Feature Request Way to force ListView update without a full Refresh.

Let me know if I understand correctly: You want to update the values displayed in the list view every frame to the current ComponentData values.

The cleanest way to do this would be some kind of one-way data-binding, but since the current in-editor DataBindings only supports SerializedObjects/Properties, you will need to poll your ComponentData every frame and assign the values to the VisualElements as they change. If your items UI is simple, it might just involve to use the scheduler to recall your bindItem delegate every frame.

However, if you're using PropertyFields, that might not be the best way performance-wise as the PropertyField currently recreates the actual UI everytime you rebind. Then a mix of UQueries to find the children to update might do the trick.

Something like this:

Code (CSharp):

1.     public class ComponentDataListItem : VisualElement
2.     {
3.         public int BoundItemIndex{get;set;}
4.  
5.         ListView mParentView;
6.  
7.         public ComponentDataListItem(ListView parent)
8.         {
9.             BoundItemIndex = -1;
10.             mParentView = parent;
11.             schedule.Execute( ()=> UpdateValues()).Every(10); //we'll poll values every frame when we're added to the hierarchy
12.         }
13.  
14.         public void UpdateValues()
15.         {
16.             if(BoundItemIndex >= 0 && mParentView != null)
17.             {
18.                 object current = mParentView.itemsSource[BoundItemIndex];
19.  
20.                 //TODO: Update elements values here, ie set a label's text, etc
21.             }
22.         }
23.  
24.     }
25.  
26.     class ComponentDataViewer: EditorWindow
27.     {
28.  
29.         void OnEnable()
30.         {
31.             //[...]
32.             ListView lv = rootElement.Q<ListView>();
33.  
34.             lv.makeItem = () => new ComponentDataListItem(lv);
35.  
36.             lv.bindItem = (element, index) =>
37.             {
38.                 var item = element as ComponentDataListItem;
39.  
40.                 item.BoundItemIndex = index;
41.                 item.UpdateValues();
42.             };
43.         }
44.     }

 

Not sure I understand your needs correctly. Can you provide a small snippet so I can figure out what you're trying to achieve?

The ListView currently requires a fixed height for its elements. Setting ListView.itemHeight should properly refresh the items. However, you need to make sure not to set it to the same value as it will trigger a refresh every time even if the height has not changed. This behavior is less than ideal and will be improved in the future.