Screen sharing: start dialog, sound, video tiles and a meeting view

- Start dialog with source list, live preview, sound and quality choices
- Sound on Linux through PipeWire: one program or everything except this
  app, fed into a virtual microphone and kept linked as programs come and go;
  system loopback on Windows; stereo Opus
- A sharer's tile shows the picture; clicking it opens a large view with the
  other tiles as a strip. Own stream is previewed in the own tile
- Stream volume for viewers, watch and stop from the profile panel
- Unit tests for the PipeWire link planner; the proxy test no longer writes to
  the root channel other tests listen in

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/App.svelte

@@ -15,7 +15,8 @@
   import ChannelDialog from './ui/ChannelDialog.svelte';
   import PublicServers from './ui/PublicServers.svelte';
   import ServerInfoDialog from './ui/ServerInfoDialog.svelte';
-  import SharePicker from './ui/SharePicker.svelte';
+  import ShareDialog from './ui/ShareDialog.svelte';
+  import { share } from './lib/share.svelte.ts';
   import ResizeHandle from './ui/ResizeHandle.svelte';
   import { identities } from './lib/identities.svelte.ts';
   import { session } from './lib/session.svelte.ts';
@@ -130,7 +131,7 @@
 {#if ui.channelDialog && session.status === 'connected'}
   {#key ui.channelDialog}<ChannelDialog {...ui.channelDialog} onclose={() => (ui.channelDialog = null)} />{/key}
 {/if}
-<SharePicker />
+{#if share.dialog}<ShareDialog onclose={() => (share.dialog = null)} />{/if}
 {#if ui.prompt}<PromptDialog {...ui.prompt} onclose={() => { const p = ui.prompt; ui.prompt = null; p?.oncancel?.(); }} />{/if}
 <ContextMenu />
 

src/lib/native.ts

@@ -31,8 +31,15 @@ interface NativeApi extends PlatformApi {
   editAction(action: string, arg?: unknown): void;
   // Screens and windows that can be shared; pick one before calling getDisplayMedia
   // chosen: the system's own picker already asked (Wayland), so `sources` is the one answer
-  screenSources(): Promise<{ sources: ScreenSource[]; chosen: boolean }>;
+  // Thumbnails are slower to get and can fail; ask for the names first
+  screenSources(thumbnails: boolean): Promise<{ sources: ScreenSource[]; chosen: boolean }>;
   pickScreenSource(id: string): void;
+  // portal: the system shows its own source picker (Wayland). audio: how other programs' sound can be captured.
+  shareInfo(): Promise<{ portal: boolean; audio: 'pipewire' | 'loopback' | 'none'; micLabel: string }>;
+  shareAudioApps(): Promise<string[]>;
+  // Linux: route one program, or everything but this app, into a virtual microphone named micLabel
+  shareAudioStart(target: { kind: 'all' } | { kind: 'app'; name: string }): Promise<void>;
+  shareAudioStop(): Promise<void>;
   open(connId: string, host: string, port: number, identityId?: string): Promise<void>;
   send(connId: string, bytes: Uint8Array): void;
   close(connId: string): void;

src/lib/settings.svelte.ts

@@ -24,6 +24,8 @@ export interface Settings {
   theme: ThemeId;
   publicListUrl: string;  // where the public server list comes from
   arrangement: Arrangement;
+  shareQuality: 'low' | 'medium' | 'high'; // bitrate and frame rate of our own stream
+  shareVolume: number;    // volume of streams we watch, 0 to 1
   stunServer: string;     // helps screen sharing connect through routers; empty contacts nobody
   shareNoticeSeen: boolean; // the note that screen sharing reveals IP addresses was confirmed
   hints: boolean;         // tooltips (title attributes) when resting the pointer on buttons
@@ -54,6 +56,8 @@ const defaults: Settings = {
   theme: 'dark',
   publicListUrl: 'https://publist.mumble.info/v1/list?version=1.5.0',
   arrangement: 'side',
+  shareQuality: 'medium',
+  shareVolume: 1,
   stunServer: '',
   shareNoticeSeen: false,
   hints: false

src/lib/share.svelte.ts

@@ -5,13 +5,21 @@
 import { SHARE, SHARE_DATA_ID, encodeShare, ShareAssembler, type ShareType } from '../core/share-signal.ts';
 import type { User } from '../core/client.ts';
 import type { Session } from './session.svelte.ts';
-import { desktop, type ScreenSource } from './native.ts';
+import { desktop } from './native.ts';
 import { store } from './settings.svelte.ts';
 import { ui } from './ui.svelte.ts';
 
