Class Canvas

Constructors

constructor

Properties

height stride type width PNG_ALL_FILTERS PNG_FILTER_AVG PNG_FILTER_NONE PNG_FILTER_PAETH PNG_FILTER_SUB PNG_FILTER_UP PNG_NO_FILTERS

Methods

createJPEGStream createPDFStream createPNGStream getContext toBuffer toDataURL

Constructors

constructor

  • new Canvas(
        width: number,
        height: number,
        type?: "image" | "svg" | "pdf",
    ): Canvas

  • Parameters

    • width: number
    • height: number
    • Optionaltype: "image" | "svg" | "pdf"

    Returns Canvas

Properties

height

height: number

Readonlystride

stride: number

Non standard. Getter. The stride used by the canvas.

Readonlytype

type: "image" | "svg" | "pdf"

Non standard. The type of the canvas.

width

width: number

Static ReadonlyPNG_ALL_FILTERS

PNG_ALL_FILTERS: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_FILTER_AVG

PNG_FILTER_AVG: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_FILTER_NONE

PNG_FILTER_NONE: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_FILTER_PAETH

PNG_FILTER_PAETH: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_FILTER_SUB

PNG_FILTER_SUB: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_FILTER_UP

PNG_FILTER_UP: number

Constant used in PNG encoding methods.

Static ReadonlyPNG_NO_FILTERS

PNG_NO_FILTERS: number

Constant used in PNG encoding methods.

Methods

createJPEGStream

  • createJPEGStream(config?: JpegConfig): JPEGStream

  • Parameters

    • Optionalconfig: JpegConfig

    Returns JPEGStream

createPDFStream

  • createPDFStream(config?: PdfConfig): PDFStream

  • Parameters

    • Optionalconfig: PdfConfig

    Returns PDFStream

createPNGStream

  • createPNGStream(config?: PngConfig): PNGStream

  • Parameters

    • Optionalconfig: PngConfig

    Returns PNGStream

getContext

  • getContext(
        contextId: "2d",
        contextAttributes?: NodeCanvasRenderingContext2DSettings,
    ): CanvasRenderingContext2D

  • Parameters

    • contextId: "2d"
    • OptionalcontextAttributes: NodeCanvasRenderingContext2DSettings

    Returns CanvasRenderingContext2D

toBuffer

  • toBuffer(cb: (err: null | Error, result: Buffer) => void): void

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • cb: (err: null | Error, result: Buffer) => void

    Returns void

  • toBuffer(
        cb: (err: null | Error, result: Buffer) => void,
        mimeType: "image/png",
        config?: PngConfig,
    ): void

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • cb: (err: null | Error, result: Buffer) => void
    • mimeType: "image/png"
    • Optionalconfig: PngConfig

    Returns void

  • toBuffer(
        cb: (err: null | Error, result: Buffer) => void,
        mimeType: "image/jpeg",
        config?: JpegConfig,
    ): void

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • cb: (err: null | Error, result: Buffer) => void
    • mimeType: "image/jpeg"
    • Optionalconfig: JpegConfig

    Returns void

  • toBuffer(): Buffer

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Returns Buffer

  • toBuffer(mimeType: "image/png", config?: PngConfig): Buffer

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • mimeType: "image/png"
    • Optionalconfig: PngConfig

    Returns Buffer

  • toBuffer(mimeType: "image/jpeg", config?: JpegConfig): Buffer

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • mimeType: "image/jpeg"
    • Optionalconfig: JpegConfig

    Returns Buffer

  • toBuffer(mimeType: "application/pdf", config?: PdfConfig): Buffer

  • For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

    Parameters

    • mimeType: "application/pdf"
    • Optionalconfig: PdfConfig

    Returns Buffer

  • toBuffer(mimeType: "raw"): Buffer

  • Returns the unencoded pixel data, top-to-bottom. On little-endian (most) systems, the array will be ordered BGRA; on big-endian systems, it will be ARGB.

    Parameters

    • mimeType: "raw"

    Returns Buffer

toDataURL

  • toDataURL(): string

  • Defaults to PNG image.

    Returns string

  • toDataURL(mimeType: "image/png"): string

  • Defaults to PNG image.

    Parameters

    • mimeType: "image/png"

    Returns string

  • toDataURL(mimeType: "image/jpeg", quality?: number): string

  • Defaults to PNG image.

    Parameters

    • mimeType: "image/jpeg"
    • Optionalquality: number

    Returns string

  • toDataURL(cb: (err: null | Error, result: string) => void): void

  • Non-standard. Defaults to PNG image.

    Parameters

    • cb: (err: null | Error, result: string) => void

    Returns void

  • toDataURL(
        mimeType: "image/png",
        cb: (err: null | Error, result: string) => void,
    ): void

  • Non-standard.

    Parameters

    • mimeType: "image/png"
    • cb: (err: null | Error, result: string) => void

    Returns void

  • toDataURL(
        mimeType: "image/jpeg",
        cb: (err: null | Error, result: string) => void,
    ): void

  • Non-standard.

    Parameters

    • mimeType: "image/jpeg"
    • cb: (err: null | Error, result: string) => void

    Returns void

  • toDataURL(
        mimeType: "image/jpeg",
        config: JpegConfig,
        cb: (err: null | Error, result: string) => void,
    ): void

  • Non-standard.

    Parameters

    • mimeType: "image/jpeg"
    • config: JpegConfig
    • cb: (err: null | Error, result: string) => void

    Returns void

  • toDataURL(
        mimeType: "image/jpeg",
        quality: number,
        cb: (err: null | Error, result: string) => void,
    ): void

  • Non-standard.

    Parameters

    • mimeType: "image/jpeg"
    • quality: number
    • cb: (err: null | Error, result: string) => void

    Returns void

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