image

Documentation

Index

• Variables
• func ClearCache()
• type HttpClient
  • func (c *HttpClient) Download(location string) ([]byte, error)
• type ImageSource
  • func ImageFromBuf(src []byte) *ImageSource
  • func ImageFromFile(src string) *ImageSource
  • func (img *ImageSource) Error() error
  • func (img *ImageSource) Format() string
  • func (img *ImageSource) ImageOp(size image.Point) *paint.ImageOp
  • func (img *ImageSource) IsNetworkImg() bool
  • func (img *ImageSource) Location() string
  • func (img *ImageSource) OnLoaded(callback func())
  • func (img *ImageSource) ScaleByRatio(ratio float32) (*paint.ImageOp, error)
  • func (img *ImageSource) ScaleBySize(size image.Point) (*paint.ImageOp, error)
  • func (img *ImageSource) ScaleRatio() float32
  • func (img *ImageSource) Size() image.Point
• type ImageStyle
  • func (img ImageStyle) Layout(gtx layout.Context) layout.Dimensions
• type Quality

Variables

var (
	// Change this if you want to load larger images from the web. Default max size is 10M.
	MaxDownloadSize = 1024 * 1024 * 10

	// Timeout for http request.
	DownloadTimeout = time.Second * 10
)

var CacheCapacity int = 100

CacheCapacity set how many network images can be cached. Set

Functions

func ClearCache

func ClearCache()

Clear the remote image cache if it is used.

Types

type HttpClient

type HttpClient struct {
	// contains filtered or unexported fields
}

Because of network anti crawler policies applied by sites, we have to disguising out http client as browsers, see below link for details: https://req.cool/blog/supported-http-fingerprint-impersonation-to-bypass-anti-crawler-detection-effortlessly/

func (*HttpClient) Download

func (c *HttpClient) Download(location string) ([]byte, error)

type ImageSource

type ImageSource struct {

	// Select the quality of the scaled image.
	ScaleQuality Quality
	// Choose whether to buffer src image or not. Buffering reduces frequent
	// image loading, but at the price of higher memory usage. Has no effect
	// for image reading from bytes.
	UseSrcBuf bool
	// contains filtered or unexported fields
}

ImageSource wraps a local or remote image. Only jpeg, png and gif format for is supported. When displaying, image scaled by the specified size and cached.

func ImageFromBuf

func ImageFromBuf(src []byte) *ImageSource

ImageFromBuf loads an image from bytes buffer.

func ImageFromFile

func ImageFromFile(src string) *ImageSource

ImageFromFile load an image from local filesystem or from network lazily. For eager image loading, use ImageFromBuf instead.

func (*ImageSource) Error

func (img *ImageSource) Error() error

func (*ImageSource) Format

func (img *ImageSource) Format() string

func (*ImageSource) ImageOp

func (img *ImageSource) ImageOp(size image.Point) *paint.ImageOp

ImageOp scales the src image dynamically or scales to the expected size if size if set. If the passed size is the zero value of image Point, image is not scaled.

func (*ImageSource) IsNetworkImg

func (img *ImageSource) IsNetworkImg() bool

IsNetworkImg check if this image is loaded/to be loaded from network.

func (*ImageSource) Location

func (img *ImageSource) Location() string

func (*ImageSource) OnLoaded

func (img *ImageSource) OnLoaded(callback func())

func (*ImageSource) ScaleByRatio

func (img *ImageSource) ScaleByRatio(ratio float32) (*paint.ImageOp, error)

func (*ImageSource) ScaleBySize

func (img *ImageSource) ScaleBySize(size image.Point) (*paint.ImageOp, error)

func (*ImageSource) ScaleRatio

func (img *ImageSource) ScaleRatio() float32

func (*ImageSource) Size

func (img *ImageSource) Size() image.Point

type ImageStyle

type ImageStyle struct {
	Src *ImageSource
	//Size   image.Point
	Radius   unit.Dp
	Fit      widget.Fit
	Scale    float32
	Position layout.Direction
}

ImageStyle is a widget displaying an image from an ImageSource. Styling parameters can be set after construction. Displayed size is specified by the max constraints of the widget.

func (ImageStyle) Layout

func (img ImageStyle) Layout(gtx layout.Context) layout.Dimensions

type Quality

type Quality uint8

const (
	// scale source image using the nearest neighbor interpolator.
	Low Quality = iota
	// scale using ApproxBiLinear interpolator.
	Medium
	// scale using BiLinear interpolator. It is slow but gives high quality.
	High
	// scale using Catmull-Rom interpolator. It is very slow but gives the
	// best quality among the four.
	Highest
)