zoomimage

Documentation

Index

• func ImCenter(im image.Image) (int, int)
• func PositionDelta(a, b fyne.Position) (float32, float32)
• type ImageElement
  • func NewImageElement(im image.Image) *ImageElement
  • func (ie *ImageElement) Contains(x, y int) bool
  • func (_ *ImageElement) Fixed() bool
  • func (_ *ImageElement) RegisterParent(_ *ZoomImage)
• type ScaleElement
  • func NewScaleElement(length int, imsize [2]int, color color.Color) *ScaleElement
  • func (re *ScaleElement) At(x, y int) color.Color
  • func (re *ScaleElement) Contains(x, y int) bool
  • func (re *ScaleElement) ContainsScalebar(x, y int) bool
  • func (re *ScaleElement) Fixed() bool
  • func (se *ScaleElement) RegisterParent(zi *ZoomImage)
• type SelectionBox
  • func NewSelectionBox(color color.Color, strokewidth float32) *SelectionBox
  • func (sb *SelectionBox) Refresh()
  • func (sb *SelectionBox) SetEnd(p fyne.Position)
  • func (sb *SelectionBox) SetStart(p fyne.Position)
  • func (sb *SelectionBox) SetVisible(vis bool)
• type ZIElement
• type ZoomImage
  • func NewZoomImage(im image.Image, ourcanvas fyne.Canvas, selectioncolor color.Color, ...) *ZoomImage
  • func (zi *ZoomImage) AddElement(e ZIElement)
  • func (zi *ZoomImage) AddScalebar(length int, color color.Color)
  • func (zi *ZoomImage) CreateRenderer() fyne.WidgetRenderer
  • func (zi *ZoomImage) CurrentSelection() [2][2]int
  • func (zi *ZoomImage) MouseDown(me *desktop.MouseEvent)
  • func (zi *ZoomImage) MouseIn(_ *desktop.MouseEvent)
  • func (zi *ZoomImage) MouseMoved(me *desktop.MouseEvent)
  • func (zi *ZoomImage) MouseOut()
  • func (zi *ZoomImage) MouseUp(_ *desktop.MouseEvent)
  • func (zi *ZoomImage) RefreshRaster()
• type ZoomStatus
  • func NewZoomStatus() *ZoomStatus
  • func (zs *ZoomStatus) SetPan(x, y float32)
  • func (zs *ZoomStatus) SetZoom(z int)

Functions

func ImCenter

func ImCenter(im image.Image) (int, int)

helper function to get the center of an image

func PositionDelta

func PositionDelta(a, b fyne.Position) (float32, float32)

Calculate a-b and return the components

Types

type ImageElement

type ImageElement struct {
	image.Image //we will wrap an image
}

func NewImageElement

func NewImageElement(im image.Image) *ImageElement

func (*ImageElement) Contains

func (ie *ImageElement) Contains(x, y int) bool

Add Contains so we implement ZIElement

func (*ImageElement) Fixed

func (_ *ImageElement) Fixed() bool

func (*ImageElement) RegisterParent

func (_ *ImageElement) RegisterParent(_ *ZoomImage)

type ScaleElement

type ScaleElement struct {
	Center [2]int //center of the rectangle
	Size   [2]int //x and y size
	Color  color.Color
	Parent *ZoomImage
}

type for rendering a scalebar

func NewScaleElement

func NewScaleElement(length int, imsize [2]int, color color.Color) *ScaleElement

make a new ScaleElement

func (*ScaleElement) At

func (re *ScaleElement) At(x, y int) color.Color

func (*ScaleElement) Contains

func (re *ScaleElement) Contains(x, y int) bool

func (*ScaleElement) ContainsScalebar

func (re *ScaleElement) ContainsScalebar(x, y int) bool

separating this out so it can be called on a 'orphan' scaleelement

func (*ScaleElement) Fixed

func (re *ScaleElement) Fixed() bool

func (*ScaleElement) RegisterParent

func (se *ScaleElement) RegisterParent(zi *ZoomImage)

type SelectionBox

type SelectionBox struct {
	P     [2]fyne.Position
	Lines [4]*canvas.Line
}

A SelectionBox is four [fyne.canvas.Line]s The lines will form the box starting at the top left and going counterclockwise. P[0] is the top

func NewSelectionBox

func NewSelectionBox(color color.Color, strokewidth float32) *SelectionBox

Make a new SelectionBox

func (*SelectionBox) Refresh

func (sb *SelectionBox) Refresh()

func (*SelectionBox) SetEnd

func (sb *SelectionBox) SetEnd(p fyne.Position)

Set the end position of a SelectionBox

func (*SelectionBox) SetStart

func (sb *SelectionBox) SetStart(p fyne.Position)

Set the start position of a SelectionBox

func (*SelectionBox) SetVisible

func (sb *SelectionBox) SetVisible(vis bool)

Change the visibility of a SelectionBox

type ZIElement

type ZIElement interface {
	Contains(x, y int) bool //does this element contain this pixel
	At(x, y int) color.Color
	Fixed() bool               //should this element be fixed to the window
	RegisterParent(*ZoomImage) //This will be called when this element is added to a ZoomWindow
}

interface for elements that we can overlay in a zoomimage

type ZoomImage

type ZoomImage struct {
	*canvas.Raster
	Selection *SelectionBox
	Status    *ZoomStatus
	Elements  *[]ZIElement

	ImSize [2]int //need to know the size of the image
	Canvas fyne.Canvas
	BaseIm *ImageElement
	// contains filtered or unexported fields
}

ZoomImage will embed a canvas.Raster to render and will keep track of its zoom and pan status

func NewZoomImage

func NewZoomImage(im image.Image, ourcanvas fyne.Canvas, selectioncolor color.Color, selectionstroke float32) *ZoomImage

func (*ZoomImage) AddElement

func (zi *ZoomImage) AddElement(e ZIElement)

add a ZIElement to a ZoomImage

func (*ZoomImage) AddScalebar

func (zi *ZoomImage) AddScalebar(length int, color color.Color)

add a scalebar to a ZoomImage

func (*ZoomImage) CreateRenderer

func (zi *ZoomImage) CreateRenderer() fyne.WidgetRenderer

func (*ZoomImage) CurrentSelection

func (zi *ZoomImage) CurrentSelection() [2][2]int

Get the current selection in terms of indices into the image we are viewing This will return a 2d array where a[0] is the start and end indices in the x direction and a[1] is the start and end indices in the y direction

func (*ZoomImage) MouseDown

func (zi *ZoomImage) MouseDown(me *desktop.MouseEvent)

func (*ZoomImage) MouseIn

func (zi *ZoomImage) MouseIn(_ *desktop.MouseEvent)

func (*ZoomImage) MouseMoved

func (zi *ZoomImage) MouseMoved(me *desktop.MouseEvent)

func (*ZoomImage) MouseOut

func (zi *ZoomImage) MouseOut()

func (*ZoomImage) MouseUp

func (zi *ZoomImage) MouseUp(_ *desktop.MouseEvent)

func (*ZoomImage) RefreshRaster

func (zi *ZoomImage) RefreshRaster()

update the raster generate func (to account for new ZIElements)

type ZoomStatus

type ZoomStatus struct {
	Zoom int
	//float so we don't get truncation error when working with [fyne.Position]
	PanX, PanY float32
}

We want zoomposition to be its own object so we can share it with our render function

func NewZoomStatus

func NewZoomStatus() *ZoomStatus

func (*ZoomStatus) SetPan

func (zs *ZoomStatus) SetPan(x, y float32)

func (*ZoomStatus) SetZoom

func (zs *ZoomStatus) SetZoom(z int)