 // Every viewer is a separate upload from the sharer
 const MAX_VIEWERS = 8;
-const MAX_BITRATE = 4_000_000;
+export const QUALITY = {
+  low: { label: 'Low (1 Mbit/s, 30 fps)', bitrate: 1_000_000, fps: 30 },
+  medium: { label: 'Medium (4 Mbit/s, 30 fps)', bitrate: 4_000_000, fps: 30 },
+  high: { label: 'High (8 Mbit/s, 60 fps)', bitrate: 8_000_000, fps: 60 }
+} as const;
+
+// Opus is negotiated as mono speech by default; shared sound is stereo and often music
+const stereo = (sdp: string) => sdp.replace(/a=fmtp:(\d+) ([^\r\n]*useinbandfec=1[^\r\n]*)/g,
+  (line, pt, rest) => rest.includes('stereo=1') ? line : `a=fmtp:${pt} ${rest};stereo=1;sprop-stereo=1;maxaveragebitrate=192000`);
 
 export interface Watching {
   host: Session;
@@ -27,8 +35,9 @@ class ScreenShare {
   viewers = $state(0);
   watching = $state.raw<Watching | null>(null);
   error = $state('');
-  // Source choice in the desktop app (the browser brings its own picker)
-  picker = $state.raw<{ sources: ScreenSource[]; choose: (id: string | null) => void } | null>(null);
+  // The server the start dialog is open for
+  dialog = $state.raw<Session | null>(null);
+  private usesVirtualMic = false;
 
   private peers = new Map<number, RTCPeerConnection>();
   private watchPc: RTCPeerConnection | null = null;
@@ -75,55 +84,50 @@ class ScreenShare {
     });
   }
 
-  private async capture(): Promise<MediaStream> {
-    if (desktop) {
-      const { sources, chosen } = await desktop.screenSources();
-      // Cancelled in the system's picker
-      if (!sources.length) throw new Error('');
-      const id = chosen ? sources[0].id
-        : await new Promise<string | null>(choose => { this.picker = { sources, choose }; });
-      this.picker = null;
-      if (!id) throw new Error('');
-      desktop.pickScreenSource(id);
-    }
-    return navigator.mediaDevices.getDisplayMedia({ video: { frameRate: 30 }, audio: false });
+  // Opens the dialog where the source, the sound and the quality are chosen
+  async start(s: Session): Promise<void> {
+    if (this.stream || this.dialog || !this.supported(s) || !(await this.notice())) return;
+    this.error = '';
+    this.dialog = s;
   }
 
-  async start(s: Session): Promise<void> {
-    if (this.stream || !this.supported(s) || !(await this.notice())) return;
-    this.error = '';
-    let stream: MediaStream;
-    try {
-      stream = await this.capture();
-    } catch (e) {
-      // Cancelling the picker is not an error worth showing
-      const msg = (e as Error).message;
-      if (msg && (e as Error).name !== 'NotAllowedError') this.error = `Could not capture the screen: ${msg}`;
+  // The dialog hands over what it captured
+  go(s: Session, stream: MediaStream, usesVirtualMic: boolean): void {
+    this.dialog = null;
+    // Disconnected while the dialog was open
+    if (!s.client || this.stream) {
+      stream.getTracks().forEach(t => t.stop());
+      if (usesVirtualMic) desktop?.shareAudioStop();
       return;
     }
-    // Disconnected while the picker was open
-    if (!s.client) return stream.getTracks().forEach(t => t.stop());
     for (const t of stream.getVideoTracks()) {
       t.contentHint = 'detail';
       // The system's "stop sharing" control
       t.addEventListener('ended', () => this.stop());
     }
+    this.usesVirtualMic = usesVirtualMic;
     this.host = s;
     this.stream = stream;
     this.send(s, this.others(s), SHARE.on);
     s.setSharing(s.client.session!, true);
   }
 
+  private release(): void {
+    this.dropPeers();
+    this.stream?.getTracks().forEach(t => t.stop());
+    this.stream = null;
+    this.host = null;
+    if (this.usesVirtualMic) desktop?.shareAudioStop();
+    this.usesVirtualMic = false;
+  }
+
   stop(): void {
     const s = this.host;
     if (s?.client) {
       this.send(s, this.others(s), SHARE.off);
       if (s.client.session != null) s.setSharing(s.client.session, false);
     }
-    this.dropPeers();
-    this.stream?.getTracks().forEach(t => t.stop());
-    this.stream = null;
-    this.host = null;
+    this.release();
   }
 
   private dropPeers(): void {
@@ -195,10 +199,10 @@ class ScreenShare {
       const params = sender.getParameters();
       // Keep the picture sharp and let the frame rate drop when the connection is tight
       params.degradationPreference = 'maintain-resolution';
-      for (const enc of params.encodings ?? []) enc.maxBitrate = MAX_BITRATE;
+      for (const enc of params.encodings ?? []) enc.maxBitrate = QUALITY[store.settings.shareQuality].bitrate;
       await sender.setParameters(params).catch(() => {});
     }
-    await pc.setLocalDescription(await pc.createOffer());
+    await pc.setLocalDescription({ type: 'offer', sdp: stereo((await pc.createOffer()).sdp ?? '') });
     await this.gathered(pc);
     if (this.peers.get(viewer) === pc && pc.localDescription) await this.send(s, [viewer], SHARE.offer, pc.localDescription.sdp);
   }
@@ -215,7 +219,7 @@ class ScreenShare {
     });
     try {
       await pc.setRemoteDescription({ type: 'offer', sdp });
-      await pc.setLocalDescription(await pc.createAnswer());
+      await pc.setLocalDescription({ type: 'answer', sdp: stereo((await pc.createAnswer()).sdp ?? '') });
       await this.gathered(pc);
       if (this.watchPc === pc && pc.localDescription) await this.send(s, [sharer], SHARE.answer, pc.localDescription.sdp);
     } catch {
@@ -275,12 +279,8 @@ class ScreenShare {
   }
 
