Actually added GTK+ ProgressBar this time.

progressbar_unix.go

@@ -0,0 +1,38 @@
+// +build !windows,!darwin
+
+// 4 november 2014
+
+package ui
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+// #include "gtk_unix.h"
+import "C"
+
+type progressbar struct {
+	*controlSingleWidget
+	pbar		*C.GtkProgressBar
+}
+
+func newProgressBar() ProgressBar {
+	widget := C.gtk_progress_bar_new();
+	p := &progressbar{
+		controlSingleWidget:	newControlSingleWidget(widget),
+		pbar:				(*C.GtkProgressBar)(unsafe.Pointer(widget)),
+	}
+	return p
+}
+
+func (p *progressbar) Percent() int {
+	return int(C.gtk_progress_bar_get_fraction(p.pbar) * 100)
+}
+
+func (p *progressbar) SetPercent(percent int) {
+	if percent < 0 || percent > 100 {
+		panic(fmt.Errorf("given ProgressBar percentage %d out of range", percent))
+	}
+	C.gtk_progress_bar_set_fraction(p.pbar, C.gdouble(percent) / 100)
+}