Minor code tweaks.

Author: awhitford

example/lib/sources/complete_form.dart

@@ -18,7 +18,7 @@ class CompleteFormState extends State<CompleteForm> {
   bool autoValidate = true;
   bool readOnly = false;
   bool showSegmentedControl = true;
-  final GlobalKey<FormBuilderState> _formKey = GlobalKey<FormBuilderState>();
+  final _formKey = GlobalKey<FormBuilderState>();
   bool _ageHasError = false;
   bool _genderHasError = false;
 

example/lib/sources/signup_form.dart

@@ -7,7 +7,7 @@ class SignupForm extends StatefulWidget {
 }
 
 class _SignupFormState extends State<SignupForm> {
-  final GlobalKey<FormBuilderState> _formKey = GlobalKey();
+  final _formKey = GlobalKey<FormBuilderState>();
 
   @override
   Widget build(BuildContext context) {

lib/src/fields/form_builder_dropdown.dart

@@ -266,9 +266,7 @@ class FormBuilderDropdown<T> extends FormBuilderField<T> {
                         iconEnabledColor: iconEnabledColor,
                         onChanged: (state.readOnly || !enabled)
                             ? null
-                            : (T value) {
-                                _changeValue<T>(field, value);
-                              },
+                            : (T value) => _changeValue<T>(field, value),
                         onTap: onTap,
                         focusNode: state.effectiveFocusNode,
                         autofocus: autofocus,
@@ -280,12 +278,10 @@ class FormBuilderDropdown<T> extends FormBuilderField<T> {
                     ),
                   ),
                   if (allowClear && !readOnly && field.value != null) ...[
-                    VerticalDivider(),
+                    const VerticalDivider(),
                     InkWell(
                       child: clearIcon,
-                      onTap: () {
-                        _changeValue(state, null);
-                      },
+                      onTap: () => _changeValue<T>(state, null),
                     ),
                   ]
                 ],

lib/src/fields/form_builder_image_picker.dart

@@ -101,7 +101,7 @@ class FormBuilderImagePicker extends FormBuilderField<List<dynamic>> {
                   scrollDirection: Axis.horizontal,
                   children: [
                     if (field.value != null)
-                      ...(field.value.map<Widget>((item) {
+                      ...field.value.map<Widget>((item) {
                         return Stack(
                           alignment: Alignment.topRight,
                           children: <Widget>[
@@ -140,7 +140,7 @@ class FormBuilderImagePicker extends FormBuilderField<List<dynamic>> {
                               ),
                           ],
                         );
-                      }).toList()),
+                      }),
                     if (!state.readOnly && !state.hasMaxImages)
                       GestureDetector(
                         child: placeholderImage != null

lib/src/form_builder.dart

@@ -74,7 +74,7 @@ class FormBuilder extends StatefulWidget {
 
 class FormBuilderState extends State<FormBuilder> {
   //TODO: Find way to assert no duplicates in field names
-  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
+  final _formKey = GlobalKey<FormState>();
 
   Map<String, FormBuilderFieldState> _fields;