   closed(s: Session): void {
-    if (this.host === s) {
-      this.dropPeers();
-      this.stream?.getTracks().forEach(t => t.stop());
-      this.stream = null;
-      this.host = null;
-    }
+    if (this.host === s) this.release();
+    if (this.dialog === s) this.dialog = null;
     if (this.watching?.host === s) this.endWatch();
   }
 }

src/ui/Chat.svelte

@@ -3,7 +3,6 @@
   import ChatLog from './ChatLog.svelte';
   import Composer from './Composer.svelte';
   import VoiceStage from './VoiceStage.svelte';
-  import ShareView from './ShareView.svelte';
   import { ui } from '../lib/ui.svelte.ts';
   import { session } from '../lib/session.svelte.ts';
 
@@ -28,8 +27,7 @@
     <button class="icon-btn" onclick={onpanel} title="Members"><Icon name="users" /></button>
   </header>
 
-  {#if showStage && session.status === 'connected'}<VoiceStage />{/if}
-  {#if session.status === 'connected'}<ShareView />{/if}
+  {#if session.status === 'connected'}<VoiceStage always={showStage} />{/if}
 
   {#if session.status === 'idle' && session.disconnectInfo}
     {@const d = session.disconnectInfo}

src/ui/RightPanel.svelte

@@ -13,6 +13,8 @@
   import { voice } from '../lib/audio/voice.svelte.ts';
   import { renderIncoming } from '../lib/html.ts';
   import RichEditor from './RichEditor.svelte';
+  import { share } from '../lib/share.svelte.ts';
+  import { sessions } from '../lib/session.svelte.ts';
 
   let { onnavigate, onclose }: { onnavigate: () => void; onclose: () => void } = $props();
 
@@ -124,6 +126,16 @@
         </div>
       </div>
 
+      {#if session.sharing[user.session]}
+        <div class="sharing">
+          <Icon name="screen" size={16} />
+          <span>{isSelf ? 'You are sharing your screen' : 'Sharing their screen'}</span>
+          {#if isSelf}<button class="btn" onclick={() => share.stop()}>Stop sharing</button>
+          {:else if share.watching?.session === user.session}<button class="btn" onclick={() => share.unwatch()}>Stop watching</button>
+          {:else}<button class="btn primary" onclick={() => share.watch(sessions.active, user.session)}>Watch</button>{/if}
+        </div>
+      {/if}
+
       {#if isSelf}
         <div class="actions"><button class="btn" onclick={() => changeNamePrompt(user)}>Change name</button></div>
       {/if}
@@ -158,6 +170,9 @@
 </aside>
 
 <style>
+  .sharing { display: flex; align-items: center; gap: 8px; margin-top: 12px; padding: 8px 10px; font-size: 13px; color: var(--speaking); border: 1px solid var(--line); background: var(--bg-0); }
+  .sharing span { flex: 1; min-width: 0; color: var(--text); }
+  .sharing .btn { padding: 4px 10px; font-size: 12px; }
   .panel { position: relative; max-width: 100%; height: 100%; flex: none; display: flex; flex-direction: column; background: var(--bg-1); border-left: 1px solid var(--line); min-height: 0; }
   header { height: 52px; flex: none; display: flex; align-items: center; gap: 8px; padding: 0 8px 0 14px; border-bottom: 1px solid var(--line); color: var(--text-dim); }
   h2 { flex: 1; min-width: 0; margin: 0; font-size: 15px; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

