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# mainwindow.cpp Example File

xmlpatterns/filetree/mainwindow.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
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     **
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     ** modification, are permitted provided that the following conditions are
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     **   * Redistributions of source code must retain the above copyright
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     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
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     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     #include <QtGui>
     #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()
     {
         QFile queryFile(":/queries/" + queryBox->currentText());
         queryFile.open(QIODevice::ReadOnly);

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

     void MainWindow::evaluateResult()
     {
         if (queryBox->currentText().isEmpty())
             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>"));
     }