[Qt-interest] Drag & Drop of hierachical items in a TreeView

[Daniel Price]

I'm trying to figure how to do drag and drop editing of hierarchical data within an QAbstractItemModel-derived adaptor within a QTreeView.

Single items with no children seem to work fine (I'm only interested in moving data, not copying it). However if I move an item with children, the children are lost and I'm not sure how I can preserve them as the dropMimeData() virtual only gives me the mime data and drop target.

I can think of same ways around this but I don't know what the 'best practice' solution would be:

1)      Encode the QModelIndex of the original item into the mime data (QDataStream) and use it to recursively iterate through and reconstruct the tree in the drop location (it seems that the source items are not removed until after dropMimeData() is called so the index should remain valid).

2)      Cache the source model index somewhere when a drag is initiated (mimeData()?) and do the above.

Any suggestions? Has anyone got this working?


Daniel Price
Software Engineer
FXhome Limited

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FXhome Limited is a limited company registered in England and Wales. Registered number: 04172812. Registered office: The Henderson Business Centre, Ivy Road, Norwich, Norfolk, NR5 8BF, U.K.
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