ui/app: (macOS) use CFTypeRef for the view factory

The os and gl packages were separate in the past, which required
uintptr for cross-package CFTypeRefs. That's no longer needed.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/app/gl_macos.go

@@ -25,8 +25,8 @@ type context struct {
 }
 
 func init() {
-	viewFactory = func() uintptr {
-		return uintptr(C.gio_createGLView())
+	viewFactory = func() C.CFTypeRef {
+		return C.gio_createGLView()
 	}
 }
 

ui/app/os_macos.go

@@ -43,7 +43,7 @@ var singleWindow struct {
 	opts    *WindowOptions
 }
 
-var viewFactory func() uintptr
+var viewFactory func() C.CFTypeRef
 
 var views = make(map[C.CFTypeRef]*window)
 
@@ -200,7 +200,7 @@ func createWindow(opts *WindowOptions) error {
 }
 
 func Main() {
-	view := C.CFTypeRef(viewFactory())
+	view := viewFactory()
 	if view == 0 {
 		// TODO: return this error from CreateWindow.
 		panic(errors.New("CreateWindow: failed to create view"))