CustomMultiChildLayout class Null safety
A widget that uses a delegate to size and position multiple children.
The delegate can determine the layout constraints for each child and can decide where to position each child. The delegate can also determine the size of the parent, but the size of the parent cannot depend on the sizes of the children.
CustomMultiChildLayout is appropriate when there are complex relationships between the size and positioning of multiple widgets. To control the layout of a single child, CustomSingleChildLayout is more appropriate. For simple cases, such as aligning a widget to one or another edge, the Stack widget is more appropriate.
Each child must be wrapped in a LayoutId widget to identify the widget for the delegate.
It responds to changes in Directionality by re-laying out its children.
flutter create --sample=widgets.CustomMultiChildLayout.1 mysample
See also:
- MultiChildLayoutDelegate, for details about how to control the layout of the children.
- CustomSingleChildLayout, which uses a delegate to control the layout of a single child.
- Stack, which arranges children relative to the edges of the container.
- Flow, which provides paint-time control of its children using transform matrices.
- The catalog of layout widgets.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- RenderObjectWidget
- MultiChildRenderObjectWidget
- CustomMultiChildLayout
Constructors
-
CustomMultiChildLayout({Key? key, required MultiChildLayoutDelegate delegate, List<
Widget> children = const <Widget>[]}) - Creates a custom multi-child layout.
Properties
-
children
→ List<
Widget> -
The widgets below this widget in the tree.
finalinherited
- delegate → MultiChildLayoutDelegate
-
The delegate that controls the layout of the children.
final
- hashCode → int
- The hash code for this object.
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
Methods
-
createElement(
) → MultiChildRenderObjectElement -
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
-
createRenderObject(
BuildContext context) → RenderCustomMultiChildLayoutBox -
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.
inherited
-
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 RenderCustomMultiChildLayoutBox 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