Drag/Drop: Drop indicator doesn't change for drags between QListView and QTableView

[mclark]

When dragging between a QListView and a QTableView the drop indicator does not change, so the QTableView::dropEvent() is never called when releasing the mouse button. But, debugging code in the QTableView::dragEnterEvent() states:

• DropAction: Qt::MoveAction
• DragDropMode: QAbstractItemView:: DropOnly
• DropIndicatorShown: TRUE
• DragDropOverwriteMode: TRUE

I have a QStandardModel that services both a QGraphicsScene/View and the QTableView (the table view is filled via QSortFilterProxyModel class. Drops into the QGraphicsScene work fine.

Any ideas about what I can do to get the QTableView to show a drop indicator and allow dropEvent() to be called?

For reference, this is my table view ctor.

SheetView::SheetView( QWidget* pParent ) : QTableView( pParent )
{
    setSelectionMode( QAbstractItemView::SingleSelection );
    setAcceptDrops( true );
    setDropIndicatorShown( true );
    setDragDropMode( QAbstractItemView::DropOnly );
    setDragDropOverwriteMode( true );
    setSelectionBehavior( QAbstractItemView::SelectRows );
}

SheetView::SheetView( QWidget* pParent ) : QTableView( pParent )
{
    setSelectionMode( QAbstractItemView::SingleSelection );
    setAcceptDrops( true );
    setDropIndicatorShown( true );
    setDragDropMode( QAbstractItemView::DropOnly );
    setDragDropOverwriteMode( true );
    setSelectionBehavior( QAbstractItemView::SelectRows );
}

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Qt Commercial 4.6.2
Windows XP SP3

[mclark]

Still no drop indicator. This seems like such a simple operation but I still can't figure out why it's not working.

I thought that using a proxy model might be causing my problems but the proxy model calls setSupportedDragActions( Qt::CopyAction | Qt::MoveAction ) in the constructor which should handle the model side of things. At the end of the proxy ctor the supported actions are:

• Drop: Qt::CopyAction
• Drag: Qt::CopyAction | Qt::MoveAction

Here is my dragEnterEvent.

void SheetView::dragEnterEvent( QDragEnterEvent* pEvent )
{
    if ( pEvent->mimeData()->hasFormat( MY_MIMETYPE ) )
        pEvent->acceptProposedAction();
    else
        pEvent->setDropAction( Qt::IgnoreAction );
}

void SheetView::dragEnterEvent( QDragEnterEvent* pEvent )
{
    if ( pEvent->mimeData()->hasFormat( MY_MIMETYPE ) )
        pEvent->acceptProposedAction();
    else
        pEvent->setDropAction( Qt::IgnoreAction );
}

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[mclark]

SOLVED:

I guess if I would reimplement all the required functions I would not have this trouble. The default implementation of dragMoveEvent() ignores events. Overridding this function fixes this problem.

void SheetView::dragMoveEvent( QDragMoveEvent* pEvent )
{
    if ( !pEvent->mimeData()->hasFormat( MY_MIMETYPE ) )
    {
        pEvent->ignore();
        return;
    }
 
    pEvent->accept();
}

void SheetView::dragMoveEvent( QDragMoveEvent* pEvent )
{
    if ( !pEvent->mimeData()->hasFormat( MY_MIMETYPE ) )
    {
        pEvent->ignore();
        return;
    }

    pEvent->accept();
}

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