A widget that aligns its child within itself and optionally sizes itself based on the child's size.
For example, to align a box at the bottom right, you would pass this box a tight constraint that is bigger than the child's natural size, with an alignment of FractionalOffset.bottomRight.
This widget will be as big as possible if its dimensions are constrained and widthFactor and heightFactor are null. If a dimension is unconstrained and the corresponding size factor is null then the widget will match its child's size in that dimension. If a size factor is non-null then the corresponding dimension of this widget will be the product of the child's dimension and the size factor. For example if widthFactor is 2.0 then the width of this widget will always be twice its child's width.
See also:
- CustomSingleChildLayout, which uses a delegate to control the layout of a single child.
- Center, which is the same as Align but with the alignment always
set to
FractionalOffset.center. - FractionallySizedBox, which sizes its child based on a fraction of its own size and positions the child according to a FractionalOffset value.
- Inheritance
Constructors
Properties
- alignment → FractionalOffset
-
How to align the child.
read-only - heightFactor → double
-
If non-null, sets its height to the child's height multipled by this factor.
read-only - widthFactor → double
-
If non-null, sets its width to the child's width multipled by this factor.
read-only - child → Widget
-
The widget below this widget in the tree.
read-only, inherited - 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
-
createRenderObject(
BuildContext context) → RenderPositionedBox -
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. -
updateRenderObject(
BuildContext context, RenderPositionedBox renderObject) → void -
Copies the configuration described by this
RenderObjectWidgetto the givenRenderObject, which will be of the same type as returned by this object'screateRenderObject. -
createElement(
) → SingleChildRenderObjectElement -
RenderObjectWidgets always inflate to a
RenderObjectElementsubclass.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