submarine/docs/ux-guide.md

UX guide

Principles

1. Attention follows severity. Healthy submodules are quiet, problems are loud, dangers are loudest. Users should be able to scan a long list and only see what needs action.
2. One word per row. At most one state word in the tree (+n for more); the detail pane lists everything.
3. Words over symbols. States are short words that need no legend. Symbols are only used where they are conventional (↑↓, ▸▾).
4. Meaning never depends on color alone (every state has a word).
5. Follow the user's terminal theme. Use ANSI 16 colors for meaning.

Layout

 ~/coding/my_project  main        1 unpushed · 1 missing · 2 off pin · 2 changed · 13 submodules 
   docs                                  origin/main                     │ src/
 misc/tools/                                                             │ my_submodule_3
     my_submodule_1                      origin/main                     │
     my_submodule_2       missing        a1b2c3d                         │ unpushed  pin not pushed to any remote
 src/                                                                    │
     my_submodule_1       off pin        origin/main                     │ Ref       origin/main · via checked out branch
   ▸ my_submodule_2 [2]   changed ·2     origin/main                     │ pin · you ● b7c8d9e Hotfix null pointer
     my_submodule_3       unpushed       origin/main    ↑1               │           ┊ 1 commit
 libs/                                                                   │ tip       ● 6f5e4d3 Release 2.1.0
     logging                             origin/main    ↓3               │
 ↑↓/jk move • ←→/hl fold • ⇧←→/HL fold all • space toggle • ? help • q quit

Area	Height / width
Header	1 line
Tree	Remaining width
Detail pane	40% of the width, at least 36 columns; hidden below 90 columns
Filter line	1 line above the footer, only while filtering
Footer	1 line (more with full help)

Key bar and palette

Keys come in three groups (keyMap.Navigation, .Submodule, .Global):

• Navigation (move, fold, toggle): left in the footer.
• Global (?, q): right-aligned in the footer, always kept.
• Submodule (act on the selected one, e.g. c): a palette on the last line of the detail pane. It is left out if the pane is shorter than 12 lines. Whenever the palette isn't shown (pane hidden or too short), these keys move into the footer after the navigation keys.

If the footer is too narrow, keys are dropped from the left group's end (submodule keys first); the global keys stay. Full help (?) lists all keys in columns, whatever the size. Keys work whether or not they are shown.

Tree row

indent ▸ name [n]   status          ref             delta

Column	Width	Content
indent	2 per depth
toggle	3	▸ collapsed, ▾ expanded, blank for leaves
name	fits the widest visible name	name, [n] = direct children (collapsed only)
status	16	issue word, +n, ● staged pin, ·k hidden issues per level (red, then yellow); blue staged or muted in sync without issues; spinner while loading
ref	widest ref, max 22	resolved ref; muted short SHA if unresolved
delta	6	↑n, ↓n, ↑n↓m

• The name column is only as wide as needed, so states stay close to names.
• Directory headers (src/, modules/) are muted and not selectable.
• Rows without issues: name and ref muted (except the selected row), status in sync in muted grey. An empty status cell would look like missing data; the muted word confirms the check ran without drawing attention.

Detail pane

For the superproject (header selected), the pin and you roles become HEAD, and Children becomes Modules (count and issues of all submodules). See Superproject.

1. Directory (muted) and name (bold); fetched <age> of the submodule, muted, right-aligned in the name's line (left out if the pane is too narrow, or the submodule is missing)
2. One line per issue: word (colored, 10 columns) + explanation; in sync nothing to do if there are none and no pin is staged; staged and detached HEAD on pin as information
3. Changes (only with uncommitted changes), see Change preview
4. Ref with · via <rule>, a blank line, then the spine; fetch failed: <git's message> (yellow word) if the last fetch failed
5. Children (count and issues below), URL

Spine

Ref       origin/main · via .gitmodules branch

tip       ● 3f1bf20 Fix: update package dependencies
          ┊ 4 commits
pin       ● 9ac01de Add ethercat node
          ┊ 2 commits
you       ● 48005ac Merge branch 'feat/ethercat…

• Newest on top, like git log: where each commit is, is read from its position, not by comparing SHAs. The commits between two nodes are not listed, only counted (┊ 4 commits; 1 commit if adjacent).

