dropping on headerItem

[drhex]

Hi fellow hackers!

In QT-4.1.4, I'm trying to drop something on A QTreeWidget's headerItem(), with little success.

In the short example below, I can drag "Node 1" and "Node 2" and drop them on each other, but QT won't let me drop on the headerItem ("Node 0") even though I've set its ItemIsDropEnabled-flag. What can be done?

#include <QApplication>
#include <QTreeWidgetItem>
 
#define S(qstring) (qstring).toLatin1().constData()
 
class Tree : public QTreeWidget
{
  public:
    Tree() : QTreeWidget() {
        setColumnCount(1);
        setDragEnabled(true);
        setAcceptDrops(true);
    }
    bool dropMimeData(QTreeWidgetItem *droppedOn, int, const QMimeData *, Qt::DropAction) {
        qDebug("Something dropped on %s", S(droppedOn->text(0)));
        return true;
    }
};
 
 
int main( int argc, char **argv )
{
    QApplication app( argc, argv );
 
    QTreeWidget *tree = new Tree;
 
    QTreeWidgetItem *i;
 
    i = new QTreeWidgetItem(tree);
    i->setText(0, "Node 1");
    i->setFlags(i->flags() | Qt::ItemIsDropEnabled);
 
    i = new QTreeWidgetItem(tree);
    i->setText(0, "Node 2");
    i->setFlags(i->flags() | Qt::ItemIsDropEnabled);
 
    tree->headerItem()->setText(0,"Node 0");
    tree->headerItem()->setFlags(tree->headerItem()->flags() | Qt::ItemIsDropEnabled);
 
    tree->show();
    app.exec();
    return 0;
}

#include <QApplication>
#include <QTreeWidgetItem>

#define S(qstring) (qstring).toLatin1().constData()

class Tree : public QTreeWidget
{
  public:
    Tree() : QTreeWidget() {
        setColumnCount(1);
        setDragEnabled(true);
        setAcceptDrops(true);
    }
    bool dropMimeData(QTreeWidgetItem *droppedOn, int, const QMimeData *, Qt::DropAction) {
        qDebug("Something dropped on %s", S(droppedOn->text(0)));
        return true;
    }
};


int main( int argc, char **argv )
{
    QApplication app( argc, argv );

    QTreeWidget *tree = new Tree;

    QTreeWidgetItem *i;

    i = new QTreeWidgetItem(tree);
    i->setText(0, "Node 1");
    i->setFlags(i->flags() | Qt::ItemIsDropEnabled);

    i = new QTreeWidgetItem(tree);
    i->setText(0, "Node 2");
    i->setFlags(i->flags() | Qt::ItemIsDropEnabled);

    tree->headerItem()->setText(0,"Node 0");
    tree->headerItem()->setFlags(tree->headerItem()->flags() | Qt::ItemIsDropEnabled);

    tree->show();
    app.exec();
    return 0;
}

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[wysota]

ItemIsDropEnabled means that you can drop some other item on this item and not that you can drop this item at all (ItemIsDragEnabled does that). I think that if you want to support dropping on headers, you have to reimplement the low level mechanisms for dropping (dragEnterEvent and family).