Sorting an Array within a SerializedProperty

So, I've hit that speedbump: How can I sort an array that I have only within a SerializedProperty? Granted, I could cast it to the proper array and then sort it but I kinda want to avoid that. Any ideas?

 

You could implement sort as normal, by using GetArrayElementAtIndex to compare the objects and MoveArrayElement to swap in-place. Implenting QuickSort or whatever based on that should be trivial.

Casting to the proper array and doing an Array.Sort sounds a lot easier, though, and built-in sorts are very well optimized.

 

Hm. Is there a way to make that undoable then? Also casting the SerializedProperty to a List gives me the "type is not a supported pptr value" error.

 

Yeah, the SerializedProperty is not the array, it's a wrapper around the array. I'm pretty sure the array (or List if that's what you're using) is hiding in the .objectReferenceValue of the serializedProperty.

You'll have to check if calling ApplyModifiedProperties on the SerializedObject (as you're already doing, right?) enables you to Undo the operation. If not, you'll have to register an Undo yourself, through the Undo class.

 

Bit of a thread necro but in case anyone else finds this - MoveArrayElement does not swap-in-place but instead removes the element at the source index and inserts it at the destination index. Had me scratching my head for a while.

 

Code (CSharp):

1. private static void Swap(SerializedProperty list, int x, int y)
2.         {
3.             if (x == y) return;
4.  
5.             if (x > y) (x, y) = (y, x);
6.  
7.             list.MoveArrayElement(x, y);
8.  
9.             if (y - x != 0) list.MoveArrayElement(y - 1, x);
10.         }