Disabled navigation to satellites fragment on empty database

app/src/main/java/com/rtbishop/look4sat/presentation/passesScreen/PassesFragment.kt

@@ -19,6 +19,7 @@ package com.rtbishop.look4sat.presentation.passesScreen
 
 import android.os.Bundle
 import android.view.View
+import android.widget.Toast
 import androidx.core.os.bundleOf
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
@@ -72,11 +73,22 @@ class PassesFragment : Fragment(R.layout.fragment_passes), PassesAdapter.PassesC
             }
             passesFilter.setOnClickListener { findNavController().navigate(R.id.nav_pass_prefs) }
             passesSettings.setOnClickListener { findNavController().navigate(R.id.nav_settings) }
-            passesFab.setOnClickListener { findNavController().navigate(R.id.nav_satellites) }
+//            passesFab.setOnClickListener { findNavController().navigate(R.id.nav_satellites) }
         }
         passesViewModel.passes.observe(viewLifecycleOwner) { passesResult ->
             handleNewPasses(passesResult, adapter, binding)
         }
+        passesViewModel.satellites.observe(viewLifecycleOwner) { satellites ->
+            satellites?.let {
+                if (satellites.isEmpty()) {
+                    binding.passesFab.setOnClickListener {
+                        Toast.makeText(requireContext(), "Nothing to show", Toast.LENGTH_SHORT).show()
+                    }
+                } else {
+                    binding.passesFab.setOnClickListener { findNavController().navigate(R.id.nav_satellites) }
+                }
+            }
+        }
         getNavResult<Pair<Int, Double>>(R.id.nav_passes, "prefs") { prefs ->
             passesViewModel.saveCalculationPrefs(prefs.first, prefs.second)
             passesViewModel.forceCalculation(prefs.first, prefs.second)

app/src/main/java/com/rtbishop/look4sat/presentation/passesScreen/PassesViewModel.kt

@@ -17,10 +17,7 @@
  */
 package com.rtbishop.look4sat.presentation.passesScreen
 
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.*
 import com.rtbishop.look4sat.data.ISettingsHandler
 import com.rtbishop.look4sat.domain.IDataRepository
 import com.rtbishop.look4sat.domain.model.DataState
@@ -32,14 +29,15 @@ import javax.inject.Inject
 
 @HiltViewModel
 class PassesViewModel @Inject constructor(
-    private val dataRepository: IDataRepository,
     private val predictor: Predictor,
-    private val preferences: ISettingsHandler
+    private val settings: ISettingsHandler,
+    private val repository: IDataRepository
 ) : ViewModel() {
 
-    private val _passes = MutableLiveData<DataState<List<SatPass>>>()
     private var passesProcessing: Job? = null
+    private val _passes = MutableLiveData<DataState<List<SatPass>>>()
     val passes: LiveData<DataState<List<SatPass>>> = _passes
+    val satellites = repository.getSatelliteItems().asLiveData()
 
     init {
         viewModelScope.launch {
@@ -51,26 +49,26 @@ class PassesViewModel @Inject constructor(
     }
 
     fun forceCalculation(
-        hoursAhead: Int = preferences.getHoursAhead(),
-        minElevation: Double = preferences.getMinElevation(),
+        hoursAhead: Int = settings.getHoursAhead(),
+        minElevation: Double = settings.getMinElevation(),
         timeRef: Long = System.currentTimeMillis()
     ) {
         viewModelScope.launch {
             _passes.postValue(DataState.Loading)
             passesProcessing?.cancelAndJoin()
-            val satellites = dataRepository.getSelectedSatellites()
-            val stationPos = preferences.loadStationPosition()
+            val satellites = repository.getSelectedSatellites()
+            val stationPos = settings.loadStationPosition()
             predictor.forceCalculation(satellites, stationPos, timeRef, hoursAhead, minElevation)
         }
     }
 
     fun shouldUseUTC(): Boolean {
-        return preferences.getUseUTC()
+        return settings.getUseUTC()
     }
 
     fun saveCalculationPrefs(hoursAhead: Int, minElevation: Double) {
-        preferences.setHoursAhead(hoursAhead)
-        preferences.setMinElevation(minElevation)
+        settings.setHoursAhead(hoursAhead)
+        settings.setMinElevation(minElevation)
     }
 
     private suspend fun tickPasses(passes: List<SatPass>) = withContext(Dispatchers.Default) {