• The label column holds the roles (pin, tip, you; HEAD for the superproject), joined by · if they sit on one commit (pin · tip, pin · you). If all of them sit on one commit it says in sync instead, which also keeps the commit column in line with the other values; the column only grows for a longer label.

• With a staged pin the spine shows both: staged (blue label) is the pin in the index, pin the one in the superproject's HEAD, so the bump is visible as a distance between two nodes. The committed pin is left out if it is not on disk. If the staged pin is older than the committed one it sits below it, and the gap above it says (staged pin moves back) (blue).

• The checkout (you) is yellow (label and SHA) when it is on its own node, i.e. off pin. Everything else is the default text color, the gap muted.

• A commit that has diverged from the pin gets its own lane to the right of the main one. The two lanes join at a base node, the commit where the histories split; the counts say how many commits each side has since:

  tip         ● e1f2a3b Drop Go 1.21 support
              ┊ 2 commits
  pin · you ● ┊ c4d5e6f Experimental HTTP/3
            ┊ ┊ 1 commit
  base      ●─╯ a9b8c7d Release 1.9.0
  

  Only one diverged commit is drawn as a fork, and only if the base is known. Otherwise the nodes stay in a line and the gap says ┊ diverged ↑n ↓m (arrows from the lower node's view, like the tree).

• The nodes are ● (o with SUBMARINE_ASCII), the gap ┊ (:), the join ─╯ (-/).

• A missing submodule has only the pin node (SHA, no subject).

Change preview

Changes   5 files · 2M 1A 1D 1R · +37 −12
          ──────────────────────────────────────
          M  render.go  src/render/  +20 −4  3d ago
          M  README.md                +3 −1  20m ago
          A  notes.md  docs/           +14  2h ago
          D  old.go  src/               −8
          R  new.go  ← old.go                1d ago
          ?  scratch.txt                     5m ago
          …  3 more (2M 1?)

• A flat list, no group headers: IDEs (VS Code, JetBrains) do the same, and headers would use up the few lines the preview has. The letter is the meaning, the color only supports it (N4).
• Letters and colors: ! red bold, M yellow, A green, D red, R cyan, ? muted. Line counts: green +n, red −n; bin for binary files, submodule for a moved nested pin, repository for an untracked directory that is a git repository itself (cloned, never added as a submodule), nothing for other untracked files.
• Order: kind (!, M, A, D, R, ?), then changed lines, largest first, because the biggest edits are the ones people remember.
• Budget: 10 files. Every kind that occurs gets at least one line, the rest is filled in sort order. … n more (<kinds>) summarizes the hidden files. With 11 files all are shown: "1 more" would take the same line as the file itself.
• The Changes line summarizes all files: count, files per kind, line totals. Everything below it describes one file per line, so no line can be mistaken for a file's detail. In a narrow pane the line totals are dropped rather than cut.
• A muted rule (─, - in ASCII mode) separates the summary from the files. It starts in the value column and is as wide as the summary or the file table, whichever is wider.
• The age (muted) is the file's modification time, so the most recently touched files stand out. Removed files have no age.
• The list starts in the value column (under 5 files), like every other value in the pane.
• File name bold, directory muted. Counts form a right-aligned column directly after the widest path (max 48 columns), not at the pane's edge, so they stay next to their file in wide panes. If space is short the age column goes first, then the directory is cut from the left (…ernal/client/), the name last. For renames the muted part is ← old/path.
• Untracked directories are shown as one entry (tmp/).

Header

The header is the superproject's row: it is selected on startup and drawn with the selected background (bold) while selected. After the branch it shows the superproject's own state word like a tree row (in sync, changed, unpushed +1, spinner, error). The counts that follow are about submodules only.

path branch ↑↓ state n error · <count> <issue>… · n pin staged · n loading · n submodules · <fetch>

The summary and <fetch> form one group at the right edge; the path, branch and state stay at the left. If the line is too narrow it is cut with … at the right end, so the most important counts stay.

Issue counts are ordered by severity (unpushed, conflict, missing, off pin, changed), each in its level color. Zero counts are omitted. n loading counts only submodules whose status is still being loaded; ones whose load failed are counted separately as n error (red, before the issue counts). A detached superproject shows (detached) as its branch.

