Dim unfocused panes to cut visual distraction

[Herve-Gakpe]

When I run several agents in split panes side by side, the unfocused panes keep streaming output. While Im working in one pane, the motion in the others constantly pulls my attention.

It would help a lot to visually de-emphasize the panes that dont have focus, so the active one stands out and the rest recede.

Simplest version: a configurable dim on unfocused panes, e.g.

[ui]
dim_unfocused = 0.4   # 0.0 = off (current), 1.0 = max

Note: since herdr renders all panes inside a single host-terminal pane, the terminals own dim-inactive-split feature cant do this. It has to come from herdr itself.

Keeping every session glanceable is the whole point of herdr; the peripheral motion is the main downside, and a dim-on-unfocus toggle would fix it without losing visibility.

[wkentaro]

i encountered the same, so protyped on v0.7.1: a [ui] pane_dim bool (default off) that dims inactive panes using a wezterm-style hsv transform.

demo, with pane_borders=false, pane_gaps=false, pane_dim=true:

code (rebased on v0.7.1): wkentaro#1

i made it a bool with fixed intensity instead of the graded dim_unfocused = 0.4 from the first post. can make it a configurable amount if you'd rather.

@ogulcancelik can we have your thoughts on this?

[wkentaro]

update: redid this on top of v0.8.0 and it got much simpler. @riveroverflows is right that the dim path already exists, so the whole thing is now a config flag that keeps that same dim applied in terminal mode:

[ui]
dim_unfocused_panes = true   # default false

diff vs the release tag: wkentaro/herdr@v0.8.0...v0.8.0-fork.1
prebuilt binaries (macos/linux): https://github.com/wkentaro/herdr/releases/tag/v0.8.0-fork.1

new look:

[kyhyco]

Exceptions process list would be awesome.

I use background dimming technique in nvim to distinguish inactive panes. Above PR will dim it again; exceptions process list would be helpful.

p.s. perhaps a separate discussion after this merges in woud be better

[riveroverflows]

Same need here. I run 14 agents across 9 workspaces in one herdr session, and in split tabs the unfocused panes keep streaming while I'm reading the focused one. The border alone isn't enough to settle attention.

What makes this feel close: herdr already dims inactive panes, it's just scoped to prefix mode. In src/ui/panes.rs:

let terminal_active = app.mode == Mode::Terminal;
let should_dim = !info.is_focused && multi_pane && !terminal_active;

The render path and the per-cell Modifier::DIM pass already exist. Letting the !terminal_active part be opt-out via config looks like the smallest version of this.

+1 to @wkentaro's [ui] pane_dim prototype. A plain bool covers my case, I don't need a graded intensity.

[LeszekBlazewski]

This would be a great addition, looking forward to it!

[walid-mos]

Strong +1. I regularly lose track of which pane I'm actually typing into. the focus border alone is too weak a signal (it's what I relied on in Ghostty splits before moving those splits into herdr).