bookwindow.cpp Example File
demos/books/bookwindow.cpp

 /****************************************************************************
 **
 ** Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: Qt Software Information (qt-info@nokia.com)
 **
 ** This file is part of the demonstration applications of the Qt Toolkit.
 **
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License versions 2.0 or 3.0 as published by the Free
 ** Software Foundation and appearing in the file LICENSE.GPL included in
 ** the packaging of this file.  Please review the following information
 ** to ensure GNU General Public Licensing requirements will be met:
 ** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
 ** http://www.gnu.org/copyleft/gpl.html.  In addition, as a special
 ** exception, Nokia gives you certain additional rights. These rights
 ** are described in the Nokia Qt GPL Exception version 1.3, included in
 ** the file GPL_EXCEPTION.txt in this package.
 **
 ** Qt for Windows(R) Licensees
 ** As a special exception, Nokia, as the sole copyright holder for Qt
 ** Designer, grants users of the Qt/Eclipse Integration plug-in the
 ** right for the Qt/Eclipse Integration to link to functionality
 ** provided by Qt Designer and its related libraries.
 **
 ** If you are unsure which license is appropriate for your use, please
 ** contact the sales department at qt-sales@nokia.com.
 **
 ****************************************************************************/

 #include "bookwindow.h"
 #include "bookdelegate.h"
 #include "initdb.h"

 #include <QtSql>

 BookWindow::BookWindow()
 {
     ui.setupUi(this);

     if (!QSqlDatabase::drivers().contains("QSQLITE"))
         QMessageBox::critical(this, "Unable to load database", "This demo needs the SQLITE driver");

     // initialize the database
     QSqlError err = initDb();
     if (err.type() != QSqlError::NoError) {
         showError(err);
         return;
     }

     // Create the data model
     model = new QSqlRelationalTableModel(ui.bookTable);
     model->setEditStrategy(QSqlTableModel::OnManualSubmit);
     model->setTable("books");

     // Remeber the indexes of the columns
     authorIdx = model->fieldIndex("author");
     genreIdx = model->fieldIndex("genre");

     // Set the relations to the other database tables
     model->setRelation(authorIdx, QSqlRelation("authors", "id", "name"));
     model->setRelation(genreIdx, QSqlRelation("genres", "id", "name"));

     // Set the localized header captions
     model->setHeaderData(authorIdx, Qt::Horizontal, tr("Author Name"));
     model->setHeaderData(genreIdx, Qt::Horizontal, tr("Genre"));
     model->setHeaderData(model->fieldIndex("title"), Qt::Horizontal, tr("Title"));
     model->setHeaderData(model->fieldIndex("year"), Qt::Horizontal, tr("Year"));
     model->setHeaderData(model->fieldIndex("rating"), Qt::Horizontal, tr("Rating"));

     // Populate the model
     if (!model->select()) {
         showError(model->lastError());
         return;
     }

     // Set the model and hide the ID column
     ui.bookTable->setModel(model);
     ui.bookTable->setItemDelegate(new BookDelegate(ui.bookTable));
     ui.bookTable->setColumnHidden(model->fieldIndex("id"), true);
     ui.bookTable->setSelectionMode(QAbstractItemView::SingleSelection);

     // Initialize the Author combo box
     ui.authorEdit->setModel(model->relationModel(authorIdx));
     ui.authorEdit->setModelColumn(model->relationModel(authorIdx)->fieldIndex("name"));

     ui.genreEdit->setModel(model->relationModel(genreIdx));
     ui.genreEdit->setModelColumn(model->relationModel(genreIdx)->fieldIndex("name"));

     QDataWidgetMapper *mapper = new QDataWidgetMapper(this);
     mapper->setModel(model);
     mapper->setItemDelegate(new BookDelegate(this));
     mapper->addMapping(ui.titleEdit, model->fieldIndex("title"));
     mapper->addMapping(ui.yearEdit, model->fieldIndex("year"));
     mapper->addMapping(ui.authorEdit, authorIdx);
     mapper->addMapping(ui.genreEdit, genreIdx);
     mapper->addMapping(ui.ratingEdit, model->fieldIndex("rating"));

     connect(ui.bookTable->selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
             mapper, SLOT(setCurrentModelIndex(QModelIndex)));

     ui.bookTable->setCurrentIndex(model->index(0, 0));
 }

 void BookWindow::showError(const QSqlError &err)
 {
     QMessageBox::critical(this, "Unable to initialize Database",
                 "Error initializing database: " + err.text());
 }