(feat): add screenshare previews

This commit is contained in:
Alois 2026-05-01 02:16:37 +02:00
commit 2f0072f422
6 changed files with 423 additions and 44 deletions

View file

@ -12,6 +12,8 @@ import {
ExternalE2EEKeyProvider,
LocalAudioTrack,
type Participant,
type RemoteParticipant,
type RemoteTrackPublication,
Room,
RoomEvent,
type RemoteTrack,
@ -59,6 +61,7 @@ type DecryptTextFn = (sharedSecret: string, text: string) => Promise<string>;
type EncryptTextFn = (sharedSecret: string, text: string) => Promise<string>;
type LoadFn = (key: string) => Promise<unknown>;
type GetUserFn = (userId: number) => Promise<{ public_key: string }>;
type RemoteVideoTrackSelector = Track.Kind | Track.Source;
type Runtime = {
navigate: NavigateFn;
@ -108,6 +111,11 @@ const room = new Room({
});
const remoteAudioElements = new Map<string, HTMLMediaElement>();
const SCREEN_SHARE_PREVIEW_MAX_WIDTH = 320;
const SCREEN_SHARE_PREVIEW_MAX_HEIGHT = 180;
const SCREEN_SHARE_PREVIEW_QUALITY = 0.7;
const SCREEN_SHARE_PREVIEW_TIMEOUT_MS = 5000;
// audio helpers
function attachRemoteAudio(trackSid: string, element: HTMLMediaElement) {
const existingElement = remoteAudioElements.get(trackSid);
@ -152,12 +160,60 @@ function getAllParticipants(): Participant[] {
return [...room.remoteParticipants.values(), room.localParticipant];
}
function getTrackPublicationBySource(
participant: Participant | undefined,
source: Track.Source,
) {
if (!participant) {
return undefined;
}
return [...participant.trackPublications.values()].find(
(publication) => publication.source === source,
);
}
function getRemoteParticipant(participantId: number) {
return [...room.remoteParticipants.values()].find(
(participant) => getParticipantId(participant.identity) === participantId,
);
}
function getRemoteTrackPublications(participantId: number) {
return [
...(getRemoteParticipant(participantId)?.trackPublications.values() ?? []),
] as RemoteTrackPublication[];
}
function matchesRemoteTrackSelector(
publication: Pick<RemoteTrackPublication, "kind" | "source">,
selector: RemoteVideoTrackSelector,
) {
return publication.source === selector || publication.kind === selector;
}
function syncRemoteParticipantTrackSubscriptions(participantId: number) {
for (const publication of getRemoteTrackPublications(participantId)) {
publication.setSubscribed(publication.kind === Track.Kind.Audio);
}
}
function syncAllRemoteTrackSubscriptions() {
for (const participant of room.remoteParticipants.values()) {
const participantId = getParticipantId(participant.identity);
if (participantId != null) {
syncRemoteParticipantTrackSubscriptions(participantId);
}
}
}
function getActiveScreenShareParticipantIds(): number[] {
return getAllParticipants()
.map((participant) => ({
participantId: getParticipantId(participant.identity),
hasScreenShare:
participant.getTrackPublication(Track.Source.ScreenShare)?.track !=
getTrackPublicationBySource(participant, Track.Source.ScreenShare) !=
null,
}))
.filter(
@ -168,11 +224,12 @@ function getActiveScreenShareParticipantIds(): number[] {
}
function getScreenShareTrackForParticipant(participantId: number) {
return getAllParticipants()
.find(
(participant) => getParticipantId(participant.identity) === participantId,
)
?.getTrackPublication(Track.Source.ScreenShare)?.track;
const participant = getAllParticipants().find(
(entry) => getParticipantId(entry.identity) === participantId,
);
return getTrackPublicationBySource(participant, Track.Source.ScreenShare)
?.track;
}
function hasParticipant(participantId: number) {
@ -181,6 +238,199 @@ function hasParticipant(participantId: number) {
);
}
function getLocalScreenShareTrack(): MediaStreamTrack | null {
const track = getTrackPublicationBySource(
room.localParticipant,
Track.Source.ScreenShare,
)?.track;
if (!track || track.kind !== Track.Kind.Video) {
return null;
}
return track.mediaStreamTrack;
}
async function updateLocalParticipantAttributes(
attributes: Record<string, string>,
