OverflowBar class Null safety
A widget that lays out its children in a row unless they "overflow" the available horizontal space, in which case it lays them out in a column instead.
This widget's width will expand to contain its children and the specified spacing until it overflows. The overflow column will consume all of the available width. The overflowAlignment defines how each child will be aligned within the overflow column and the overflowSpacing defines the gap between each child.
The order that the children appear in the horizontal layout is defined by the textDirection, just like the Row widget. If the layout overflows, then children's order within their column is specified by overflowDirection instead.
This example defines a simple approximation of a dialog
layout, where the layout of the dialog's action buttons are
defined by an OverflowBar. The content is wrapped in a
SingleChildScrollView, so that if overflow occurs, the
action buttons will still be accessible by scrolling,
no matter how much vertical space is available.
To create a local project with this code sample, run:
flutter create --sample=widgets.OverflowBar.1 mysample
flutter create --sample=widgets.OverflowBar.1 mysample
- Inheritance
Constructors
-
OverflowBar({Key? key, double spacing = 0.0, MainAxisAlignment? alignment, double overflowSpacing = 0.0, OverflowBarAlignment overflowAlignment = OverflowBarAlignment.start, VerticalDirection overflowDirection = VerticalDirection.down, TextDirection? textDirection, Clip clipBehavior = Clip.none, List<
Widget> children = const <Widget>[]}) - Constructs an OverflowBar.
Properties
- alignment → MainAxisAlignment?
-
Defines the children's horizontal layout according to the same
rules as for Row.mainAxisAlignment.
final
-
children
→ List<
Widget> -
The widgets below this widget in the tree.
finalinherited
- clipBehavior → Clip
-
The content will be clipped (or not) according to this option.
final
- hashCode → int
- The hash code for this object.
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- overflowAlignment → OverflowBarAlignment
-
The horizontal alignment of the children within the vertical
"overflow" layout.
final
- overflowDirection → VerticalDirection
-
Defines the order that the children appear in, if
the horizontal layout overflows.
final
- overflowSpacing → double
-
The height of the gap between children in the vertical
"overflow" layout.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- spacing → double
-
The width of the gap between children for the default
horizontal layout.
final
- textDirection → TextDirection?
-
Determines the order that the children appear in for the default
horizontal layout, and the interpretation of
OverflowBarAlignment.start and OverflowBarAlignment.end for
the vertical overflow layout.
final
Methods
-
createElement(
) → MultiChildRenderObjectElement -
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
-
createRenderObject(
BuildContext context) → RenderObject -
Creates an instance of the RenderObject class that this
RenderObjectWidget represents, using the configuration described by this
RenderObjectWidget.
override
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of
DiagnosticsNode
objects describing this node's children.protected">@protectedinherited -
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
override
-
didUnmountRenderObject(
covariant RenderObject renderObject) → void -
A render object previously associated with this widget has been removed
from the tree. The given RenderObject will be of the same type as
returned by this object's createRenderObject.
protected">@protectedinherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent 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
-
updateRenderObject(
BuildContext context, covariant RenderObject renderObject) → void -
Copies the configuration described by this RenderObjectWidget to the
given RenderObject, which will be of the same type as returned by this
object's createRenderObject.
override
Operators
-
operator ==(
Object other) → bool -
The equality operator.
nonVirtual">@nonVirtualinherited