- Qt 5.5
- Qt Widgets
- Interview
- model.cpp Example File
- Qt 5.5.1 Reference Documentation

# model.cpp Example File

itemviews/interview/model.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
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    ** 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.
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    ** As a special exception, The Qt Company gives you certain additional
    ** rights. These rights are described in The Qt Company LGPL Exception
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    ****************************************************************************/

    #include "model.h"

    #include <QIcon>
    #include <QPixmap>

    Model::Model(int rows, int columns, QObject *parent)
        : QAbstractItemModel(parent),
          services(QPixmap(":/images/services.png")),
          rc(rows), cc(columns),
          tree(new QVector<Node>(rows, Node(0)))
    {

    }

    Model::~Model()
    {
        delete tree;
    }

    QModelIndex Model::index(int row, int column, const QModelIndex &parent) const
    {
        if (row < rc && row >= 0 && column < cc && column >= 0) {
            Node *parentNode = static_cast<Node*>(parent.internalPointer());
            Node *childNode = node(row, parentNode);
            if (childNode)
                return createIndex(row, column, childNode);
        }
        return QModelIndex();
    }

    QModelIndex Model::parent(const QModelIndex &child) const
    {
        if (child.isValid()) {
            Node *childNode = static_cast<Node*>(child.internalPointer());
            Node *parentNode = parent(childNode);
            if (parentNode)
                return createIndex(row(parentNode), 0, parentNode);
        }
        return QModelIndex();
    }

    int Model::rowCount(const QModelIndex &parent) const
    {
        return (parent.isValid() && parent.column() != 0) ? 0 : rc;
    }

    int Model::columnCount(const QModelIndex &parent) const
    {
        Q_UNUSED(parent);
        return cc;
    }

    QVariant Model::data(const QModelIndex &index, int role) const
    {
        if (!index.isValid())
            return QVariant();
        if (role == Qt::DisplayRole)
            return QVariant("Item " + QString::number(index.row()) + ":" + QString::number(index.column()));
        if (role == Qt::DecorationRole) {
            if (index.column() == 0)
                return iconProvider.icon(QFileIconProvider::Folder);
            return iconProvider.icon(QFileIconProvider::File);
        }
        return QVariant();
    }

    QVariant Model::headerData(int section, Qt::Orientation orientation, int role) const
    {
        if (role == Qt::DisplayRole)
            return QString::number(section);
        if (role == Qt::DecorationRole)
            return QVariant::fromValue(services);
        return QAbstractItemModel::headerData(section, orientation, role);
    }

    bool Model::hasChildren(const QModelIndex &parent) const
    {
        if (parent.isValid() && parent.column() != 0)
            return false;
        return rc > 0 && cc > 0;
    }

    Qt::ItemFlags Model::flags(const QModelIndex &index) const
    {
        if (!index.isValid())
            return 0;
        return Qt::ItemIsDragEnabled|QAbstractItemModel::flags(index);
    }

    Model::Node *Model::node(int row, Node *parent) const
    {
        if (parent && !parent->children)
            parent->children = new QVector<Node>(rc, Node(parent));
        QVector<Node> *v = parent ? parent->children : tree;
        return const_cast<Node*>(&(v->at(row)));
    }

    Model::Node *Model::parent(Node *child) const
    {
        return child ? child->parent : 0;
    }

    int Model::row(Node *node) const
    {
        const Node *first = node->parent ? &(node->parent->children->at(0)) : &(tree->at(0));
        return node - first;
    }