) {
log(2, "call", "purple", "Updating local participant attributes", {
attributeKeys: Object.keys(attributes),
screenSharePreviewLength: attributes.screenSharePreview?.length ?? 0,
});
await room.localParticipant.setAttributes(attributes).catch((error) => {
log(1, "call", "red", "Failed to update local participant attributes", {
attributes: Object.keys(attributes),
error,
});
throw error;
});
log(2, "call", "purple", "Updated local participant attributes", {
attributeKeys: Object.keys(attributes),
screenSharePreviewLength: attributes.screenSharePreview?.length ?? 0,
});
}
async function waitForScreenSharePreviewFrame(video: HTMLVideoElement) {
if (
video.readyState >= HTMLMediaElement.HAVE_CURRENT_DATA &&
video.videoWidth > 0 &&
video.videoHeight > 0
) {
log(2, "call", "purple", "Screen share preview frame already ready", {
readyState: video.readyState,
width: video.videoWidth,
height: video.videoHeight,
});
return;
}
log(2, "call", "purple", "Waiting for screen share preview frame", {
readyState: video.readyState,
});
await new Promise<void>((resolve, reject) => {
const timeoutId = window.setTimeout(() => {
cleanup();
reject(new Error("Timed out waiting for screen share preview frame."));
}, SCREEN_SHARE_PREVIEW_TIMEOUT_MS);
const cleanup = () => {
window.clearTimeout(timeoutId);
video.onloadeddata = null;
video.oncanplay = null;
video.onerror = null;
};
const ready = () => {
if (video.videoWidth > 0 && video.videoHeight > 0) {
log(2, "call", "purple", "Screen share preview frame became ready", {
readyState: video.readyState,
width: video.videoWidth,
height: video.videoHeight,
});
cleanup();
resolve();
}
};
video.onloadeddata = ready;
video.oncanplay = ready;
video.onerror = () => {
cleanup();
reject(new Error("Failed to load screen share preview frame."));
};
if (typeof video.requestVideoFrameCallback === "function") {
video.requestVideoFrameCallback(() => {
ready();
});
}
ready();
});
}
async function publishScreenSharePreview() {
const videoTrack = getLocalScreenShareTrack();
if (!videoTrack) {
log(
2,
"call",
"purple",
"Skipping screen share preview publish: no local video track",
);
return;
}
log(2, "call", "purple", "Publishing screen share preview", {
trackId: videoTrack.id,
readyState: videoTrack.readyState,
muted: videoTrack.muted,
});
const video = document.createElement("video");
video.muted = true;
video.playsInline = true;
video.autoplay = true;
video.srcObject = new MediaStream([videoTrack]);
try {
await video.play().catch(() => undefined);
log(2, "call", "purple", "Screen share preview video play attempted", {
readyState: video.readyState,
});
await waitForScreenSharePreviewFrame(video);
if (!video.videoWidth || !video.videoHeight) {
throw new Error("Screen share preview video has no dimensions.");
}
log(2, "call", "purple", "Capturing screen share preview frame", {
width: video.videoWidth,
height: video.videoHeight,
});
const canvas = document.createElement("canvas");
const context = canvas.getContext("2d");
if (!context) {
throw new Error("Failed to create screen share preview canvas.");
}
canvas.width = SCREEN_SHARE_PREVIEW_MAX_WIDTH;
canvas.height = SCREEN_SHARE_PREVIEW_MAX_HEIGHT;
const scale = Math.min(
canvas.width / video.videoWidth,
canvas.height / video.videoHeight,
);
const drawWidth = Math.max(1, Math.round(video.videoWidth * scale));
const drawHeight = Math.max(1, Math.round(video.videoHeight * scale));
const x = Math.floor((canvas.width - drawWidth) / 2);
const y = Math.floor((canvas.height - drawHeight) / 2);
context.fillStyle = "#111111";
context.fillRect(0, 0, canvas.width, canvas.height);
context.drawImage(video, x, y, drawWidth, drawHeight);
const preview = canvas.toDataURL(
"image/webp",
SCREEN_SHARE_PREVIEW_QUALITY,
);
log(2, "call", "purple", "Generated screen share preview", {
previewLength: preview.length,
canvasWidth: canvas.width,
canvasHeight: canvas.height,
});
await updateLocalParticipantAttributes({
screenSharePreview: preview,
});
