aerc/widgets/spinner.go
2019-03-14 21:37:00 -04:00

92 lines
1.3 KiB
Go

package widgets
import (
"time"
"github.com/gdamore/tcell"
"git.sr.ht/~sircmpwn/aerc2/lib/ui"
)
var (
frames = []string{
"[..] ",
" [..] ",
" [..] ",
" [..] ",
" [..]",
" [..] ",
" [..] ",
" [..] ",
}
)
type Spinner struct {
frame int
onInvalidate func(d ui.Drawable)
stop chan interface{}
}
func NewSpinner() *Spinner {
spinner := Spinner{
stop: make(chan interface{}),
frame: -1,
}
return &spinner
}
func (s *Spinner) Start() {
if s.IsRunning() {
return
}
s.frame = 0
go func() {
for {
select {
case <-s.stop:
return
case <-time.After(200 * time.Millisecond):
s.frame++
if s.frame >= len(frames) {
s.frame = 0
}
s.Invalidate()
}
}
}()
}
func (s *Spinner) Stop() {
if !s.IsRunning() {
return
}
s.stop <- nil
s.frame = -1
s.Invalidate()
}
func (s *Spinner) IsRunning() bool {
return s.frame != -1
}
func (s *Spinner) Draw(ctx *ui.Context) {
if !s.IsRunning() {
return
}
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[s.frame])
}
func (s *Spinner) OnInvalidate(onInvalidate func(d ui.Drawable)) {
s.onInvalidate = onInvalidate
}
func (s *Spinner) Invalidate() {
if s.onInvalidate != nil {
s.onInvalidate(s)
}
}