fix: show "Loading note…" in single-note widget on boot instead of "Note not found"

Before this change, the placeholder text was always "Note not found", even when the
widget was still connecting to its data service on initial phone start. The default
layout text now reads "Loading note…" and is only swapped to "Note not found" once
onDataSetChanged() has confirmed the note is genuinely absent from the database.

Fixes #1611

AI-assisted: Claude Code (Sonnet 4.6)
Signed-off-by: Jan C. Borchardt <925062+jancborchardt@users.noreply.github.com>

Author: jancborchardt

app/src/main/java/it/niedermann/owncloud/notes/widget/singlenote/SingleNoteWidgetFactory.java

@@ -55,6 +55,12 @@ public void onDataSetChanged() {
 
             if (note == null) {
                 Log.e(TAG, "Error: note not found");
+                // Switch placeholder from "Loading note…" to "Note not found" now that we've
+                // confirmed the note is genuinely missing rather than still loading.
+                final var views = new RemoteViews(context.getPackageName(), R.layout.widget_single_note);
+                views.setTextViewText(R.id.widget_single_note_placeholder_tv,
+                        context.getString(R.string.widget_single_note_note_not_found));
+                AppWidgetManager.getInstance(context).partiallyUpdateAppWidget(appWidgetId, views);
             }
         } else {
             Log.w(TAG, "Widget with ID " + appWidgetId + " seems to be not configured yet.");
@@ -110,7 +116,6 @@ public RemoteViews getViewAt(int position) {
     }
 
 
-    // TODO Set loading view
     @Override
     public RemoteViews getLoadingView() {
         return null;

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

@@ -241,7 +241,8 @@
     <string name="widget_note_list_title">Note list</string>
     <string name="widget_note_list_placeholder">No notes</string>
     <string name="widget_single_note_title">Single note</string>
-    <string name="widget_single_note_placeholder_tv">Note not found</string>
+    <string name="widget_single_note_placeholder_tv">Loading note…</string>
+    <string name="widget_single_note_note_not_found">Note not found</string>
     <string name="widget_not_logged_in">Please login to Notes before using this widget</string>
     <string name="widget_entry_fav_contentDescription">Star icon is used to denote an item as a favorite</string>