resize.go RawHistoryFolder

1package term
2
3import (
4	"os"
5
6	"github.com/bnema/vev/internal/domain"
7)
8
9// resizeLoop watches sig for signal notifications (SIGWINCH in
10// production) and emits the coalesced terminal geometry on out: a burst of
11// signals collapses to a single emitted value, since any signals still
12// queued once the first is observed are drained before querying the
13// geometry. getGeometry is called to resolve the value to emit; an error is
14// treated as "no event this round" and the loop continues waiting.
15//
16// The loop exits and closes out when quit is closed.
17func resizeLoop(sig <-chan os.Signal, out chan<- domain.Geometry, quit <-chan struct{}, getGeometry func() (domain.Geometry, error)) {
18	defer close(out)
19	for {
20		select {
21		case <-quit:
22			return
23		case <-sig:
24			drainSignals(sig)
25			geometry, err := getGeometry()
26			if err != nil {
27				continue
28			}
29			select {
30			case out <- geometry:
31			case <-quit:
32				return
33			}
34		}
35	}
36}
37
38// drainSignals removes any currently queued signals from sig without
39// blocking. Called right after receiving one signal, it collapses a
40// burst that arrived (or queued up) concurrently into that single
41// wakeup.
42func drainSignals(sig <-chan os.Signal) {
43	for {
44		select {
45		case <-sig:
46		default:
47			return
48		}
49	}
50}