Created switchInput constructor for FormBuilderInput

Author: danvick

example/lib/main.dart

@@ -27,7 +27,7 @@ class MyHomePage extends StatelessWidget {
         margin: EdgeInsets.all(15.0),
         child: FormBuilder(
           context,
-          autovalidate: true,
+          autovalidate: false,
           // showResetButton: true,
           // resetButtonContent: Text("Clear Form"),
           controls: [
@@ -71,6 +71,7 @@ class MyHomePage extends StatelessWidget {
               type: FormBuilderInput.TYPE_PHONE,
               attribute: "phone",
               label: "Phone",
+              hint: "Including country code (+254)"
               //require: true,
             ),
             FormBuilderInput.password(
@@ -88,6 +89,7 @@ class MyHomePage extends StatelessWidget {
             ),
             FormBuilderInput.checkboxList(
               label: "The Languages of my people",
+              hint: "The Languages of my people",
               attribute: "languages",
               require: false,
               value: ["Dart"],
@@ -120,6 +122,15 @@ class MyHomePage extends StatelessWidget {
                   return "Accept terms to continue";
               }
             ),
+            FormBuilderInput.switchInput(
+                label: "I accept the terms and conditions",
+                attribute: "accept_terms_switch",
+                hint: "Kindly make sure you've read all the terms and conditions",
+                validator: (value){
+                  if(!value)
+                    return "Accept terms to continue";
+                }
+            ),
             FormBuilderInput.slider(
               label: "Slider",
               attribute: "slider",
@@ -140,7 +151,7 @@ class MyHomePage extends StatelessWidget {
             FormBuilderInput.rate(
               label: "Rate",
               attribute: "rate",
-              iconSize: 48.0,
+              iconSize: 32.0,
               value: 1,
               max: 5,
               hint: "Hint",

lib/src/form_builder_input.dart

@@ -190,6 +190,18 @@ class FormBuilderInput {
     type = FormBuilderInput.TYPE_CHECKBOX;
   }
 
+  FormBuilderInput.switchInput({
+    @required this.label,
+    @required this.attribute,
+    this.hint,
+    this.value,
+    this.require = false,
+    this.validator,
+  }) : assert(value == null || value is bool,
+  "Initial value for a switch should be boolean") {
+    type = FormBuilderInput.TYPE_SWITCH;
+  }
+
   FormBuilderInput.checkboxList({
     @required this.label,
     @required this.options,

lib/src/form_builder_type_ahead.dart

@@ -35,7 +35,7 @@ class _FormBuilderTypeAheadState extends State<FormBuilderTypeAhead> {
       textFieldConfiguration: TextFieldConfiguration(
         controller: _typeAheadController,
         decoration: InputDecoration(
-          labelText: formControl.label ?? formControl.attribute,
+          labelText: formControl.label,
         ),
       ),
       suggestionsCallback: formControl.suggestionsCallback,