update validation and version

CHANGELOG.md

@@ -1,3 +1,6 @@
+# 2.1.0
+* Prefix and suffix attribute
+
 # 2.0.0+4
 * Change minimum version for dart
 

README.md

@@ -298,20 +298,24 @@ new DrawerScaffold(
 ```dart
 new DrawerScaffold(
   headerView: headerView(context),
-  itemBuilder:
-      (BuildContext context, MenuItem menuItem, bool isSelected) {
-    return Container(
-      color: isSelected
-          ? Theme.of(context).accentColor.withOpacity(0.7)
-          : Colors.transparent,
-      padding: EdgeInsets.fromLTRB(24, 16, 24, 16),
-      child: Text(
-        menuItem.title,
-        style: Theme.of(context).textTheme.subhead?.copyWith(
-            color: isSelected ? Colors.black87 : Colors.white70),
-      ),
-    );
-  }
+  drawers: [
+      SideDrawer(
+        itemBuilder:
+            (BuildContext context, MenuItem menuItem, bool isSelected) {
+          return Container(
+            color: isSelected
+                ? Theme.of(context).accentColor.withOpacity(0.7)
+                : Colors.transparent,
+            padding: EdgeInsets.fromLTRB(24, 16, 24, 16),
+            child: Text(
+              menuItem.title,
+              style: Theme.of(context).textTheme.subhead?.copyWith(
+                  color: isSelected ? Colors.black87 : Colors.white70),
+            ),
+          );
+        }
+      )
+  ],
   ...
 );
 ```

lib/menu_screen.dart

@@ -637,10 +637,20 @@ class Menu {
 class MenuItem<T> {
   final T? id;
   final String title;
+
+  /// set icon from [MenuItem], if the icon is not null, the prefix must be null
   final IconData? icon;
+
+  /// set prefix widget from [MenuItem], if the prefix is not null, the icon must be null
   final Widget? prefix;
+
+  /// set prefix widget from [MenuItem]
   final Widget? suffix;
+
+  /// set independent text style for title
   final TextStyle? textStyle;
+
+  /// append data with [MenuItem], then can be use on itemBuilder
   final dynamic data;
 
   MenuItem({
@@ -651,7 +661,7 @@ class MenuItem<T> {
     this.suffix,
     this.textStyle,
     this.data,
-  }) : assert(prefix != null && icon != null);
+  }) : assert(prefix == null || icon == null);
 
   MenuItem<T> copyWith({
     T? id,

pubspec.yaml

@@ -5,7 +5,7 @@ version: 2.1.0
 homepage: https://github.com/shiburagi/Drawer-Behavior-Flutter
 
 environment:
-  sdk: '>=2.12.0-259.9.beta <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: