chore: import upstream snapshot with attribution

debounce/debounce.go

@@ -0,0 +1,58 @@
+package debounce
+
+import (
+	"fmt"
+	"time"
+)
+
+func NewDebouncer(timeout time.Duration, callback func()) *Debouncer {
+	var debouncer Debouncer
+	debouncer.setTimeout(timeout)
+	debouncer.setCallback(callback)
+	return &debouncer
+}
+
+type Debouncer struct {
+	callback func()
+	running  bool
+	canceled bool
+	timeout  time.Duration
+	timer    *time.Timer
+}
+
+func (d *Debouncer) setTimeout(timeout time.Duration) {
+	// TODO: Return err if d.running
+	d.timeout = timeout
+}
+
+func (d *Debouncer) setCallback(callback func()) {
+	callbackWrapped := func() {
+		if !d.canceled {
+			callback()
+		}
+		d.running = false
+	}
+
+	d.callback = callbackWrapped
+}
+
+func (d *Debouncer) Cancel() {
+	d.canceled = true
+}
+
+func (d *Debouncer) SetOn() error {
+	if d.canceled {
+		return fmt.Errorf("debouncer cancelled")
+	}
+	if d.running {
+		return nil
+	}
+
+	d.running = true
+	d.timer = time.AfterFunc(d.timeout, d.callback)
+	return nil
+}
+
+func (d *Debouncer) IsOn() bool {
+	return d.running
+}