expose clock types and ToGstClock, add convinience function to create a SystemClock

gst/gst_clock.go

@@ -167,6 +167,17 @@ func FromGstClockUnsafeFull(clock unsafe.Pointer) *Clock {
 	return wrapClock(glib.TransferFull(clock))
 }
 
+// ToGstClock wraps the given glib.Object or gst.Object in a Clock instance.
+func ToGstClock(obj interface{}) *Clock {
+	switch obj := obj.(type) {
+	case *Object:
+		return &Clock{Object: obj}
+	case *glib.Object:
+		return wrapClock(obj)
+	}
+	return nil
+}
+
 // Instance returns the underlying GstClock instance.
 func (c *Clock) Instance() *C.GstClock { return C.toGstClock(c.Unsafe()) }
 

gst/gst_system_clock.go

@@ -4,12 +4,45 @@ package gst
 import "C"
 import (
 	"unsafe"
+
+	"github.com/go-gst/go-glib/glib"
 )
 
 // SystemClock wraps GstSystemClock
 type SystemClock struct{ *Clock }
 
+var TYPE_SYSTEM_CLOCK = glib.Type(C.GST_TYPE_SYSTEM_CLOCK)
+
+// ClockType represents GstClockType
+type ClockType int
+
+const (
+	//time since Epoch
+	ClockTypeRealtime = C.GST_CLOCK_TYPE_REALTIME
+	//monotonic time since some unspecified starting point
+	ClockTypeMonotonic = C.GST_CLOCK_TYPE_MONOTONIC
+	// some other time source is used (Since: 1.0.5)
+	ClockTypeOther = C.GST_CLOCK_TYPE_OTHER
+	// time since Epoch, but using International Atomic Time as reference (Since: 1.18)
+	ClockTypeTAI = C.GST_CLOCK_TYPE_TAI
+)
+
 // ObtainSystemClock returns the default SystemClock.
 func ObtainSystemClock() *SystemClock {
 	return &SystemClock{FromGstClockUnsafeFull(unsafe.Pointer(C.gst_system_clock_obtain()))}
 }
+
+// NewSystemClock creates a new instance of a SystemClock, with the given clock type parameter
+//
+// This is only a convenience wrapper for glib.NewObjectWithProperties
+func NewSystemClock(clockType ClockType) (*SystemClock, error) {
+	clockObj, err := glib.NewObjectWithProperties(TYPE_SYSTEM_CLOCK, map[string]any{
+		"clock-type": clockType,
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &SystemClock{ToGstClock(clockObj)}, nil
+}