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

     1  // SPDX-License-Identifier: Unlicense OR MIT
     2  
     3  package material
     4  
     5  import (
     6  	"image"
     7  	"image/color"
     8  
     9  	"gioui.org/font"
    10  	"gioui.org/internal/f32color"
    11  	"gioui.org/layout"
    12  	"gioui.org/op"
    13  	"gioui.org/op/clip"
    14  	"gioui.org/op/paint"
    15  	"gioui.org/text"
    16  	"gioui.org/unit"
    17  	"gioui.org/widget"
    18  )
    19  
    20  type checkable struct {
    21  	Label              string
    22  	Color              color.NRGBA
    23  	Font               font.Font
    24  	TextSize           unit.Sp
    25  	IconColor          color.NRGBA
    26  	Size               unit.Dp
    27  	shaper             *text.Shaper
    28  	checkedStateIcon   *widget.Icon
    29  	uncheckedStateIcon *widget.Icon
    30  }
    31  
    32  func (c *checkable) layout(gtx layout.Context, checked, hovered bool) layout.Dimensions {
    33  	var icon *widget.Icon
    34  	if checked {
    35  		icon = c.checkedStateIcon
    36  	} else {
    37  		icon = c.uncheckedStateIcon
    38  	}
    39  
    40  	dims := layout.Flex{Alignment: layout.Middle}.Layout(gtx,
    41  		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
    42  			return layout.Stack{Alignment: layout.Center}.Layout(gtx,
    43  				layout.Stacked(func(gtx layout.Context) layout.Dimensions {
    44  					size := gtx.Dp(c.Size) * 4 / 3
    45  					dims := layout.Dimensions{
    46  						Size: image.Point{X: size, Y: size},
    47  					}
    48  					if !hovered {
    49  						return dims
    50  					}
    51  
    52  					background := f32color.MulAlpha(c.IconColor, 70)
    53  
    54  					b := image.Rectangle{Max: image.Pt(size, size)}
    55  					paint.FillShape(gtx.Ops, background, clip.Ellipse(b).Op(gtx.Ops))
    56  
    57  					return dims
    58  				}),
    59  				layout.Stacked(func(gtx layout.Context) layout.Dimensions {
    60  					return layout.UniformInset(2).Layout(gtx, func(gtx layout.Context) layout.Dimensions {
    61  						size := gtx.Dp(c.Size)
    62  						col := c.IconColor
    63  						if !gtx.Enabled() {
    64  							col = f32color.Disabled(col)
    65  						}
    66  						gtx.Constraints.Min = image.Point{X: size}
    67  						icon.Layout(gtx, col)
    68  						return layout.Dimensions{
    69  							Size: image.Point{X: size, Y: size},
    70  						}
    71  					})
    72  				}),
    73  			)
    74  		}),
    75  
    76  		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
    77  			return layout.UniformInset(2).Layout(gtx, func(gtx layout.Context) layout.Dimensions {
    78  				colMacro := op.Record(gtx.Ops)
    79  				paint.ColorOp{Color: c.Color}.Add(gtx.Ops)
    80  				return widget.Label{}.Layout(gtx, c.shaper, c.Font, c.TextSize, c.Label, colMacro.Stop())
    81  			})
    82  		}),
    83  	)
    84  	return dims
    85  }