fix(app): smooth switching in the bot's computer, and a page you can see

app/src/features/browser/BrowserPanel.tsx

@@ -16,7 +16,7 @@ import { Callout } from "../../ui/Callout";
 import { EmptyState } from "../../ui/EmptyState";
 import { SidePanel } from "../../ui/SidePanel";
 import { BotAvatar } from "../bots/BotAvatar";
-import { ComputerDock } from "../terminal/ComputerDock";
+import { ComputerFooter } from "../terminal/ComputerDock";
 import { AddressBar } from "./AddressBar";
 import { AskCallout, ControlPill, HeldNotes, TakeNotes } from "./HandsBars";
 import { HandsLayer } from "./HandsLayer";
@@ -34,12 +34,10 @@ const PAD = 12;
  * The bot's color around the page, in px: on the sides and top, and below,
  * where the pill that says who is in control hangs over its edge.
  */
-const STAGE = 14;
-const STAGE_BOTTOM = 30;
+const STAGE = 10;
+const STAGE_BOTTOM = 26;
 /** Kept under the page, for the pill and what the bot just did. */
 const UNDER = 56;
-/** The dock of the bot's computer, on the desk under the page. */
-const DOCK = 56;
 
 export function BrowserPanel({
   bot,
@@ -70,7 +68,7 @@ export function BrowserPanel({
   const [inside, body] = useRoom();
   const room = inside && {
     width: inside.width - 2 * PAD - 2 * STAGE,
-    height: inside.height - 2 * PAD - STAGE - STAGE_BOTTOM - UNDER - DOCK,
+    height: inside.height - 2 * PAD - STAGE - STAGE_BOTTOM - UNDER,
   };
   useFitPage(bot, room, watched);
   // A new tab is blank: the owner says where it goes.
@@ -92,7 +90,7 @@ export function BrowserPanel({
   }, [take, watched, status, hands.held, hands.take]);
 
   return (
-    <SidePanel label={t.panel(bot.name)} name="browser" defaultWidth={560} expanded={expanded}>
+    <SidePanel label={t.panel(bot.name)} name="computer" defaultWidth={600} expanded={expanded}>
       <header className="flex h-11 shrink-0 items-center justify-between border-line border-b pr-1.5 pl-4">
         <h2 className="flex items-center gap-2 font-semibold text-sm">
           {t.heading}
@@ -146,12 +144,7 @@ export function BrowserPanel({
             )}
           </Callout>
         ) : status === "closed" && !frame ? (
-          !windowed && (
-            <>
-              <Empty bot={bot} />
-              <ComputerDock className="mt-auto" />
-            </>
-          )
+          !windowed && <Empty bot={bot} />
         ) : (
           <>
             {live && ask && !hands.held && <AskCallout bot={bot} task={ask} hands={hands} />}
@@ -199,7 +192,6 @@ export function BrowserPanel({
                   )}
                 </div>
               </div>
-              <ComputerDock className="mt-3" />
             </div>
             {(hands.held || (live && !ask)) && (
               <ControlPill key={String(hands.held)} bot={bot} hands={hands} lesson={lesson} />
@@ -229,6 +221,7 @@ export function BrowserPanel({
           </>
         )}
       </div>
+      <ComputerFooter />
       {lesson.done && <LessonDialog bot={bot} lesson={lesson} />}
     </SidePanel>
   );

app/src/features/browser/browser.test.tsx

@@ -74,25 +74,25 @@ describe("browser panel", () => {
   test("gives the page the shape of the room the panel has, and shows it as large as fits", async () => {
     const { fake, scout } = crew();
     fake.browser.open(scout.id, "https://example.com/", "Example");
-    // The panel under its address row, as the app measures it: 508 by 624
+    // The panel under its address row, as the app measures it: 516 by 688
     // for the page, once what goes around and under it is set aside.
     vi.spyOn(Element.prototype, "clientWidth", "get").mockReturnValue(560);
     vi.spyOn(Element.prototype, "clientHeight", "get").mockReturnValue(804);
     await openScout(fake);
     fireEvent.click(toggle());
     const resized = () =>
       fake.calls.filter((call) => call.method === "browser.resize").map((call) => call.params);
-    await waitFor(() => expect(resized()).toEqual([{ botId: scout.id, width: 508, height: 624 }]));
-    // As wide as ever, and as tall as the room's shape asks.
-    expect(fake.browser.size(scout.id)).toEqual({ width: 1280, height: 1572 });
+    await waitFor(() => expect(resized()).toEqual([{ botId: scout.id, width: 516, height: 688 }]));
+    // A narrow room keeps the desktop layout's width, in the room's shape.
+    expect(fake.browser.size(scout.id)).toEqual({ width: 800, height: 1066 });
 