<fetch> on the right:

State	Shows
fetching	spinner + fetching 12/174 (repositories done / total)
done	nothing
some failed	3 failed (count in yellow)

The header has no fetch age: the age belongs to one repository, and a header age would be read as the age of everything. It is in the detail pane, for the selected repository (the superproject's own when the header is selected).

Colors

All colors are defined in internal/tui/theme/theme.go. Never hard-code colors in components.

Role	Color	Used for
Danger	ANSI 1 red, bold	unpushed, conflict, error, ↑n of an unpushed pin
Warn	ANSI 3 yellow	missing, off pin, changed, differing checkout SHA
Info	ANSI 4 blue	staged, the ● staged marker
Primary	ANSI 6 cyan	branch names, commit hashes, spinner
Muted	ANSI 8 grey	quiet rows, directory headers, arrows, labels
Text	terminal default	normal text
Border	ANSI 8 grey	pane and help separators
Bar	adaptive 254 (light) / 235 (dark)	header background
Selected	adaptive 253 (light) / 237 (dark)	selected row background
Backdrop	adaptive 252 (light) / 238 (dark)	the screen behind a popup

• Background shades have no ANSI-16 equivalent, so they use AdaptiveColor. The background is detected once in main before Bubble Tea starts.
• Styles that render on a background (header, selected row) take a base style (LevelStyle(level, base), Delta(pin, base)), so inner segments keep the background.

Wording

Word	Detail pane text
unpushed	pin not pushed to any remote
conflict	merge conflict
missing	not initialized / directory missing
off pin	checkout differs from pin
changed	uncommitted changes / untracked files
staged	pin change staged, not committed
in sync	nothing to do

Navigation

Key	Behavior
↑ / k, ↓ / j	Previous / next submodule; directory headers are skipped. ↑ from the first submodule selects the header (superproject)
space	Toggle expand/collapse of the selected submodule
→ / l	Header selected: first submodule. Collapsed with children: expand and select the first child. Expanded: select the first child. Leaf: nothing
← / h	Expanded: collapse it (stays selected). Otherwise: collapse the parent and select it. Top level: select the header (superproject)
L / shift+→ / ctrl+→	Expand all; then follow the first child from the selection down to a submodule without children
H / shift+← / ctrl+←	Collapse all (resets remembered expansion); select the top-level ancestor
home / g, end / G	Header (superproject) / last submodule
pgup, pgdn	Move by one screen
?	Toggle full help
q, ctrl+c	Quit
f	Fetch all repositories (does nothing while a fetch runs)
r	Reload everything (e.g. after editing files)
c	Copy the absolute directory of the selected submodule to the clipboard (OSC 52, so it also works over SSH; needs terminal support, in tmux set -g set-clipboard on). The footer confirms with copied <path>. Without a local provider (mock) the path relative to the superproject is copied
/	Open the filter, see Filter
!	Toggle problems only, see Problems only
x	Restore the selection, see Restore

"First child" always means the first child as displayed (children are grouped by directory).

Collapsing an ancestor of the selection moves the selection to that ancestor. The view scrolls so the selection is always visible; when the first submodule is selected, headers above it are shown too.

Filter

/ shows a text input above the footer (/ term). While it is open the tree shows only the submodules whose path (which includes the name) contains the term, ignoring case; their ancestors stay as context and are shown expanded, whatever the user folded. Directory headers without a match vanish. If nothing matches the tree says no submodule matches.

• Selection. If the selected submodule is filtered out, the next visible one (in display order) is selected, else the previous one; if none is left, nothing is selected (the detail pane is empty).
• Typing. The input has the focus: letters edit the term, so j, q etc. are text. ↑ ↓ pgup pgdn still move the selection. enter hands the keys back to the tree (the filter stays, all keys work again); / edits the term again.
• esc closes the input and removes the filter, in both modes. The selection stays; its ancestors are expanded so it is still visible.
• The superproject is never filtered out; if nothing matches it is selected.
• The filter line shows the keys that apply on its right.
• The header counts are not filtered.

Problems only

! reduces the tree to what needs attention. It uses the filter's rules (matches with their ancestors, shown expanded, see Filter), with "match" meaning has an issue (Status.Issues()) instead of path contains the term.

