PrependLoadStateBuilder<PageKey, Value> class
A widget that builds a custom UI at the start of the list (prepend) based on the DataSource's loading state.
It provides hasMore and isLoading states to the builder, allowing you to:
- Show a button only when
hasMoreis true. - Disable the button when
isLoadingis true.
Example:
PrependLoadStateBuilder(
dataSource: dataSource,
builder: (context, hasMore, isLoading) {
// If there is no more data, show nothing.
if (!hasMore) {
return const SizedBox.shrink();
}
// Show a manual trigger button.
// Disable it while loading to prevent double-tapping.
return FilledButton(
onPressed: isLoading ? null : () => dataSource.prepend(),
child: const Text('Load Previous'),
);
},
)
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatelessWidget
- PrependLoadStateBuilder
Constructors
-
PrependLoadStateBuilder({Key? key, required DataSource<
PageKey, Value> dataSource, required Widget builder(BuildContext context, bool hasMore, bool isLoading)}) -
Creates a PrependLoadStateBuilder.
const
Properties
- builder → Widget Function(BuildContext context, bool hasMore, bool isLoading)
-
A builder function that constructs the widget based on the current state.
final
-
dataSource
→ DataSource<
PageKey, Value> -
The DataSource to listen to for paging state changes.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- 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
-
build(
BuildContext context) → Widget -
Describes the part of the user interface represented by this widget.
override
-
createElement(
) → StatelessElement -
Creates a StatelessElement to manage this widget's location in the tree.
inherited
-
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