Decorator class

Decorator is an abstract class that encapsulates a particular visual effect that should apply to drawing commands wrapped by this class.

The simplest way to apply a Decorator to a component is to override its renderTree method like this:

@override
void renderTree(Canvas canvas) {
  decorator.applyChain(super.renderTree, canvas);
}

Decorators have ability to form a chain, where multiple decorators can be applied in a sequence. This chain is essentially a unary tree, or a linked list: each decorator knows only about the next decorator on the chain.

The following implementations are available:

• PaintDecorator
• Rotate3DDecorator
• Shadow3DDecorator
• Transform2DDecorator

Implementers

• PaintDecorator
• Rotate3DDecorator
• Shadow3DDecorator
• Transform2DDecorator

Constructors

Decorator()

Properties

hashCode → int

The hash code for this object.

no setter, inherited

isLastDecorator → bool

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

addLast(Decorator? decorator) → void

Adds a new decorator onto the chain of decorators

apply(void draw(Canvas), Canvas canvas) → void

Applies visual effect while drawing on the canvas.

applyChain(void draw(Canvas), Canvas canvas) → void

Applies this and all subsequent decorators if any.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

removeLast() → void

Removes the last decorator from the chain of decorators

replaceLast(Decorator? decorator) → void

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited