feat: add expandable diff excerpts with configurable context

2026-10-11 01:45:13 +02:00
parent 5e0700bb8c
commit 704dce2539
8 changed files with 590 additions and 21 deletions
@@ -215,11 +215,17 @@ The read-only comparison has Before on the left, After on the right, and the cha

 File rows show colored **A** (added, green), **M** (modified, yellow), **D** (removed, red), or **R** (renamed, cyan) markers in Tree and List views, including filtered results. Rename rows show the new name followed by `← old/path`; directories have no file-status marker. Ordinary file exploration remains unannotated.

+Text panes show change excerpts with **10 unchanged lines above and below** each change, preserving original file line numbers. Overlapping or touching excerpts merge; omitted stretches show an unchanged-line count in both panes. Files with only metadata changes show their notice or “No text changes” rather than unrelated source.
+
+With a text pane focused, **`[` expands above** and **`]` expands below** the excerpt at the top of the viewport, revealing up to **15 lines** per keypress. A hidden-line marker targets the following excerpt, or the preceding excerpt at the end of the file. Expansion clamps at file boundaries and merges excerpts when they meet. Existing visible source stays anchored; expanding above a leading/interior marker brings the newly revealed context into view. Opening a file resets its excerpts to the configured initial context.
+
+Configure these counts in Ruby with `config.diff_context_lines = 10` (nonnegative; `0` shows changes only) and `config.diff_expand_lines = 15` (positive).
+
 Changed text rows use muted red backgrounds in Before and muted green backgrounds in After, including blank tails and real empty lines. Foreground colors use the editor's bundled Tree-sitter syntax highlighting, parsed independently for each snapshot and its path (including the old path for renames). Unknown languages retain the normal foreground; historical snapshots do not borrow live-buffer LSP tokens.

 Missing counterparts use adjacent muted `╱` diagonals (U+2571, box drawings light diagonal) on the normal terminal background, one per column. Unlike the text slash `/`, this glyph is designed to reach cell corners so diagonals can join end to end across successive rows. Pixel-perfect joins depend on the terminal's font and line-spacing rendering. Actual empty source lines retain their normal/change background and are not hatched.

-Tab/Shift+Tab cycles focus between Files, Before, and After. In text panes, Up/Down or Ctrl+j/k scrolls both panes together; Left/Right or Ctrl+h/l scrolls the focused pane horizontally. Home/End goes to the first/last tree row or aligned text row. Wheel input over a text pane scrolls both panes; over Files it navigates visible tree rows without opening them. Esc first leaves filtering when the tree is focused; otherwise it closes the diff and preserves the editor's buffers, cursors, unsaved text, and undo history. Typing and pasted text cannot edit either snapshot.
+Tab/Shift+Tab cycles focus between Files, Before, and After. In text panes, Up/Down or Ctrl+j/k scrolls both panes together; Left/Right or Ctrl+h/l scrolls the focused pane horizontally. Home/End goes to the first/last tree row or displayed excerpt/hidden-line row. Wheel input over a text pane scrolls both panes; over Files it navigates visible tree rows without opening them. Esc first leaves filtering when the tree is focused; otherwise it closes the diff and preserves the editor's buffers, cursors, unsaved text, and undo history. Typing and pasted text cannot edit either snapshot.

 Binary data, missing final newlines, permission/type changes, symlink targets, and submodule pointers have explicit notices. Symlinks are not followed and submodule contents are not traversed. jj conflicts use jj's file-content projection and carry conflict notices; ordinary files remain readable. Identical-content moves are shown as renames; modified moves appear as an added and removed file.