- Qt 5.5
- Qt SQL
- Books
- bookdelegate.cpp Example File
- Qt 5.5.1 Reference Documentation

# bookdelegate.cpp Example File

books/bookdelegate.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL21$
    ** Commercial License Usage
    ** Licensees holding valid commercial Qt licenses may use this file in
    ** accordance with the commercial license agreement provided with the
    ** Software or, alternatively, in accordance with the terms contained in
    ** a written agreement between you and The Qt Company. For licensing terms
    ** and conditions see http://www.qt.io/terms-conditions. For further
    ** information use the contact form at http://www.qt.io/contact-us.
    **
    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
    ** General Public License version 2.1 or version 3 as published by the Free
    ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
    ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
    ** following information to ensure the GNU Lesser General Public License
    ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
    ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    **
    ** As a special exception, The Qt Company gives you certain additional
    ** rights. These rights are described in The Qt Company LGPL Exception
    ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
    **
    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    #include "bookdelegate.h"

    #include <QtWidgets>

    BookDelegate::BookDelegate(QObject *parent)
        : QSqlRelationalDelegate(parent), star(QPixmap(":images/star.png"))
    {
    }

    void BookDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                               const QModelIndex &index) const
    {
        if (index.column() != 5) {
            QStyleOptionViewItemV3 opt = option;
            opt.rect.adjust(0, 0, -1, -1); // since we draw the grid ourselves
            QSqlRelationalDelegate::paint(painter, opt, index);
        } else {
            const QAbstractItemModel *model = index.model();
            QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled) ?
                (option.state & QStyle::State_Active) ? QPalette::Normal : QPalette::Inactive : QPalette::Disabled;

            if (option.state & QStyle::State_Selected)
                painter->fillRect(option.rect, option.palette.color(cg, QPalette::Highlight));

            int rating = model->data(index, Qt::DisplayRole).toInt();
            int width = star.width();
            int height = star.height();
            int x = option.rect.x();
            int y = option.rect.y() + (option.rect.height() / 2) - (height / 2);
            for (int i = 0; i < rating; ++i) {
                painter->drawPixmap(x, y, star);
                x += width;
            }
            drawFocus(painter, option, option.rect.adjusted(0, 0, -1, -1)); // since we draw the grid ourselves
        }

        QPen pen = painter->pen();
        painter->setPen(option.palette.color(QPalette::Mid));
        painter->drawLine(option.rect.bottomLeft(), option.rect.bottomRight());
        painter->drawLine(option.rect.topRight(), option.rect.bottomRight());
        painter->setPen(pen);
    }

    QSize BookDelegate::sizeHint(const QStyleOptionViewItem &option,
                                     const QModelIndex &index) const
    {
        if (index.column() == 5)
            return QSize(5 * star.width(), star.height()) + QSize(1, 1);

        return QSqlRelationalDelegate::sizeHint(option, index) + QSize(1, 1); // since we draw the grid ourselves
    }

    bool BookDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
                                   const QStyleOptionViewItem &option,
                                   const QModelIndex &index)
    {
        if (index.column() != 5)
            return QSqlRelationalDelegate::editorEvent(event, model, option, index);

        if (event->type() == QEvent::MouseButtonPress) {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
            int stars = qBound(0, int(0.7 + qreal(mouseEvent->pos().x()
                - option.rect.x()) / star.width()), 5);
            model->setData(index, QVariant(stars));
            return false; //so that the selection can change
        }

        return true;
    }

    QWidget *BookDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option,
                                        const QModelIndex &index) const
    {
        if (index.column() != 4)
            return QSqlRelationalDelegate::createEditor(parent, option, index);

        // for editing the year, return a spinbox with a range from -1000 to 2100.
        QSpinBox *sb = new QSpinBox(parent);
        sb->setFrame(false);
        sb->setMaximum(2100);
        sb->setMinimum(-1000);

        return sb;
    }