src/ui/ShareDialog.svelte

@@ -0,0 +1,224 @@
+<script lang="ts">
+  import { onDestroy } from 'svelte';
+  import Modal from './Modal.svelte';
+  import { share, QUALITY } from '../lib/share.svelte.ts';
+  import { desktop, type ScreenSource } from '../lib/native.ts';
+  import { store } from '../lib/settings.svelte.ts';
+
+  // Everything is chosen here, with a preview, before anything is sent: what to show, which
+  // sound goes with it and the quality. In a browser, and on Wayland, the system's own dialog
+  // picks the screen or window.
+  let { onclose }: { onclose: () => void } = $props();
+  const target = share.dialog!;
+
+  let info = $state<{ portal: boolean; audio: 'pipewire' | 'loopback' | 'browser' | 'none'; micLabel: string }>({ portal: true, audio: desktop ? 'none' : 'browser', micLabel: '' });
+  let sources = $state<ScreenSource[]>([]);
+  let selected = $state('');
+  let preview = $state.raw<MediaStream | null>(null);
+  let apps = $state<string[]>([]);
+  // '' none, 'all' everything, 'app:<name>' one program
+  let audio = $state('');
+  let browserAudio = $state(false);
+  let busy = $state(false);
+  let error = $state('');
+  let handedOver = false;
+  let video = $state<HTMLVideoElement>();
+  $effect(() => { if (video) video.srcObject = preview; });
+
+  const fps = () => QUALITY[store.settings.shareQuality].fps;
+
+  let listing = $state(false);
+  async function loadSources() {
+    if (!desktop) return;
+    listing = true;
+    try {
+      sources = (await desktop.screenSources(false)).sources;
+    } finally {
+      listing = false;
+    }
+    // Pictures follow when they are ready
+    const pictures = new Map((await desktop.screenSources(true)).sources.map(s => [s.id, s.thumbnail]));
+    sources = sources.map(s => ({ ...s, thumbnail: pictures.get(s.id) ?? s.thumbnail }));
+  }
+  const loadApps = async () => { if (desktop && info.audio === 'pipewire') apps = await desktop.shareAudioApps(); };
+
+  if (desktop) {
+    desktop.shareInfo().then(async i => {
+      info = i;
+      loadApps();
+      if (!i.portal) await loadSources();
+    });
+  }
+
+  function dropPreview() {
+    preview?.getTracks().forEach(t => t.stop());
+    preview = null;
+  }
+
+  async function show(id: string) {
+    error = '';
+    dropPreview();
+    selected = id;
+    try {
+      desktop!.pickScreenSource(id);
+      preview = await navigator.mediaDevices.getDisplayMedia({ video: { frameRate: fps() }, audio: false });
+    } catch (e) {
+      error = `Could not capture this: ${(e as Error).message}`;
+    }
+  }
+
+  // The system's or the browser's picker
+  async function chooseElsewhere() {
+    error = '';
+    try {
+      if (desktop) {
+        const { sources: picked } = await desktop.screenSources(false);
+        if (!picked.length) return;
+        sources = picked;
+        await show(picked[0].id);
+      } else {
+        dropPreview();
+        preview = await navigator.mediaDevices.getDisplayMedia({ video: { frameRate: fps() }, audio: browserAudio });
+      }
+    } catch (e) {
+      if ((e as Error).name !== 'NotAllowedError') error = `Could not capture the screen: ${(e as Error).message}`;
+    }
+  }
+
+  // The virtual microphone shows up as a recording device a moment after it is created
+  async function virtualMic(): Promise<MediaStreamTrack> {
+    const find = async () => (await navigator.mediaDevices.enumerateDevices()).find(d => d.kind === 'audioinput' && d.label.includes(info.micLabel));
+    let device = await find();
+    for (let i = 0; i < 20 && !device; i++) {
+      await new Promise(r => setTimeout(r, 150));
+      device = await find();
+    }
+    if (!device) throw new Error('The audio capture device did not appear.');
+    const s = await navigator.mediaDevices.getUserMedia({
+      audio: { deviceId: { exact: device.deviceId }, echoCancellation: false, autoGainControl: false, noiseSuppression: false, channelCount: 2 }
+    });
+    return s.getAudioTracks()[0];
+  }
+
+  async function start() {
+    if (!preview) return;
+    busy = true;
+    error = '';
+    let usesVirtualMic = false;
+    try {
+      if (audio && info.audio === 'pipewire') {
+        usesVirtualMic = true;
+        await desktop!.shareAudioStart(audio === 'all' ? { kind: 'all' } : { kind: 'app', name: audio.slice(4) });
+        preview.addTrack(await virtualMic());
+      } else if (audio && info.audio === 'loopback') {
+        // System sound comes with a capture request; only its audio track is kept
+        desktop!.pickScreenSource(selected);
+        const extra = await navigator.mediaDevices.getDisplayMedia({ video: true, audio: true });
+        extra.getVideoTracks().forEach(t => t.stop());
+        const track = extra.getAudioTracks()[0];
+        if (track) preview.addTrack(track);
+      }
+    } catch (e) {
+      if (usesVirtualMic) desktop!.shareAudioStop();
+      error = `Could not capture the sound: ${(e as Error).message}`;
+      busy = false;
+      return;
+    }
+    handedOver = true;
+    share.go(target, preview, usesVirtualMic);
+    onclose();
+  }
+
+  onDestroy(() => { if (!handedOver) dropPreview(); });
+</script>
+
+<Modal title="Share your screen" {onclose} width={760}>
+  <p class="help">mumh5 users in your channel can watch. Nothing is sent until you press Start sharing.</p>
+
+  {#if !desktop && info.audio === 'browser'}
+    <label class="check"><input type="checkbox" bind:checked={browserAudio} disabled={!!preview} /> Include sound (the browser offers what it can share, usually a tab's sound)</label>
+  {/if}
+
+  {#if desktop && !info.portal}
+    <div class="row head"><label for="sh-src">Screen or window</label><button class="link" onclick={loadSources}>Refresh</button></div>
+    <ul class="sources" id="sh-src">
+      {#each sources as s (s.id)}
+        <li>
+          <button class:active={selected === s.id} aria-pressed={selected === s.id} onclick={() => show(s.id)}>
+            {#if s.thumbnail}<img src={s.thumbnail} alt="" />{:else}<span class="blank"></span>{/if}
+            <span class="name">{s.name}</span>
+          </button>
+        </li>
+      {:else}
+        <li class="dim">{listing ? 'Looking for screens and windows...' : 'Nothing found. Try Refresh.'}</li>
+      {/each}
+    </ul>
+  {:else}
+    <div class="row"><button class="btn" onclick={chooseElsewhere}>{preview ? 'Choose another screen or window...' : 'Choose a screen or window...'}</button></div>
+  {/if}
+
+  <span class="label">Preview</span>
+  <div class="preview">
+    <!-- svelte-ignore a11y_media_has_caption -->
+    <video bind:this={video} autoplay playsinline muted></video>
+    {#if !preview}<p>Nothing chosen yet</p>{/if}
+  </div>
+
+  <div class="row two">
+    {#if desktop}
+      <div>
+        <label for="sh-audio">Sound</label>
+        {#if info.audio === 'pipewire'}
+          <select id="sh-audio" bind:value={audio} onfocus={loadApps}>
+            <option value="">No sound</option>
+            <option value="all">Everything except mumh5</option>
+            {#each apps as a (a)}<option value={`app:${a}`}>{a}</option>{/each}
+          </select>
+        {:else if info.audio === 'loopback'}
+          <select id="sh-audio" bind:value={audio}>
+            <option value="">No sound</option>
+            <option value="all">Whole system (viewers also hear the voice chat again)</option>
+          </select>
+        {:else}
+          <select id="sh-audio" disabled><option>Not available on this system</option></select>
+        {/if}
+      </div>
+    {/if}
+    <div>
+      <label for="sh-quality">Quality</label>
+      <select id="sh-quality" bind:value={store.settings.shareQuality} onchange={() => store.saveSettings()}>
+        {#each Object.entries(QUALITY) as [id, q] (id)}<option value={id}>{q.label}</option>{/each}
+      </select>
+    </div>
+  </div>
+
+  {#if error}<p class="err">{error}</p>{/if}
+
+  {#snippet footer()}
+    <button class="btn" onclick={onclose}>Cancel</button>
+    <button class="btn primary" disabled={!preview || busy} onclick={start}>{busy ? 'Starting...' : 'Start sharing'}</button>
+  {/snippet}
+</Modal>
+
+<style>
+  .help { margin: 8px 0 0; font-size: 13px; color: var(--text-dim); }
+  .row { display: flex; align-items: center; gap: 8px; margin-top: 12px; }
+  .row.head { justify-content: space-between; margin-top: 0; }
+  .row.two { align-items: flex-end; gap: 12px; }
+  .row.two > div { flex: 1; min-width: 0; }
+  .label { display: block; font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-dim); margin: 14px 0 6px; }
+  .link { color: var(--link); font-size: 13px; margin-top: 8px; }
+  .sources { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; max-height: 190px; overflow-y: auto; }
+  .sources button { width: 100%; display: flex; flex-direction: column; gap: 4px; padding: 6px; text-align: left; border: 1px solid var(--line); background: var(--bg-0); }
+  .sources button:hover { border-color: var(--text-faint); }
+  .sources button.active { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
+  img, .blank { width: 100%; aspect-ratio: 16 / 9; object-fit: contain; background: #000; display: block; }
+  .name { font-size: 12px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+  .preview { position: relative; background: #000; aspect-ratio: 16 / 9; max-height: 240px; margin: 0 auto; width: 100%; }
+  .preview video { width: 100%; height: 100%; object-fit: contain; display: block; }
+  .preview p { position: absolute; inset: 0; margin: 0; display: flex; align-items: center; justify-content: center; color: #aaa; font-size: 13px; }
+  .check { display: flex; align-items: center; gap: 8px; text-transform: none; font-weight: 400; letter-spacing: 0; font-size: 14px; color: var(--text); margin-top: 12px; }
+  .check input { width: auto; }
+  .dim { color: var(--text-dim); font-size: 13px; }
+  .err { color: var(--danger); font-size: 13px; margin: 10px 0 0; }
+</style>

