prompt-nav

1import { ownOrigins, emptyState, track, trackRow, candidates } from "./stops.mjs";
2
3export function register(on) {
4  let state = emptyState();
5
6  // Full-height panes leave this row free for the navigation added below.
7  on("state.get", { plugin: "prompt-nav", key: "paneRows" }, () => ({ value: { value: 1, version: 0 } }));
8
9  on("session.start", async ($, e, next) => {
10    const result = await next(e);
11    state = emptyState();
12    return result;
13  });
14
15  on("session.end", ($, e, next) => { state = emptyState(); return next(e); });
16  on("session.compact", async ($, e, next) => { const result = await next(e); state = emptyState(); return result; });
17
18  // Track the end of the transcript as well as its prompts: a visible final
19  // reply or turn footer tells Next chat that there is nothing below to visit.
20  on("ui.render", { component: ["UserMessage", "AssistantMessage", "ToolUse", "ToolResult", "ToolGroup", "CommandOutput", "TurnDuration"] }, async ($, e, next) => {
21    const result = await next(e);
22    if (e.surface === "terminal") {
23      trackRow(state, `${e.component}:${e.requestId}`, e.props.onScreen);
24      if (e.component === "UserMessage" && ownOrigins.has(e.props.origin?.kind)) track(state, e.requestId, e.props.onScreen);
25    }
26    return result;
27  });
28
29  on("ui.render", { component: ["AbovePrompt", "Pane"] }, async ($, e, next) => {
30    const original = await next(e);
31    if (e.surface !== "terminal" || e.props.hasSurvey || e.props.view?.agentId || original?.type === "engine") return original;
32    const { Box, Button } = $.ui.resolve(e);
33    const arrows = [
34      Button({ key: "prompt-nav-up", plain: true, color: "cyan", label: "Prev chat", onPress: () => jump($, state, -1) }),
35      Button({ key: "prompt-nav-down", plain: true, color: "cyan", label: "Next chat", onPress: () => jump($, state, 1) }),
36    ];
37    // Give the longer labels their own row so they never cover the pane's tabs
38    // or controls, including in the narrow Mod controls pane.
39    if (e.component === "Pane") {
40      return Box({ flexDirection: "column", children: [
41        Box({ flexDirection: "row", justifyContent: "flex-end", gap: 2, children: arrows }), original] });
42    }
43    if ((await $.ui.panes()).some(pane => pane.isShown)) return original;
44    return Box({ flexDirection: "column", children: [
45      Box({ flexDirection: "row", justifyContent: "flex-end", gap: 2, children: arrows }), original,
46    ] });
47  });
48}
49
50async function jump($, state, step) {
51  for (const id of candidates(state, step)) {
52    const { deny } = await $.ui.scroll({ to: { requestId: id }, block: "start" });
53    if (!deny) { state.landed = id; return; }
54  }
55}
56

1// Where the person's prompts sit relative to the transcript's viewport, from the engine's onScreen reports.
2
3// The person's own prompts; notifications and other agents' messages are not stops.
4export const ownOrigins = new Set(["composer", "bridge"]);
5
6export function emptyState() {
7  return { order: [], shown: new Map(), above: new Map(), landed: null, rows: [], rowVisibility: new Map() };
8}
9
10export function trackRow(state, id, seen) {
11  if (!state.rows.includes(id)) state.rows.push(id);
12  if (seen !== undefined) state.rowVisibility.set(id, seen);
13}
14
15export function atBottom(state) {
16  const last = state.rowVisibility.get(state.rows.at(-1));
17  return !!last && last.last >= last.of - 1;
18}
19
20export function track(state, id, seen) {
21  if (!state.order.includes(id)) state.order.push(id);
22  if (seen) {
23    state.shown.set(id, seen);
24    const index = state.order.indexOf(id);
25    state.order.forEach((other, i) => { if (i !== index) state.above.set(other, i < index); });
26    state.above.set(id, seen.first > 0);
27  } else if (seen === null && state.shown.has(id)) {
28    // A prompt whose top had scrolled away left upward; one cut at the bottom left downward.
29    const before = state.shown.get(id);
30    state.shown.delete(id);
31    state.above.set(id, before.first > 0 || before.last >= before.of - 1);
32  }
33}
34
35// The prompts to try for ▲ (step -1) or ▼ (step 1), nearest first: a stop the transcript
36// refuses (rewound, cleared) gives way to the next one the same way.
37export function candidates(state, step) {
38  const { order, shown, above, landed } = state;
39  // A short conversation can show several prompts while its end is already in
40  // view. Advancing from the first visible prompt would scroll backward there.
41  if (atBottom(state)) {
42    if (step > 0) return [];
43    const latest = order.at(-1);
44    const end = shown.get(latest)?.first === 0 ? order.length - 1 : order.length;
45    return order.slice(0, end).reverse();
46  }
47  const reference = landed && shown.has(landed) ? landed : order.find(id => shown.has(id));
48  let up, down;
49  if (reference) {
50    const index = order.indexOf(reference);
51    up = shown.get(reference).first > 0 ? index : index - 1;
52    down = index + 1;
53  } else {
54    // A prompt never reported in view (new rows push it off before it draws) counts as above:
55    // the viewport sits just before the first prompt known to lie below it.
56    const firstBelow = order.findIndex(id => above.get(id) === false);
57    up = (firstBelow >= 0 ? firstBelow : order.length) - 1;
58    down = up + 1;
59  }
60  return step < 0 ? order.slice(0, up + 1).reverse() : order.slice(down);
61}
62

1declare module "claude-code" {
2  interface PluginState {
3    "prompt-nav": { paneRows: number };
4  }
5}
6