Class ImageCanvas

A function that is called to trigger asynchronous canvas drawing. It is called with a "done" callback that should be called when drawing is done. If any error occurs during drawing, the "done" callback should be called with that error.

Hierarchy (view full)

Constructors

constructor

Properties

disposed extent loader resolution state

Methods

addEventListener changed dispatchEvent dispose disposeInternal getError getExtent getImage getListeners getPixelRatio getResolution getState hasListener load removeEventListener setImage setResolution

Constructors

constructor

  • new ImageCanvas(extent, resolution, pixelRatio, canvas, loader?): external.ol.ImageCanvas

  • Parameters

    • extent: Extent

      Extent.

    • resolution: number

      Resolution.

    • pixelRatio: number

      Pixel ratio.

    • canvas: HTMLCanvasElement

      Canvas.

    • Optional loader: Loader

      Optional loader function to support asynchronous canvas drawing.

    Returns external.ol.ImageCanvas

Properties

Protected disposed

disposed: boolean

The object has already been disposed.

Protected extent

extent: Extent

Protected loader

loader: Loader

Protected resolution

resolution: undefined | number | number[]

Protected state

state: any

Methods

addEventListener

  • addEventListener(type, listener): void

  • Parameters

    • type: string

      Type.

    • listener: Listener

      Listener.

    Returns void

Protected changed

  • changed(): void
  • Protected

    Returns void

dispatchEvent

  • dispatchEvent(event): undefined | boolean

  • Dispatches an event and calls all listeners listening for events of this type. The event parameter can either be a string or an Object with a type property.

    Parameters

    • event: string | BaseEvent

      Event object.

    Returns undefined | boolean

    false if anyone called preventDefault on the event object or if any of the listeners returned false.

    Api

dispose

  • dispose(): void

  • Clean up.

    Returns void

Protected disposeInternal

  • disposeInternal(): void
  • Protected

    Extension point for disposable objects.

    Returns void

getError

  • getError(): null | Error

  • Get any error associated with asynchronous rendering.

    Returns null | Error

    Any error that occurred during rendering.

getExtent

  • getExtent(): Extent

  • Returns Extent

    Extent.

getImage

  • getImage(): HTMLCanvasElement

  • Returns HTMLCanvasElement

    Canvas element.

getListeners

  • getListeners(type): undefined | Listener[]

  • Get the listeners for a specified event type. Listeners are returned in the order that they will be called in.

    Parameters

    • type: string

      Type.

    Returns undefined | Listener[]

    Listeners.

getPixelRatio

  • getPixelRatio(): number

  • Returns number

    PixelRatio.

getResolution

  • getResolution(): number | number[]

  • Returns number | number[]

    Resolution.

getState

  • getState(): any

  • Returns any

    State.

hasListener

  • hasListener(type?): boolean

  • Parameters

    • Optional type: string

      Type. If not provided, true will be returned if this event target has any listeners.

    Returns boolean

    Has listeners.

load

  • load(): void

  • Load not yet loaded URI.

    Returns void

removeEventListener

  • removeEventListener(type, listener): void

  • Parameters

    • type: string

      Type.

    • listener: Listener

      Listener.

    Returns void

setImage

  • setImage(image): void

  • Parameters

    • image: ImageLike

      The image.

    Returns void

setResolution

  • setResolution(resolution): void

  • Parameters

    • resolution: number | number[]

      Resolution.

    Returns void

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