audio/internal/readdriver: Bug fix: Implement Suspend/Resume for browsers

Closes #1630

audio/audio.go

@@ -127,9 +127,15 @@ func NewContext(sampleRate int) *Context {
 	h := getHook()
 	h.OnSuspendAudio(func() {
 		c.semaphore <- struct{}{}
+		if s, ok := np.(interface{ suspend() }); ok {
+			s.suspend()
+		}
 	})
 	h.OnResumeAudio(func() {
 		<-c.semaphore
+		if s, ok := np.(interface{ resume() }); ok {
+			s.resume()
+		}
 	})
 
 	h.AppendHookOnBeforeUpdate(func() error {

audio/internal/readerdriver/driver.go

@@ -21,6 +21,8 @@ import (
 type Context interface {
 	NewPlayer(io.Reader) Player
 	MaxBufferSize() int
+	Suspend()
+	Resume()
 	io.Closer
 }
 

audio/internal/readerdriver/driver_js.go

@@ -139,6 +139,14 @@ func (c *context) MaxBufferSize() int {
 	return c.oneBufferSize() * 2
 }
 
+func (c *context) Suspend() {
+	c.audioContext.Call("suspend")
+}
+
+func (c *context) Resume() {
+	c.audioContext.Call("resume")
+}
+
 func (p *player) Pause() {
 	if p.state != playerPlay {
 		return
@@ -299,6 +307,14 @@ func (w *go2cppDriverWrapper) MaxBufferSize() int {
 	return w.c.MaxBufferSize()
 }
 
+func (w *go2cppDriverWrapper) Suspend() {
+	// Do nothing so far.
+}
+
+func (w *go2cppDriverWrapper) Resume() {
+	// Do nothing so far.
+}
+
 func (w *go2cppDriverWrapper) Close() error {
 	return w.c.Close()
 }

audio/readerplayer.go

@@ -60,6 +60,20 @@ func (f *readerPlayerFactory) newPlayerImpl(context *Context, src io.Reader) (pl
 	return p, nil
 }
 
+func (f *readerPlayerFactory) suspend() {
+	if f.context == nil {
+		return
+	}
+	f.context.Suspend()
+}
+
+func (f *readerPlayerFactory) resume() {
+	if f.context == nil {
+		return
+	}
+	f.context.Resume()
+}
+
 func (p *readerPlayer) ensurePlayer() error {
 	// Initialize the underlying player lazily to enable calling NewContext in an 'init' function.
 	// Accessing the underlying player functions requires the environment to be already initialized,