gioui.org@v0.6.1-0.20240506124620-7a9ce51988ce/widget/border.go (about)

     1  // SPDX-License-Identifier: Unlicense OR MIT
     2  
     3  package widget
     4  
     5  import (
     6  	"image"
     7  	"image/color"
     8  
     9  	"gioui.org/layout"
    10  	"gioui.org/op/clip"
    11  	"gioui.org/op/paint"
    12  	"gioui.org/unit"
    13  )
    14  
    15  // Border lays out a widget and draws a border inside it.
    16  type Border struct {
    17  	Color        color.NRGBA
    18  	CornerRadius unit.Dp
    19  	Width        unit.Dp
    20  }
    21  
    22  func (b Border) Layout(gtx layout.Context, w layout.Widget) layout.Dimensions {
    23  	dims := w(gtx)
    24  	sz := dims.Size
    25  
    26  	rr := gtx.Dp(b.CornerRadius)
    27  	width := gtx.Dp(b.Width)
    28  	whalf := (width + 1) / 2
    29  	sz.X -= whalf * 2
    30  	sz.Y -= whalf * 2
    31  
    32  	r := image.Rectangle{Max: sz}
    33  	r = r.Add(image.Point{X: whalf, Y: whalf})
    34  
    35  	paint.FillShape(gtx.Ops,
    36  		b.Color,
    37  		clip.Stroke{
    38  			Path:  clip.UniformRRect(r, rr).Path(gtx.Ops),
    39  			Width: float32(width),
    40  		}.Op(),
    41  	)
    42  
    43  	return dims
    44  }