Keep active task transcripts in memory for instant task switching

web/src/task.ts

@@ -4,7 +4,7 @@ import { markdown } from "./markdown.js";
 import { previewURL } from "./preview.js";
 import { findingCount, reviewCounts, severityCounts, unignoredFindings } from "./reviews.js";
 import { composerText, endSend, flushDrafts, forgetLostImages, lostImageCount, setComposerImages, setComposerText, startSend } from "./drafts.js";
-import { currentSession, findTask, focusTab, focusTask, on, onEach, pickReview, pinSnapshot, setFocus, showReview, state, type Topic } from "./state.js";
+import { currentSession, findTask, focusTab, focusTask, on, onEach, pickReview, pinSnapshot, setFocus, showReview, state, transcriptLoading, type Topic } from "./state.js";
 import { taskStyle } from "./taskcolor.js";
 import { fillTodoLinks } from "./todolink.js";
 
@@ -15,6 +15,7 @@ type Review = Schemas["Review"];
 export type ChatSource = {
   key: () => string | undefined;
   events: () => ByreEvent[];
+  loading: () => boolean;
   session: () => AgentSession | undefined;
   root: () => string;
   taskId: () => string | undefined;
@@ -22,6 +23,7 @@ export type ChatSource = {
   refreshTopics: Topic[];
   transcriptTopic: Topic;
   streamTopic: Topic;
+  readyTopic: Topic;
   empty: string;
   canSend: (sessionState: string) => boolean;
   placeholder: string;
@@ -84,6 +86,7 @@ type Ctx = {
 const taskSource: ChatSource = {
   key: () => state.selectedTaskId,
   events: () => state.transcript,
+  loading: transcriptLoading,
   session: () => (state.selectedTaskId ? currentSession(state.selectedTaskId) : undefined),
   root: () => (state.selectedTaskId ? (findTask(state.selectedTaskId)?.worktree_path ?? "") : ""),
   taskId: () => state.selectedTaskId,
@@ -91,6 +94,7 @@ const taskSource: ChatSource = {
   refreshTopics: ["tasks", "sessions"],
   transcriptTopic: "transcript",
   streamTopic: "stream",
+  readyTopic: "ready",
   empty: "No task selected. Ask your lead, or pick one with ⌘K.",
   canSend: () => true,
   placeholder: "Message the agent. Paste or drop images to attach them.",
@@ -235,6 +239,7 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
   const headImpl = makeHead(() => renderHead());
 
   const scanner = h("div", { class: "scanner", hidden: true });
+  const loading = h("div", { class: "empty" }, "loading…");
   const setRunning = (running: boolean) => {
     transcript.classList.toggle("running", running);
     scanner.hidden = !running;
@@ -541,6 +546,9 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
       return;
     }
     replace(transcript, scanner);
+    if (src.loading()) {
+      transcript.prepend(loading);
+    }
     appendEvents(src.events());
     renderComposer();
   };
@@ -553,6 +561,7 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
     }),
     onEach([src.transcriptTopic], (fresh) => appendEvents(fresh as ByreEvent[])),
     onEach([src.streamTopic], (ev) => appendDelta(ev as ByreEvent)),
+    onEach([src.readyTopic], () => loading.remove()),
     onEach(["tasks", "sessions"], () => fillTodoLinks(transcript, models[0]!)),
   ];