mirror of
https://git.sr.ht/~eliasnaur/gio
synced 2026-07-02 16:06:19 +00:00
Egon Elbre
296303210f
Remove padding from the sides of the Slider to align them with
other components.
However, since sliders still need to be used with fingers try to
enforce a minimum finger height, if there is sufficient room.
The sides don't need similar treatment since after grabbing it's
possible to move the finger beyond the touch area, without losing
interaction.
To not enforce finger size, the theme can be adjusted:
theme.FingerSize = unit.Px(0)
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
123 lines
2.7 KiB
Go
123 lines
2.7 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/f32"
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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, min, max float32) SliderStyle {
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return SliderStyle{
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Min: min,
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Max: max,
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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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Min, Max float32
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Color color.NRGBA
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Float *widget.Float
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FingerSize unit.Value
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}
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func (s SliderStyle) Layout(gtx layout.Context) layout.Dimensions {
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thumbRadiusInt := gtx.Px(unit.Dp(6))
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trackWidth := float32(gtx.Px(unit.Dp(2)))
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thumbRadius := float32(thumbRadiusInt)
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size := gtx.Constraints.Min
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// Keep a minimum length so that the track is always visible.
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minLength := thumbRadiusInt + 3*thumbRadiusInt + thumbRadiusInt
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if size.X < minLength {
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size.X = minLength
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}
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size.Y = 2 * thumbRadiusInt
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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 := gtx.Px(s.FingerSize)
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if touchSizePx > gtx.Constraints.Max.Y {
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touchSizePx = gtx.Constraints.Max.Y
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}
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if size.Y < touchSizePx {
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size.Y = 2 * (touchSizePx / 2)
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}
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st := op.Push(gtx.Ops)
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op.Offset(f32.Pt(thumbRadius, 0)).Add(gtx.Ops)
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gtx.Constraints.Min = image.Pt(size.X-2*thumbRadiusInt, size.Y)
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s.Float.Layout(gtx, thumbRadiusInt, s.Min, s.Max)
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gtx.Constraints.Min.Y = size.Y
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thumbPos := thumbRadius + s.Float.Pos()
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st.Pop()
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color := s.Color
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if gtx.Queue == nil {
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color = f32color.MulAlpha(color, 150)
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}
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// Draw track before thumb.
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st = op.Push(gtx.Ops)
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track := f32.Rectangle{
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Min: f32.Point{
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X: thumbRadius,
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Y: float32(size.Y/2) - trackWidth/2,
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},
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Max: f32.Point{
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X: thumbPos,
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Y: float32(size.Y/2) + trackWidth/2,
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},
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}
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clip.RRect{Rect: track}.Add(gtx.Ops)
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paint.ColorOp{Color: color}.Add(gtx.Ops)
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paint.PaintOp{}.Add(gtx.Ops)
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st.Pop()
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// Draw track after thumb.
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st = op.Push(gtx.Ops)
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track.Min.X = thumbPos
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track.Max.X = float32(size.X) - thumbRadius
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clip.RRect{Rect: track}.Add(gtx.Ops)
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paint.ColorOp{Color: f32color.MulAlpha(color, 96)}.Add(gtx.Ops)
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paint.PaintOp{}.Add(gtx.Ops)
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st.Pop()
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// Draw thumb.
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st = op.Push(gtx.Ops)
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thumb := f32.Rectangle{
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Min: f32.Point{
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X: thumbPos - thumbRadius,
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Y: float32(size.Y/2) - thumbRadius,
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},
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Max: f32.Point{
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X: thumbPos + thumbRadius,
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Y: float32(size.Y/2) + thumbRadius,
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},
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}
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rr := thumbRadius
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clip.RRect{
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Rect: thumb,
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NE: rr, NW: rr, SE: rr, SW: rr,
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}.Add(gtx.Ops)
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paint.ColorOp{Color: color}.Add(gtx.Ops)
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paint.PaintOp{}.Add(gtx.Ops)
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st.Pop()
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return layout.Dimensions{Size: size}
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}
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