forked from Mirrors/bubbletea
100 lines
1.5 KiB
Go
100 lines
1.5 KiB
Go
package tea
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import (
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"bytes"
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"io"
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"sync"
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"time"
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"github.com/muesli/termenv"
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)
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const (
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defaultFramerate = time.Millisecond * 16
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)
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type renderer struct {
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out io.Writer
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buf bytes.Buffer
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framerate time.Duration
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ticker *time.Ticker
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mtx sync.Mutex
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done chan struct{}
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lastRender string
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linesRendered int
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}
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func newRenderer(out io.Writer) *renderer {
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return &renderer{
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out: out,
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framerate: defaultFramerate,
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}
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}
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func (r *renderer) start() {
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if r.ticker == nil {
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r.ticker = time.NewTicker(r.framerate)
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}
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r.done = make(chan struct{})
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go r.listen()
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}
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func (r *renderer) stop() {
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r.flush()
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r.done <- struct{}{}
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}
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func (r *renderer) listen() {
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for {
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select {
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case <-r.ticker.C:
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if r.ticker != nil {
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r.flush()
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}
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case <-r.done:
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r.mtx.Lock()
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r.ticker.Stop()
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r.ticker = nil
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r.mtx.Unlock()
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close(r.done)
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return
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}
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}
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}
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func (r *renderer) flush() {
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if r.buf.Len() == 0 || r.buf.String() == r.lastRender {
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// Nothing to do
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return
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}
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r.mtx.Lock()
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defer r.mtx.Unlock()
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if r.linesRendered > 0 {
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termenv.ClearLines(r.linesRendered)
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}
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r.linesRendered = 0
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var out bytes.Buffer
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for _, b := range r.buf.Bytes() {
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if b == '\n' {
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r.linesRendered++
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out.Write([]byte("\r\n"))
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} else {
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// TODO: don't write past the terminal width
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_, _ = out.Write([]byte{b})
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}
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}
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_, _ = r.out.Write(out.Bytes())
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r.lastRender = r.buf.String()
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r.buf.Reset()
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}
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func (w *renderer) write(s string) {
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w.mtx.Lock()
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defer w.mtx.Unlock()
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w.buf.WriteString(s)
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}
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