Combo Boxes in Item Views
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Sample code to use combo boxes as editor widgets in an item view or item widget.
The delegate creates a combo box if the index is in the second column of a list view. For the other columns it just returns the default editor, that QStyledItemDelegate creates.
File comboboxitemdelegate.h
#ifndef COMBOBOXITEMDELEGATE_H #define COMBOBOXITEMDELEGATE_H #include <QStyledItemDelegate> class ComboBoxItemDelegate : public QStyledItemDelegate { Q_OBJECT public: ComboBoxItemDelegate(QObject *parent = nullptr); ~ComboBoxItemDelegate(); QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const override; void setEditorData(QWidget *editor, const QModelIndex &index) const override; void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const override; }; #endif // COMBOBOXITEMDELEGATE_H
File comboboxitemdelegate.cpp
#include "comboboxitemdelegate.h" #include <QComboBox> ComboBoxItemDelegate::ComboBoxItemDelegate(QObject *parent) : QStyledItemDelegate(parent) { } ComboBoxItemDelegate::~ComboBoxItemDelegate() { } QWidget *ComboBoxItemDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const { // Create the combobox and populate it QComboBox *cb = new QComboBox(parent); const int row = index.row(); cb->addItem(QString("one in row %1").arg(row)); cb->addItem(QString("two in row %1").arg(row)); cb->addItem(QString("three in row %1").arg(row)); return cb; } void ComboBoxItemDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const { QComboBox *cb = qobject_cast<QComboBox *>(editor); Q_ASSERT(cb); // get the index of the text in the combobox that matches the current value of the item const QString currentText = index.data(Qt::EditRole).toString(); const int cbIndex = cb->findText(currentText); // if it is valid, adjust the combobox if (cbIndex >= 0) cb->setCurrentIndex(cbIndex); } void ComboBoxItemDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const { QComboBox *cb = qobject_cast<QComboBox *>(editor); Q_ASSERT(cb); model->setData(index, cb->currentText(), Qt::EditRole); }
File main.cpp
#include <QApplication> #include <QTableWidget> #include "comboboxitemdelegate.h" int main(int argc, char *argv[]) { QApplication a(argc, argv); QTableWidget tw; ComboBoxItemDelegate* cbid = new ComboBoxItemDelegate(&tw); // ComboBox only in column 2 tw.setItemDelegateForColumn(1, cbid); tw.setColumnCount(4); tw.setRowCount(10); tw.resize(600,400); tw.show(); return a.exec(); }