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Version: 6.0

Screen share in a group call

This page provides a code example for screen share in a group call (conference).

Sender - Start sending screen share​

The code implementation for starting screen share is as follows.

Collect the devices for screen capture and select one from them.

func collectCaptureDevices() -> [PlanetKitScreenCaptureDevice] {
    var captureDevices = [PlanetKitScreenCaptureDevice]()
    autoreleasepool {
        for display in PlanetKitScreen.shared.displays {
            let name: String
            if let screen = NSScreen.screens.first(where: { $0.displayID == display.displayID }) {
                name = screen.localizedName
            }
            ...

            captureDevices.append(PlanetKitScreenCaptureDevice(display: display))
        }

        let windows = PlanetKitScreen.shared.windows.filter {
            $0.sharingType != .none &&
            $0.alpha > 0 &&
            $0.level == kCGNormalWindowLevel
        }
        let myAppId = Bundle.main.bundleIdentifier
        for window in windows {
            guard let image = window.image, window.sharingType != .none, window.bundleId != nil else {
                continue
            }
            if myAppId == window.bundleId {
                continue
            }
            ...

            captureDevices.append(PlanetKitScreenCaptureDevice(window: window))
        }
    }
    return captureDevices
}

To start sending screen share, call startMyScreenShare().

  • The subgroupName parameter determines the destination of screen share.
  • If the subgroupName parameter is nil, screen share is sent to the main room.
func startMyScreenShare(_ device: PlanetKitScreenCaptureDevice) {
    ...

    conference.startMyScreenShare(device: device, subgroupName: nil) { success in
        guard success else { return }
        // UI code here if success
    }
}

Sender - Change the destination of screen share​

Depending on the type of destination, you can change the destination of screen share as follows:

  • To change the destination to a subgroup other than the main room, call changeMyScreenShareDestination() with the subgroup name.
  • To change the destination to the main room, call changeMyScreenShareDestinationToMainRoom().
// Change the destination to a subgroup other than the main room
conference.changeMyScreenShareDestination(subgroupName: subgroupName) { success in
    guard success else { return }
    // UI code here if success
}

// Change the destination to the main room
conference.changeMyScreenShareDestinationToMainRoom() { success in
    guard success else { return }
    // UI code here if success
}

Sender - Stop sending screen share​

The code implementation for stopping screen share is as follows.

To stop screen share, call stopMyScreenShare().

conference.stopMyScreenShare() { success in
    self.delegate?.screenShare(self, willDismiss: dismiss)
}

Receiver - Receive screen share update events​

​Check whether a peer's screen share has started or stopped through the screenShareDidUpdate event of PlanetKitConferenceDelegate.

Note

If you have already created peer control, skip the next step and use it for the Receiver - Start or stop a peer's screen share video step. Otherwise, create peer control as in the next step.

extension VideoConferenceViewController: PlanetKitConferenceDelegate {
    ...
    func screenShareDidUpdate(_ conference: PlanetKitConference, updated: PlanetKitConferenceScreenShareUpdateParam) {
        if updated.state == .enabled {
            NSLog("start screen share - \(updated.peerId) \(updated.subgroupName ?? "main")")
        }
        else {
            NSLog("stop screen share - \(updated.peerId) \(updated.subgroupName ?? "main")")
        }

        // UI code here
        DispatchQueue.main.async {
            self.loadPage(self.currentPage)
        }
    }
}

Receiver - Create and register peer control​

When a peer is connected to the call, create and register peer control for the peer.

extension VideoConferenceViewController {
    ...

    var peers: [PlanetKitConferencePeer]
    var peerViews: [ScreenPeerVideoView]

    func loadPage(_ page: Int) {
        ...

        peerViews[index].setupPeerControl(conference: conference, peer: peers[index])
    }
}

#if os(macOS)
typealias UIView = NSView
#endif

class ScreenPeerVideoView: UIView {
    ...

    var peerControl: PlanetKitPeerControl!

    func setupPeerControl(conference: PlanetKitConference, peer: PlanetKitConferencePeer) {
        guard let peerControl = conference.createPeerControl(peer: peer) else {
            // Error code here
            return
        }
        peerControl.register(self) { success in
            // UI code here
            self.setScreenShareEnabled(peer.screenShareState == .enabled)
        }
        self.peerControl = peerControl
    }

    func finalPeerControl() {
        peerControl.unregister() { success in
            // UI code here
        }
    }
}

Receiver - Start or stop a peer's screen share video​

Check whether a peer's screen share has started or stopped through the didUpdateScreenShare event of PlanetKitPeerControlDelegate.

  • When the peer's screen share started, add a peer screen share view and call startScreenShare() of PlanetKitPeerControl.
  • When the peer's screen share stopped, remove the peer screen share view and call stopScreenShare() of PlanetKitPeerControl.
#if os(macOS)
typealias UIView = NSView
#endif

class ScreenPeerVideoView: UIView {
    ...

    var peerControl: PlanetKitPeerControl!
    var peerScreenShareView: PlanetKitMTKView!

    func setScreenShareEnabled(_ enabled: Bool) {
        if enabled {
            peerScreenShareView = PlanetKitMTKView(frame: view.bounds, device: nil)
            view.addSubview(peerScreenShareView)

            let subgroupName = peerControl.peer.currentScreenShareSubgroupName
            peerControl.startScreenShare(delegate: peerScreenShareView, subgroupName: subgroupName) { success in
                // UI code here
            }
        }
        else {
            peerScreenShareView.removeFromSuperview()

            peerControl.stopScreenShare() { success in
                // UI code here
            }
        }
    }
}

extension ScreenPeerVideoView: PlanetKitPeerControlDelegate {
    ...

    func didUpdateScreenShare(_ peerControl: PlanetKitPeerControl, subgroup: PlanetKitSubgroup, status: PlanetKitScreenShareStatus) {
        DispatchQueue.main.async {
            self.setScreenShareEnabled((status.state == .enabled))
        }
    }
}