Qt4 drop (xml)files from win explorer rejected by TableModel - windows

Question

I got a project that required drag & drop xml files from windows explorer into a TableModel, whatever I tried, that widget rejects(with the annoying block icon) the process and not any functions below are called.
i've tried the following:
reimplement QAbstarctTableView::flags to support drag & drop
remiplement QAbstractTableView::supportedDropActions.
remiplement QAbstractTableView::mimeTypes. return "text/uri-list", "text/plain", "application/xml", "text/xml". (some said that "text/uri-list" shall be enough.)
according to most posts i found in the internet, I shall be able to drag files into the TableView Widget now. That's not true for me. T_T
here's my code.
// set the flags to accept drop & drag
Qt::ItemFlags XMLFileModel::flags(const QModelIndex& index) const {
Qt::ItemFlags defaultFlags = Qt::ItemIsEditable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
if (index.isValid())
return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled | defaultFlags;
else
return Qt::ItemIsDropEnabled | defaultFlags;
}
.
// drop mime data
bool XMLFileModel::dropMimeData(const QMimeData *data,
Qt::DropAction action, int row, int column, const QModelIndex &parent)
{
qDebug() << "Drop Mime data" << endl;
if (action == Qt::IgnoreAction)
return true;
if (! data->hasUrls())
return false;
QList<QUrl> urls = data->urls();
foreach(QUrl url , urls) {
std::shared_ptr<QFile> file(new QFile(url.path()));
if (! file->open(QIODevice::ReadOnly | QIODevice::Text))
{
QMessageBox::warning(NULL, QString("note"), QString("unable to open file!"));
return false;
}
XMLFilePtr xml(new XMLFile(file->fileName(), file));
addXMLFile(xml);
}
return true;
}
.
Qt::DropActions XMLFileModel::supportedDropActions() const
{
qDebug () << "supportedDropActions";
return Qt::CopyAction | Qt::MoveAction;
}
.
// define the acceptable mime type
QStringList XMLFileModel::mimeTypes() const
{
qDebug () << "mimeTypes";
QStringList types;
types << "text/uri-list" << "text/plain" << "application/xml" << "text/xml";
qDebug() << types;
return types;
}
.
I tried to add
QMimeData* mimeData(const QModelIndexList &indexes) const;
and now I could drag&drop inside the tableview or even between table views. debug messages print as well.
then I continued to do the test.
I wrote a test class:
class test : public QTableView
{
Q_OBJECT
public:
explicit test(QWidget *parent = 0);
virtual void dropEvent(QDropEvent *event);
virtual void dragEnterEvent ( QDragEnterEvent * event );
void startDrag ( Qt::DropActions supportedActions );
};
.
void test::dropEvent(QDropEvent *event) {
qDebug() << "test";
qDebug() << event->mimeData()->formats();
event->accept();
}
void test::dragEnterEvent(QDragEnterEvent *event) {
qDebug() << "drag enter";
qDebug() << event->mimeData();
event->accept();
}
void test::startDrag(Qt::DropActions supportedActions) {
qDebug() << "true";
}
.
and add a new test widget in the mainWindow that accepts the same model.
It amazed me that drag&drop internally or between table views is still working. but when I tried to drop the item from my desktop, none of these three functions are called.
now I am thinking that the problem might be the incompatible mime-type between my OS and Qt D&D framework. I may not return the right mime type
any one suffered and solved this problem or any suggestions? >_<
= = = = = = = =
hey, I got the same problem with the drop site example, too!

Answer 1

I don't think you need to reimplement any of those functions except for dragEnterEvent and dropEvent. Did you call QWidget::setAcceptDrops(true)? This is important.