Cherry-pick jimmijj@ece762e.

So, I think the way forward is:

1. Work with zsh-workers to document whether $region_highlight takes precedence over $zle_highlight (current behaviour: it does).
2. Assuming the current behaviour becomes documented upstream, merge @jimmijj's patch, and improve it to have the code do the right thing even when $zle_highlight contains no region:… element, as is the default. (That patch is part of PR colors for files, command_prefix + more minor modifications #152.)

[ Update: started a zsh-workers thread. ]
[ Update: upstream has documented the behaviour in question. ]

[danielshahaf]

Proposed fix: danielshahaf@0e31d6e

(It's the i165-region-v1 branch in my repository.)

[danielshahaf]

Merged in 51102bf.