Qt 5.7 | Qt XML Patterns | File System Example | mainwindow.cpp Example File

Qt 5.7.1 Reference Documentation

# mainwindow.cpp Example File

filetree/mainwindow.cpp

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      #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>"));
      }