add pref for background feed loading

app/src/main/java/com/github/libretube/constants/PreferenceKeys.kt

@@ -19,6 +19,7 @@ object PreferenceKeys {
     const val AUTO_ROTATION = "auto_rotation"
     const val BREAK_REMINDER_TOGGLE = "break_reminder_toggle"
     const val BREAK_REMINDER = "break_reminder"
+    const val SAVE_FEED = "save_feed"
 
     /**
      * Appearance

app/src/main/java/com/github/libretube/fragments/SubscriptionsFragment.kt

@@ -39,6 +39,11 @@ class SubscriptionsFragment : BaseFragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
+        val loadFeedInBackground = PreferenceHelper.getBoolean(
+            PreferenceKeys.SAVE_FEED,
+            false
+        )
+
         binding.subRefresh.isEnabled = true
 
         binding.subProgress.visibility = View.VISIBLE
@@ -50,7 +55,10 @@ class SubscriptionsFragment : BaseFragment() {
 
         binding.subFeed.layoutManager = GridLayoutManager(view.context, grid.toInt())
 
-        if (viewModel.videoFeed.value == null) viewModel.fetchFeed()
+        if (viewModel.videoFeed.value == null || !loadFeedInBackground) {
+            viewModel.videoFeed.value = null
+            viewModel.fetchFeed()
+        }
 
         // listen for error responses
         viewModel.errorResponse.observe(viewLifecycleOwner) {

app/src/main/res/drawable/ic_loading.xml

@@ -0,0 +1,11 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/black"
+        android:fillType="evenOdd"
+        android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM18,12c0,3.31 -2.69,6 -6,6s-6,-2.69 -6,-6h2c0,2.21 1.79,4 4,4s4,-1.79 4,-4 -1.79,-4 -4,-4v3L8,7l4,-4v3c3.31,0 6,2.69 6,6z" />
+</vector>

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

@@ -327,6 +327,8 @@
     <string name="local_subscriptions">Local subscriptions</string>
     <string name="preferences">Preferences</string>
     <string name="backup_customInstances">Custom Instances</string>
+    <string name="save_feed">Load feed in background</string>
+    <string name="save_feed_summary">Load the subscription feed in the background and prevent it from being auto-refreshed.</string>
 
     <!-- Notification channel strings -->
     <string name="download_channel_name">Download Service</string>

app/src/main/res/xml/advanced_settings.xml

@@ -30,6 +30,12 @@
             app:key="new_videos_badge"
             app:title="@string/new_videos_badge" />
 
+        <SwitchPreferenceCompat
+            android:icon="@drawable/ic_loading"
+            android:summary="@string/save_feed_summary"
+            app:key="save_feed"
+            app:title="@string/save_feed" />
+
     </PreferenceCategory>
 
     <PreferenceCategory app:title="@string/preferences">