static object ListField <T>(object v, Type type, Func <T, int, string, object> customElementGUI)
{
var list = v as IList;
var hasElem = (list != null) && list.Count > 0;
var elemType = TypeUtility.GetListInterface(type).GetGenericArguments().First();
var addIdx = -1;
var deleteIdx = -1;
using (new GUILayout.VerticalScope("box"))
{
if (v == null)
{
WarningLabelNoStyle("List is null.");
}
else if (!hasElem)
{
WarningLabelNoStyle("List is empty.");
}
else
{
for (var i = 0; i < list.Count; ++i)
{
var label = TypeUtility.IsMultiLine(elemType) ? $"Element {i}" : null;
using (new IndentScope(20f))
{
list[i] = (customElementGUI != null)
? customElementGUI((T)list, i, label)
: Field(list[i], elemType, label);
}
var result = PopupOnLastRect(ListPopupButtonNames, 1);
switch (result)
{
case 0:
addIdx = i + 1;
break;
case 1:
deleteIdx = i;
break;
}
}
}
if (addIdx >= 0)
{
list = AddElement(list, elemType, list[addIdx - 1], addIdx);
}
if (deleteIdx >= 0)
{
list = DeleteElement(list, elemType, deleteIdx);
}
// +/- button
using (new GUILayout.HorizontalScope())
{
GUILayout.FlexibleSpace();
var width = GUILayout.Width(20f);
if (GUILayout.Button("+", width))
{
if (list == null)
{
list = (IList)Activator.CreateInstance(type, 0);
}
var baseElem = hasElem ? list[list.Count - 1] : null;
list = AddElement(list, elemType, baseElem, list.Count);
}
using (new EnabledScope(hasElem))
{
if (GUILayout.Button("-", width))
{
list = DeleteElement(list, elemType, list.Count - 1);
}
}
}
}
return(list);
}