log(2, "call", "purple", "Published screen share preview");
} catch (error) {
log(1, "call", "red", "Failed to publish screen share preview", error);
} finally {
video.pause();
video.srcObject = null;
}
}
async function clearScreenSharePreview() {
log(2, "call", "purple", "Clearing screen share preview");
await updateLocalParticipantAttributes({
screenSharePreview: "",
}).catch((error) => {
log(1, "call", "red", "Failed to clear screen share preview", error);
});
}
function syncScreenShareParticipants() {
const activeScreenShareParticipantIds = getActiveScreenShareParticipantIds();
const state = useCall.getState();
@ -220,6 +470,7 @@ function requireRuntime(runtime: Runtime | null): Runtime {
export function getRoomMetadata() {
const roomMetadata = room.metadata;
log(3, "call", "purple", "Room metadata:", { roomMetadata });
try {
const data = JSON.parse(roomMetadata || '{"admin": 0}');
return data as { admin: number };
@ -325,13 +576,11 @@ export async function sendCallInvite(userId: number) {
}
// Start tracking a participant's shared screen in the call UI.
export function startWatchingStream(
participantId: number,
options?: { focus?: boolean },
) {
const focus = options?.focus ?? false;
export function startWatchingStream(participantId: number) {
const trackReady = getScreenShareTrackForParticipant(participantId) != null;
setParticipantTrackSubscribed(participantId, Track.Source.ScreenShare);
useCall.setState((state) => ({
watchedStreamParticipantIds: state.watchedStreamParticipantIds.includes(
participantId,
@ -343,11 +592,25 @@ export function startWatchingStream(
: state.pendingWatchedParticipantIds.includes(participantId)
? state.pendingWatchedParticipantIds
: [...state.pendingWatchedParticipantIds, participantId],
focusedParticipantId: focus ? participantId : state.focusedParticipantId,
view: focus ? "focused" : state.view,
focusedParticipantId: participantId,
}));
}
// Toggle remote track subscriptions using LiveKit's built-in publication API.
export function setParticipantTrackSubscribed(
participantId: number,
selector: RemoteVideoTrackSelector,
subscribed = true,
) {
for (const publication of getRemoteTrackPublications(participantId)) {
if (matchesRemoteTrackSelector(publication, selector)) {
publication.setSubscribed(subscribed);
}
}
syncParticipantState();
}
// Focus a participant in the main call view even when they are not sharing a screen.
export function focusParticipant(participantId: number) {
useCall.setState({
@ -358,6 +621,8 @@ export function focusParticipant(participantId: number) {
// Stop tracking a participant's shared screen and clean up related UI state.
export function stopWatchingStream(participantId: number) {
setParticipantTrackSubscribed(participantId, Track.Source.ScreenShare, false);
useCall.setState((state) => ({
watchedStreamParticipantIds: state.watchedStreamParticipantIds.filter(
(id) => id !== participantId,
@ -431,15 +696,21 @@ export async function connect(callId: string) {
callSecret: useCall.getState().callSecret,
});
await room.connect("wss://call.tensamin.net", token).catch((error) => {
useCall.setState({ state: "closed", livekitToken: null });
log(1, "call", "red", "Failed to connect to room", error);
toast(
"error",
error instanceof Error ? error.message : "Failed to connect to call.",
);
throw error;
});
await room
.connect("wss://call.tensamin.net", token, {
autoSubscribe: false,
})
.catch((error) => {
useCall.setState({ state: "closed", livekitToken: null });
log(1, "call", "red", "Failed to connect to room", error);
toast(
"error",
error instanceof Error ? error.message : "Failed to connect to call.",
);
throw error;
});
syncAllRemoteTrackSubscriptions();
await room.localParticipant.setMicrophoneEnabled(true).catch((error) => {
log(1, "call", "red", "Failed to enable microphone", error);
@ -452,6 +723,8 @@ export async function connect(callId: string) {
// Tear down the active call session and return the store to a closed state.
