osx: implements quicklook

osx/kordophone2/XPC/XPCConvertible.swift

@@ -76,6 +76,22 @@ extension Array: XPCConvertible where Element: XPCConvertible
     }
 }
 
+extension Bool: XPCConvertible
+{
+    static func fromXPC(_ value: xpc_object_t) -> Bool? {
+        if xpc_get_type(value) == XPC_TYPE_BOOL {
+            return xpc_bool_get_value(value)
+        }
+
+        if xpc_get_type(value) == XPC_TYPE_STRING {
+            guard let cstr = xpc_string_get_string_ptr(value) else { return nil }
+            return strcmp(cstr, "true") == 0
+        }
+
+        return nil
+    }
+}
+
 extension xpc_object_t
 {
     func getObject(_ key: String) -> xpc_object_t? {