EnhanceExpansionPanelList class

A material expansion panel list that lays out its children and animates expansions.

Note that expansionCallback behaves differently for EnhanceExpansionPanelList and EnhanceExpansionPanelList.radio.

{@tool dartpad --template=stateful_widget_scaffold}

Here is a simple example of how to implement EnhanceExpansionPanelList.

// stores EnhanceExpansionPanel state information
class Item {
  Item({
    required this.expandedValue,
    required this.headerValue,
    this.isExpanded = false,
  });

  String expandedValue;
  String headerValue;
  bool isExpanded;
}

List<Item> generateItems(int numberOfItems) {
  return List<Item>.generate(numberOfItems, (int index) {
    return Item(
      headerValue: 'Panel $index',
      expandedValue: 'This is item number $index',
    );
  });
}

final List<Item> _data = generateItems(8);

@override
Widget build(BuildContext context) {
  return SingleChildScrollView(
    child: Container(
      child: _buildPanel(),
    ),
  );
}

Widget _buildPanel() {
  return EnhanceExpansionPanelList(
    expansionCallback: (int index, bool isExpanded) {
      setState(() {
        _data[index].isExpanded = !isExpanded;
      });
    },
    children: _data.map<EnhanceExpansionPanel>((Item item) {
      return EnhanceExpansionPanel(
        headerBuilder: (BuildContext context, bool isExpanded) {
          return ListTile(
            title: Text(item.headerValue),
          );
        },
        body: ListTile(
          title: Text(item.expandedValue),
          subtitle: const Text('To delete this panel, tap the trash can icon'),
          trailing: const Icon(Icons.delete),
          onTap: () {
            setState(() {
              _data.removeWhere((Item currentItem) => item == currentItem);
            });
          }
        ),
        isExpanded: item.isExpanded,
      );
    }).toList(),
  );
}

{@end-tool}

See also:

Inheritance

Constructors

EnhanceExpansionPanelList({Key? key, List<EnhanceExpansionPanel> children = const <EnhanceExpansionPanel>[], ExpansionPanelCallback? expansionCallback, Duration animationDuration = kThemeAnimationDuration, EdgeInsets expandedHeaderPadding = _kPanelHeaderExpandedDefaultPadding, Color? dividerColor, double elevation = 2, double materialGapSize = 16.0})
Creates an expansion panel list widget. The expansionCallback is triggered when an expansion panel expand/collapse button is pushed.
const
EnhanceExpansionPanelList.radio({Key? key, List<EnhanceExpansionPanel> children = const <EnhanceExpansionPanelRadio>[], ExpansionPanelCallback? expansionCallback, Duration animationDuration = kThemeAnimationDuration, Object? initialOpenPanelValue, EdgeInsets expandedHeaderPadding = _kPanelHeaderExpandedDefaultPadding, Color? dividerColor, double elevation = 2, double materialGapSize = 16})
Creates a radio expansion panel list widget.
const

Properties

animationDuration → Duration
The duration of the expansion animation.
final
children → List<EnhanceExpansionPanel>
The children of the expansion panel list. They are laid out in a similar fashion to ListBody.
final
dividerColor → Color?
Defines color for the divider when EnhanceExpansionPanel.isExpanded is false.
final
elevation → double
Defines elevation for the EnhanceExpansionPanel while it's expanded.
final
expandedHeaderPadding → EdgeInsets
The padding that surrounds the panel header when expanded.
final
expansionCallback → ExpansionPanelCallback?
The callback that gets called whenever one of the expand/collapse buttons is pressed. The arguments passed to the callback are the index of the pressed panel and whether the panel is currently expanded or not.
final
hashCode → int
The hash code for this object.
no setterinherited
initialOpenPanelValue → Object?
The value of the panel that initially begins open. (This value is only used when initializing with the EnhanceExpansionPanelList.radio constructor.)
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
materialGapSize → double
Defines the MaterialGap.size of the MaterialGap which is placed between the ExpansionPanelList.children when they're expanded.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<StatefulWidget>
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