where to emit closeEditor() when subclass from QItemDelegate ?

QtTester

Hi guys.
I have a tableview , one column need to set to combobox, so i subclass QItemDelegate. it works, except it cannot emit closeEditor() signal, I invoke emit closeEditor in setModelData(), but compiler says:

error: C2662: “void QAbstractItemDelegate::closeEditor(QWidget *,QAbstractItemDelegate::EndEditHint)”: 不能将“this”指针从“const ComboboxDelegate”转换为“QAbstractItemDelegate &”

here is the code:

class ComboboxDelegate: public QItemDelegate
{

public:
    ComboboxDelegate(QWidget *parent = nullptr,QStringList items=QStringList(),int currentIndex=0):QItemDelegate(parent)
    {
        m_items = items;
        m_initIdx = currentIndex;
    }

    QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
                            const QModelIndex &index) const override //final
    {
        Q_UNUSED(parent)
        Q_UNUSED(option)
        Q_UNUSED(index)

        QComboBox *channelBox = new QComboBox(parent); 
        channelBox->setFixedHeight(option.rect.height());

        for(int i=0;i<m_items.size();i++){
            QString item = m_items.at(i);
            channelBox->addItem(item);
        }
        channelBox->setCurrentIndex(m_initIdx);
        return channelBox;
    }

    void setEditorData(QWidget *editor, const QModelIndex &index) const
    {
        QComboBox *comboBox = static_cast<QComboBox*>(editor);
        if(comboBox){
            QString str = index.model()->data(index, Qt::EditRole).toString();
            comboBox->setCurrentIndex(comboBox->findText(str));
        }
    }

    void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
    {
        QComboBox *comboBox = static_cast<QComboBox*>(editor);
        if(comboBox!=0){
            model->setData(index, comboBox->currentText(), Qt::EditRole);
            emit closeEditor(editor); // ERROR HERE ~~~~
        }
    }

    void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
        editor->setGeometry(option.rect);
    }
    // still cannot work with my signal ~~~
signals:
    void closeEditor2(QWidget *editor, QAbstractItemDelegate::EndEditHint hint = NoHint);
private:
    int m_initIdx;
    QStringList m_items;
};

Any help will be appreciated.

Christian Ehrlicher

You don't have to emit this signal, it's emitted by QAbstractItemDelegate to notify the view.

JonB

@QtTester
As @Christian-Ehrlicher has said. Your code will be fine without any emits here.

But (quite separate issue) you might want to change your static_cast<QComboBox*>s to qobject_cast<QComboBox*>s. It's safer, and allows you to use the delegate against different columns/widget types without having to invent separate delegates for each one. Depending on how you like to do these things.

QtTester

@Christian-Ehrlicher said in where to emit closeEditor() when subclass from QItemDelegate ?:

You don't have to emit this signal, it's emitted by QAbstractItemDelegate to notify the view.

@JonB said in where to emit closeEditor() when subclass from QItemDelegate ?:

@QtTester
As @Christian-Ehrlicher has said. Your code will be fine without any emits here.

But (quite separate issue) you might want to change your static_cast<QComboBox*>s to qobject_cast<QComboBox*>s. It's safer, and allows you to use the delegate against different columns/widget types without having to invent separate delegates for each one. Depending on how you like to do these things.

Thanks you both. But I didnot recevie the signal, after I connect the abstractitemdelegate signal, when I finish edit the default lineedit cell ,it emits a signal ,but after I choose the combobox , the signal did not send out!

connect(ui->tableViewSpdLimit->itemDelegate(),&QAbstractItemDelegate::closeEditor,this,[=](){
        qDebug("detect edit!");
        ui->pushButtonSubmitLimit->setEnabled(true);
    });

QtTester

Already solved, use ui->tableViewSpdLimit->itemDelegateForColumn()