From d8f011b64b8106c8f3df0dc4f1c8bf811b7e31e2 Mon Sep 17 00:00:00 2001
From: Johan von Forstner <johan.forstner@gmail.com>
Date: Sun, 14 Jun 2020 19:19:27 +0200
Subject: [PATCH] Add error message when internet is not available

---
 .../vonforst/evmap/fragment/MapFragment.kt    | 29 +++++++++--
 .../vonforst/evmap/viewmodel/MapViewModel.kt  | 51 ++++++++++++-------
 app/src/main/res/values-de/strings.xml        |  2 +
 app/src/main/res/values/strings.xml           |  2 +
 4 files changed, 64 insertions(+), 20 deletions(-)

diff --git a/app/src/main/java/net/vonforst/evmap/fragment/MapFragment.kt b/app/src/main/java/net/vonforst/evmap/fragment/MapFragment.kt
index 855244af..ee4fa32b 100644
--- a/app/src/main/java/net/vonforst/evmap/fragment/MapFragment.kt
+++ b/app/src/main/java/net/vonforst/evmap/fragment/MapFragment.kt
@@ -89,6 +89,7 @@ class MapFragment : Fragment(), OnMapReadyCallback, MapsActivity.FragmentCallbac
     private var markers: MutableBiMap<Marker, ChargeLocation> = HashBiMap()
     private var clusterMarkers: List<Marker> = emptyList()
     private var searchResultMarker: Marker? = null
+    private var connectionErrorSnackbar: Snackbar? = null
 
     private lateinit var clusterIconGenerator: ClusterIconGenerator
     private lateinit var chargerIconGenerator: ChargerIconGenerator
@@ -312,9 +313,31 @@ class MapFragment : Fragment(), OnMapReadyCallback, MapsActivity.FragmentCallbac
                 unhighlightAllMarkers()
             }
         })
-        vm.chargepoints.observe(viewLifecycleOwner, Observer {
-            val chargepoints = it.data
-            if (chargepoints != null) updateMap(chargepoints)
+        vm.chargepoints.observe(viewLifecycleOwner, Observer { res ->
+            when (res.status) {
+                Status.ERROR -> {
+                    val view = view ?: return@Observer
+
+                    connectionErrorSnackbar?.dismiss()
+                    connectionErrorSnackbar = Snackbar
+                        .make(view, R.string.connection_error, Snackbar.LENGTH_INDEFINITE)
+                        .setAction(R.string.retry) {
+                            connectionErrorSnackbar?.dismiss()
+                            vm.reloadChargepoints()
+                        }
+                    connectionErrorSnackbar!!.show()
+                }
+                Status.SUCCESS -> {
+                    connectionErrorSnackbar?.dismiss()
+                }
+                Status.LOADING -> {
+                }
+            }
+
+            val chargepoints = res.data
+            if (chargepoints != null) {
+                updateMap(chargepoints)
+            }
         })
         vm.favorites.observe(viewLifecycleOwner, Observer {
             updateFavoriteToggle()
diff --git a/app/src/main/java/net/vonforst/evmap/viewmodel/MapViewModel.kt b/app/src/main/java/net/vonforst/evmap/viewmodel/MapViewModel.kt
index 34e2bb64..2bcc0208 100644
--- a/app/src/main/java/net/vonforst/evmap/viewmodel/MapViewModel.kt
+++ b/app/src/main/java/net/vonforst/evmap/viewmodel/MapViewModel.kt
@@ -16,6 +16,7 @@ import net.vonforst.evmap.ui.cluster
 import retrofit2.Call
 import retrofit2.Callback
 import retrofit2.Response
+import java.io.IOException
 
 data class MapPosition(val bounds: LatLngBounds, val zoom: Float)
 
@@ -76,9 +77,7 @@ class MapViewModel(application: Application, geApiKey: String) : AndroidViewMode
                 value = Resource.loading(emptyList())
                 listOf(mapPosition, filtersWithValue).forEach {
                     addSource(it) {
-                        val pos = mapPosition.value ?: return@addSource
-                        val filters = filtersWithValue.value ?: return@addSource
-                        loadChargepoints(pos, filters)
+                        reloadChargepoints()
                     }
                 }
             }
@@ -174,6 +173,12 @@ class MapViewModel(application: Application, geApiKey: String) : AndroidViewMode
         }
     }
 
+    fun reloadChargepoints() {
+        val pos = mapPosition.value ?: return
+        val filters = filtersWithValue.value ?: return
+        loadChargepoints(pos, filters)
+    }
+
     private fun loadChargepoints(
         mapPosition: MapPosition,
         filters: List<FilterWithValue<out FilterValue>>
@@ -229,20 +234,32 @@ class MapViewModel(application: Application, geApiKey: String) : AndroidViewMode
         val data = mutableListOf<ChargepointListItem>()
         do {
             // load all pages of the response
-            val response = api.getChargepoints(
-                bounds.southwest.latitude, bounds.southwest.longitude,
-                bounds.northeast.latitude, bounds.northeast.longitude,
-                clustering = useGeClustering, zoom = zoom,
-                clusterDistance = clusterDistance, freecharging = freecharging, minPower = minPower,
-                freeparking = freeparking, plugs = connectors, chargecards = chargeCards,
-                networks = networks, startkey = startkey
-            )
-            if (!response.isSuccessful || response.body()!!.status != "ok") {
-                return Resource.error(response.message(), chargepoints.value?.data)
-            } else {
-                val body = response.body()!!
-                data.addAll(body.chargelocations)
-                startkey = body.startkey
+            try {
+                val response = api.getChargepoints(
+                    bounds.southwest.latitude,
+                    bounds.southwest.longitude,
+                    bounds.northeast.latitude,
+                    bounds.northeast.longitude,
+                    clustering = useGeClustering,
+                    zoom = zoom,
+                    clusterDistance = clusterDistance,
+                    freecharging = freecharging,
+                    minPower = minPower,
+                    freeparking = freeparking,
+                    plugs = connectors,
+                    chargecards = chargeCards,
+                    networks = networks,
+                    startkey = startkey
+                )
+                if (!response.isSuccessful || response.body()!!.status != "ok") {
+                    return Resource.error(response.message(), chargepoints.value?.data)
+                } else {
+                    val body = response.body()!!
+                    data.addAll(body.chargelocations)
+                    startkey = body.startkey
+                }
+            } catch (e: IOException) {
+                return Resource.error(e.message, chargepoints.value?.data)
             }
         } while (startkey != null && startkey < 10000)
 
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index e4fd7270..cfa1cae7 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -92,4 +92,6 @@
     <string name="ok">OK</string>
     <string name="pref_language">Sprache</string>
     <string name="pref_language_summary">App-Sprache ändern</string>
+    <string name="connection_error">Ladesäulen konnten nicht geladen werden</string>
+    <string name="retry">Wiederholen</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 234268f0..534d73f3 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -91,4 +91,6 @@
     <string name="ok">OK</string>
     <string name="pref_language">Language</string>
     <string name="pref_language_summary">Change the app language</string>
+    <string name="connection_error">Could not load charging stations</string>
+    <string name="retry">Retry</string>
 </resources>