Implementing CallState
Call state of the app is a mandatory Class. At least IDLE and IN_CALL must be implemented.
App States
AppState represents the global state of the App. The following diagram shows different triggers that changes different flags within the AppState.

The classes ON_HOLD, SHARING_CONTENT and SHARING_WHITEBOARD are optional.
When creating the PolyOsManager, pass a PolyAppCallBacks object:
PolyOsManager(context, polyAppCallBacks).
On this object, there is a method called registerAppStateListener(polyAppListener:IPolyAppListener). On the polyAppListener parameter, call
onAppStateChanged(\@ParamIn AppState appState) with the new callState property set to appState.
CallStatecallState - CallState of the app
booleancameraMuted - Whether user has muted the camera
booleanmicMuted - Whether user has muted the microphone