Fetch values from QWidgets added to QTreeWidgets via QTreeWidgetItems

Question

I've searched many places and found lots of interesting information, but none of that seems to work for what I want. I've tried to follow the solution shown at https://stackoverflow.com/a/9986293/11035837 to no avail.

Basics of my structure: I have a QTreeWidget. I add top level QTreeWidgetItems dynamically (upon the push of a button in a header button box). Each top level QTreeWidgetItem then gets other widgets added to it using:

    QTreeWidget* treeWidget = new QTreeWidget;
    QTreeWidgetItem* new_record = new QTreeWidgetItem;
    QPushButton* add_child = new QPushButton;
    QLineEdit* user_input = new QLineEdit;
    treeWidget->setItemWidget(new_record,1,add_child);
    treeWidget->setItemWidget(new_record,2,user_input);

The add_child button works perfectly. I have a display that inserts all my QLabels, QLineEdits, and QPushButtons in a tree tiered fashion. My buttons work for adding and removing the visual display of items even triggering the visibility of various other elements.

However, I cannot get the user input data out of the QLineEdits to process for anything (such as writing to an output file).

I have my output function iterate through the QTreeWidget:

    QTreeWidgetItemIterator iter(treeWidget);
    while (*iter) 
    {
        stream.writeStartElement("record");
        if ((*iter) != nullptr)
        {
            for (int i = 0; i < 12; i++)
            {
                if((*iter)->text(i) != nullptr) stream.writeAttribute("record_name", (*iter)->text(i));
            }
        }
        for (int i = 0; i < 12; i++)
        {
            if ((*iter) != nullptr && (*iter)->child(i) != nullptr)
            {
                for (int j = 0; j < 12; j++)
                {
                    if ((*iter)->child(i)->text(j) != nullptr)  stream.writeAttribute("record_name", (*iter)->child(i)->text(j));
                }
            }
        }
        ++iter;
    }

This prints as many records with record_name displayed as were created, but it doesn't display any of the other data, because the pointer defined by (*iter)->child(i) is nullptr regardless of i

I then tried using data();

    stream.writeAttribute("record_name ", (*iter)->data(2, Qt::UserRole).toString());

This doesn't err out because of nullptr, but it prints out record_name="" rather than record_name="<user_input>"

I'm able to get the user input for QLineEdit widgets that are not in the QTreeWidget, just not the ones in the tree. I assume if I can figure out how to get the data out of the QLineEdits within the tree that I should be able to adapt that to getting the QLineEdits out of a custom QWidget also within the tree.

score 0 · Answer 1 · answered Mar 15 '22 at 19:35

I found a solution using information from https://www.qtcentre.org/threads/23228-typecast-of-QWidget

stream.writeAttribute("record_name", qobject_cast<QLineEdit*>(treeWidget->itemWidget((*iter), 2))->text() );

The issue was that the QLineEdit widgets were being recalled as QWidgets and not as QLineEdit widgets and as such the text() method/function was not available to it until I cast it back as the desired type.

Fetch values from QWidgets added to QTreeWidgets via QTreeWidgetItems

1 Answers1