ConditionalStickyBottomBarVisibility class

A widget that animates the visibility of the child based on a condition.

Intended to be used as the SheetContentScaffold.bottomBar.

The getIsVisible callback is called whenever the sheet metrics changes. Returning true keeps the child visible regardless of the sheet position, and false hides it with an animation which has the duration and the curve.

The following example shows the ConditionalStickyBottomBarVisibility, which keeps the enclosed BottomAppBar visible as long as the keyboard is hidden (insets.bottom == 0) and at least 50% of the sheet is visible.

final scaffold = SheetContentScaffold(
  body: SizedBox.expand(),
  bottomBar: ConditionalStickyBottomBarVisibility(
    getIsVisible: (metrics) =>
        metrics.viewportInsets.bottom == 0 &&
        metrics.pixels >
            const Extent.proportional(0.5)
                .resolve(metrics.contentSize),
    child: BottomAppBar(),
  ),
);
Inheritance
Implemented types

Constructors

ConditionalStickyBottomBarVisibility({Key? key, required bool getIsVisible(SheetMetrics), Duration duration = const Duration(milliseconds: 150), Curve curve = Curves.easeInOut, required Widget? child})
Creates a widget that animates the visibility of the child based on a condition.
const

Properties

child → Widget?
The widget to manage the visibility of.
final
curve → Curve
The curve of the visibility animation.
final
duration → Duration
The duration of the visibility animation.
final
getIsVisible → bool Function(SheetMetrics)
Whether the child should be visible.
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

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