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|
package widgets
import (
"sync/atomic"
"time"
"github.com/gdamore/tcell"
"git.sr.ht/~sircmpwn/aerc/lib/ui"
)
var (
frames = []string{
"[..] ",
" [..] ",
" [..] ",
" [..] ",
" [..]",
" [..] ",
" [..] ",
" [..] ",
}
)
type Spinner struct {
ui.Invalidatable
frame int64 // access via atomic
stop chan struct{}
}
func NewSpinner() *Spinner {
spinner := Spinner{
stop: make(chan struct{}),
frame: -1,
}
return &spinner
}
func (s *Spinner) Start() {
if s.IsRunning() {
return
}
atomic.StoreInt64(&s.frame, 0)
go func() {
for {
select {
case <-s.stop:
atomic.StoreInt64(&s.frame, -1)
s.stop <- struct{}{}
return
case <-time.After(200 * time.Millisecond):
atomic.AddInt64(&s.frame, 1)
s.Invalidate()
}
}
}()
}
func (s *Spinner) Stop() {
if !s.IsRunning() {
return
}
s.stop <- struct{}{}
<-s.stop
s.Invalidate()
}
func (s *Spinner) IsRunning() bool {
return atomic.LoadInt64(&s.frame) != -1
}
func (s *Spinner) Draw(ctx *ui.Context) {
if !s.IsRunning() {
s.Start()
}
cur := int(atomic.LoadInt64(&s.frame) % int64(len(frames)))
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
col := ctx.Width()/2 - len(frames[0])/2 + 1
ctx.Printf(col, 0, tcell.StyleDefault, "%s", frames[cur])
}
func (s *Spinner) Invalidate() {
s.DoInvalidate(s)
}
|