widget refresh enhancements

android/app/build.gradle

@@ -65,5 +65,9 @@ flutter {
 
 dependencies {
     implementation 'com.android.support:multidex:2.0.1'
+    // Same version as workmanager_android pins — needed to enqueue its
+    // BackgroundWorker from native widget code (the plugin uses
+    // `implementation`, so androidx.work is not exposed transitively).
+    implementation 'androidx.work:work-runtime:2.11.2'
     coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:2.1.4'
 }

android/app/src/main/kotlin/eu/mhsl/marianum/mobile/client/TimetableDayWidget.kt

@@ -4,6 +4,7 @@ import android.appwidget.AppWidgetManager
 import android.appwidget.AppWidgetProvider
 import android.content.Context
 import android.os.Bundle
+import eu.mhsl.marianum.mobile.client.widgets.WidgetRefreshRequester
 import eu.mhsl.marianum.mobile.client.widgets.WidgetRenderer
 
 /**
@@ -11,6 +12,11 @@ import eu.mhsl.marianum.mobile.client.widgets.WidgetRenderer
  * Flutter plugin resolves the receiver class as `<app-package>.<androidName>`.
  */
 class TimetableDayWidget : AppWidgetProvider() {
+    override fun onEnabled(context: Context) {
+        // First widget of this kind placed → fetch fresh data right away.
+        WidgetRefreshRequester.enqueueOneOffRefresh(context)
+    }
+
     override fun onUpdate(
         context: Context,
         appWidgetManager: AppWidgetManager,

android/app/src/main/kotlin/eu/mhsl/marianum/mobile/client/TimetableWeekWidget.kt

@@ -4,9 +4,15 @@ import android.appwidget.AppWidgetManager
 import android.appwidget.AppWidgetProvider
 import android.content.Context
 import android.os.Bundle
+import eu.mhsl.marianum.mobile.client.widgets.WidgetRefreshRequester
 import eu.mhsl.marianum.mobile.client.widgets.WidgetRenderer
 
 class TimetableWeekWidget : AppWidgetProvider() {
+    override fun onEnabled(context: Context) {
+        // First widget of this kind placed → fetch fresh data right away.
+        WidgetRefreshRequester.enqueueOneOffRefresh(context)
+    }
+
     override fun onUpdate(
         context: Context,
         appWidgetManager: AppWidgetManager,

android/app/src/main/kotlin/eu/mhsl/marianum/mobile/client/widgets/WidgetRefreshRequester.kt

@@ -0,0 +1,40 @@
+package eu.mhsl.marianum.mobile.client.widgets
+
+import android.content.Context
+import androidx.work.Constraints
+import androidx.work.Data
+import androidx.work.NetworkType
+import androidx.work.OneTimeWorkRequest
+import androidx.work.WorkManager
+import dev.fluttercommunity.workmanager.BackgroundWorker
+
+/**
+ * Enqueues the app's Dart one-off widget refresh from native code, so a
+ * freshly placed widget populates within seconds instead of waiting for the
+ * next periodic slot.
+ *
+ * DART_TASK_KEY is public plugin API but no semver guarantee — re-verify on
+ * workmanager upgrades. The Dart callback handle comes from SharedPreferences
+ * persisted by Workmanager().initialize(); if the app never ran, the worker
+ * fails gracefully and the widget keeps rendering its cached/empty state.
+ */
+object WidgetRefreshRequester {
+    // Mirrors WidgetBackgroundTask.oneOffTaskName on the Dart side.
+    private const val DART_ONE_OFF_TASK = "eu.mhsl.marianum.widget.refresh.once"
+
+    fun enqueueOneOffRefresh(context: Context) {
+        val request = OneTimeWorkRequest.Builder(BackgroundWorker::class.java)
+            .setInputData(
+                Data.Builder()
+                    .putString(BackgroundWorker.DART_TASK_KEY, DART_ONE_OFF_TASK)
+                    .build(),
+            )
+            .setConstraints(
+                Constraints.Builder()
+                    .setRequiredNetworkType(NetworkType.CONNECTED)
+                    .build(),
+            )
+            .build()
+        WorkManager.getInstance(context).enqueue(request)
+    }
+}

android/app/src/main/kotlin/eu/mhsl/marianum/mobile/client/widgets/WidgetRenderer.kt

@@ -736,8 +736,11 @@ object WidgetRenderer {
         )
     }
 
+    // Mirrors lib/widget_data/widget_sync.dart (the canonical key list) — a
+    // schema bump must land in Dart, Swift (WidgetData.swift) and here
+    // together, or the out-of-sync platform silently renders empty.
     const val KEY_DAY_DATA = "widget_data_day_v1"
-    const val KEY_WEEK_DATA = "widget_data_week_v1"
+    const val KEY_WEEK_DATA = "widget_data_week_v2"
     const val KEY_LOGGED_IN = "widget_data_logged_in_v1"
     const val KEY_THEME_MODE = "widget_setting_theme_mode_v1"
 }