auto select first proposition of QCompleter in PopupCompletion mode

Question

I didn't manage to select the first item of the completer when the popup is displayed in PopupCompletion mode. My current code that doesnt work:

completer->setCompletionPrefix(text);
QItemSelectionModel* sm = new QItemSelectionModel(completer->completionModel());
sm->select(completer->completionModel()->index(0,0), QItemSelectionModel::Select);
completer->popup()->setSelectionModel(sm);

Any suggestions?

score 2 · Answer 1 · answered Jul 22 '13 at 09:59

I would try changing the order of the last 2 lines:

completer->popup()->setSelectionModel(sm);
sm->select(completer->completionModel()->index(0,0), QItemSelectionModel::Select);

Probably the change of the selection for the popup (its a view) ocurs when selectionChanged() is emited. So you have to set first the selection model, then do the select.

void QItemSelectionModel::select ( const QModelIndex & index, QItemSelectionModel::SelectionFlags command ) [virtual slot]

Selects the model item index using the specified command, and emits selectionChanged().

BTW, u dont have to create a new selection model, just ask the popup for it (Againt, its a view):

completer->popup()->selectionModel();

http://qt-project.org/doc/qt-5.0/qtwidgets/qabstractitemview.html#selectionModel

@AntoineLafarge Hey man, if this worked for you you need to accept the answer — Jonathan Mee, Apr 23 '14 at 19:01
@Antoine Did this work? If yes pls accept the answer. Thanks in advance. — Bill, Nov 24 '20 at 11:14

Adriel Jr · Answer 2 · 2019-03-12T16:10:32.503

I don't know if this is what you wanted, but in my case I wanted to be able to press enter and auto-select the first item in the pop-up list (as it does with UnfilteredPopupCompletion). What worked for me was:

class AutoSelectFirstFilter : public QObject
{
    Q_OBJECT

protected:
    virtual bool eventFilter(QObject *obj, QEvent *event) override
    {
        if (event->type() == QEvent::KeyPress)
        {
            if(static_cast<QKeyEvent *>(event)->key() == Qt::Key_Return)
            {
                QAbstractItemView* l = static_cast<QAbstractItemView*>(obj);
                QModelIndex i = l->model()->index(0,0);
                if(i.isValid())
                    l->selectionModel()->select(i, QItemSelectionModel::Select);
            }
        }
        return false;
    }
};

and than:

AutoSelectFirstFilter tmp;
completer->popup()->installEventFilter(&tmp);

PS: Don't forget to re-run qmake.

This worked for me, but rather than "selecting" when the users presses `Qt::Key_Return` (which doesn't capture presses to `Qt::Key_Enter`) I'd recommend changing the "current" index instead (which is like highlighting the top choice). Don't cast `QKeyEvent` nor compare with any specific keys, just use: `l->selectionModel()->setCurrentIndex(i, QItemSelectionModel::Current);` — MasterHD, Aug 13 '22 at 16:32

auto select first proposition of QCompleter in PopupCompletion mode

2 Answers2