Fixed an NPE in the PolarViewFragment

app/src/main/java/com/rtbishop/look4sat/MainViewModel.kt

@@ -65,7 +65,7 @@ class MainViewModel(application: Application) : AndroidViewModel(application) {
     val debugMessage: LiveData<String> = _debugMessage
 
     private val _satPassList = MutableLiveData<MutableList<SatPass>>()
-    val passSatList: LiveData<MutableList<SatPass>> = _satPassList
+    val satPassList: LiveData<MutableList<SatPass>> = _satPassList
 
     private val _gsp = MutableLiveData<GroundStationPosition>()
     val gsp: LiveData<GroundStationPosition> = _gsp

app/src/main/java/com/rtbishop/look4sat/ui/MapViewFragment.kt

@@ -96,7 +96,7 @@ class MapViewFragment : Fragment() {
     private fun setupComponents() {
         val delay = viewModel.delay
         gsp = viewModel.gsp.value ?: GroundStationPosition(0.0, 0.0, 0.0)
-        satPassList = viewModel.passSatList.value ?: emptyList()
+        satPassList = viewModel.satPassList.value ?: emptyList()
 
         if (satPassList.isNotEmpty()) {
             satPassList = satPassList.distinctBy { it.tle }

app/src/main/java/com/rtbishop/look4sat/ui/PassListFragment.kt

@@ -115,7 +115,7 @@ class PassListFragment : Fragment() {
     }
 
     private fun setupObservers() {
-        viewModel.passSatList.observe(viewLifecycleOwner, Observer {
+        viewModel.satPassList.observe(viewLifecycleOwner, Observer {
             satPassList = it
             satPassAdapter.setList(satPassList)
             if (satPassList.isNotEmpty()) {

app/src/main/java/com/rtbishop/look4sat/ui/PolarViewFragment.kt

@@ -82,9 +82,6 @@ class PolarViewFragment : Fragment() {
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
-        val delay = viewModel.delay
-        satPass = viewModel.passSatList.value!![args.satPassIndex]
-        mainActivity.supportActionBar?.title = satPass.tle.name
 
         polarViewFrame = view.findViewById(R.id.polar_view_frame)
         transRecycler = view.findViewById(R.id.polar_recycler)
@@ -94,11 +91,22 @@ class PolarViewFragment : Fragment() {
         polarAltitude = view.findViewById(R.id.polar_altitude)
         noTransFound = view.findViewById(R.id.polar_no_trans)
 
-        polarView = PolarView(mainActivity, delay)
-        polarViewFrame.addView(polarView)
-        service.scheduleAtFixedRate({ polarView.invalidate() }, delay, delay, TimeUnit.MILLISECONDS)
+        viewModel.satPassList.value?.let {
+            val refreshRate = viewModel.delay
+            satPass = it[args.satPassIndex]
+            mainActivity.supportActionBar?.title = satPass.tle.name
 
-        setupTransRecycler()
+            polarView = PolarView(mainActivity, refreshRate)
+            polarViewFrame.addView(polarView)
+            service.scheduleAtFixedRate(
+                { polarView.invalidate() },
+                refreshRate,
+                refreshRate,
+                TimeUnit.MILLISECONDS
+            )
+
+            setupTransRecycler()
+        }
     }
 
     private fun setupTransRecycler() {

app/src/main/java/com/rtbishop/look4sat/ui/adapters/SatPassAdapter.kt

@@ -136,9 +136,11 @@ class SatPassAdapter(val viewModel: MainViewModel) :
             progressBar.progress = satPass.progress
 
             itemView.setOnClickListener {
-                val satPassIndex = viewModel.passSatList.value!!.indexOf(satPass)
-                val action = PassListFragmentDirections.actionPassToPolar(satPassIndex)
-                it.findNavController().navigate(action)
+                viewModel.satPassList.value?.let {
+                    val satPassIndex = it.indexOf(satPass)
+                    val action = PassListFragmentDirections.actionPassToPolar(satPassIndex)
+                    itemView.findNavController().navigate(action)
+                }
             }
         }
     }
@@ -162,9 +164,11 @@ class SatPassAdapter(val viewModel: MainViewModel) :
                 String.format(context.getString(R.string.pat_elevation), satPass.pass.maxEl)
 
             itemView.setOnClickListener {
-                val satPassIndex = viewModel.passSatList.value!!.indexOf(satPass)
-                val action = PassListFragmentDirections.actionPassToPolar(satPassIndex)
-                it.findNavController().navigate(action)
+                viewModel.satPassList.value?.let {
+                    val satPassIndex = it.indexOf(satPass)
+                    val action = PassListFragmentDirections.actionPassToPolar(satPassIndex)
+                    itemView.findNavController().navigate(action)
+                }
             }
         }
     }