image: Fix crash when Image property is nil pointer. #18

ui/image_cocoa.go

@@ -65,7 +65,9 @@ func (c *Image) draw() {
 
 	switch img := c.Image.(type) {
 	case *image.RGBA:
-		c.ref.SetImage(img)
+		if img != nil {
+			c.ref.SetImage(img)
+		}
 	default:
 		panic(fmt.Sprintf("unsupported image type: %T", img))
 	}

ui/image_fltk.go

@@ -75,7 +75,7 @@ func (c *Image) handleEvent(e goFltk.Event) bool {
 }
 
 func (c *Image) draw() {
-	if c.ref == nil {
+	if c.ref == nil || isImageNil(c.Image) {
 		return
 	}
 

ui/imgutils.go

@@ -0,0 +1,19 @@
+package ui
+
+import (
+	"image"
+	"reflect"
+)
+
+func isImageNil(i image.Image) bool {
+	if i == nil {
+		return true
+	}
+
+	switch reflect.TypeOf(i).Kind() {
+	case reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice:
+		return reflect.ValueOf(i).IsNil()
+	}
+
+	return false
+}