Transfer Items between Views with Drag-and-Drop in

问题:

I have 2 views in my application. In one of the views I can see a TreeStructure containing custom defined elements (such as MDocument, MVersion...).

I would like to be able to drag items of type MVersion from my view to the other one but I don't know how to declare the transfer types or to check if the item selected is a supported type.

Any ideas?

回答1:

The easiest way is to use LocalSelectionTransfer. Once you have added drag/drop support to your viewers...

You set the ISelection that is dragged in DragSourceListener.dragStart() method:

LocalSelectionTransfer.getTransfer().setSelection(selection);

In the DropTargetListener.drop() you check if the type is supported and retrieve the selection:

if (LocalSelectionTransfer.getTransfer().isSupportedType(event.currentDataType))
    ISelection sel = LocalSelectionTransfer.getTransfer().getSelection();
    ...