Builds a widget tree that can depend on the parent widget's size.
Similar to the Builder widget except that the framework calls the builder function at layout time and provides the parent widget's constraints. This is useful when the parent constrains the child's size and doesn't depend on the child's intrinsic size. The LayoutBuilder's final size will match its child's size.
If the child should be smaller than the parent, consider wrapping the child in an Align widget. If the child might want to be bigger, consider wrapping it in a ScrollableViewport.
See also:
- Builder, which calls a
builderfunction at build time. - StatefulBuilder, which passes its
builderfunction asetStatecallback. - CustomSingleChildLayout, which positions its child during layout.
- Inheritance
- Object
- Widget
- RenderObjectWidget
- LayoutBuilder
Constructors
- LayoutBuilder({Key key, @required LayoutWidgetBuilder builder })
-
Creates a widget that defers its building until layout.
Properties
- builder → LayoutWidgetBuilder
-
Called at layout time to construct the widget tree. The builder must not return null.
read-only - hashCode → int
-
Get a hash code for this object.
read-only, inherited - key → Key
-
Controls how one widget replaces another widget in the tree.
read-only, inherited - runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Operators
-
operator ==(
other) → bool -
The equality operator.
inherited
Methods
-
createElement(
) → _LayoutBuilderElement -
RenderObjectWidgets always inflate to a
RenderObjectElementsubclass. -
createRenderObject(
BuildContext context) → _RenderLayoutBuilder -
Creates an instance of the
RenderObjectclass that thisRenderObjectWidgetrepresents, using the configuration described by thisRenderObjectWidget. -
debugFillDescription(
List<String> description) → void -
Add additional information to the given description for use by toString.
inherited -
didUnmountRenderObject(
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.
inherited -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited -
toString(
) → String -
Returns a string representation of this object.
inherited -
toStringShort(
) → String -
A short, textual description of this widget.
inherited -
updateRenderObject(
BuildContext context, 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.
inherited