Interface OffscreenCanvas

MDN Reference

Hierarchy

EventTarget
- OffscreenCanvas

Index

Properties

height oncontextlost oncontextrestored width

Methods

addEventListener convertToBlob dispatchEvent getContext removeEventListener transferToImageBitmap

Properties

height

height: number

These attributes return the dimensions of the OffscreenCanvas object's bitmap.

They can be set, to replace the bitmap with a new, transparent black bitmap of the specified dimensions (effectively resizing it).

MDN Reference

oncontextlost

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

Type declaration

- (this, ev): any
- Parameters
  - this: OffscreenCanvas
  - ev: Event
  Returns any

oncontextrestored

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

Type declaration

- (this, ev): any
- Parameters
  - this: OffscreenCanvas
  - ev: Event
  Returns any

width

width: number

These attributes return the dimensions of the OffscreenCanvas object's bitmap.

They can be set, to replace the bitmap with a new, transparent black bitmap of the specified dimensions (effectively resizing it).

MDN Reference

Methods

addEventListener

addEventListener<K>(type, listener, options?): void
Type Parameters
- K extends keyof OffscreenCanvasEventMap
Parameters
- type: K
- listener: ((this, ev) => any)
  - - (this, ev): any
    - Parameters
      this: OffscreenCanvas
      ev: OffscreenCanvasEventMap[K]
      Returns any
- Optional options: boolean | AddEventListenerOptions
Returns void
Overrides EventTarget.addEventListener
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16619
addEventListener(type, listener, options?): void
Parameters
- type: string
- listener: EventListenerOrEventListenerObject
- Optional options: boolean | AddEventListenerOptions
Returns void
Overrides EventTarget.addEventListener
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16620

convertToBlob

convertToBlob(options?): Promise<Blob>
Returns a promise that will fulfill with a new Blob object representing a file containing the image in the OffscreenCanvas object.

The argument, if provided, is a dictionary that controls the encoding options of the image file to be created. The type field specifies the file format and has a default value of "image/png"; that type is also used if the requested type isn't supported. If the image format supports variable quality (such as "image/jpeg"), then the quality field is a number in the range 0.0 to 1.0 inclusive indicating the desired quality level for the resulting image.

MDN Reference
Parameters
- Optional options: ImageEncodeOptions
Returns Promise<Blob>
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16598

dispatchEvent

dispatchEvent(event): boolean
Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

MDN Reference
Parameters
- event: Event
Returns boolean
Inherited from EventTarget.dispatchEvent
- Defined in node_modules/typescript/lib/lib.dom.d.ts:8215

getContext

getContext(contextId, options?): null | OffscreenCanvasRenderingContext2D
Returns an object that exposes an API for drawing on the OffscreenCanvas object. contextId specifies the desired API: "2d", "bitmaprenderer", "webgl", or "webgl2". options is handled by that API.

This specification defines the "2d" context below, which is similar but distinct from the "2d" context that is created from a canvas element. The WebGL specifications define the "webgl" and "webgl2" contexts. [WEBGL]

Returns null if the canvas has already been initialized with another context type (e.g., trying to get a "2d" context after getting a "webgl" context).

MDN Reference
Parameters
- contextId: "2d"
- Optional options: any
Returns null | OffscreenCanvasRenderingContext2D
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16608
getContext(contextId, options?): null | ImageBitmapRenderingContext
Parameters
- contextId: "bitmaprenderer"
- Optional options: any
Returns null | ImageBitmapRenderingContext
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16609
getContext(contextId, options?): null | WebGLRenderingContext
Parameters
- contextId: "webgl"
- Optional options: any
Returns null | WebGLRenderingContext
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16610
getContext(contextId, options?): null | WebGL2RenderingContext
Parameters
- contextId: "webgl2"
- Optional options: any
Returns null | WebGL2RenderingContext
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16611
getContext(contextId, options?): null | OffscreenRenderingContext
Parameters
- contextId: OffscreenRenderingContextId
- Optional options: any
Returns null | OffscreenRenderingContext
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16612

removeEventListener

removeEventListener<K>(type, listener, options?): void
Type Parameters
- K extends keyof OffscreenCanvasEventMap
Parameters
- type: K
- listener: ((this, ev) => any)
  - - (this, ev): any
    - Parameters
      this: OffscreenCanvas
      ev: OffscreenCanvasEventMap[K]
      Returns any
- Optional options: boolean | EventListenerOptions
Returns void
Overrides EventTarget.removeEventListener
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16621
removeEventListener(type, listener, options?): void
Parameters
- type: string
- listener: EventListenerOrEventListenerObject
- Optional options: boolean | EventListenerOptions
Returns void
Overrides EventTarget.removeEventListener
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16622

transferToImageBitmap

transferToImageBitmap(): ImageBitmap
Returns a newly created ImageBitmap object with the image in the OffscreenCanvas object. The image in the OffscreenCanvas object is replaced with a new blank image.

MDN Reference

Returns ImageBitmap
- Defined in node_modules/typescript/lib/lib.dom.d.ts:16618

Interface OffscreenCanvas

Hierarchy

Index

Properties

Methods

Properties

height

oncontextlost

Type declaration

Parameters

this: OffscreenCanvas

ev: Event

Returns any

oncontextrestored

Type declaration

Parameters

this: OffscreenCanvas

ev: Event

Returns any

width

Methods

addEventListener

Type Parameters

K extends keyof OffscreenCanvasEventMap

Parameters

type: K

listener: ((this, ev) => any)

Parameters

this: OffscreenCanvas

ev: OffscreenCanvasEventMap[K]

Returns any

Optional options: boolean | AddEventListenerOptions

Returns void

Parameters

type: string

listener: EventListenerOrEventListenerObject

Optional options: boolean | AddEventListenerOptions

Returns void

convertToBlob

Parameters

Optional options: ImageEncodeOptions

Returns Promise<Blob>

dispatchEvent

Parameters

event: Event

Returns boolean

getContext

Parameters

contextId: "2d"

Optional options: any

Returns null | OffscreenCanvasRenderingContext2D

Parameters

contextId: "bitmaprenderer"

Optional options: any

Returns null | ImageBitmapRenderingContext

Parameters

contextId: "webgl"

Optional options: any

Returns null | WebGLRenderingContext

Parameters

contextId: "webgl2"

Optional options: any

Returns null | WebGL2RenderingContext

Parameters

contextId: OffscreenRenderingContextId

Optional options: any

Returns null | OffscreenRenderingContext

removeEventListener

Type Parameters

K extends keyof OffscreenCanvasEventMap

Parameters

type: K

listener: ((this, ev) => any)

Parameters

this: OffscreenCanvas

ev: OffscreenCanvasEventMap[K]

Returns any

Optional options: boolean | EventListenerOptions

Returns void

Parameters

`Optional` options: boolean | AddEventListenerOptions

`Optional` options: boolean | AddEventListenerOptions

`Optional` options: ImageEncodeOptions

`Optional` options: any

`Optional` options: any

`Optional` options: any

`Optional` options: any

`Optional` options: any

`Optional` options: boolean | EventListenerOptions

`Optional` options: boolean | EventListenerOptions