     act(() => {
       fake.browser.frame(scout.id, "AAAA");
     });
     // The bot's cursor lands where it acted on the taller page.
     const screenshot = within(panel()).getByRole("figure", { name: "What Scout sees" });
     act(() => {
-      fake.browser.act(scout.id, "click", { x: 640, y: 1572, label: "More" });
+      fake.browser.act(scout.id, "click", { x: 400, y: 1066, label: "More" });
     });
     const cursor = screenshot.querySelector(".bot-cursor") as HTMLElement;
     expect(cursor.style.top).toBe("100%");

app/src/features/browser/useBrowserView.ts

@@ -2,7 +2,7 @@
 // asks for its live frames and hears what the bot does, and stops asking
 // when the panel closes. The browser's state itself lives in the store.
 
-import { useEffect, useState } from "react";
+import { useCallback, useEffect, useState } from "react";
 import type { Bot, BrowserAction, BrowserFrame } from "../../lib/protocol.gen";
 import { useApi, useApp } from "../../store/context";
 
@@ -15,17 +15,44 @@ export interface BrowserView {
   watched: boolean;
 }
 
+/**
+ * The newest picture of each bot's page, so the panel opening again (from
+ * the dock) shows it at once while the watch starts again.
+ */
+const lastFrames = new WeakMap<object, Map<string, BrowserFrame>>();
+
+function framesOf(api: object): Map<string, BrowserFrame> {
+  let frames = lastFrames.get(api);
+  if (!frames) {
+    frames = new Map();
+    lastFrames.set(api, frames);
+  }
+  return frames;
+}
+
 export function useBrowserView(bot: Bot, watching: boolean): BrowserView {
   const api = useApi();
   const connected = useApp((state) => state.connection.kind === "open");
   const putBrowser = useApp((state) => state.putBrowser);
-  const [frame, setFrame] = useState<BrowserFrame | null>(null);
+  const frames = framesOf(api);
+  const [frame, setShown] = useState<BrowserFrame | null>(() => frames.get(bot.id) ?? null);
+  const setFrame = useCallback(
+    (next: BrowserFrame | null | ((current: BrowserFrame | null) => BrowserFrame | null)) =>
+      setShown((current) => {
+        const value = typeof next === "function" ? next(current) : next;
+        if (value) {
+          frames.set(value.botId, value);
+        }
+        return value;
+      }),
+    [frames],
+  );
   const [action, setAction] = useState<BrowserAction | null>(null);
   const [watched, setWatched] = useState(false);
 
   // biome-ignore lint/correctness/useExhaustiveDependencies: another bot's page is not this bot's
   useEffect(() => {
-    setFrame(null);
+    setFrame(frames.get(bot.id) ?? null);
     setAction(null);
   }, [bot.id]);
 
@@ -59,7 +86,7 @@ export function useBrowserView(bot: Bot, watching: boolean): BrowserView {
       unsubscribe();
       api.call("browser.unwatch").catch(() => {});
     };
-  }, [api, bot.id, watching, connected, putBrowser]);
+  }, [api, bot.id, watching, connected, putBrowser, setFrame]);
 
   return { frame, action, watched };
 }

app/src/features/files/FilesPanel.tsx

@@ -11,7 +11,7 @@ import { Button } from "../../ui/Button";
 import { Callout } from "../../ui/Callout";
 import { EmptyState } from "../../ui/EmptyState";
 import { SidePanel } from "../../ui/SidePanel";
-import { ComputerDock } from "../terminal/ComputerDock";
+import { ComputerFooter } from "../terminal/ComputerDock";
 import { FilePreview } from "./FilePreview";
 import { fileKind, kindIcon } from "./kinds";
 import type { BotFiles } from "./useBotFiles";
@@ -42,7 +42,7 @@ export function FilesPanel({
     (described?.path === path ? described : undefined);
 
   return (
-    <SidePanel label={t.panel(bot.name)} name="files" defaultWidth={416}>
+    <SidePanel label={t.panel(bot.name)} name="computer" defaultWidth={600}>
       <header className="flex h-11 shrink-0 items-center justify-between border-line border-b pr-1.5 pl-4">
         <h2 className="font-semibold text-sm">{t.heading}</h2>
         <div className="flex items-center gap-0.5">
@@ -63,9 +63,7 @@ export function FilesPanel({
       ) : (
         <List bot={bot} data={data} since={since} onOpen={onPath} />
       )}
-      <div className="shrink-0 border-line border-t py-2">
-        <ComputerDock />
-      </div>
+      <ComputerFooter />
     </SidePanel>
   );
 }

app/src/features/terminal/ComputerDock.tsx

@@ -1,5 +1,7 @@
 // The dock of a bot's computer (spec 15.1): its browser, its terminal and
-// its files, one click apart, at the foot of each of those panels.
+// its files, one click apart, at the foot of each of those panels. The
+// three share one width (`computer`), so moving between them only changes
+// what is inside.
 
 import { Folder, Globe, type LucideIcon, SquareTerminal } from "lucide-react";
 import { createContext, useContext } from "react";
@@ -17,6 +19,22 @@ const PLACES: { place: Place; icon: LucideIcon }[] = [
   { place: "files", icon: Folder },
 ];
 
+/**
+ * The dock as the foot of a panel: the same place in the browser, the
+ * terminal and the files, so it stays still while the panel above changes.
+ */
+export function ComputerFooter() {
+  const dock = useContext(Dock);
+  if (!dock) {
+    return null;
+  }
+  return (
+    <div data-steady className="shrink-0 border-line border-t py-2">
+      <ComputerDock />
+    </div>
+  );
+}
+
 export function ComputerDock({ className = "" }: { className?: string }) {
   const t = useT().terminal.dock;
   const dock = useContext(Dock);

app/src/features/terminal/TerminalPanel.tsx

@@ -7,11 +7,12 @@ import { LoaderCircle, X } from "lucide-react";
 import { useEffect, useRef } from "react";
 import { useT } from "../../i18n";
 import type { Bot, ToolItem } from "../../lib/protocol.gen";
+import { useApi } from "../../store/context";
 import { Button } from "../../ui/Button";
 import { SidePanel } from "../../ui/SidePanel";
 import { commandOf, isCommand } from "../chat/command";
 import { useChat } from "../chat/useChat";
-import { ComputerDock } from "./ComputerDock";
+import { ComputerFooter } from "./ComputerDock";
 
 function Command({ tool }: { tool: ToolItem }) {
   const t = useT().terminal;
@@ -45,14 +46,27 @@ function Command({ tool }: { tool: ToolItem }) {
   );
 }
 
+/**
+ * The commands each terminal showed last, so coming back to it (from the
+ * dock) shows them at once while the chat loads again.
+ */
+const lastShown = new WeakMap<object, Map<string, { id: string; tool: ToolItem }[]>>();
+
 export function TerminalPanel({ bot, onClose }: { bot: Bot; onClose(): void }) {
   const t = useT().terminal;
   const chat = useChat(bot.id);
-  const commands = chat.items.flatMap((item) =>
+  const api = useApi();
+  const shown = lastShown.get(api) ?? new Map<string, { id: string; tool: ToolItem }[]>();
+  lastShown.set(api, shown);
+  const loaded = chat.items.flatMap((item) =>
     item.body.kind === "tool" && isCommand(item.body.name)
       ? [{ id: item.id, tool: item.body }]
       : [],
   );
+  const commands = chat.loading && loaded.length === 0 ? (shown.get(bot.id) ?? []) : loaded;
+  if (!chat.loading) {
+    shown.set(bot.id, loaded);
+  }
   const screen = useRef<HTMLDivElement>(null);
   const last = commands.at(-1);
   // Follows the newest command, as a terminal does.
@@ -65,14 +79,14 @@ export function TerminalPanel({ bot, onClose }: { bot: Bot; onClose(): void }) {
   }, [last?.id, last?.tool.status]);
 
   return (
-    <SidePanel label={t.panel(bot.name)} name="terminal" defaultWidth={560}>
+    <SidePanel label={t.panel(bot.name)} name="computer" defaultWidth={600}>
       <header className="flex h-11 shrink-0 items-center justify-between border-line border-b pr-1.5 pl-4">
         <h2 className="font-semibold text-sm">{t.heading}</h2>
         <Button variant="ghost" size="sm" icon={X} label={t.close} onClick={onClose} />
       </header>
       <div className="flex min-h-0 flex-1 flex-col p-3">
         <div
-          className="bot-stage flex min-h-0 flex-1 flex-col gap-3 p-3.5"
+          className="bot-stage flex min-h-0 flex-1 flex-col p-2.5"
           style={{ "--bot": bot.color } as React.CSSProperties}
         >
           <div className="terminal-window flex min-h-0 flex-1 flex-col overflow-hidden rounded-xl">
@@ -102,9 +116,9 @@ export function TerminalPanel({ bot, onClose }: { bot: Bot; onClose(): void }) {
               )}
             </div>
           </div>
-          <ComputerDock />
         </div>
       </div>
+      <ComputerFooter />
     </SidePanel>
   );
 }

