- Qt 5.5
- Qt XML Patterns
- File System Example
- mainwindow.cpp Example File
- Qt 5.5.1 Reference Documentation

# mainwindow.cpp Example File

filetree/mainwindow.cpp

    /****************************************************************************
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    ** Copyright (C) 2015 The Qt Company Ltd.
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    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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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>"));
    }