Info end user about beacon feature

Author: bailuk

aat-gtk/src/main/kotlin/ch/bailu/aat_gtk/view/preferences/NetworkPreferencesPage.kt

@@ -1,5 +1,6 @@
 package ch.bailu.aat_gtk.view.preferences
 
+import ch.bailu.aat_gtk.view.LabelTextView
 import ch.bailu.aat_lib.app.AppContext
 import ch.bailu.aat_lib.preferences.beacon.*
 import ch.bailu.gtk.adw.PreferencesGroup
@@ -10,6 +11,7 @@ class NetworkPreferencesPage(appContext: AppContext) : PreferencesPageParent("Ne
         page.add(PreferencesGroup().apply {
             setTitle("Beacon")
             add(SolidBooleanSwitchView(SolidBeaconEnabled(appContext.storage)).layout)
+            add(LabelTextView(SolidBeaconEnabled.toolTip).layout)
             add(SolidEntryView(SolidBeaconServer(appContext.storage)).layout)
             add(SolidEntryView(SolidBeaconKey(appContext.storage)).layout)
         })

aat-lib/src/main/java/ch/bailu/aat_lib/preferences/beacon/SolidBeaconEnabled.kt

@@ -2,13 +2,19 @@ package ch.bailu.aat_lib.preferences.beacon
 
 import ch.bailu.aat_lib.preferences.SolidBoolean
 import ch.bailu.aat_lib.preferences.StorageInterface
+import ch.bailu.aat_lib.resources.ToDo
 
 class SolidBeaconEnabled(storage: StorageInterface) : SolidBoolean(storage, KEY) {
     override fun getLabel(): String {
         return "Enabled"
     }
 
+    override fun getToolTip(): String? {
+        return toolTip
+    }
+
     companion object {
         const val KEY = "BEACON_ENABLED"
+        val toolTip = ToDo.translate("Experimental: Service for sharing live GPS locations. See https://github.com/MaxKellermann/beacon")
     }
 }