Expansible class
A StatefulWidget that expands and collapses.
An Expansible consists of a header, which is always shown, and a body, which is hidden in its collapsed state and shown in its expanded state.
The Expansible is expanded or collapsed with an animation driven by an AnimationController. When the widget is expanded, the height of its body animates from 0 to its fully expanded height.
This widget is typically used with ListView to create an "expand / collapse" list entry. When used with scrolling widgets like ListView, a unique PageStorageKey must be specified as the key, to enable the Expansible to save and restore its expanded state when it is scrolled in and out of view.
Provide headerBuilder and bodyBuilder callbacks to build the header and body widgets. An additional expansibleBuilder callback can be provided to further customize the layout of the widget.
The Expansible does not inherently toggle the expansion state. To toggle the expansion state, call ExpansibleController.expand and ExpansibleController.collapse as needed, most typically when the header returned in headerBuilder is tapped.
See also:
- ExpansionTile, a Material-styled widget that expands and collapses.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- Expansible
Constructors
- Expansible({Key? key, required ExpansibleComponentBuilder headerBuilder, required ExpansibleComponentBuilder bodyBuilder, required ExpansibleController controller, ExpansibleBuilder expansibleBuilder = _defaultExpansibleBuilder, Duration duration = const Duration(milliseconds: 200), Curve curve = Curves.ease, Curve? reverseCurve, bool maintainState = true})
-
Creates an instance of Expansible.
const
Properties
- bodyBuilder → ExpansibleComponentBuilder
-
Builds the collapsible body.
final
- controller → ExpansibleController
-
Expands and collapses the widget.
final
- curve → Curve
-
The curve of the expansion animation.
final
- duration → Duration
-
The duration of the expansion animation.
final
- expansibleBuilder → ExpansibleBuilder
-
Builds the widget with the results of headerBuilder and bodyBuilder.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- headerBuilder → ExpansibleComponentBuilder
-
Builds the always-displayed header.
final
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- maintainState → bool
-
Whether the state of the body is maintained when the widget expands or
collapses.
final
- reverseCurve → Curve?
-
The reverse curve of the expansion animation.
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, int wrapWidth = 65}) → 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