EasyFormGenericField<T> class abstract

Base class for creating a form field.

It can be used as a basis for creating a custom field for a form, where controller support and processing of value changes are already implemented.

The value property allows you to read the value of the associated controller and change it; when the value changes, the field widget will also be rebuilt.

The descendant at least needs to implement a constructor and the build method.

An example of implementing a custom form field for choosing a color, together with the EasyFormFieldController constructor:

class ColorController extends EasyFormFieldController<Color> {
  ColorController(Color value) : super(value);
}

class ColorField extends EasyFormGenericField<Color> {
  ColorField({
    Key key,
    @required ColorController controller,
    ValueChanged<Color> onChange,
  }) : super(
          key: key,
          controller: controller,
          onChange: onChange,
        );

  void _change() {
    value = _getRandomColor();
  }

  Color _getRandomColor() {
    return Color((Random().nextDouble() * 0xFFFFFF).toInt()).withOpacity(1.0);
  }

  @override
  Widget build(BuildContext context) {
    return Align(
      alignment: Alignment.centerLeft,
      child: GestureDetector(
        onTap: _change,
        child: Container(
          width: 50,
          height: 50,
          decoration: BoxDecoration(
            color: value,
            border: Border.all(
              color: Color(0xFF000000),
              width: 2,
            ),
            shape: BoxShape.circle,
          ),
        ),
      ),
    );
  }
}
Inheritance

Constructors

EasyFormGenericField({Key? key, required EasyFormFieldController<T> controller, ValueChanged<T?>? onChange})
const

Properties

controller → EasyFormFieldController<T>
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onChange → ValueChanged<T?>?
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
value ↔ T?
The current value of the form field.
getter/setter pair

Methods

build(BuildContext context) → Widget
createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → EasyFormGenericFieldState<T>
Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited