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++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "window.h"
++
++ #include <QComboBox>
++ #include <QDataWidgetMapper>
++ #include <QGridLayout>
++ #include <QLabel>
++ #include <QLineEdit>
++ #include <QMessageBox>
++ #include <QPushButton>
++ #include <QSqlQuery>
++ #include <QSqlRelationalDelegate>
++ #include <QSqlTableModel>
++ #include <QTextEdit>
++
++ //! [Set up widgets]
++ Window::Window(QWidget *parent)
++ : QWidget(parent)
++ {
++ setupModel();
++
++ nameLabel = new QLabel(tr("Na&me:"));
++ nameEdit = new QLineEdit();
++ addressLabel = new QLabel(tr("&Address:"));
++ addressEdit = new QTextEdit();
++ typeLabel = new QLabel(tr("&Type:"));
++ typeComboBox = new QComboBox();
++ nextButton = new QPushButton(tr("&Next"));
++ previousButton = new QPushButton(tr("&Previous"));
++
++ nameLabel->setBuddy(nameEdit);
++ addressLabel->setBuddy(addressEdit);
++ typeLabel->setBuddy(typeComboBox);
++ //! [Set up widgets]
++
++ //! [Set up the mapper]
++ QSqlTableModel *relModel = model->relationModel(typeIndex);
++ typeComboBox->setModel(relModel);
++ typeComboBox->setModelColumn(relModel->fieldIndex("description"));
++
++ mapper = new QDataWidgetMapper(this);
++ mapper->setModel(model);
++ mapper->setItemDelegate(new QSqlRelationalDelegate(this));
++ mapper->addMapping(nameEdit, model->fieldIndex("name"));
++ mapper->addMapping(addressEdit, model->fieldIndex("address"));
++ mapper->addMapping(typeComboBox, typeIndex);
++ //! [Set up the mapper]
++
++ //! [Set up connections and layouts]
++ connect(previousButton, &QPushButton::clicked,
++ mapper, &QDataWidgetMapper::toPrevious);
++ connect(nextButton, &QPushButton::clicked,
++ mapper, &QDataWidgetMapper::toNext);
++ connect(mapper, &QDataWidgetMapper::currentIndexChanged,
++ this, &Window::updateButtons);
++
++ QGridLayout *layout = new QGridLayout();
++ layout->addWidget(nameLabel, 0, 0, 1, 1);
++ layout->addWidget(nameEdit, 0, 1, 1, 1);
++ layout->addWidget(previousButton, 0, 2, 1, 1);
++ layout->addWidget(addressLabel, 1, 0, 1, 1);
++ layout->addWidget(addressEdit, 1, 1, 2, 1);
++ layout->addWidget(nextButton, 1, 2, 1, 1);
++ layout->addWidget(typeLabel, 3, 0, 1, 1);
++ layout->addWidget(typeComboBox, 3, 1, 1, 1);
++ setLayout(layout);
++
++ setWindowTitle(tr("SQL Widget Mapper"));
++ mapper->toFirst();
++ }
++ //! [Set up connections and layouts]
++
++ //! [Set up the main table]
++ void Window::setupModel()
++ {
++ QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
++ db.setDatabaseName(":memory:");
++ if (!db.open()) {
++ QMessageBox::critical(0, tr("Cannot open database"),
++ tr("Unable to establish a database connection.\n"
++ "This example needs SQLite support. Please read "
++ "the Qt SQL driver documentation for information how "
++ "to build it."), QMessageBox::Cancel);
++ return;
++ }
++
++ QSqlQuery query;
++ query.exec("create table person (id int primary key, "
++ "name varchar(20), address varchar(200), typeid int)");
++ query.exec("insert into person values(1, 'Alice', "
++ "'<qt>123 Main Street<br/>Market Town</qt>', 101)");
++ query.exec("insert into person values(2, 'Bob', "
++ "'<qt>PO Box 32<br/>Mail Handling Service"
++ "<br/>Service City</qt>', 102)");
++ query.exec("insert into person values(3, 'Carol', "
++ "'<qt>The Lighthouse<br/>Remote Island</qt>', 103)");
++ query.exec("insert into person values(4, 'Donald', "
++ "'<qt>47338 Park Avenue<br/>Big City</qt>', 101)");
++ query.exec("insert into person values(5, 'Emma', "
++ "'<qt>Research Station<br/>Base Camp<br/>"
++ "Big Mountain</qt>', 103)");
++ //! [Set up the main table]
++
++ //! [Set up the address type table]
++ query.exec("create table addresstype (id int, description varchar(20))");
++ query.exec("insert into addresstype values(101, 'Home')");
++ query.exec("insert into addresstype values(102, 'Work')");
++ query.exec("insert into addresstype values(103, 'Other')");
++
++ model = new QSqlRelationalTableModel(this);
++ model->setTable("person");
++ model->setEditStrategy(QSqlTableModel::OnManualSubmit);
++
++ typeIndex = model->fieldIndex("typeid");
++
++ model->setRelation(typeIndex,
++ QSqlRelation("addresstype", "id", "description"));
++ model->select();
++ }
++ //! [Set up the address type table]
++
++ //! [Slot for updating the buttons]
++ void Window::updateButtons(int row)
++ {
++ previousButton->setEnabled(row > 0);
++ nextButton->setEnabled(row < model->rowCount() - 1);
++ }
++ //! [Slot for updating the buttons]