Crash when trying to change QCompleter

cheezus

Here is the full source code. What I'm trying to do is create a QCompleter where I can update the list as the user types stuff in. Changing an external model does not seem to work, so I tried to change it by creating a new QCompleter each time. However, that results in a crash. If you run the code below and just type in "comp" it will crash.

So, any ideas on:

What is the proper way to update the completions for a QCompleter?
Why this is crashing?

#include <QLineEdit>
#include <QApplication>
#include <QCompleter>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QLineEdit edit;

    edit.connect(&edit,&QLineEdit::textChanged,
                 &edit,[&edit]() {
        auto list = QStringList() << "completion1" << "completion2" << "completion3";
        auto completer = new QCompleter(list,&edit);
        edit.setCompleter(completer);
    });

    edit.show();
    return a.exec();
}

cheezus

This post is deleted!

cheezus

Here is the ultimate solution. After getting a QSqlQueryModel to work, I compared the code of QSqlQueryModel and QStringListModel and realized that the only difference was a call to begin/endInsertRows. And voila, it worked.

For completless sake:

#include <QLineEdit>
#include <QApplication>
#include <QCompleter>
#include <QStringListModel>

struct MyStringListModel : public QStringListModel {
public:
  using QStringListModel::QStringListModel;

  void setStringList(QStringList const & list) {
    QStringListModel::setStringList(list);
    Q_EMIT beginInsertRows(QModelIndex(),0,list.size()-1);
    Q_EMIT endInsertRows();
  }
};


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

    QLineEdit edit;
    MyStringListModel model;
    QCompleter completer(&model,&edit);
    edit.setCompleter(&completer);

    edit.connect(&edit,&QLineEdit::textChanged,
                 &model,[&model]() {
        auto lst = model.stringList();
        lst << QString("completion-%1").arg(lst.size());
        model.setStringList(lst);
    });

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