ExpansionElementWidget class

A single-line ListTile with a trailing button that expands or collapses the tile to reveal or hide the children.

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 to enable the ExpansionElementWidget to save and restore its expanded state when it is scrolled in and out of view.

See also:

• ListTile, useful for creating expansion tile children when the expansion tile represents a sublist.
• The "Expand/collapse" section of material.io/guidelines/components/lists-controls.html.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatefulWidget
• ExpansionElementWidget

Constructors

ExpansionElementWidget({Key? key, String title = "", String? subtitle, Color? backgroundColor, ValueChanged<bool>? onExpansionChanged, List<Widget> children = const <Widget>[], bool initiallyExpanded = false, String? deleteText, VoidCallback? callback, SantoFormItemConfig? themeData})

Creates a single-line ListTile with a trailing button that expands or collapses the tile to reveal or hide the children. The initiallyExpanded property must be non-null.

Properties

backgroundColor → Color?

The color to display behind the sublist when expanded.

final

callback → VoidCallback?

final

children → List<Widget>

The widgets that are displayed when the tile expands.

final

deleteText → String?

final

hashCode → int

The hash code for this object.

no setter, inherited

initiallyExpanded → bool

Specifies if the list tile is initially expanded (true) or collapsed (false, the default).

final

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

onExpansionChanged → ValueChanged<bool>?

Called when the tile expands or collapses.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

subtitle → String?

Additional content displayed below the title.

final

themeData ↔ SantoFormItemConfig?

getter/setter pair

title → String

The primary content of the list item.

final

Methods

createElement() → StatefulElement

Creates a StatefulElement to manage this widget's location in the tree.

inherited

createState() → _ExpansionElementState

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