• A submodule that is still loading or failed to load (error) counts as a problem, since its state is unknown (as in the hidden counts, D7). Healthy submodules vanish when their status arrives.
• A staged pin is not an issue and does not show the row.
• It combines with the filter (both must match). Unlike the filter it is a mode, not an input: it stays until ! is pressed again, also after esc closed the filter.
• A line above the footer shows problems only (yellow) and ! show all. While the filter line is open, its hint starts with problems only (!) instead.
• With no problem the tree says no problems.
• The selection follows the filter's rule: if it stops being visible (also when a status changes), the next visible submodule is selected, else the previous one. The superproject stays selectable.
• The header counts are not filtered.

Restore

x makes the selection, and everything below it, exactly what git records (see actions.md). It uses the line above the footer:

Phase	Line
the submodule has a staged pin	yellow Restore src/app to, s staged pin · c committed pin (unstages it), right-aligned any other key cancels
reading what is lost	spinner, muted checking src/app…
something would be lost	yellow Restore src/app?, red Discards 7 changed files in 3 repositories, 2 commits on no branch, 1 untracked repository., right-aligned y restore · n cancel
running	spinner, yellow restoring src/app…
failed	red restore of src/app failed: <git's message>, until the next key

y restores, any other key cancels; the keys are not passed on while a question is open. After c the name reads src/app to the committed pin. Without a loss there is no question. Success flashes restored src/app in the footer. For the header the name is the superproject. This line takes precedence over the filter line and the problems-only notice.

Switch branch

b opens a popup in the middle of the screen (see actions.md). The screen around it stays visible but dimmed: its colors are dropped and it is drawn in Backdrop, darker than Muted, so the popup has the focus.

╭──────────────────────────────────────────────────────────────────────╮
│ Switch libs/feature                                                  │
│ / filter branches                                                    │
│ ──────────────────────────────────────────────────────────────────── │
│ * main                                             92d1583  3d ago   │
│   origin/feat/search                               58a2bf1  2h ago   │
│ ↑↓ select · enter switch · esc cancel                                │
╰──────────────────────────────────────────────────────────────────────╯

• Border Border, title in Primary bold, search prompt Primary, the selected row on the Selected background, SHA and age Muted, the remote prefix Muted, the checked-out branch bold with *.
• Width at most 72 columns, height as the list (at most 14 rows), so filtering does not resize it. While reading: spinner and reading branches…; no match: no branch matches; error: red, inside the popup.
• Enter closes the popup and continues on the line above the footer like a restore: checking, the question Switch src/app to origin/feat? Discards … y switch · n cancel, switching ….

Key reference

Every key in the UI, where it is shown. Update this table when a key is added or moved. "Bar" is the short footer bar, "Palette" the detail pane's palette (the footer takes its keys over where the palette can't be shown, see Key bar and palette), "Help" the full help (?).

Key	Action	Group	Shown in
↑ / k, ↓ / j	Move selection	Navigation	Bar, Help
← / h, → / l	Fold / unfold, parent / first child	Navigation	Bar, Help
H / ⇧←, L / ⇧→	Collapse / expand all	Navigation	Bar, Help
space	Toggle expand/collapse	Navigation	Bar, Help
home / g, end / G	Header / last submodule	Navigation	Help
pgup, pgdn	Move by one screen	Navigation	Help
c	Copy path	Submodule	Palette, Help
b	Switch branch (popup)	Submodule	Palette, Help
x	Restore	Submodule	Palette, Help
f	Fetch all repositories	Global	Help
r	Reload everything	Global	Help
/	Filter	Global	Help
!	Problems only (toggle)	Global	Help
?	Toggle full help	Global	Bar, Help
q, ctrl+c	Quit	Global	Bar, Help

Mouse

• Click a row: select it. Click the header: select the superproject.
• Click ▸ / ▾: select and toggle.
• Scroll wheel: move the selection.
• In the branch popup: click a branch to switch to it, wheel to move, click outside to close. The popup is hit-tested by its own position, not with bubblezone, since it is drawn after zone.Scan.

Accessibility and terminals

• SUBMARINE_ASCII=1: ASCII symbols (^ v > v . *) instead of Unicode.
• Many setups capture ctrl+←/→ (macOS Mission Control, some terminals and multiplexers), so expand/collapse all also work as shift+→/← and as L / H, the shifted vim keys for → / ← (for terminals that don't report shift+arrows).