At the heart of Connect SDK is DiscoveryManager, a multi-protocol service discovery engine with a pluggable architecture. Much of your initial experience with Connect SDK will be with the DiscoveryManager class, as it consolidates discovered service information into ConnectableDevice objects.
DiscoveryManager supports discovering services of differing protocols by using DiscoveryProviders. Many services are discoverable over SSDP and are registered to be discovered with the SSDPDiscoveryProvider class.
As services are discovered on the network, the DiscoveryProviders will notify DiscoveryManager. DiscoveryManager is capable of attributing multiple services, if applicable, to a single ConnectableDevice instance. Thus, it is possible to have a mixed-mode ConnectableDevice object that is theoretically capable of more functionality than a single service can provide.
DiscoveryManager keeps a running list of all discovered devices and maintains a filtered list of devices that have satisfied any of your CapabilityFilters. This filtered list is used by the DevicePicker when presenting the user with a list of devices.
Connect SDK device discovery can be started in one line.
Filtering devices by capability¶
It will be necessary in many cases to filter out devices that don’t support a desired feature-set. DiscoveryManager provides the setCapabilityFilters method to provide for this ability.
Here is a simple example that discovers devices that support (video playback AND any media controls AND volume up/down) OR (image display).
var videoFilter = new ConnectSDK.CapabilityFilter([ ConnectSDK.Capabilities.MediaPlayer.Play.Video, ConnectSDK.Capabilities.MediaControl.Any, ConnectSDK.Capabilities.VolumeControl.UpDown ]); var imageFilter = new ConnectSDK.CapabilityFilter([ ConnectSDK.Capabilities.MediaPlayer.Display.Image ]); ConnectSDK.discoveryManager.setCapabilityFilters([videoFilter, imageFilter]); app.setupDiscovery();
Connect SDK has support for pairing with certain devices. Having pairing disabled may reduce the number of supported capabilities that a ConnectableDevice has. Certain devices, although they may support the features you are filtering for, may not pass your CapabilityFilter if pairing is disabled.
See the Supported Features list for information on what devices require pairing for certain capabilities.
For the best user experience, Connect SDK has disabled pairing by default. Pairing can be enabled very easily, but it must be enabled before DiscoveryManager is started for the first time.
// Include capabilities that require pairing ConnectSDK.discoveryManager.setPairingLevel(ConnectSDK.PairingLevel.ON); // Exclude capabilities that require pairing (this is the default) ConnectSDK.discoveryManager.setPairingLevel(ConnectSDK.PairingLevel.OFF);
Automatic stop/resume on app state change¶
If DiscoveryManager is running while your app enters a background state, it will resume immediately upon returning to a foreground state. This is to prevent battery drain on the user’s device.