export async function disconnect() {
await clearScreenSharePreview();
try {
await getScreenShareController().clearPublishedScreenShare();
} catch (error) {
@ -567,7 +840,7 @@ export async function toggleDeaf() {
await toggleMute();
}
await room.localParticipant.setAttributes({
await updateLocalParticipantAttributes({
deafened: nextDeaf ? "true" : "false",
});
@ -589,16 +862,19 @@ export async function toggleMute() {
// Start browser-native screen sharing for the current participant.
export async function startScreenShare(options?: ScreenShareCaptureOptions) {
await getScreenShareController().startScreenShare(options);
await publishScreenSharePreview();
}
// Start the Linux desktop capture path that renders frames through Tauri.
export async function startLinuxDesktopScreenShare(sourceId: string) {
await getScreenShareController().startLinuxDesktopScreenShare(sourceId);
await publishScreenSharePreview();
}
// Stop the local participant's active screen share and related previews.
export async function stopScreenShare() {
await getScreenShareController().stopScreenShare();
await clearScreenSharePreview();
}
// Toggle screen sharing on or off from UI controls.
@ -607,6 +883,13 @@ export async function setScreenShareEnabled(
options?: ScreenShareCaptureOptions,
) {
await getScreenShareController().setScreenShareEnabled(enabled, options);
if (enabled) {
await publishScreenSharePreview();
return;
}
await clearScreenSharePreview();
}
// Reset the in-memory call store when leaving the call experience entirely.
@ -808,6 +1091,7 @@ export function useInitializeCall() {
};
const onParticipantConnected = () => {
syncAllRemoteTrackSubscriptions();
syncParticipantState();
};
@ -836,6 +1120,23 @@ export function useInitializeCall() {
void ensureNoiseFilter(noiseFilter);
};
const onTrackPublished = (
publication: RemoteTrackPublication,
participant: RemoteParticipant,
) => {
const participantId = getParticipantId(participant.identity);
if (participantId != null) {
if (publication.kind === Track.Kind.Audio) {
publication.setSubscribed(true);
} else {
publication.setSubscribed(false);
}
}
onParticipantStateChange();
};
const onTrackSubscribed = (track: RemoteTrack) => {
if (track.kind === "audio" && track.sid) {
attachRemoteAudio(track.sid, track.attach());
@ -858,7 +1159,8 @@ export function useInitializeCall() {
if (
participantId != null &&
participant.getTrackPublication(Track.Source.ScreenShare)?.track == null
getTrackPublicationBySource(participant, Track.Source.ScreenShare)
?.track == null
) {
stopWatchingStream(participantId);
}
@ -871,7 +1173,7 @@ export function useInitializeCall() {
room.on(RoomEvent.Disconnected, onDisconnected);
room.on(RoomEvent.TrackSubscribed, onTrackSubscribed);
room.on(RoomEvent.TrackUnsubscribed, onTrackUnsubscribed);
room.on(RoomEvent.TrackPublished, onParticipantStateChange);
room.on(RoomEvent.TrackPublished, onTrackPublished);
room.on(RoomEvent.TrackUnpublished, onParticipantStateChange);
room.on(RoomEvent.ParticipantConnected, onParticipantConnected);
room.on(RoomEvent.ParticipantDisconnected, onParticipantDisconnected);
@ -892,7 +1194,7 @@ export function useInitializeCall() {
room.off(RoomEvent.Disconnected, onDisconnected);
room.off(RoomEvent.TrackSubscribed, onTrackSubscribed);
room.off(RoomEvent.TrackUnsubscribed, onTrackUnsubscribed);
room.off(RoomEvent.TrackPublished, onParticipantStateChange);
room.off(RoomEvent.TrackPublished, onTrackPublished);
room.off(RoomEvent.TrackUnpublished, onParticipantStateChange);
room.off(RoomEvent.ParticipantConnected, onParticipantConnected);
room.off(RoomEvent.ParticipantDisconnected, onParticipantDisconnected);