src/ui/SharePicker.svelte

@@ -1,35 +0,0 @@
-<script lang="ts">
-  import Modal from './Modal.svelte';
-  import { share } from '../lib/share.svelte.ts';
-
-  // Desktop app only: choose the screen or window to share
-  const picker = $derived(share.picker);
-</script>
-
-{#if picker}
-  <Modal title="Share your screen" onclose={() => picker.choose(null)} width={720}>
-    <p class="help">Pick a screen or a window. mumh5 users in your channel can then watch it.</p>
-    <ul class="sources">
-      {#each picker.sources as s (s.id)}
-        <li>
-          <button onclick={() => picker.choose(s.id)}>
-            {#if s.thumbnail}<img src={s.thumbnail} alt="" />{:else}<span class="blank"></span>{/if}
-            <span class="name">{s.name}</span>
-          </button>
-        </li>
-      {/each}
-    </ul>
-    {#snippet footer()}
-      <button class="btn" onclick={() => picker.choose(null)}>Cancel</button>
-    {/snippet}
-  </Modal>
-{/if}
-
-<style>
-  .help { margin: 8px 0 0; font-size: 13px; color: var(--text-dim); }
-  .sources { list-style: none; margin: 12px 0 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; }
-  .sources button { width: 100%; display: flex; flex-direction: column; gap: 6px; padding: 8px; text-align: left; border: 1px solid var(--line); background: var(--bg-0); }
-  .sources button:hover { border-color: var(--accent); }
-  img, .blank { width: 100%; aspect-ratio: 16 / 9; object-fit: contain; background: #000; display: block; }
-  .name { font-size: 13px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
-</style>

