mainwindow.cpp Example File | Qt XML Patterns 5.4

- Qt 5.4
- Qt XML Patterns
- File System Example
- mainwindow.cpp Example File
- Qt 5.4.2 Reference Documentation

# mainwindow.cpp Example File

filetree/mainwindow.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
    ** Contact: http://www.qt-project.org/legal
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** 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 Digia Plc and its Subsidiary(-ies) 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."
    **
    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    #include <QFileDialog>
    #include <QMessageBox>
    #include <QLibraryInfo>
    #include <QtXmlPatterns>

    #include "mainwindow.h"
    #include "xmlsyntaxhighlighter.h"

    MainWindow::MainWindow() : m_fileTree(m_namePool)
    {
        setupUi(this);

        new XmlSyntaxHighlighter(fileTree->document());

        // Set up the font.
        {
            QFont font("Courier",10);
            font.setFixedPitch(true);

            fileTree->setFont(font);
            queryEdit->setFont(font);
            output->setFont(font);
        }

        const QString dir(QLibraryInfo::location(QLibraryInfo::ExamplesPath) + "/xmlpatterns/filetree");
        qDebug() << dir;

        if (QDir(dir).exists())
            loadDirectory(dir);
        else
            fileTree->setPlainText(tr("Use the Open menu entry to select a directory."));

        const QStringList queries(QDir(":/queries/", "*.xq").entryList());
        int len = queries.count();

        for (int i = 0; i < len; ++i)
            queryBox->addItem(queries.at(i));

    }

    void MainWindow::on_queryBox_currentIndexChanged(const QString &currentText)
    {
        QFile queryFile(":/queries/" + currentText);
        queryFile.open(QIODevice::ReadOnly);

        queryEdit->setPlainText(QString::fromLatin1(queryFile.readAll()));
        evaluateResult();
    }

    void MainWindow::evaluateResult()
    {
        if (queryBox->currentText().isEmpty() || m_fileNode.isNull())
            return;

        QXmlQuery query(m_namePool);
        query.bindVariable("fileTree", m_fileNode);
        query.setQuery(QUrl("qrc:/queries/" + queryBox->currentText()));

        QByteArray formatterOutput;
        QBuffer buffer(&formatterOutput);
        buffer.open(QIODevice::WriteOnly);

        QXmlFormatter formatter(query, &buffer);
        query.evaluateTo(&formatter);

        output->setText(QString::fromLatin1(formatterOutput.constData()));
    }

    void MainWindow::on_actionOpenDirectory_triggered()
    {
        const QString directoryName = QFileDialog::getExistingDirectory(this);
        if (!directoryName.isEmpty())
            loadDirectory(directoryName);
    }

    void MainWindow::loadDirectory(const QString &directory)
    {
        Q_ASSERT(QDir(directory).exists());

        m_fileNode = m_fileTree.nodeFor(directory);

        QXmlQuery query(m_namePool);
        query.bindVariable("fileTree", m_fileNode);
        query.setQuery(QUrl("qrc:/queries/wholeTree.xq"));

        QByteArray output;
        QBuffer buffer(&output);
        buffer.open(QIODevice::WriteOnly);

        QXmlFormatter formatter(query, &buffer);
        query.evaluateTo(&formatter);

        treeInfo->setText(tr("Model of %1 output as XML.").arg(directory));
        fileTree->setText(QString::fromLatin1(output.constData()));
        evaluateResult();
    }

    void MainWindow::on_actionAbout_triggered()
    {
        QMessageBox::about(this, tr("About File Tree"),
                       tr("<p>Select <b>File->Open Directory</b> and "
                          "choose a directory. The directory is then "
                          "loaded into the model, and the model is "
                          "displayed on the left as XML.</p>"

                          "<p>From the query menu on the right, select "
                          "a query. The query is displayed and then run "
                          "on the model. The results are displayed below "
                          "the query.</p>"));
    }