Added workaround for drawer labels with PropertyFields

Author: Antoine Lelievre

Editor/Resources/GraphProcessorStyles/BaseNodeView.uss

@@ -247,4 +247,10 @@ ParameterNodeView #controls EnumField > VisualElement > VisualElement {
     width: 16px;
     height: 16px;
     margin: 4px;
+}
+
+/* In Unity 2020.3, we need to manually hide labels of property fields with empty label */
+.DrawerField_2020_3 > * > Label
+{
+    display: none;
 }

Editor/Views/BaseNodeView.cs

@@ -841,6 +841,11 @@ protected VisualElement AddControlField(FieldInfo field, string label = null, bo
 			var element = new PropertyField(FindSerializedProperty(field.Name), showInputDrawer ? "" : label);
 			element.Bind(owner.serializedGraph);
 
+#if UNITY_2020_3 // In Unity 2020.3 the empty label on property field doesn't hide it, so we do it manually
+			if (showInputDrawer && element != null)
+				element.AddToClassList("DrawerField_2020_3");
+#endif
+
 			element.RegisterValueChangeCallback(e => {
 				UpdateFieldVisibility(field.Name, field.GetValue(nodeTarget));
 			});