document that a valid image list is required for item dragging under MSW (see #4390)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60052 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/interface/wx/treectrl.h b/interface/wx/treectrl.h
index d4da034876e48b71efbd491eb3a8112bc0972e81..38bf3342f688ed1bc925e8c56dee124043313ab2 100644 (file)
--- a/interface/wx/treectrl.h
+++ b/interface/wx/treectrl.h
@@ -920,13 +920,15 @@ public:
 
     @beginEventTable{wxTreeEvent}
     @event{EVT_TREE_BEGIN_DRAG(id, func)}
-        Begin dragging with the left mouse button.
-          If you want to enable left-dragging you need to intercept this event
-          and explicitely call wxTreeEvent::Allow(), as it's vetoed by default.
+        Begin dragging with the left mouse button. If you want to enable
+        left-dragging you need to intercept this event and explicitely call
+        wxTreeEvent::Allow(), as it's vetoed by default. Also notice that the
+        control must have an associated image list (see SetImageList()) to
+        drag its items under MSW.
     @event{EVT_TREE_BEGIN_RDRAG(id, func)}
-          Begin dragging with the right mouse button.
-          If you want to enable right-dragging you need to intercept this event
-          and explicitely call wxTreeEvent::Allow(), as it's vetoed by default.
+        Begin dragging with the right mouse button. If you want to enable
+        right-dragging you need to intercept this event and explicitely call
+        wxTreeEvent::Allow(), as it's vetoed by default.
     @event{EVT_TREE_END_DRAG(id, func)}
         End dragging with the left or right mouse button.
     @event{EVT_TREE_BEGIN_LABEL_EDIT(id, func)}