ParticleField class

ParticleField lets you add custom particle effects anywhere in your Flutter application easily. Simply provide a SpriteSheet (or ImageFrameProvider) and an onTick handler that manages your Particle list.

ParticleField field = ParticleField(
  spriteSheet: sparkleSpriteSheet,
  // top left will be 0,0:
  origin: Alignment.topLeft,
  // onTick is where all the magic happens:
  onTick: (controller, elapsed, size) {
    List<Particle> particles = controller.particles;
    // add a new particle each frame:
    particles.add(Particle(x: rnd(size.width), vx: rnd(-1, 1)));
    // update existing particles:
    for (int i = particles.length - 1; i >= 0; i--) {
      Particle particle = particles[i];
      // call update, which automatically adds vx/vy to x/y
      // add some gravity (ie. increase vertical velocity)
      // and increment the frame
      particle.update(vy: particle.vy + 0.1, frame: particle.frame + 1);
      // remove particle if it's out of bounds:
      if (!size.contains(particle.toOffset())) particles.removeAt(i);
    }
  },
)
Inheritance

Constructors

ParticleField({required ImageFrameProvider spriteSheet, required ParticleFieldTick onTick, ParticleFieldInit? onInit, BlendMode blendMode = BlendMode.srcIn, Alignment origin = Alignment.center, Alignment anchor = Alignment.center, Key? key})
const

Properties

anchor → Alignment
Specifies the anchor point (ie. where x=0, y=0) for the particles. This is the point around which the particle rotates, and from which it is drawn.
final
blendMode → BlendMode
The BlendMode to use when compositing Particle.color with the particle frame image. Defaults to BlendMode.srcIn.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onInit → ParticleFieldInit?
Called when the ParticleController first initializes. This provides an opportunity to perform setup functions, like pre-populating the particle list with initial particles.
final
onTick → ParticleFieldTick
Called each frame immediately before _ParticleFieldPainter renders the particles. This is where logic to add, remove, and update your particles will normally live.
final
origin → Alignment
Specifies the origin point (ie. where x=0, y=0) of the particle field's coordinate system. For example, Alignment.center would position the origin in the middle of the field, Alignment.topLeft would set the origin at the top left.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
spriteSheet → ImageFrameProvider
Provides the image frames for this particle system. See SpriteSheet.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<ParticleField>
Creates the mutable state for this widget at a given location in the tree.
override
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
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
stackAbove({double scale = 1.0, required Widget child}) → Widget
A convenience function that layers this ParticleField in front of the specified child, sizes it to match, and optionally scales it (this can be useful for providing an "overscan" region).
stackBelow({double scale = 1.0, required Widget child}) → Widget
A convenience function that layers this ParticleField behind the specified child, sizes it to match, and optionally scales it (this can be useful for providing an "overscan" region).
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}) → 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