From 39f6476b8429079e079fa691e2bb40cdd072341b Mon Sep 17 00:00:00 2001
From: Robert Lillack <rob@lillack.net>
Date: Sat, 29 Jun 2024 17:52:47 +0200
Subject: [PATCH] image: Fix crash when `Image` property is `nil` pointer. #18

---
 ui/image_cocoa.go |  4 +++-
 ui/image_fltk.go  |  2 +-
 ui/imgutils.go    | 19 +++++++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 ui/imgutils.go

diff --git a/ui/image_cocoa.go b/ui/image_cocoa.go
index c384cdd..1387ab7 100644
--- a/ui/image_cocoa.go
+++ b/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))
 	}
diff --git a/ui/image_fltk.go b/ui/image_fltk.go
index 35296ed..00b8d33 100644
--- a/ui/image_fltk.go
+++ b/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
 	}
 
diff --git a/ui/imgutils.go b/ui/imgutils.go
new file mode 100644
index 0000000..639cb2b
--- /dev/null
+++ b/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
+}