How to disable the Connect button after the button clicked? - viewmodel

Question

My OutPut is this Here,
I'm using the 'connect' button in MainActivity and 'disconnect' button in MainFragment and create the Function for connect and disconnect in MainViewModel.
Whenever I click the 'connect button', it should moves to fragment using databinding to open the Fragment page.(i.e., MainActivity.kt--->MainViewmodel.kt--->MainFragment.kt).
Note that: If I click 'connect' button should be is invisible in MainFragment, once return to MainActivity, then it should in visible. Not-need to declare the "android:visibility="#{viewModel.connectButtonVisible ? View.VISIBLE : View.GONE}" " in .xml files because it getting error in dataBindingImplemention. I want this visibility in Koltin files as code
Whenever I click the 'Disconnect button', it should get back to MainActivity using databinding.
(i.e.,MainFragment.kt --->MainViewmodel.kt--->MainActivity.kt)
4.Don't use the navigation_graph.xml because databinding is not sufficient for navigation only viewbinding is ok. But I'm using DataBinding only.
I give my sample code.
MainViewModel.kt
class MainViewModel : ViewModel() {
val connectionState = MutableLiveData<Boolean>()
fun connect(){
connectionState.value = true
}
fun disconnect(){
connectionState.value = false
}
}
Activity_Main.xml
<!-- layout for MainActivity -->
<layout>
<data>
<variable
name="viewModel"
type="com.example.myapp.MainViewModel" />
</data>
<LinearLayout>
<!-- other layout elements -->
<Button
android:id="#+id/connect_button"
android:onClick="#{() -> viewModel.connectionState}"
android:text="Connect" />
<!-- other layout elements -->
</LinearLayout>
</layout>
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
private lateinit var viewModel: MainViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
viewModel = ViewModelProvider(this).get(MainViewModel::class.java)
binding.viewModel = viewModel
viewModel.connectionState.observe(this, Observer { isConnected ->
if (isConnected) {
supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, MainFragment())
.addToBackStack(null)
.commit()
}
})
}
}
Fragment_main.xml
<!-- layout for MainFragment -->
<layout>
<data>
<variable
name="viewModel"
type="com.example.myapp.MainViewModel" />
</data>
<LinearLayout>
<!-- other layout elements -->
<Button
android:id="#+id/disconnect_button"
android:onClick="#{() -> viewModel.connectionState}"
android:text="Disconnect" />
<!-- other layout elements -->
</LinearLayout>
</layout>
MainFragment.kt
class MainFragment : Fragment() {
private lateinit var binding: FragmentMainBinding
private lateinit var viewModel: MainViewModel
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_main, container, false)
viewModel = ViewModelProvider(activity!!).get(MainViewModel::class.java)
binding.viewModel = viewModel
viewModel.connectionState.observe(viewLifecycleOwner, Observer { isConnected ->
if (!isConnected) {
activity!!.supportFragmentManager.popBackStack()
}
})
return binding.root
}
}
My problem is Once the Click the Connect Button it should be disabled and it show the Fragment_main.xml. Again When I Click the Disconnect Button is return back to Activity_main.xml, in Connect will be visible.
Note that: Without using navagation_graph.xml and android:visibility="#{viewModel.connectButtonVisible ? View.VISIBLE : View.GONE}".