Class Canvas

Canvas Wrapper Class for interacting with HTMLCanvas and CanvasKit

Hierarchy

Canvas

Index

Constructors

Methods

adapterInitialized checkCanvasAdapter create createImage createImageData disposeCanvas disposeImage drawText getImageData initializeAdapter measureText mergeCanvas registerCanvasAdapter scaleImage scaleImageToDimensions toBytes toDataURL writeImageToBytes

Constructors

constructor

new Canvas(): Canvas
Returns Canvas

Methods

`Static` adapterInitialized

adapterInitialized(): boolean
Returns boolean
- Defined in lib/canvas/canvas.ts:16

`Static` checkCanvasAdapter

checkCanvasAdapter(): void
Returns void
- Defined in lib/canvas/canvas.ts:34

`Static` create

create(width: any, height: any): HTMLCanvasElement
Parameters
- width: any
- height: any
Returns HTMLCanvasElement
- Defined in lib/canvas/canvas.ts:42

`Static` createImage

createImage(data: string | Buffer | Uint8Array, contentType?: string): Promise<GeoPackageImage>
Parameters
- data: string | Buffer | Uint8Array
- contentType: string = 'image/png'
Returns Promise<GeoPackageImage>
- Defined in lib/canvas/canvas.ts:47

`Static` createImageData

createImageData(width: any, height: any): ImageData
Parameters
- width: any
- height: any
Returns ImageData
- Defined in lib/canvas/canvas.ts:52

`Static` disposeCanvas

disposeCanvas(canvas: any): void
Parameters
- canvas: any
Returns void
- Defined in lib/canvas/canvas.ts:57

`Static` disposeImage

disposeImage(image: GeoPackageImage): void
Parameters
- image: GeoPackageImage
Returns void
- Defined in lib/canvas/canvas.ts:98

`Static` drawText

drawText(context: CanvasRenderingContext2D, text: string, location: number[], fontFace: string, fontSize: number, fontColor: string): void
Parameters
- context: CanvasRenderingContext2D
- text: string
- location: number[]
- fontFace: string
- fontSize: number
- fontColor: string
Returns void
- Defined in lib/canvas/canvas.ts:67

`Static` getImageData

getImageData(image: GeoPackageImage): ImageData
Parameters
- image: GeoPackageImage
Returns ImageData
- Defined in lib/canvas/canvas.ts:112

`Static` initializeAdapter

initializeAdapter(): Promise<void>
Returns Promise<void>
- Defined in lib/canvas/canvas.ts:20

`Static` measureText

measureText(context: CanvasRenderingContext2D, fontFace: string, fontSize: number, text: string): number
Parameters
- context: CanvasRenderingContext2D
- fontFace: string
- fontSize: number
- text: string
Returns number
- Defined in lib/canvas/canvas.ts:62

`Static` mergeCanvas

mergeCanvas(fromCanvas: any, toContext: any): void
Draw content of fromCanvas into the toContext
Parameters
- fromCanvas: any
- toContext: any
Returns void
- Defined in lib/canvas/canvas.ts:121

`Static` registerCanvasAdapter

registerCanvasAdapter(adapter: (new () => CanvasAdapter)): void
Parameters
- adapter: (new () => CanvasAdapter)
  - - new (): CanvasAdapter
    - Returns CanvasAdapter
Returns void
- Defined in lib/canvas/canvas.ts:12

`Static` scaleImage

scaleImage(image: GeoPackageImage, scale: number): Promise<GeoPackageImage>
Parameters
- image: GeoPackageImage
- scale: number
Returns Promise<GeoPackageImage>
- Defined in lib/canvas/canvas.ts:79

`Static` scaleImageToDimensions

scaleImageToDimensions(image: GeoPackageImage, scaledWidth: number, scaledHeight: number): Promise<GeoPackageImage>
Parameters
- image: GeoPackageImage
- scaledWidth: number
- scaledHeight: number
Returns Promise<GeoPackageImage>
- Defined in lib/canvas/canvas.ts:84

`Static` toBytes

toBytes(canvas: any, imageFormat?: ImageType, compressionQuality?: number): Promise<Uint8Array>
Returns the byte array representing the drawn content of a canvas.
Parameters
- canvas: any
- imageFormat: ImageType = ImageType.PNG
- Optional compressionQuality: number
Returns Promise<Uint8Array>
- Defined in lib/canvas/canvas.ts:132

`Static` toDataURL

toDataURL(canvas: any, format?: string, quality?: number): Promise<string>
Parameters
- canvas: any
- format: string = 'image/png'
- Optional quality: number
Returns Promise<string>
- Defined in lib/canvas/canvas.ts:93

`Static` writeImageToBytes

writeImageToBytes(image: GeoPackageImage, imageFormat: ImageType, compressionQuality: number): Promise<Uint8Array>
Parameters
- image: GeoPackageImage
- imageFormat: ImageType
- compressionQuality: number
Returns Promise<Uint8Array>
- Defined in lib/canvas/canvas.ts:103

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