How to implement a well behaved editor for QAbstractItem::createEditor()

[spud]

This is a repost of this.

I have created a custom item delegate which let's users edit a list of file paths:
item_delegate.png
I have achieved this through a custom class DirEdit. Now the selected path is commited and the editor is closed when the user presses enter, but I would like to add two cases where the editor should be closed without the user having to press enter:

1. When the user selects a file by activating a combo box entry(by clicking or pressing return)
2. When the user selects a file by clicking the "ellipsis" tool button.

I have been experimenting with clearFocus() and other methods, but nothing seems to work. Below is a complete example:

#include <QtWidgets>
 
class DirEdit : public QWidget
{
    QLineEdit* lineEdit=nullptr;
public:
    DirEdit(QWidget* parent=nullptr)
        : QWidget(parent)
    {
        new QHBoxLayout(this);
        layout()->setMargin(0);
        layout()->addWidget(lineEdit=new QLineEdit(this));
 
        QCompleter *completer = new QCompleter(this);
 
        auto model = new QDirModel(completer);
        model->setFilter(QDir::AllDirs|QDir::NoDotAndDotDot);
        completer->setModel(model);
 
        lineEdit->setCompleter(completer);
        connect(completer, static_cast<void (QCompleter::*)(const QString&)>(&QCompleter::activated), [this](const QString& text)
            {
// >>>>>>>>>>>>>>>>>>>>>>> TODO: Make the editor close here <<<<<<<<<<<<<<<<<<<<<<<<<<<<
            });
 
        QToolButton* dotDotDot;
        layout()->addWidget(dotDotDot=new QToolButton(this));
        dotDotDot->setText("...");
        connect(dotDotDot, &QToolButton::clicked, this, [this]()
            {
                QString dir = QFileDialog::getExistingDirectory(window(), "Select Directory", lineEdit->text());
                if(dir!="")
                {
                    lineEdit->setText(dir);
// >>>>>>>>>>>>>>>>>>>>>>> TODO: Make the editor close here <<<<<<<<<<<<<<<<<<<<<<<<<<<<
                }
            });
        setFocusProxy(lineEdit);
    }
    void setPath(const QString& path)
    {
        lineEdit->setText(path);
    }
    QString path()const
    {
        return lineEdit->text();
    }
};
 
class MyDelegate : public QItemDelegate
{
    QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &index) const
    {
        return new DirEdit(parent);
    }
 
    void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem& option, const QModelIndex &)const
    {
        editor->setGeometry(option.rect);
    }
 
    void setEditorData(QWidget *editor, const QModelIndex &index) const
    {
        QVariant value = index.model()->data(index, Qt::DisplayRole);
 
        if (DirEdit *dirEdit = dynamic_cast<DirEdit *>(editor))
            dirEdit->setPath(value.toString());
    }
 
    void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
    {
        if (DirEdit *dirEdit = dynamic_cast<DirEdit *>(editor))
            model->setData(index, dirEdit->path());
    }
};
 
int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QListWidget listWidget;
 
    listWidget.setItemDelegate(new MyDelegate);
 
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DesktopLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::MusicLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DownloadLocation));
 
    for (int i = 0; i<listWidget.count(); i++)
        listWidget.item(i)->setFlags(listWidget.item(0)->flags()|Qt::ItemIsEditable);
 
    listWidget.show();
    return app.exec();
}

#include <QtWidgets>

class DirEdit : public QWidget
{
    QLineEdit* lineEdit=nullptr;
public:
    DirEdit(QWidget* parent=nullptr)
        : QWidget(parent)
    {
        new QHBoxLayout(this);
        layout()->setMargin(0);
        layout()->addWidget(lineEdit=new QLineEdit(this));

        QCompleter *completer = new QCompleter(this);

        auto model = new QDirModel(completer);
        model->setFilter(QDir::AllDirs|QDir::NoDotAndDotDot);
        completer->setModel(model);

        lineEdit->setCompleter(completer);
        connect(completer, static_cast<void (QCompleter::*)(const QString&)>(&QCompleter::activated), [this](const QString& text)
            {
// >>>>>>>>>>>>>>>>>>>>>>> TODO: Make the editor close here <<<<<<<<<<<<<<<<<<<<<<<<<<<<
            });

        QToolButton* dotDotDot;
        layout()->addWidget(dotDotDot=new QToolButton(this));
        dotDotDot->setText("...");
        connect(dotDotDot, &QToolButton::clicked, this, [this]()
            {
                QString dir = QFileDialog::getExistingDirectory(window(), "Select Directory", lineEdit->text());
                if(dir!="")
                {
                    lineEdit->setText(dir);
// >>>>>>>>>>>>>>>>>>>>>>> TODO: Make the editor close here <<<<<<<<<<<<<<<<<<<<<<<<<<<<
                }
            });
        setFocusProxy(lineEdit);
    }
    void setPath(const QString& path)
    {
        lineEdit->setText(path);
    }
    QString path()const
    {
        return lineEdit->text();
    }
};

class MyDelegate : public QItemDelegate
{
    QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &index) const
    {
        return new DirEdit(parent);
    }

    void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem& option, const QModelIndex &)const
    {
        editor->setGeometry(option.rect);
    }

    void setEditorData(QWidget *editor, const QModelIndex &index) const
    {
        QVariant value = index.model()->data(index, Qt::DisplayRole);

        if (DirEdit *dirEdit = dynamic_cast<DirEdit *>(editor))
            dirEdit->setPath(value.toString());
    }

    void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
    {
        if (DirEdit *dirEdit = dynamic_cast<DirEdit *>(editor))
            model->setData(index, dirEdit->path());
    }
};

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

    listWidget.setItemDelegate(new MyDelegate);

    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DesktopLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::MusicLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation));
    listWidget.addItem(QStandardPaths::writableLocation(QStandardPaths::DownloadLocation));

    for (int i = 0; i<listWidget.count(); i++)
        listWidget.item(i)->setFlags(listWidget.item(0)->flags()|Qt::ItemIsEditable);

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

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The only restraint is that DirEdit should be a standard element and not need to know about the Item View/Delegate framework.

thanks

---

Added after 1 20 minutes:

Ok, I found one solution for this myself. It consists of replacing the TODOs with

QApplication::postEvent(this, new QKeyEvent(QKeyEvent::KeyPress, Qt::Key_Enter, Qt::NoModifier));

QApplication::postEvent(this, new QKeyEvent(QKeyEvent::KeyPress, Qt::Key_Enter, Qt::NoModifier));

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See Stack Overflow for an explanation.