add fullscree toggle to home page

lib/home_page.dart

@@ -1,4 +1,6 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_fullscreen/flutter_fullscreen.dart';
 import 'package:logging/logging.dart';
 import 'package:sheetless/login_page.dart';
 import 'package:sheetless/sheet_viewer_page.dart';
@@ -17,7 +19,7 @@ class MyHomePage extends StatefulWidget {
   State<MyHomePage> createState() => _MyHomePageState();
 }
 
-class _MyHomePageState extends State<MyHomePage> {
+class _MyHomePageState extends State<MyHomePage> with FullScreenListener {
   ApiClient? apiClient;
   Future<bool> apiLoggedIn = Future.value(false);
   final StorageHelper _storageHelper = StorageHelper();
@@ -29,11 +31,22 @@ class _MyHomePageState extends State<MyHomePage> {
 
   @override
   void initState() {
+    FullScreen.addListener(this);
+
+    // Load saved fullscreen
+    FullScreen.setFullScreen(widget.config.fullscreen);
+
     super.initState();
     _loadAppInfo();
     sheets = acquireSheets();
   }
 
+  @override
+  void dispose() {
+    FullScreen.removeListener(this);
+    super.dispose();
+  }
+
   Future<void> _loadAppInfo() async {
     final info = await PackageInfo.fromPlatform();
     setState(() {
@@ -120,13 +133,17 @@ class _MyHomePageState extends State<MyHomePage> {
                       switchShufflingState(!shuffling);
                     },
                   ),
-                  // ListTile(
+                  ListTile(
-                  //   leading: const Icon(Icons.sync),
+                    leading: Icon(
-                  //   title: const Text('Sync Mode'),
+                      widget.config.fullscreen
-                  //   onTap: () {
+                          ? Icons.fullscreen_exit
-                  //     // TODO
+                          : Icons.fullscreen,
-                  //   },
+                    ),
-                  // ),
+                    title: widget.config.fullscreen
+                        ? const Text('Exit Fullscreen')
+                        : const Text('Enter Fullscreen'),
+                    onTap: toggleFullscreen,
+                  ),
                   ListTile(
                     leading: const Icon(Icons.logout),
                     title: const Text('Logout'),
@@ -150,6 +167,18 @@ class _MyHomePageState extends State<MyHomePage> {
     );
   }
 
+  @override
+  void onFullScreenChanged(bool enabled, SystemUiMode? systemUiMode) {
+    setState(() {
+      widget.config.fullscreen = enabled;
+      _storageHelper.writeConfig(widget.config);
+    });
+  }
+
+  void toggleFullscreen() {
+    FullScreen.setFullScreen(!widget.config.fullscreen);
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

lib/sheet_viewer_page.dart

@@ -68,6 +68,9 @@ class _SheetViewerPageState extends State<SheetViewerPage>
 
       document = await PdfDocument.openFile(file.path);
     }
+    setState(() {
+      // document changed
+    });
     return true;
   }
 
@@ -97,6 +100,17 @@ class _SheetViewerPageState extends State<SheetViewerPage>
     return AppBar(
       title: Text(widget.sheet.name),
       actions: [
+        IconButton(
+          icon: Icon(
+            widget.config.fullscreen ? Icons.fullscreen_exit : Icons.fullscreen,
+          ),
+          tooltip: widget.config.fullscreen
+              ? 'Exit Fullscreen'
+              : 'Enter Fullscreen',
+          onPressed: () {
+            toggleFullscreen();
+          },
+        ),
         IconButton(
           onPressed: () {
             setState(() {