LazyLoadRefreshIndicator class

A widget that supports the Material "swipe to refresh" idiom and lazy loading.

When the child's Scrollable descendant overscrolls at the top, an animated circular progress indicator is faded into view. When the scroll ends, if the indicator has been dragged far enough for it to become completely opaque, the onRefresh callback is called. The callback is expected to update the scrollable's contents and then complete the Future it returns. The refresh indicator disappears after the callback's Future has completed.

The trigger mode is configured by RefreshIndicator.triggerMode.

When the child's Scrollable descendant overscrolls at the end and the overscroll is higher than the scrollOffset the onEndOfPage callback is called.

A LazyLoadRefreshIndicator can only be used with a vertical scroll view.

Inheritance

Constructors

LazyLoadRefreshIndicator({Key? key, required Widget child, required VoidCallback onEndOfPage, required RefreshCallback onRefresh, int scrollOffset = 100, bool isLoading = false, double displacement = 40.0, Color? color, Color? backgroundColor, ScrollNotificationPredicate notificationPredicate = defaultScrollNotificationPredicate, String? semanticsLabel, String? semanticsValue, double strokeWidth = 2.0, RefreshIndicatorTriggerMode triggerMode = RefreshIndicatorTriggerMode.onEdge})
Creates a lazy load refresh indicator.
const

Properties

backgroundColor → Color?
The progress indicator's background color. The current theme's ThemeData.canvasColor by default.
final
child → Widget
The widget below this widget in the tree.
final
color → Color?
The progress indicator's foreground color. The current theme's ThemeData.accentColor by default.
final
displacement → double
The distance from the child's top or bottom edge to where the refresh indicator will settle. During the drag that exposes the refresh indicator, its actual displacement may significantly exceed this value.
final
hashCode → int
The hash code for this object.
no setterinherited
isLoading → bool
Used to determine if loading of new data has finished. You should use set this if you aren't using a FutureBuilder or StreamBuilder
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
notificationPredicate → ScrollNotificationPredicate
A check that specifies whether a ScrollNotification should be handled by this widget.
final
onEndOfPage → VoidCallback
Called when the child reaches the end of the list
final
onRefresh → RefreshCallback
A function that's called when the user has dragged the refresh indicator far enough to demonstrate that they want the app to refresh. The returned Future must complete when the refresh operation is finished.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scrollOffset → int
The offset to take into account when triggering onEndOfPage in pixels
final
semanticsLabel → String?
The SemanticsProperties.label for this progress indicator.
final
semanticsValue → String?
The SemanticsProperties.value for this progress indicator.
final
strokeWidth → double
Defines strokeWidth for RefreshIndicator.
final
triggerMode → RefreshIndicatorTriggerMode
Defines how this RefreshIndicator can be triggered when users overscroll.
final

Methods

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