mainwindow.cpp Example File | Qt Widgets 5.9

Qt 5.9 | Qt Widgets | Syntax Highlighter Example | mainwindow.cpp Example File

Qt 5.9.9 Reference Documentation

# mainwindow.cpp Example File

richtext/syntaxhighlighter/mainwindow.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2016 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 <QtWidgets>

      #include "mainwindow.h"

      MainWindow::MainWindow(QWidget *parent)
          : QMainWindow(parent)
      {
          setupFileMenu();
          setupHelpMenu();
          setupEditor();

          setCentralWidget(editor);
          setWindowTitle(tr("Syntax Highlighter"));
      }

      void MainWindow::about()
      {
          QMessageBox::about(this, tr("About Syntax Highlighter"),
                      tr("<p>The <b>Syntax Highlighter</b> example shows how " \
                         "to perform simple syntax highlighting by subclassing " \
                         "the QSyntaxHighlighter class and describing " \
                         "highlighting rules using regular expressions.</p>"));
      }

      void MainWindow::newFile()
      {
          editor->clear();
      }

      void MainWindow::openFile(const QString &path)
      {
          QString fileName = path;

          if (fileName.isNull())
              fileName = QFileDialog::getOpenFileName(this, tr("Open File"), "", "C++ Files (*.cpp *.h)");

          if (!fileName.isEmpty()) {
              QFile file(fileName);
              if (file.open(QFile::ReadOnly | QFile::Text))
                  editor->setPlainText(file.readAll());
          }
      }

      void MainWindow::setupEditor()
      {
          QFont font;
          font.setFamily("Courier");
          font.setFixedPitch(true);
          font.setPointSize(10);

          editor = new QTextEdit;
          editor->setFont(font);

          highlighter = new Highlighter(editor->document());

          QFile file("mainwindow.h");
          if (file.open(QFile::ReadOnly | QFile::Text))
              editor->setPlainText(file.readAll());
      }

      void MainWindow::setupFileMenu()
      {
          QMenu *fileMenu = new QMenu(tr("&File"), this);
          menuBar()->addMenu(fileMenu);

          fileMenu->addAction(tr("&New"), this, SLOT(newFile()), QKeySequence::New);
          fileMenu->addAction(tr("&Open..."), this, SLOT(openFile()), QKeySequence::Open);
          fileMenu->addAction(tr("E&xit"), qApp, SLOT(quit()), QKeySequence::Quit);
      }

      void MainWindow::setupHelpMenu()
      {
          QMenu *helpMenu = new QMenu(tr("&Help"), this);
          menuBar()->addMenu(helpMenu);

          helpMenu->addAction(tr("&About"), this, SLOT(about()));
          helpMenu->addAction(tr("About &Qt"), qApp, SLOT(aboutQt()));
      }