Fix demo project

@@ -117,7 +117,7 @@ class MyAppState extends State<MyApp> with SingleTickerProviderStateMixin {
 
     final appDocDir = await getApplicationDocumentsDirectory();
     final appDocPath = appDocDir.path;
-    final file = File(appDocPath + '/' + 'document.pdf');
+    final file = File('$appDocPath/document.pdf');
     print('Save as file ${file.path} ...');
     await file.writeAsBytes(bytes);
     await OpenFile.open(file.path);

@@ -93,7 +93,7 @@ class Calendar extends StatelessWidget {
     }
 
     if (date.day == 1) {
-      text += ' ' + DateFormat.MMM().format(date);
+      text += ' ${DateFormat.MMM().format(date)}';
     }
 
     return Container(
@@ -109,12 +109,12 @@ class Calendar extends StatelessWidget {
 
   @override
   Widget build(Context context) {
-    final _date = date ?? DateTime.now();
-    final _year = year ?? _date.year;
-    final _month = month ?? _date.month;
+    final localDate = date ?? DateTime.now();
+    final localYear = year ?? localDate.year;
+    final localMnth = month ?? localDate.month;
 
-    final start = DateTime(_year, _month, 1, 12);
-    final end = DateTime(_year, _month + 1, 1, 12).subtract(
+    final start = DateTime(localYear, localMnth, 1, 12);
+    final end = DateTime(localYear, localMnth + 1, 1, 12).subtract(
       const Duration(days: 1),
     );
 
@@ -148,9 +148,9 @@ class Calendar extends StatelessWidget {
       children: List<Widget>.generate(42, (int index) {
         final d = start.add(Duration(days: index - startId));
         final currentMonth = index >= startId && index < endId;
-        final currentDay = d.year == _date.year &&
-            d.month == _date.month &&
-            d.day == _date.day;
+        final currentDay = d.year == localDate.year &&
+            d.month == localDate.month &&
+            d.day == localDate.day;
         return Container(
           foregroundDecoration: BoxDecoration(
               border: Border(
@@ -170,7 +170,7 @@ class Calendar extends StatelessWidget {
         mainAxisAlignment: MainAxisAlignment.start,
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
-          title(context, DateTime(_year, _month)),
+          title(context, DateTime(localYear, localMnth)),
           head,
           Expanded(child: body),
         ],

@@ -62,7 +62,7 @@ Future<Uint8List> generateDocument(
               pw.RichText(
                   text: pw.TextSpan(children: [
                 pw.TextSpan(
-                  text: DateTime.now().year.toString() + '\n',
+                  text: '${DateTime.now().year}\n',
                   style: pw.TextStyle(
                     fontWeight: pw.FontWeight.bold,
                     color: PdfColors.grey600,

@@ -10,18 +10,20 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  intl: ^0.17.0
+  intl: ^0.18.0
   open_file: ^3.2.1
-  path_provider: ^2.0.2
-  printing: ^5.3.0
-  url_launcher: ^6.0.6
+  path_provider: ^2.0.12
+  pdf:
+  printing:
+  url_launcher: ^6.1.8
+  vector_math: ^2.1.4
 
 dev_dependencies:
   # flutter_launcher_icons: ^0.10.0
-  flutter_lints: ^1.0.4
+  flutter_lints: ^2.0.1
   flutter_test:
     sdk: flutter
-  test: ^1.16.5
+  test: ^1.22.0
 
 dependency_overrides:
   pdf: