Infralution Support

[rnemchev]

Hi,

I have implemented drag and drop using appropriate events of the virtual tree. However when I set drag/drop effect to DragDropEffects.Link in GetRowDropEffect handler the shown cursor is wrong - instead of link cursor I get DragDropEffects.None (forbidden) cursor. When I set drag/drop effect to Move or Copy everything is OK (the proper cursors are shown).
I tried to set my own cursor using ViretualTree.DragLinkCursor property but without success.

Can you give me a clue?

[Infralution]

Are you trying to drag into or from VirtualTree (or both)?

I think that probably you have handled the GetRowDropEffect event however you haven't handled the GetAllowedRowDropLocations event. If you are dragging custom data into VirtualTree then you will need to handle this event and set the e.AllowedDropLocations - otherwise you won't be allowed to drop the data. I've checked by modifying the Simple Tree sample and was able to set the RowDropEffect to link without any issues (ie it displayed the link cursor).
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Infralution Support

[rnemchev]

I have handled both GetRowDropEffect event and GetAllowedRowDropLocations event. I suspect that because my drag starts from the tree and the drop is in the same tree the link behavior is not allowed.

This is my implementation (I am using custom IList implementation for binding):

protected override RowDropLocation AllowedRowDropLocations( Row row, IDataObject data )
{
return RowDropLocation.OnRow;
}
protected override bool AllowRowDrag( Row row )
{
return true;
}
protected override DragDropEffects RowDropEffect( Row row, RowDropLocation dropLocation, IDataObject data )
{
return DragDropEffects.Link;
}

[Infralution]

You are right there is an issue when Virtual Tree is the source of the drag event. The reason for this is rather curious. To initiate the drag operation the RowWidget.DoDragDrop method calls:

[rnemchev]

Thank you! Your solution works fine.

Rado

[Infralution]

Version 3.15.1 has now been released and fixes this issue (so that you do not need to override DoDragDrop)
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Infralution Support