Message List View Model

MessageListViewModel works with MessageListView and uses StreamChatAndroidOffline library to communicate with Stream API.

The view model exposes two LiveData objects, as well as two values:

• mode - distincts if the view is in thread mode, can be one of:

  • Thread

  • Normal

• state - can be one of:

  • Loading

  • Result

  • NavigateUp

• currentUser

• channel

You can inform the view model about new events using onEvent method. Currently, MessageListViewModel supports the following events:

• BaskButtonPressed

• EndRegionReached

• LastMessageRead

• ThreadModeEntered

• DeleteMessage

• FlagMessage

• GiphyActionSelected

• RetryMessage

MessageListViewModel can be instantiated using ChannelViewModelFactory:

MessageListViewModel can be bound with MessageListView using MessageListViewModelBinding:

Calling bind method results in:

• Initializing view with the channel and current user

• Displaying new messages

• Setting:

  • EndRegionReachedHandler

  • LastMessageReadHandler

  • OnMessageDeleteHandler

  • OnStartThreadHandler

  • OnMessageFlagHandler

  • OnSendGiphyHandler

  • OnMessageRetryHandler

MessageListViewModel contains a mechanism for handling back button behaviour when you're in a thread. If you want to use it, you need to override Activitiy's back button behaviour:

The view model will exit the thread if needed and emit MessageListViewModel.State.NavigateUp if user isn't inside a thread. You need to handle this state by yourself - for example, by finishing the current Activity: