Question

I have a Qt application that contains a QTreeWidget.
I want to replace one of the items.

I have a pointer:

QTreeWidgetItem *elementToSubstitute;

and a function that returns a QTreeWidgetItem*.

I want to overwrite the previous one with this new element, in the same place.
If I delete the previous element and insert the new one after that, the new item is placed at the bottom of the tree.

How should I proceed to have the new branch replace exactly the previous one?

EDIT for example

---

void MainWindow::addRoot(QString name ,QString description)
{
    QTreeWidgetItem *itm = new QTreeWidgetItem(ui->tree);
    itm->setText(0,name);
    itm->setText(1,description);

    QTreeWidgetItem *child1 = addChild(itm,"one","hello");
    QTreeWidgetItem *child2 = addChild(itm,"two","hello");
    QTreeWidgetItem *child3 = addChild(itm,"tree","hello");
    QTreeWidgetItem *child4 = addChild(itm,"four","hello");


    QTreeWidgetItem *parent = child2->parent(); 
    int itemIndex = parent-indexOfChid(child2); 
    parent->removeChild(child2); 
    parent->insertChild(itemIndex, child4 );

}

QTreeWidgetItem MainWindow::addChild(QTreeWidgetItem *parent,QString name ,QString description)
{
    QTreeWidgetItem *itm = new QTreeWidgetItem();
    itm->setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled );
    itm->setText(0,name);
    itm->setText(1,description);

    addChild2(itm,"sub-one","subchild2");
    addChild2(itm,"sub-two","subchild2");
    addChild2(itm,"sub-tree","subchild2");

    parent->addChild(itm);
    return itm;

}

void MainWindow::addChild2(QTreeWidgetItem *parent,QString name ,QString description)
{
    QTreeWidgetItem *itm = new QTreeWidgetItem();

    itm->setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled | Qt::ItemIsEditable);

    itm->setText(0,name);
    itm->setText(1,description);
    itm->setText(2,"test third coloumn");
    parent->addChild(itm);
}

…..

Now i have a pointer to one of the chiled. ( let’s sa of level 1) ans i want to replace it with another. for instance i want to replace child “2” with child “4” but i want this to be put in the place f child 2.

Answer 1

You could try doing something like this:

QTreeWidgetItem *parent = elementToSubstitute->parent();
int itemIndex = parent->indexOfChid(elementToSubstitute);
parent->removeChild(elementToSubstitute);
parent->insertChild(itemIndex, yourNewTreeItem);

Note: if yourNewTreeItem is already in the tree, this will have no effect on its position, i.e. it will not duplicate a node.