querymainwindow.cpp Example File

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

 #include "querymainwindow.h"
 #include "xmlsyntaxhighlighter.h"

 QueryMainWindow::QueryMainWindow() : ui_defaultQueries(0)
 {
     setupUi(this);

     new XmlSyntaxHighlighter(findChild<QTextEdit*>("inputTextEdit")->document());
     new XmlSyntaxHighlighter(findChild<QTextEdit*>("outputTextEdit")->document());

     ui_defaultQueries = findChild<QComboBox*>("defaultQueries");
     QMetaObject::connectSlotsByName(this);
     connect(ui_defaultQueries, SIGNAL(currentIndexChanged(int)), SLOT(displayQuery(int)));

     loadInputFile();
     const QStringList queries(QDir(":/files/", "*.xq").entryList());
     int len = queries.count();
     for(int i = 0; i < len; ++i)
         ui_defaultQueries->addItem(queries.at(i));
 }

 void QueryMainWindow::displayQuery(int index)
 {
     QFile queryFile(QString(":files/") + ui_defaultQueries->itemText(index));
     queryFile.open(QIODevice::ReadOnly);
     const QString query(QString::fromLatin1(queryFile.readAll()));
     findChild<QTextEdit*>("queryTextEdit")->setPlainText(query);

     evaluate(query);
 }

 void QueryMainWindow::loadInputFile()
 {
     QFile forView;
     forView.setFileName(":/files/cookbook.xml");
     if (!forView.open(QIODevice::ReadOnly)) {
         QMessageBox::information(this,
             tr("Unable to open file"), forView.errorString());
         return;
     }

     QTextStream in(&forView);
     QString inputDocument = in.readAll();
     findChild<QTextEdit*>("inputTextEdit")->setPlainText(inputDocument);
 }

 void QueryMainWindow::evaluate(const QString &str)
 {
     QFile sourceDocument;
     sourceDocument.setFileName(":/files/cookbook.xml");
     sourceDocument.open(QIODevice::ReadOnly);

     QByteArray outArray;
     QBuffer buffer(&outArray);
     buffer.open(QIODevice::ReadWrite);

     QXmlQuery query;
     query.bindVariable("inputDocument", &sourceDocument);
     query.setQuery(str);
     if (!query.isValid())
         return;

     QXmlFormatter formatter(query, &buffer);
     if (!query.evaluateTo(&formatter))
         return;

     buffer.close();
     findChild<QTextEdit*>("outputTextEdit")->setPlainText(QString::fromUtf8(outArray.constData()));

 }