add some documentation

lib/celement.dart

@@ -1,23 +1,27 @@
 import 'package:flutter/foundation.dart';
 
+/// Country element. This is the element that contains all the information
 class CElement {
+  /// the name of the country
   String name;
+
+  /// the flag of the country
   String flag;
+
+  /// the country code (IT,AF..)
   String code;
+
+  /// the dial code (+39,+93..)
   String dialCode;
 
   CElement({this.name, this.flag, this.code, this.dialCode});
 
   @override
   String toString() {
-    return defaultTargetPlatform == TargetPlatform.android
-        ? "$flag $dialCode"
-        : dialCode;
+    return defaultTargetPlatform == TargetPlatform.android ? "$flag $dialCode" : dialCode;
   }
 
   String toLongString() {
-    return defaultTargetPlatform == TargetPlatform.android
-        ? "$flag $dialCode $name"
-        : "$dialCode $name";
+    return defaultTargetPlatform == TargetPlatform.android ? "$flag $dialCode $name" : "$dialCode $name";
   }
 }

lib/country_code_picker.dart

@@ -55,8 +55,9 @@ class _CountryCodePickerState extends State<CountryCodePicker> {
 
     favoriteElements = elements
         .where((e) =>
-            widget.favorite
-                .firstWhere((f) => e.code == f.toUpperCase() || e.dialCode == f.toString(), orElse: () => null) !=
+            widget.favorite.firstWhere(
+                (f) => e.code == f.toUpperCase() || e.dialCode == f.toString(),
+                orElse: () => null) !=
             null)
         .toList();
     super.initState();

lib/selection_dialog.dart

@@ -1,8 +1,11 @@
-import 'package:flutter/material.dart';
 import 'package:country_code_picker/celement.dart';
+import 'package:flutter/material.dart';
 
+/// selection dialog used for selection of the country code
 class SelectionDialog extends StatefulWidget {
   final List<CElement> elements;
+
+  /// elements passed as favorite
   final List<CElement> favoriteElements;
 
   SelectionDialog(this.elements, this.favoriteElements);
@@ -12,6 +15,7 @@ class SelectionDialog extends StatefulWidget {
 }
 
 class _SelectionDialogState extends State<SelectionDialog> {
+  /// this is useful for filtering purpose
   List<CElement> showedElements = [];
 
   @override
@@ -56,10 +60,7 @@ class _SelectionDialogState extends State<SelectionDialog> {
     s = s.toUpperCase();
     setState(() {
       showedElements = widget.elements
-          .where((e) =>
-              e.code.contains(s) ||
-              e.dialCode.contains(s) ||
-              e.name.toUpperCase().contains(s))
+          .where((e) => e.code.contains(s) || e.dialCode.contains(s) || e.name.toUpperCase().contains(s))
           .toList();
     });
   }