src/ui/ShareView.svelte

@@ -1,60 +0,0 @@
-<script lang="ts">
-  import Icon from './Icon.svelte';
-  import { share } from '../lib/share.svelte.ts';
-  import { session } from '../lib/session.svelte.ts';
-  import { store } from '../lib/settings.svelte.ts';
-
-  // Above the chat: the stream being watched, and a note while we are sharing ourselves
-  const watching = $derived(share.watching && share.watching.host.server?.id === session.server?.id ? share.watching : null);
-  const sharer = $derived(watching ? session.user(watching.session) : undefined);
-  const mine = $derived(share.stream && share.host?.server?.id === session.server?.id);
-
-  let video = $state<HTMLVideoElement>();
-  let frame = $state<HTMLElement>();
-  $effect(() => { if (video) video.srcObject = watching?.stream ?? null; });
-
-  function fullscreen() {
-    if (document.fullscreenElement) document.exitFullscreen();
-    else frame?.requestFullscreen().catch(() => {});
-  }
-</script>
-
-{#if mine}
-  <div class="bar" role="status">
-    <Icon name="screen" size={16} />
-    <span>You are sharing your screen{share.viewers ? `, ${share.viewers} watching` : ''}</span>
-    <button class="btn" onclick={() => share.stop()}>Stop sharing</button>
-  </div>
-{/if}
-{#if share.error}<div class="bar bad" role="alert"><span>{share.error}</span><button class="btn" onclick={() => (share.error = '')}>Dismiss</button></div>{/if}
-
-{#if watching}
-  <section class="watch" aria-label="Screen share" bind:this={frame}>
-    <header>
-      <Icon name="screen" size={16} />
-      <span class="who">{sharer ? store.displayName(sharer) : 'Screen share'}</span>
-      <button class="icon-btn" title="Full screen" aria-label="Full screen" onclick={fullscreen}><Icon name="expand" size={16} /></button>
-      <button class="icon-btn" title="Stop watching" aria-label="Stop watching" onclick={() => share.unwatch()}><Icon name="x" size={16} /></button>
-    </header>
-    <div class="stagebox">
-      <!-- svelte-ignore a11y_media_has_caption -->
-      <video bind:this={video} autoplay playsinline muted ondblclick={fullscreen}></video>
-      {#if watching.state === 'connecting'}<p class="note">Connecting...</p>
-      {:else if watching.state === 'failed'}<p class="note">Could not connect. You and the other person may both be behind routers that block direct connections; a STUN server in Settings, Voice can help.</p>{/if}
-    </div>
-  </section>
-{/if}
-
-<style>
-  .bar { flex: none; display: flex; align-items: center; gap: 8px; padding: 6px 12px; font-size: 13px; background: var(--bg-1); border-bottom: 1px solid var(--line); color: var(--text-dim); }
-  .bar span { flex: 1; min-width: 0; }
-  .bar .btn { padding: 4px 10px; font-size: 12px; }
-  .bar.bad { color: var(--danger); }
-  .watch { flex: none; display: flex; flex-direction: column; max-height: 62%; min-height: 160px; background: #000; border-bottom: 1px solid var(--line); }
-  .watch header { flex: none; display: flex; align-items: center; gap: 8px; padding: 2px 6px 2px 12px; background: var(--bg-1); color: var(--text-dim); font-size: 13px; }
-  .who { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--text); font-weight: 600; }
-  .stagebox { position: relative; flex: 1; min-height: 0; display: flex; }
-  video { width: 100%; height: 100%; min-height: 0; object-fit: contain; background: #000; display: block; }
-  .note { position: absolute; inset: 0; margin: 0; display: flex; align-items: center; justify-content: center; text-align: center; padding: 16px; color: #ddd; font-size: 14px; }
-  .watch:fullscreen { max-height: none; }
-</style>

src/ui/VoiceStage.svelte

@@ -7,11 +7,45 @@
   import { ui } from '../lib/ui.svelte.ts';
   import { userMenu } from '../lib/actions.ts';
   import { voice } from '../lib/audio/voice.svelte.ts';
+  import { share } from '../lib/share.svelte.ts';
+  import { sessions } from '../lib/session.svelte.ts';
+
+  // People in your voice channel as tiles. Shown on windows too narrow for the member list
+  // (always), and on any window while someone in the channel shares a screen: a sharer's tile
+  // carries the picture, and clicking it puts it on a large stage with the tiles as a strip.
+  let { always = false }: { always?: boolean } = $props();
 
