[qooxdoo-devel] Drag & Drop target widget problem

[bibliograph <in...@bi...>]

Hello,

Derrell and I are working on finalizing the drag & drop support for the 
TreeVirtual and have run into a problem that requires deeper knowledge 
about the drag&drop operations. During a drag session *within* a 
TreeVirtual, the sourceWidget property of the dragCache object passed to 
the supportsDrop method is not (always?) the TreeVirtual widget 
instance, but a HorizontalBoxLayout widget instance. I could not find 
out what object this referred to. I tested this on Firefox and IE7. For 
a correct supportsDrop check, however, the reference passed must be the 
TreeVirtual itself.

To reproduce this, try the "TreeVirtual_6" example in the demobrowser in 
a up-to-date legacy_07 branch. In the left tree, try to drag "Message 
#1" on the folders above it (Such as "Inbox"). Even though the 
MDragAndDropSupport._supportsDrop method returns true for these folders, 
dropping is denied because the DragDrop manager sees a 
HorizontalBoxLayout and not the TreeVirtual. This is different, however, 
if I drag nodes from the right tree to the left tree. Then everything 
works well, because the "dropOnSelf" check is bypassed.

Christian