Qt 5.9 | Qt XML Patterns | File System Example | mainwindow.cpp Example File

Qt 5.9.3 Reference Documentation

# mainwindow.cpp Example File

filetree/mainwindow.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2017 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."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #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>"));
      }