app/src/features/terminal/terminal.test.tsx

@@ -63,7 +63,8 @@ describe("the bot's terminal", () => {
     expect(dock("Terminal").getAttribute("aria-current")).toBe("page");
 
     fireEvent.click(dock("Browser"));
-    expect(panel("Scout's browser")).toBeDefined();
+    // It replaces the terminal in place: its content fades up, nothing slides in.
+    expect(panel("Scout's browser").className).toContain("panel-swapped");
     fireEvent.click(dock("Files"));
     expect(panel("Files from Scout")).toBeDefined();
     expect(dock("Files").getAttribute("aria-current")).toBe("page");

app/src/lib/fakePages.ts

@@ -10,10 +10,11 @@ export interface PageSize {
 
 export const PAGE: PageSize = { width: 1280, height: 800 };
 
-/** The page for a panel with `width` by `height` of room. */
+/** The page for a panel with `width` by `height` of room, as the daemon fits it. */
 export function fitting(width: number, height: number): PageSize {
-  const tall = Math.floor((PAGE.width * height) / width);
-  return { width: PAGE.width, height: Math.min(2000, Math.max(600, tall)) };
+  const wide = Math.min(1600, Math.max(800, width));
+  const tall = Math.floor((wide * height) / Math.max(1, width));
+  return { width: wide, height: Math.min(2000, Math.max(600, tall)) };
 }
 
 /**

app/src/panels.css

@@ -21,6 +21,20 @@
   animation: panel-open 460ms cubic-bezier(0.4, 0, 0.2, 1) both;
 }
 
+/* One panel replacing another (the dock, or a header button while one is
+   open): it does not slide in again, its content fades up in place. The
+   dock at its foot stays still. */
+@keyframes panel-swap {
+  from {
+    opacity: 0;
+    transform: translateY(4px);
+  }
+}
+
+.panel-swapped > :not([data-steady]):not([role="separator"]) {
+  animation: panel-swap 220ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
+}
+
 /* Out of the flow, on the right edge of the chat and its panel. */
 .panel-closing {
   position: absolute;

app/src/terminal.css

@@ -38,9 +38,8 @@
   color: var(--terminal-danger);
 }
 
-/* The dock sits on the desk, frosted, as a dock does. */
+/* The dock at the foot of the panel, the same in the three places. */
 .computer-dock {
-  background: color-mix(in oklab, var(--panel) 55%, transparent);
-  backdrop-filter: blur(8px);
-  box-shadow: inset 0 0 0 1px color-mix(in oklab, var(--panel) 70%, transparent);
+  background: var(--sunken);
+  box-shadow: inset 0 0 0 1px var(--line);
 }

app/src/ui/SidePanel.tsx

@@ -122,7 +122,11 @@ export function SidePanel({
         } as CSSProperties
       }
       className={`relative flex shrink-0 flex-col border-line border-l bg-panel ${
-        motion === "opening" ? "panel-opening" : motion === "closing" ? "panel-closing" : ""
+        motion === "opening"
+          ? `panel-opening ${from > 0 ? "panel-swapped" : ""}`
+          : motion === "closing"
+            ? "panel-closing"
+            : ""
       }`}
       onAnimationEnd={ended}
     >

crates/botloftd/src/browser/input.rs

@@ -279,7 +279,7 @@ mod tests {
         assert!(!fits(&mouse(f64::NAN, 10.0)));
         assert!(!fits(&mouse(10.0, 900.0)));
         // A taller page takes points further down.
-        let tall = Viewport::fitting(640, 700);
+        let tall = Viewport::fitting(640, 1000);
         assert!(super::fits(&mouse(10.0, 900.0), tall));
         let long = BrowserInput::Text {
             text: "x".repeat(TEXT_MAX + 1),

crates/botloftd/src/browser/session.rs

@@ -16,7 +16,7 @@ use tracing::debug;
 use super::cdp::Cdp;
 use super::events::pump;
 use super::launch::{self, BrowserProcess};
-use super::viewport::{MAX_HEIGHT, Viewport, WIDTH};
+use super::viewport::{MAX_HEIGHT, MAX_WIDTH, Viewport};
 use super::{BrowserError, agent};
 
 /// Most tabs a browser keeps; past this, the one active longest ago closes.
@@ -253,7 +253,7 @@ impl Session {
         let result = if on {
             // Frames come the size of the page, however tall it is.
             let params = json!({
-                "format": "jpeg", "quality": 60, "maxWidth": WIDTH, "maxHeight": MAX_HEIGHT,
+                "format": "jpeg", "quality": 60, "maxWidth": MAX_WIDTH, "maxHeight": MAX_HEIGHT,
             });
             self.cdp
                 .call(Some(session), "Page.startScreencast", params)