mirror of
https://git.sr.ht/~eliasnaur/gio
synced 2026-07-01 07:35:40 +00:00
Walter Werner SCHNEIDER
97 lines
2.4 KiB
Go
97 lines
2.4 KiB
Go
// SPDX-License-Identifier: Unlicense OR MIT
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package material
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import (
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"image"
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"image/color"
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"gioui.org/internal/f32color"
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"gioui.org/layout"
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"gioui.org/op"
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"gioui.org/op/clip"
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"gioui.org/op/paint"
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"gioui.org/unit"
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"gioui.org/widget"
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)
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// Slider is for selecting a value in a range.
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func Slider(th *Theme, float *widget.Float) SliderStyle {
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return SliderStyle{
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Color: th.Palette.ContrastBg,
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Float: float,
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FingerSize: th.FingerSize,
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}
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}
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type SliderStyle struct {
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Axis layout.Axis
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Color color.NRGBA
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Float *widget.Float
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FingerSize unit.Dp
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}
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func (s SliderStyle) Layout(gtx layout.Context) layout.Dimensions {
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const thumbRadius unit.Dp = 6
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tr := gtx.Dp(thumbRadius)
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trackWidth := gtx.Dp(2)
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axis := s.Axis
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// Keep a minimum length so that the track is always visible.
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minLength := tr + 3*tr + tr
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// Try to expand to finger size, but only if the constraints
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// allow for it.
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touchSizePx := min(gtx.Dp(s.FingerSize), axis.Convert(gtx.Constraints.Max).Y)
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sizeMain := max(axis.Convert(gtx.Constraints.Min).X, minLength)
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sizeCross := max(2*tr, touchSizePx)
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size := axis.Convert(image.Pt(sizeMain, sizeCross))
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o := axis.Convert(image.Pt(tr, 0))
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trans := op.Offset(o).Push(gtx.Ops)
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gtx.Constraints.Min = axis.Convert(image.Pt(sizeMain-2*tr, sizeCross))
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dims := s.Float.Layout(gtx, axis, thumbRadius)
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gtx.Constraints.Min = gtx.Constraints.Min.Add(axis.Convert(image.Pt(0, sizeCross)))
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thumbPos := tr + int(s.Float.Value*float32(axis.Convert(dims.Size).X))
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trans.Pop()
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color := s.Color
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if !gtx.Enabled() {
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color = f32color.Disabled(color)
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}
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rect := func(minx, miny, maxx, maxy int) image.Rectangle {
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r := image.Rect(minx, miny, maxx, maxy)
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if axis == layout.Vertical {
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r.Max.X, r.Min.X = sizeMain-r.Min.X, sizeMain-r.Max.X
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}
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r.Min = axis.Convert(r.Min)
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r.Max = axis.Convert(r.Max)
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return r
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}
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// Draw track before thumb.
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track := rect(
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tr, sizeCross/2-trackWidth/2,
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thumbPos, sizeCross/2+trackWidth/2,
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)
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paint.FillShape(gtx.Ops, color, clip.Rect(track).Op())
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// Draw track after thumb.
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track = rect(
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thumbPos, axis.Convert(track.Min).Y,
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sizeMain-tr, axis.Convert(track.Max).Y,
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)
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paint.FillShape(gtx.Ops, f32color.MulAlpha(color, 96), clip.Rect(track).Op())
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// Draw thumb.
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pt := image.Pt(thumbPos, sizeCross/2)
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thumb := rect(
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pt.X-tr, pt.Y-tr,
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pt.X+tr, pt.Y+tr,
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)
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paint.FillShape(gtx.Ops, color, clip.Ellipse(thumb).Op(gtx.Ops))
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return layout.Dimensions{Size: size}
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}
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