72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
package mujica
|
|
|
|
import (
|
|
"log/slog"
|
|
"time"
|
|
|
|
"github.com/egoist/mygo/ui"
|
|
|
|
"mujicaui/theme"
|
|
)
|
|
|
|
// StaggerOptions configure a Stagger.
|
|
type StaggerOptions struct {
|
|
// Interval between items; zero means 60 ms.
|
|
Interval time.Duration
|
|
// Duration of each item's entry; zero means PopupDuration.
|
|
Duration time.Duration
|
|
// Horizontal lays items in a row.
|
|
Horizontal bool
|
|
}
|
|
|
|
type staggerState struct {
|
|
born time.Time
|
|
shown int
|
|
done bool
|
|
}
|
|
|
|
// Stagger builds n items, each entering after the one before, once when it first appears.
|
|
// Items added after the sequence ends appear with their own entry.
|
|
func Stagger(c *ui.Context, n int, opts StaggerOptions, item func(i int)) *ui.Element {
|
|
if n < 0 || opts.Interval < 0 || opts.Duration < 0 {
|
|
panic("mujica: Stagger needs non-negative n, Interval and Duration")
|
|
}
|
|
every, d := opts.Interval, opts.Duration
|
|
if every == 0 {
|
|
every = 60 * time.Millisecond
|
|
}
|
|
if d == 0 {
|
|
d = theme.PopupDuration
|
|
}
|
|
box := ui.Column(c).AlignItems(ui.Stretch)
|
|
if opts.Horizontal {
|
|
box.Row().AlignItems(ui.Start)
|
|
}
|
|
st := ui.Local(box, "stagger", func() *staggerState { return &staggerState{born: c.Now()} })
|
|
s := *st
|
|
upto := n
|
|
if !s.done && !c.Preferences().ReduceMotion {
|
|
upto = min(n, 1+int(c.Now().Sub(s.born)/every))
|
|
if upto < n {
|
|
c.After(s.born.Add(time.Duration(upto) * every).Sub(c.Now()))
|
|
} else {
|
|
s.done = true
|
|
slog.Debug("mujica: stagger done", "items", n)
|
|
}
|
|
}
|
|
if c.Preferences().ReduceMotion {
|
|
s.done = true
|
|
}
|
|
enter := &ui.Motion{Y: 8}
|
|
if opts.Horizontal {
|
|
enter = &ui.Motion{X: 8}
|
|
}
|
|
box.Children(func() {
|
|
for i := range upto {
|
|
ui.Column(c).Key(i).AlignItems(ui.Stretch).
|
|
Transition(ui.ElementTransition{Duration: d, Enter: enter}).Children(func() { item(i) })
|
|
}
|
|
})
|
|
return box
|
|
}
|