How to set max width for QTreeView resizeColumnToContents?

Question

I'm using QTreeView::resizeColumnToContents(int column)

but if even after that I'm doing something alike

  if (t->columnWidth(0) > 10) {
    t->setColumnWidth(0, 10);
  }

it doesn't work, how can I set max width there?

Answer 1

It would be worth checking whether your if-statement gets executed at all or if the pointer t is able to modify the object.

I've modified the Qt demo "simpletreemodel" to use this function and it works fine. I'm using Qt 5.7.0 for this.

int main(int argc, char *argv[])
{
    Q_INIT_RESOURCE(simpletreemodel);

    QApplication app(argc, argv);

    QFile file(":/default.txt");
    file.open(QIODevice::ReadOnly);

    TreeModel model(file.readAll());
    file.close();

    QTreeView view;
    view.setModel(&model);
    view.setWindowTitle(QObject::tr("Simple Tree Model"));

    std::cout<< view.columnWidth(0) <<std::endl;
    if (view.columnWidth(0) <= 100)
    {
        std::cout<< "resizing column width >> ";
        view.resizeColumnToContents(0);
        std::cout<< view.columnWidth(0) <<std::endl;

        if (view.columnWidth(0) > 250)
        {
            std::cout<< "oops! This is too much.. (max width = 250)" <<std::endl;
            view.setColumnWidth(0,250);
        }
    }
    std::cout<< view.columnWidth(0) <<std::endl;

    view.show();
    return app.exec();
}

The output from the above is:

100
resizing column width >> 269
oops! This is too much.. (max width = 250)
250

Some more information on this would be nice.