Disable specific items in QComboBox

Question

In my application, I want to disable some items (i.e. not selectable, no highlights when mouse hovering above, and the texts are greyed out) in the QComboBox when certain co

Answer 1

The answer linked in my comment above seems to be talking about an old version of Qt. I have tested on Qt5.4 and Qt5.6 and there is no need set the color yourself here, you just need to set and/or clear the Qt::ItemIsEnabled flag, here is an example:

#include <QtWidgets>

int main(int argc, char *argv[]) {
  QApplication a(argc, argv);
  QComboBox comboBox;
  comboBox.addItem(QObject::tr("item1"));
  comboBox.addItem(QObject::tr("item2"));
  comboBox.addItem(QObject::tr("item3"));
  QStandardItemModel *model =
      qobject_cast<QStandardItemModel *>(comboBox.model());
  Q_ASSERT(model != nullptr);
  bool disabled = true;
  QStandardItem *item = model->item(2);
  item->setFlags(disabled ? item->flags() & ~Qt::ItemIsEnabled
                          : item->flags() | Qt::ItemIsEnabled);
  comboBox.show();
  return a.exec();
}

Answer 2

Here is the technique @Mike describes, wrapped up in a convenient utility function:

void SetComboBoxItemEnabled(QComboBox * comboBox, int index, bool enabled)
{
    auto * model = qobject_cast<QStandardItemModel*>(comboBox->model());
    assert(model);
    if(!model) return;

    auto * item = model->item(index);
    assert(item);
    if(!item) return;
    item->setEnabled(enabled);
}