Solved: Problem with const in dragMoveEvent

Rory_1

I'm a beginner and struggling with const, so I'm hoping someone here can help me "over the hump". I am trying to subclass QTextEdit to intercept a drag from a QListWidget. I need to determine what the text is in the QListItem and set the QMimeData data to text/plain. Here is what I have so far:

@void TextEditDrop::dragEnterEvent(QDragEnterEvent *e)
{
const QMimeData *mimeData = e->mimeData();
QByteArray encoded = mimeData->data("application/x-qabstractitemmodeldatalist");
QDataStream stream(&encoded, QIODevice::ReadOnly);
QString item;
int row, col;
QMap<int, QVariant> roleDataMap;
while (!stream.atEnd())
{
stream >> row >> col >> roleDataMap;
item = roleDataMap.value( Qt::DisplayRole ).toString();
}

// Next statement generates error
// error: C2662: 'QMimeData::setText' : cannot convert 'this' pointer from 
//               'const QMimeData' to 'QMimeData &'
mimeData->setText(item);

// this also does not work:
mimeData->setText(const_cast<QString>(item));  // cannot convert from QString to QString

}@

I believe I have to const_cast item but I have not been able to discover a syntax that works. Any help much appreciated.

Sam

First of all you need to perform your operations in dropEvent(), Secondly why are you using const QMimeData you can use QMimeData instead.

Check "Drag and Drop Puzzle Example":http://qt-project.org/doc/qt-4.8/draganddrop-puzzle.html

Rory_1

Thanks. I'll check out the example.

Rory_1

I solved this issue by subclassing QListWidget::startDrag and creating a QMimeData->setText.