-  // People in your voice channel as tiles, for windows too narrow for the member list
   const self = $derived(session.self);
   const channel = $derived(self ? session.channel(self.channelId) : undefined);
   const people = $derived(self ? session.usersIn(self.channelId) : []);
+  const here = (s: { server?: { id: string } | null } | null | undefined) => !!s && s.server?.id === session.server?.id;
+
+  const watching = $derived(share.watching && here(share.watching.host) ? share.watching : null);
+  const mine = $derived(share.stream && here(share.host) ? share.stream : null);
+  const anySharing = $derived(people.some(u => session.sharing[u.session]));
+  const visible = $derived(!!self && (always || anySharing || !!watching || !!mine));
+
+  // The picture a tile can show: our own stream, or the one we are watching
+  function streamOf(s: number): MediaStream | null {
+    if (s === self?.session) return mine;
+    return watching?.session === s ? watching.stream : null;
+  }
+
+  // Tile on the large stage
+  let focus = $state<number | null>(null);
+  const focused = $derived(focus != null ? streamOf(focus) : null);
+  const focusUser = $derived(focus != null ? session.user(focus) : undefined);
+  // A stream we just started watching goes to the stage; it leaves when the stream ends
+  let lastWatch: number | null = null;
+  $effect(() => {
+    const now = watching?.session ?? null;
+    if (now !== lastWatch) {
+      if (now != null) focus = now;
+      else if (focus === lastWatch) focus = null;
+      lastWatch = now;
+    }
+  });
+  $effect(() => { if (focus === self?.session && !mine) focus = null; });
 
   let collapsed = $state(load());
   function load(): boolean {
@@ -23,10 +57,39 @@
   }
 
   const talking = (s: number) => !!voice.talking[s] || (s === self?.session && voice.transmitting);
+
+  // The same stream can sit in a tile and on the stage at once
+  function media(node: HTMLMediaElement, stream: MediaStream | null) {
+    node.srcObject = stream;
+    return { update(next: MediaStream | null) { if (node.srcObject !== next) node.srcObject = next; } };
+  }
+
+  // Sound comes from one hidden player, so it plays once however many pictures are shown
+  let player = $state<HTMLAudioElement>();
+  const hasSound = $derived(!!watching?.stream?.getAudioTracks().length);
+  $effect(() => {
+    if (!player) return;
+    player.volume = store.settings.shareVolume;
+    player.muted = store.settings.shareVolume === 0;
+  });
+
+  function tileClick(session_: number) {
+    if (streamOf(session_)) focus = focus === session_ ? null : session_;
+    else if (session.sharing[session_] && session_ !== self?.session) share.watch(sessions.active, session_);
+    else { session.showUser(session_); ui.panelOpen = true; }
+  }
+
+  let frame = $state<HTMLElement>();
+  function fullscreen() {
+    if (document.fullscreenElement) document.exitFullscreen();
+    else frame?.requestFullscreen().catch(() => {});
+  }
 </script>
 
