nativeaudio

commit 54d36e7969249bef53db07591ffd595cc19bcd05
parent 8b40d468a0c715b6d0ad4b18fa6b6e6bbb531d78
Author: Jack Mordaunt <jackmordaunt.dev@gmail.com>
Date:   Fri,  5 Jan 2024 18:23:20 +0800

internal: TriggerReader

This type triggers a callback when it's internal Reader hits EOF.

This is useful with ebitengine/oto/v3 because it doesn't provide a nice
way to detect end of playback.

Signed-off-by: Jack Mordaunt <jackmordaunt.dev@gmail.com>

Diffstat:
A
internal/trigger-reader.go
 | 
27
+++++++++++++++++++++++++++

1 file changed, 27 insertions(+), 0 deletions(-)
diff --git a/internal/trigger-reader.go b/internal/trigger-reader.go
@@ -0,0 +1,27 @@
+package internal
+
+import "io"
+
+// TriggerReader invokes a callback when EOF is reached.
+type TriggerReader struct {
+	r  io.Reader
+	cb func()
+}
+
+func NewTriggerReader(src io.Reader, cb func()) *TriggerReader {
+	return &TriggerReader{r: src, cb: cb}
+}
+
+func (t *TriggerReader) Read(p []byte) (n int, err error) {
+	n, err = t.r.Read(p)
+	if err == io.EOF {
+		t.Callback()
+	}
+	return n, err
+}
+
+func (t *TriggerReader) Callback() {
+	if t.cb != nil {
+		t.cb()
+	}
+}