Interface OffscreenCanvas

When using the canvas element or the Canvas API, rendering, animation, and user interaction usually happen on the main execution thread of a web application.

MDN Reference

interface OffscreenCanvas {
    height: number;
    oncontextlost: ((this: OffscreenCanvas, ev: Event) => any) | null;
    oncontextrestored: ((this: OffscreenCanvas, ev: Event) => any) | null;
    width: number;
    addEventListener<K extends keyof OffscreenCanvasEventMap>(
        type: K,
        listener: (this: OffscreenCanvas, ev: OffscreenCanvasEventMap[K]) => any,
        options?: boolean | AddEventListenerOptions,
    ): void;
    addEventListener(
        type: string,
        listener: EventListenerOrEventListenerObject,
        options?: boolean | AddEventListenerOptions,
    ): void;
    convertToBlob(options?: ImageEncodeOptions): Promise<Blob>;
    dispatchEvent(event: Event): boolean;
    getContext(
        contextId: "2d",
        options?: any,
    ): OffscreenCanvasRenderingContext2D | null;
    getContext(
        contextId: "bitmaprenderer",
        options?: any,
    ): ImageBitmapRenderingContext | null;
    getContext(contextId: "webgl", options?: any): WebGLRenderingContext | null;
    getContext(
        contextId: "webgl2",
        options?: any,
    ): WebGL2RenderingContext | null;
    getContext(
        contextId: OffscreenRenderingContextId,
        options?: any,
    ): OffscreenRenderingContext | null;
    removeEventListener<K extends keyof OffscreenCanvasEventMap>(
        type: K,
        listener: (this: OffscreenCanvas, ev: OffscreenCanvasEventMap[K]) => any,
        options?: boolean | EventListenerOptions,
    ): void;
    removeEventListener(
        type: string,
        listener: EventListenerOrEventListenerObject,
        options?: boolean | EventListenerOptions,
    ): void;
    transferToImageBitmap(): ImageBitmap;
}
Hierarchy
  • EventTarget
    • OffscreenCanvas
Index

Properties

height oncontextlost oncontextrestored width

Methods

addEventListener convertToBlob dispatchEvent getContext removeEventListener transferToImageBitmap

Properties

height: number

The height property returns and sets the height of an OffscreenCanvas object.

MDN Reference

oncontextlost: ((this: OffscreenCanvas, ev: Event) => any) | null

MDN Reference

oncontextrestored: ((this: OffscreenCanvas, ev: Event) => any) | null

MDN Reference

width: number

The width property returns and sets the width of an OffscreenCanvas object.

MDN Reference

Methods

  • The OffscreenCanvas.convertToBlob() method creates a Blob object representing the image contained in the canvas.

    MDN Reference

    Parameters

    Returns Promise<Blob>

  • The dispatchEvent() method of the EventTarget sends an Event to the object, (synchronously) invoking the affected event listeners in the appropriate order.

    MDN Reference

    Parameters

    • event: Event

    Returns boolean

  • The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener() from the target.

    MDN Reference

    Type Parameters

    Parameters

    Returns void

  • The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener() from the target.

    MDN Reference

    Parameters

    Returns void

  • The OffscreenCanvas.transferToImageBitmap() method creates an ImageBitmap object from the most recently rendered image of the OffscreenCanvas.

    MDN Reference

    Returns ImageBitmap

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Properties
Methods