Files
8bitMyGoUI/input/slotpicker.go
T

103 lines
2.6 KiB
Go

package input
import (
"fmt"
"log/slog"
"github.com/egoist/mygo/ui"
"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
)
type SlotPickerOptions struct {
Disabled bool
}
type SlotPickerResult struct {
Element *ui.Element
Changed bool
}
type reelKey struct{}
// reel holds a drag's and the wheel's leftover DIPs.
type reel struct {
drag, wheel float32
changed bool
}
// SlotPicker spins a looping reel; the centered option is chosen.
func SlotPicker(c *ui.Context, text string, value *int, options []string, o SlotPickerOptions) SlotPickerResult {
k := pixel.K(c)
n := len(options)
if *value < 0 || *value >= n {
panic(fmt.Sprintf("input: SlotPicker value %d outside %d options", *value, n))
}
shell, base, st := pixel.Shell(c, func() *ui.Element {
return ui.Box(c).Focusable().Role(ui.RoleSlider).Label(text).Description(options[*value]).Disabled(o.Disabled)
})
s := ui.Local(base, reelKey{}, func() reel { return reel{} })
spin := func(d int) {
*value = ((*value+d)%n + n) % n
s.changed = true
}
row := k.D(pixel.LineHeight)
base.HandleInput(func(ev ui.InputEvent) bool {
if ev.Kind != ui.InputScroll || o.Disabled {
return false
}
s.wheel += ev.DY
turn(&s.wheel, row, spin)
return true
})
if base.Shortcut(0, ui.KeyDown) {
spin(1)
}
if base.Shortcut(0, ui.KeyUp) {
spin(-1)
}
if _, dy, held := base.Dragged(); held && !o.Disabled {
s.drag += dy
turn(&s.drag, row, func(d int) { spin(-d) })
} else {
s.drag = 0
}
res := SlotPickerResult{Element: shell, Changed: s.changed}
s.changed = false
if res.Changed {
slog.Debug("8bit: slot picker", "label", text, "value", options[*value])
}
off := int(s.drag / k.Dot())
shell.Size(k.D(widest(options)+28), k.D(3*pixel.LineHeight+4)).Draw(func(p *ui.Painter, r ui.Rect) {
g := k.Canvas(p, r)
g.Frame(0, 0, g.W, g.H, pixel.Sunken, pixel.Well)
g.Clip(2, 2, g.W-4, g.H-4, func() {
for i := -2; i <= 2; i++ {
ink := pixel.Faint
if i == 0 {
ink = pixel.Ink
}
opt := options[((*value+i)%n+n)%n]
g.Text((g.W-pixel.Measure(opt))/2, 2+pixel.LineHeight*(1+i)+off, opt, ink, 1)
}
})
g.Veil(2, 2, g.W-4, 6, pixel.Shade, 4)
g.Veil(2, g.H-8, g.W-4, 6, pixel.Shade, 4)
mid := 2 + pixel.LineHeight + (pixel.LineHeight-tinyRight.H)/2
g.Sprite(3, mid, tinyRight, 0, pixel.Accent, 1)
g.Sprite(g.W-6, mid, tinyLeft, 0, pixel.Accent, 1)
finish(g, st)
})
return res
}
// turn spends whole rows of *left on step.
func turn(left *float32, row float32, step func(int)) {
for ; *left >= row; *left -= row {
step(1)
}
for ; *left <= -row; *left += row {
step(-1)
}
}