Simplified expressions and added const keyword.

Author: awhitford

lib/src/fields/form_builder_checkbox_list.dart

@@ -136,19 +136,18 @@ class _FormBuilderCheckboxListState extends State<FormBuilderCheckboxList> {
               onTap: _readOnly
                   ? null
                   : () {
-                      var currentValue = [...field.value];
-                      if (!currentValue.contains(widget.options[i].value)) {
-                        currentValue.add(widget.options[i].value);
+                      final optionValue = widget.options[i].value;
+                      final currentValue = [...field.value];
+                      if (!currentValue.contains(optionValue)) {
+                        currentValue.add(optionValue);
                       } else {
-                        currentValue.remove(widget.options[i].value);
+                        currentValue.remove(optionValue);
                       }
                       field.didChange(currentValue);
-                      if (widget.onChanged != null) {
-                        widget.onChanged(currentValue);
-                      }
+                      widget.onChanged?.call(currentValue);
                     },
             ),
-            Divider(height: 0.0),
+            const Divider(height: 0.0),
           ]);
         }
         return InputDecorator(

lib/src/fields/form_builder_country_picker.dart

@@ -123,7 +123,7 @@ class _FormBuilderCountryPickerState extends State<FormBuilderCountryPicker> {
                 ),
                 Expanded(
                   child: Text(
-                    "${field.value?.name ?? ''}",
+                    field.value?.name ?? '',
                     style: widget.style,
                   ),
                 ),
@@ -163,7 +163,7 @@ class _FormBuilderCountryPickerState extends State<FormBuilderCountryPicker> {
             primaryColor: widget.cursorColor ?? Theme.of(context).primaryColor,
           ),
           child: CountryPickerDialog(
-            titlePadding: widget.titlePadding ?? EdgeInsets.all(8.0),
+            titlePadding: widget.titlePadding ?? const EdgeInsets.all(8.0),
             searchCursorColor:
                 widget.cursorColor ?? Theme.of(context).primaryColor,
             searchInputDecoration:

lib/src/fields/form_builder_dropdown.dart

@@ -141,7 +141,7 @@ class _FormBuilderDropdownState extends State<FormBuilderDropdown> {
                 if (widget.allowClear &&
                     !widget.readOnly &&
                     field.value != null) ...[
-                  VerticalDivider(),
+                  const VerticalDivider(),
                   InkWell(
                     child: widget.clearIcon,
                     onTap: () {

lib/src/fields/form_builder_image_picker.dart

@@ -131,7 +131,7 @@ class _FormBuilderImagePickerState extends State<FormBuilderImagePicker> {
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: <Widget>[
-              SizedBox(
+              const SizedBox(
                 height: 8,
               ),
               Container(

lib/src/fields/form_builder_phone_field.dart

@@ -263,14 +263,14 @@ class FormBuilderPhoneFieldState extends State<FormBuilderPhoneField> {
         }
       },
       child: ConstrainedBox(
-        constraints: BoxConstraints(
+        constraints: const BoxConstraints(
           minWidth: 100,
           maxWidth: 120,
         ),
         child: Row(
           mainAxisAlignment: MainAxisAlignment.spaceEvenly,
           children: <Widget>[
-            Icon(Icons.arrow_drop_down),
+            const Icon(Icons.arrow_drop_down),
             CountryPickerUtils.getDefaultFlagImage(_selectedDialogCountry),
             Text(
               '+${_selectedDialogCountry.phoneCode} ',
@@ -319,7 +319,7 @@ class FormBuilderPhoneFieldState extends State<FormBuilderPhoneField> {
             primaryColor: widget.cursorColor ?? Theme.of(context).primaryColor,
           ),
           child: CountryPickerDialog(
-            titlePadding: widget.titlePadding ?? EdgeInsets.all(8.0),
+            titlePadding: widget.titlePadding ?? const EdgeInsets.all(8.0),
             searchCursorColor:
                 widget.cursorColor ?? Theme.of(context).primaryColor,
             searchInputDecoration:

lib/src/fields/form_builder_radio.dart

@@ -79,13 +79,11 @@ class _FormBuilderRadioState extends State<FormBuilderRadio> {
   }
 
   Widget _leading(FormFieldState<dynamic> field, int i) {
-    if (widget.leadingInput) return _radio(field, i);
-    return null;
+    return widget.leadingInput ? _radio(field, i) : null;
   }
 
   Widget _trailing(FormFieldState<dynamic> field, int i) {
-    if (!widget.leadingInput) return _radio(field, i);
-    return null;
+    return !widget.leadingInput ? _radio(field, i) : null;
   }
 
   @override
@@ -129,7 +127,7 @@ class _FormBuilderRadioState extends State<FormBuilderRadio> {
                       widget.onChanged?.call(value);
                     },
             ),
-            Divider(
+            const Divider(
               height: 0.0,
             ),
           ]);

lib/src/fields/form_builder_text_field.dart

@@ -114,7 +114,7 @@ class FormBuilderTextFieldState extends State<FormBuilderTextField> {
     if (widget.controller != null) {
       _effectiveController = widget.controller;
     } else {
-      _effectiveController.text = "${_initialValue ?? ''}";
+      _effectiveController.text = _initialValue ?? '';
     }
 
     _effectiveController.addListener(() {

lib/src/form_builder_field_option.dart

@@ -16,11 +16,7 @@ class FormBuilderFieldOption extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    if (child != null) {
-      return child;
-    } else {
-      // ignore: deprecated_member_use_from_same_package
-      return Text(label ?? value.toString());
-    }
+    // ignore: deprecated_member_use_from_same_package
+    return child ?? Text(label ?? value.toString());
   }
 }