Files
gio-patched/widget/image.go
T
2020-05-19 11:03:30 +02:00

44 lines
1.0 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
package widget
import (
"image"
"gioui.org/f32"
"gioui.org/layout"
"gioui.org/op"
"gioui.org/op/clip"
"gioui.org/op/paint"
"gioui.org/unit"
)
// Image is a widget that displays an image.
type Image struct {
// Src is the image to display.
Src paint.ImageOp
// Scale is the ratio of image pixels to
// dps. If Scale is zero Image falls back to
// a scale that match a standard 72 DPI.
Scale float32
}
func (im Image) Layout(gtx *layout.Context) {
scale := im.Scale
if scale == 0 {
scale = 160.0 / 72.0
}
size := im.Src.Rect.Size()
wf, hf := float32(size.X), float32(size.Y)
w, h := gtx.Px(unit.Dp(wf*scale)), gtx.Px(unit.Dp(hf*scale))
cs := gtx.Constraints
d := cs.Constrain(image.Pt(w, h))
var s op.StackOp
s.Push(gtx.Ops)
clip.Rect{Rect: f32.Rectangle{Max: layout.FPt(d)}}.Op(gtx.Ops).Add(gtx.Ops)
im.Src.Add(gtx.Ops)
paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: float32(w), Y: float32(h)}}}.Add(gtx.Ops)
s.Pop()
gtx.Dimensions = layout.Dimensions{Size: d}
}