A widget that insets its child by the given padding.

When passing layout constraints to its child, padding shrinks the constraints by the given padding, causing the child to layout at a smaller size. Padding then sizes itself to its child's size, inflated by the padding, effectively creating empty space around the child.

Design discussion

Why use a Padding widget rather than a Container with a Container.padding property?

There isn't really any difference between the two. If you supply a Container.padding argument, Container simply builds a Padding widget for you.

Container doesn't implement its properties directly. Instead, Container combines a number of simpler widgets together into a convenient package. For example, the Container.padding property causes the container to build a Padding widget and the Container.decoration property causes the container to build a DecoratedBox widget. If you find Container convenient, feel free to use it. If not, feel free to build these simpler widgets in whatever combination meets your needs.

In fact, the majority of widgets in Flutter are simply combinations of other simpler widgets. Composition, rather than inheritance, is the primary mechansim for building up widgets.

Inheritance

Constructors

Padding({Key key, EdgeInsets padding, Widget child })

Creates a widget that insets its child.

const

Properties

padding EdgeInsets

The amount of space by which to inset the child.

final
child Widget

The widget below this widget in the tree.

final, inherited
hashCode int

The hash code for this object.

read-only, inherited
key Key

Controls how one widget replaces another widget in the tree.

final, inherited
runtimeType Type

A representation of the runtime type of the object.

read-only, inherited

Methods

createRenderObject(BuildContext context) RenderPadding

Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.

updateRenderObject(BuildContext context, RenderPadding 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.

createElement() SingleChildRenderObjectElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

inherited
debugFillDescription(List<String> description) → void

Add additional information to the given description for use by toString.

@mustCallSuper, @protected, 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.

@protected, 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

Operators

operator ==(other) bool

The equality operator.

inherited