Show sign in button for HTTP 401

app/src/debug/res/values/keys.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources xmlns:tools="http://schemas.android.com/tools">
   <string name="app_name" tools:ignore="PrivateResource">Tasks Debug</string>
-  <string name="tasks_caldav_url">https://192.168.1.120:8443</string>
+  <string name="tasks_caldav_url">https://caldav.tasks.org</string>
   <string name="debug_strict_mode_thread">Strict mode - Thread</string>
   <string name="debug_strict_mode_vm">Strict mode - VM</string>
   <string name="debug_leakcanary">LeakCanary</string>

app/src/main/java/org/tasks/preferences/fragments/TasksAccount.kt

@@ -20,7 +20,9 @@ import org.tasks.billing.PurchaseDialog
 import org.tasks.data.CaldavAccount
 import org.tasks.data.CaldavDao
 import org.tasks.injection.InjectingPreferenceFragment
+import org.tasks.preferences.IconPreference
 import java.net.HttpURLConnection.HTTP_PAYMENT_REQUIRED
+import java.net.HttpURLConnection.HTTP_UNAUTHORIZED
 import javax.inject.Inject
 
 @AndroidEntryPoint
@@ -43,7 +45,7 @@ class TasksAccount : InjectingPreferenceFragment() {
                     caldavAccount.error = null
                     caldavDao.update(caldavAccount)
                 }
-                refreshSubscription()
+                refreshUi()
             }
         }
     }
@@ -78,6 +80,8 @@ class TasksAccount : InjectingPreferenceFragment() {
             billingClient.queryPurchases()
             false
         }
+
+        refreshUi()
     }
 
     private fun removeAccount() = lifecycleScope.launch {
@@ -92,7 +96,7 @@ class TasksAccount : InjectingPreferenceFragment() {
         localBroadcastManager.registerPurchaseReceiver(purchaseReceiver)
         localBroadcastManager.registerRefreshListReceiver(purchaseReceiver)
 
-        refreshSubscription()
+        refreshUi()
     }
 
     override fun onPause() {
@@ -101,7 +105,12 @@ class TasksAccount : InjectingPreferenceFragment() {
         localBroadcastManager.unregisterReceiver(purchaseReceiver)
     }
 
-    private fun refreshSubscription() {
+    private fun refreshUi() {
+        (findPreference(R.string.sign_in_with_google) as IconPreference).apply {
+            isVisible = caldavAccount.error.isLoggedOut()
+            iconVisible = true
+        }
+
         if (BuildConfig.FLAVOR == "generic") {
             return
         }
@@ -158,6 +167,9 @@ class TasksAccount : InjectingPreferenceFragment() {
             return fragment
         }
 
+        private fun String?.isLoggedOut(): Boolean =
+                this?.startsWith("HTTP $HTTP_UNAUTHORIZED") == true
+
         private fun String?.isPaymentRequired(): Boolean =
                 this?.startsWith("HTTP $HTTP_PAYMENT_REQUIRED") == true
     }

app/src/main/res/values/strings.xml

@@ -667,4 +667,5 @@ File %1$s contained %2$s.\n\n
   <string name="follow_reddit">Follow r/tasks</string>
   <string name="authorization_cancelled">Authorization cancelled</string>
   <string name="sign_in_with_google">Sign in with Google</string>
+  <string name="authentication_required">Authentication required</string>
 </resources>

app/src/main/res/xml/preferences_tasks.xml

@@ -4,9 +4,11 @@
   xmlns:tools="http://schemas.android.com/tools"
   android:key="@string/preference_screen">
 
-  <Preference
+  <org.tasks.preferences.IconPreference
     android:key="@string/sign_in_with_google"
+    android:layout="@layout/preference_icon"
     android:title="@string/sign_in_with_google"
+    android:summary="@string/authentication_required"
     app:isPreferenceVisible="false"
     tools:isPreferenceVisible="true"/>