DisposableLazyIndexedStack class

A custom version of IndexedStack that lazily builds child widgets and disposes previous children once they are replaced.

⚠️ This widget holds and shows only one child at a time. Each time the index changes:

  • The widget at the new index is rebuilt via its builder.
  • The previously shown widget is discarded and no longer kept in memory.
  • Any StatefulWidget that was replaced will be fully disposed, as it is removed from the widget tree.

Use Cases:

  • Ideal for tab views or navigation where only one view is needed at a time.
  • Useful when you want to avoid building all children upfront (unlike IndexedStack).
  • Automatically handles memory management by discarding previous screens.

Limitation:

  • Previously shown widgets are not cached. If the user returns to a previous tab, it will be rebuilt from scratch.

Example Usage:

DisposableLazyIndexedStack(
  index: currentTabIndex,
  builders: [
    (_) => DashboardView(),
    (_) => ProfileView(),
    (_) => SettingsView(),
  ],
)
Inheritance

Constructors

DisposableLazyIndexedStack({Key? key, required int index, required List<WidgetBuilder> builders})
const

Properties

builders → List<WidgetBuilder>
List of widget builders (like children), where each builder is responsible for creating the widget when its index is selected.
final
hashCode → int
The hash code for this object.
no setterinherited
index → int
The index of the child widget to display. Changing this will dispose the previous child and build a new one from builders.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
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<DisposableLazyIndexedStack>
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