Dart Documentationbot_retainedImgElement

ImgElement class

class ImgElement extends PElement {
  final ImageElement _image;

  bool _waitingOnLoad = false;

  factory ImgElement.fromUrl(String src, num w, num h) {
    final img = new ImageElement(src, null, null);

    return new ImgElement(w, h, img);
  }

  ImgElement(num width, num height, this._image, [bool cacheEnabled = false]) :
    super(width, height, cacheEnabled);

  void drawOverride(CanvasRenderingContext2D ctx) {
    if(_image.complete) {
      _doDraw(ctx);
    } else if(!_waitingOnLoad) {
      _waitingOnLoad = true;
      // TODO: some day we'll have a way to remove these cleanly
      //       ...because this handled should be disposed :-/
      _image.on.load.add(_onImageLoad);
    }
  }

  void _doDraw(CanvasRenderingContext2D ctx) {
    ctx.drawImage(_image, 0, 0, width, height);
  }

  void _onImageLoad(Event event) {
    invalidateDraw();
    // TODO: should unwire event, here, too
  }
}

Extends

DisposableImpl > AttachableObject > PElement > ImgElement

Subclasses

SpriteElement

Constructors

new ImgElement(num width, num height, ImageElement _image, [bool cacheEnabled = false]) #

ImgElement(num width, num height, this._image, [bool cacheEnabled = false]) :
  super(width, height, cacheEnabled);

factory ImgElement.fromUrl(String src, num w, num h) #

factory ImgElement.fromUrl(String src, num w, num h) {
  final img = new ImageElement(src, null, null);

  return new ImgElement(w, h, img);
}

Properties

final bool cacheEnabled #

inherited from PElement
final bool cacheEnabled;

bool clip #

inherited from PElement
bool clip = false;

num height #

inherited from PElement
num get height => _height;
void set height(num value) {
  assert(isValidNumber(value));
  _height = value;
  invalidateDraw();
}

final EventRoot<EventArgs> invalidated #

inherited from PElement
EventRoot<EventArgs> get invalidated => _invalidatedEventHandle;

final bool isDisposed #

inherited from DisposableImpl
bool get isDisposed => _disposed;

final ElementParent parent #

inherited from PElement
ElementParent get parent => _parent;

final Type runtimeType #

inherited from Object

A representation of the runtime type of the object.

external Type get runtimeType;

Size size #

inherited from PElement
Size get size => new Size(_width, _height);
void set size(Size value) {
  assert(value.isValid);
  _width = value.width;
  _height = value.height;
  invalidateDraw();
}

num width #

inherited from PElement
num get width => _width;
void set width(num value) {
  assert(isValidNumber(value));
  _width = value;
  invalidateDraw();
}

Operators

bool operator ==(other) #

inherited from Object

The equality operator.

The default behavior for all Objects is to return true if and only if this and other are the same object.

If a subclass overrides the equality operator it should override the hashCode method as well to maintain consistency.

bool operator ==(other) => identical(this, other);

Methods

AffineTransform addTransform() #

inherited from PElement
AffineTransform addTransform(){
  validateNotDisposed();
  var tx = new AffineTransform();
  _transforms.add(tx);
  return tx;
}

void dispose() #

inherited from DisposableImpl
void dispose(){
  if (!_disposed) {
    // Set disposed_ to true first, in case during the chain of disposal this
    // gets disposed recursively.
    this._disposed = true;
    this.disposeInternal();
  }
}

void disposeInternal() #

inherited from PElement

Do not call this method directly. Call dispose instead. Subclasses should override this method to implement Disposable behavior.

docs inherited from DisposableImpl
void disposeInternal(){
  super.disposeInternal();
  _invalidatedEventHandle.dispose();
}

void drawCore(CanvasRenderingContext2D ctx) #

inherited from PElement
void drawCore(CanvasRenderingContext2D ctx){
  if(cacheEnabled) {
    _drawCached(ctx);
  } else {
    _drawNormal(ctx);
  }
}

void drawOverride(CanvasRenderingContext2D ctx) #

void drawOverride(CanvasRenderingContext2D ctx) {
  if(_image.complete) {
    _doDraw(ctx);
  } else if(!_waitingOnLoad) {
    _waitingOnLoad = true;
    // TODO: some day we'll have a way to remove these cleanly
    //       ...because this handled should be disposed :-/
    _image.on.load.add(_onImageLoad);
  }
}

AffineTransform getTransform() #

inherited from PElement
AffineTransform getTransform() {
  var tx = new AffineTransform();
  _transforms.forEach(tx.concatenate);
  return tx;
}

AffineTransform getTransformToRoot() #

inherited from PElement
AffineTransform getTransformToRoot(){
  var tx = new AffineTransform();
  if(_parent != null){
    tx.concatenate(_parent.getTransformToRoot());
  }
  tx.concatenate(getTransform());
  return tx;
}

int hashCode() #

inherited from Object

Get a hash code for this object.

All objects have hash codes. Hash codes are guaranteed to be the same for objects that are equal when compared using the equality operator ==. Other than that there are no guarantees about the hash codes. They will not be consistent between runs and there are no distribution guarantees.

If a subclass overrides hashCode it should override the equality operator as well to maintain consistency.

external int hashCode();

new ImgElement(num width, num height, ImageElement _image, [bool cacheEnabled = false]) #

ImgElement(num width, num height, this._image, [bool cacheEnabled = false]) :
  super(width, height, cacheEnabled);

factory ImgElement.fromUrl(String src, num w, num h) #

factory ImgElement.fromUrl(String src, num w, num h) {
  final img = new ImageElement(src, null, null);

  return new ImgElement(w, h, img);
}

void invalidateDraw() #

inherited from PElement
void invalidateDraw(){
  validateNotDisposed();
  if(_lastDrawSize != null){
    _lastDrawSize = null;
    _invalidateParent();
  }
}

noSuchMethod(String name, List args) #

inherited from Object

noSuchMethod is invoked when users invoke a non-existant method on an object. The name of the method and the arguments of the invocation are passed to noSuchMethod. If noSuchMethod returns a value, that value becomes the result of the original invocation.

The default behavior of noSuchMethod is to throw a noSuchMethodError.

external Dynamic noSuchMethod(String name, List args);

const Object() #

inherited from Object

Creates a new Object instance.

Object instances have no meaningful state, and are only useful through their identity. An Object instance is equal to itself only.

const Object();

new PElement(num _width, num _height, [bool cacheEnabled = false]) #

inherited from PElement
PElement(this._width, this._height, [this.cacheEnabled = false]);

void registerParent(ElementParent parent) #

inherited from PElement
void registerParent(ElementParent parent) {
  assert(_parent == null);
  assert(parent != null);
  _parent = parent;
}

String toString() #

inherited from Object

Returns a string representation of this object.

external String toString();

void update() #

inherited from PElement
void update(){ }

void validateNotDisposed() #

inherited from DisposableImpl
void validateNotDisposed() {
  assert(!_disposed);
}