package widgets import ( "strings" "sync/atomic" "time" "github.com/gdamore/tcell" "git.sr.ht/~sircmpwn/aerc/config" "git.sr.ht/~sircmpwn/aerc/lib/ui" ) type Spinner struct { ui.Invalidatable frame int64 // access via atomic frames []string stop chan struct{} } func NewSpinner(uiConf *config.UIConfig) *Spinner { spinner := Spinner{ stop: make(chan struct{}), frame: -1, frames: strings.Split(uiConf.Spinner, uiConf.SpinnerDelimiter), } 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(s.frames))) ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault) col := ctx.Width()/2 - len(s.frames[0])/2 + 1 ctx.Printf(col, 0, tcell.StyleDefault, "%s", s.frames[cur]) } func (s *Spinner) Invalidate() { s.DoInvalidate(s) }