-{#if self}
-  <section class="stage" aria-label="Voice channel">
+{#if share.error}<div class="bar bad" role="alert"><span>{share.error}</span><button class="btn" onclick={() => (share.error = '')}>Dismiss</button></div>{/if}
+
+{#if visible && self}
+  <section class="stage" class:meeting={!!focused} aria-label="Voice channel">
     <header>
       <button class="title" onclick={toggle} aria-expanded={!collapsed}>
         <svg class="caret" class:collapsed width="10" height="10" viewBox="0 0 10 10" aria-hidden="true"><path d="M2 3l3 4 3-4" fill="none" stroke="currentColor" stroke-width="1.6" /></svg>
@@ -38,6 +101,10 @@
           </span>
         {/if}
       </button>
+      {#if mine}
+        <span class="status" role="status">You are sharing your screen{mine.getAudioTracks().length ? ' with sound' : ''}{share.viewers ? `, ${share.viewers} watching` : ''}</span>
+        <button class="btn small" onclick={() => share.stop()}>Stop sharing</button>
+      {/if}
       <button class="icon-btn" class:on={self.selfMute} aria-label={self.selfMute ? 'Unmute' : 'Mute'} title={self.selfMute ? 'Unmute' : 'Mute'}
         onclick={() => session.setSelfMute(!self.selfMute)}>
         <Icon name={self.selfMute ? 'mic-off' : 'mic'} size={18} />
@@ -47,16 +114,52 @@
         <Icon name={self.selfDeaf ? 'headphones-off' : 'headphones'} size={18} />
       </button>
     </header>
+
+    {#if watching?.stream}<audio bind:this={player} use:media={watching.stream} autoplay></audio>{/if}
+
+    {#if focused && focus != null}
+      <div class="spot" role="region" aria-label="Screen share" bind:this={frame}>
+        <div class="spot-head">
+          <Icon name="screen" size={16} />
+          <span class="spot-who">{focus === self.session ? 'Your screen' : focusUser ? store.displayName(focusUser) : 'Screen share'}</span>
+          {#if focus !== self.session && hasSound}
+            <Icon name={store.settings.shareVolume === 0 ? 'headphones-off' : 'headphones'} size={16} />
+            <input class="vol" type="range" min="0" max="1" step="0.01" bind:value={store.settings.shareVolume} onchange={() => store.saveSettings()}
+              aria-label="Stream volume" title="Stream volume" />
+          {/if}
+          <button class="icon-btn" title="Full screen" aria-label="Full screen" onclick={fullscreen}><Icon name="expand" size={16} /></button>
+          {#if focus !== self.session}<button class="btn small" onclick={() => share.unwatch()}>Stop watching</button>{/if}
+          <button class="icon-btn" title="Back to tiles" aria-label="Back to tiles" onclick={() => (focus = null)}><Icon name="x" size={16} /></button>
+        </div>
+        <!-- svelte-ignore a11y_media_has_caption -->
+        <video use:media={focused} autoplay playsinline muted ondblclick={fullscreen}></video>
+      </div>
+    {/if}
+
     {#if !collapsed}
-      <ul class="tiles">
+      <ul class="tiles" class:strip={!!focused}>
         {#each people as u (u.session)}
-          <li>
-            <button class="tile" class:talking={talking(u.session)} class:self={u.session === self.session}
-              onclick={() => { session.showUser(u.session); ui.panelOpen = true; }}
-              oncontextmenu={e => menu.show(e, userMenu(u))} title={store.displayName(u)}>
-              <Avatar name={u.name} size={44} speaking={talking(u.session)} />
+          {@const stream = streamOf(u.session)}
+          {@const sharing = !!session.sharing[u.session]}
+          {@const isSelf = u.session === self.session}
+          <li class:wide={!!stream}>
+            <button class="tile" class:talking={talking(u.session)} class:self={isSelf} class:video={!!stream} class:focused={focus === u.session}
+              onclick={() => tileClick(u.session)}
+              oncontextmenu={e => menu.show(e, userMenu(u))}
+              title={stream ? (focus === u.session ? 'Back to tiles' : 'Show large') : sharing && !isSelf ? 'Sharing their screen. Click to watch' : store.displayName(u)}
+              aria-label={stream ? `${focus === u.session ? 'Shrink' : 'Enlarge'} the screen of ${store.displayName(u)}` : sharing && !isSelf ? `Watch the screen of ${store.displayName(u)}` : store.displayName(u)}>
+              {#if stream}
+                <!-- svelte-ignore a11y_media_has_caption -->
+                <video use:media={stream} autoplay playsinline muted></video>
+              {:else}
+                <Avatar name={u.name} size={44} speaking={talking(u.session)} />
+              {/if}
               <span class="who">{store.displayName(u)}</span>
-              {#if u.deaf || u.selfDeaf}
+              {#if watching?.session === u.session && watching.state !== 'live'}
+                <span class="note">{watching.state === 'connecting' ? 'Connecting...' : 'Could not connect'}</span>
+              {/if}
+              {#if sharing}<span class="badge live"><Icon name="screen" size={13} /></span>
+              {:else if u.deaf || u.selfDeaf}
                 <span class="badge" class:admin={u.deaf}><Icon name="headphones-off" size={13} /></span>
               {:else if u.mute || u.selfMute || u.suppress}
                 <span class="badge" class:admin={u.mute || u.suppress}><Icon name="mic-off" size={13} /></span>
@@ -65,6 +168,9 @@
           </li>
         {/each}
       </ul>
+      {#if watching?.state === 'failed'}
+        <p class="failed">Could not connect to the stream. You and the other person may both be behind routers that block direct connections; a STUN server in Settings, Voice can help.</p>
+      {/if}
     {/if}
   </section>
 {/if}
@@ -89,4 +195,28 @@
   .tile.self .who { color: var(--text); font-weight: 600; }
   .badge { position: absolute; top: 4px; right: 4px; display: inline-flex; color: var(--text-faint); }
   .badge.admin { color: var(--danger); }
+  .badge.live { color: var(--speaking); }
+
+  /* Streams */
+  .bar { flex: none; display: flex; align-items: center; gap: 8px; padding: 6px 12px; font-size: 13px; background: var(--bg-1); border-bottom: 1px solid var(--line); }
+  .bar span { flex: 1; min-width: 0; }
+  .bar.bad { color: var(--danger); }
+  .btn.small, .bar .btn { padding: 4px 10px; font-size: 12px; flex: none; }
+  .status { font-size: 12px; color: var(--speaking); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; min-width: 0; margin-right: 4px; }
+  .tiles li.wide { grid-column: span 2; }
+  .tile.video { padding: 0 0 6px; overflow: hidden; }
+  .tile.video video { width: 100%; aspect-ratio: 16 / 9; object-fit: contain; background: #000; display: block; }
+  .tile.focused { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
+  .note { font-size: 11px; color: var(--text-faint); }
+  .failed { margin: 0; padding: 0 12px 10px; font-size: 12px; color: var(--danger); }
+  /* Meeting view: the chosen picture large, everyone else in one row below */
+  .stage.meeting { display: flex; flex-direction: column; max-height: 72%; min-height: 220px; }
+  .spot { flex: 1; min-height: 0; display: flex; flex-direction: column; background: #000; }
+  .spot-head { flex: none; display: flex; align-items: center; gap: 8px; padding: 2px 6px 2px 12px; background: var(--bg-0); color: var(--text-dim); font-size: 13px; }
+  .spot-who { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--text); font-weight: 600; }
+  .spot video { flex: 1; min-height: 0; width: 100%; object-fit: contain; background: #000; display: block; }
+  .vol { width: 110px; flex: none; padding: 0; }
+  .tiles.strip { flex: none; display: flex; overflow-x: auto; overflow-y: hidden; padding-top: 8px; max-height: none; }
+  .tiles.strip li { flex: 0 0 96px; }
+  .tiles.strip li.wide { flex-basis: 150px; }
 </style>