add support for retrieving tracers

gst/gst_tracer.go

@@ -0,0 +1,29 @@
+package gst
+
+// #include "gst.go.h"
+import "C"
+import (
+	"unsafe"
+
+	"github.com/go-gst/go-glib/glib"
+)
+
+type Tracer struct {
+	*Object
+}
+
+func TracingGetActiveTracers() []*Tracer {
+	cglist := C.gst_tracing_get_active_tracers()
+
+	wrapped := glib.WrapList(unsafe.Pointer(cglist))
+	defer wrapped.Free()
+
+	out := make([]*Tracer, 0)
+	wrapped.Foreach(func(item interface{}) {
+		ctracer := item.(unsafe.Pointer) // item is a *C.GstTracer
+		out = append(out, &Tracer{
+			Object: wrapObject(glib.Take(ctracer)),
+		})
+	})
+	return out
+}