TransformModifier class

A widget that applies a transformation before painting its child.

Unlike RotatedBox, which applies a rotation prior to layout, this object applies its transformation just prior to painting, which means the transformation is not taken into account when calculating how much space this widget's child (and thus this widget) consumes.

{@tool snippet}

This example rotates and skews an orange box containing text, keeping the top right corner pinned to its original position.

Container(
  color: Colors.black,
  child: Transform(
    alignment: Alignment.topRight,
    transform: Matrix4.skewY(0.3)..rotateZ(-math.pi / 12.0),
    child: Container(
      padding: const EdgeInsets.all(8.0),
      color: const Color(0xFFE8581C),
      child: const Text('Apartment for rent!'),
    ),
  ),
)

{@end-tool}

See also:

• RotatedBox, which rotates the child widget during layout, not just during painting.
• FractionalTranslation, which applies a translation to the child that is relative to the child's size.
• FittedBox, which sizes and positions its child widget to fit the parent according to a given BoxFit discipline.
• The catalog of layout widgets.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• SingleChildStatelessModifier
• TransformModifier

Available extensions

• ModifierTransformer

Constructors

TransformModifier({Key? key, Widget? child, Key? modifierKey, required Matrix4 transform, Offset? origin, AlignmentGeometry? alignment, bool transformHitTests = true, FilterQuality? filterQuality})

Creates a widget that transforms its child.

const

TransformModifier.rotate({Key? key, Widget? child, Key? modifierKey, required double angle, Offset? origin, AlignmentGeometry? alignment = Alignment.center, bool transformHitTests = true, FilterQuality? filterQuality})

Creates a widget that transforms its child using a rotation around the center.

TransformModifier.scale({Key? key, Widget? child, Key? modifierKey, double? scale, double? scaleX, double? scaleY, Offset? origin, AlignmentGeometry? alignment = Alignment.center, bool transformHitTests = true, FilterQuality? filterQuality})

Creates a widget that scales its child along the 2D plane.

TransformModifier.translate({Key? key, Widget? child, Key? modifierKey, required Offset offset, bool transformHitTests = true, FilterQuality? filterQuality})

Creates a widget that transforms its child using a translation.

Properties

alignment → AlignmentGeometry?

The alignment of the origin, relative to the size of the box.

final

filterQuality → FilterQuality?

The filter quality with which to apply the transform as a bitmap operation.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

modifierKey → Key?

The actual key of the widget, which Modifier wrapped

final, inherited

origin → Offset?

The origin of the coordinate system (relative to the upper left corner of this render object) in which to apply the matrix.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

transform → Matrix4

The matrix to transform the child by during painting.

final

transformHitTests → bool

Whether to apply the transformation when performing hit tests.

final

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

inherited

buildWithChild(BuildContext context, Widget? child) → Widget

A build method that receives an extra child parameter.

override

createElement() → SingleChildStatelessElement

Create a SingleChildStatelessElement

inherited

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

inherited

modified() → Modifier

Available on Widget, provided by the ModifierTransformer extension

Transform normal widget to Modifier

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent 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, int wrapWidth = 65}) → 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

Operators

operator ==(Object other) → bool

The equality operator.

inherited