/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/

//! [quoting modelview_a]
#include <QTreeView>
#include <QStandardItemModel>
#include <QItemSelectionModel>
#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    treeView = new QTreeView(this);
    setCentralWidget(treeView);
    standardModel = new QStandardItemModel ;
    QStandardItem *rootNode = standardModel->invisibleRootItem();


    //defining a couple of items
    QStandardItem *americaItem = new QStandardItem("America");
    QStandardItem *mexicoItem =  new QStandardItem("Canada");
    QStandardItem *usaItem =     new QStandardItem("USA");
    QStandardItem *bostonItem =  new QStandardItem("Boston");
    QStandardItem *europeItem =  new QStandardItem("Europe");
    QStandardItem *italyItem =   new QStandardItem("Italy");
    QStandardItem *romeItem =    new QStandardItem("Rome");
    QStandardItem *veronaItem =  new QStandardItem("Verona");

    //building up the hierarchy
    rootNode->    appendRow(americaItem);
    rootNode->    appendRow(europeItem);
    americaItem-> appendRow(mexicoItem);
    americaItem-> appendRow(usaItem);
    usaItem->     appendRow(bostonItem);
    europeItem->  appendRow(italyItem);
    italyItem->   appendRow(romeItem);
    italyItem->   appendRow(veronaItem);

    //register the model
    treeView->setModel(standardModel);
    treeView->expandAll();

    //selection changes shall trigger a slot
    QItemSelectionModel *selectionModel= treeView->selectionModel();
    connect(selectionModel, SIGNAL(selectionChanged (const QItemSelection &, const QItemSelection &)),
            this, SLOT(selectionChangedSlot(const QItemSelection &, const QItemSelection &)));
}
//! [quoting modelview_a]

//------------------------------------------------------------------------------------

//! [quoting modelview_b]
void MainWindow::selectionChangedSlot(const QItemSelection & /*newSelection*/, const QItemSelection & /*oldSelection*/)
{
    //get the text of the selected item
    const QModelIndex index = treeView->selectionModel()->currentIndex();
    QString selectedText = index.data(Qt::DisplayRole).toString();
    //find out the hierarchy level of the selected item
    int hierarchyLevel=1;
    QModelIndex seekRoot = index;
    while(seekRoot.parent() != QModelIndex())
    {
        seekRoot = seekRoot.parent();
        hierarchyLevel++;
    }
    QString showString = QString("%1, Level %2").arg(selectedText)
                         .arg(hierarchyLevel);
    setWindowTitle(showString);
}
//! [quoting modelview_b]