mirror of
https://git.sr.ht/~eliasnaur/gio
synced 2026-07-01 07:35:40 +00:00
Gordon Klaus
22aa00f476
Setting Float.Invert=true not only inverts the order of values (which was already easily done by swapping min and max), it also draws the widget inverted so that the track is darkened on the opposite side from usual. This patch also fixes a bug wherein a vertical slider was drawn inverted by default. Signed-off-by: Gordon Klaus <gordon.klaus@gmail.com>
104 lines
2.2 KiB
Go
104 lines
2.2 KiB
Go
// SPDX-License-Identifier: Unlicense OR MIT
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package widget
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import (
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"image"
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"gioui.org/gesture"
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"gioui.org/io/pointer"
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"gioui.org/layout"
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"gioui.org/op/clip"
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)
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// Float is for selecting a value in a range.
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type Float struct {
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Value float32
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Axis layout.Axis
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Invert bool
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drag gesture.Drag
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pos float32 // position normalized to [0, 1]
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length float32
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changed bool
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}
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// Dragging returns whether the value is being interacted with.
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func (f *Float) Dragging() bool { return f.drag.Dragging() }
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// Layout updates the value according to drag events along the f's main axis.
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//
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// The range of f is set by the minimum constraints main axis value.
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func (f *Float) Layout(gtx layout.Context, pointerMargin int, min, max float32) layout.Dimensions {
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size := gtx.Constraints.Min
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f.length = float32(f.Axis.Convert(size).X)
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var de *pointer.Event
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for _, e := range f.drag.Events(gtx.Metric, gtx, gesture.Axis(f.Axis)) {
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if e.Type == pointer.Press || e.Type == pointer.Drag {
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de = &e
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}
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}
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value := f.Value
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if de != nil {
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xy := de.Position.X
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if f.Axis == layout.Vertical {
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xy = f.length - de.Position.Y
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}
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if f.Invert {
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xy = f.length - xy
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}
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f.pos = xy / f.length
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value = min + (max-min)*f.pos
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} else if min != max {
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f.pos = (value - min) / (max - min)
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}
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// Unconditionally call setValue in case min, max, or value changed.
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f.setValue(value, min, max)
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if f.pos < 0 {
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f.pos = 0
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} else if f.pos > 1 {
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f.pos = 1
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}
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margin := f.Axis.Convert(image.Pt(pointerMargin, 0))
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rect := image.Rectangle{
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Min: margin.Mul(-1),
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Max: size.Add(margin),
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}
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defer clip.Rect(rect).Push(gtx.Ops).Pop()
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f.drag.Add(gtx.Ops)
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return layout.Dimensions{Size: size}
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}
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func (f *Float) setValue(value, min, max float32) {
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if min > max {
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min, max = max, min
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}
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if value < min {
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value = min
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} else if value > max {
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value = max
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}
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if f.Value != value {
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f.Value = value
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f.changed = true
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}
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}
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// Pos reports the selected position.
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func (f *Float) Pos() float32 {
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return f.pos * f.length
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}
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// Changed reports whether the value has changed since
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// the last call to Changed.
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func (f *Float) Changed() bool {
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changed := f.changed
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f.changed = false
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return changed
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}
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