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adr/0014-responsive-tiers.mdRaw Markdown · GitHub ↗

ADR-0014: Responsive tiers and the unified-diff fallback

  • Status: Accepted, not implemented (the TUI is deferred, ADR-0112)
  • Date: 2026-06-24
  • Deciders: jka
  • Decision: D14

Context

ADR-0009 places the layout rule in a shared function. The function needs concrete outputs, and side-by-side diffs need a plan for screens too narrow to show two columns.

Decision

The layout function resolves to three tiers:

  • Wide: nav | editor | chat as columns, one status line below. No bottom pane.
  • Mid: one side column (the focused one) stays; the other collapses to a toggle.
  • Narrow: a single column; nav and chat become collapsible sections stacked around the editor, and only expanded sections take height.

Two editor groups sit side by side when there is room. A side-by-side diff falls back to a unified diff when the width is too small. Initial breakpoints are wide at about 100 columns or more and narrow below about 70; the GUI maps window width onto the same tiers.

Consequences

  • Diffs stay readable on small terminals, where the TUI has no mouse (ADR-0005).
  • The tiers target the TUI. The GUI uses user-sized dock sites (ADR-0035) and shows the compare view side by side only (ADR-0028); the unified fallback is not built.