mainwindow.cpp Example File | Qt Widgets 5.12.10

- Qt 5.12
- Qt Widgets
- Syntax Highlighter Example
- mainwindow.cpp Example File
- Qt 5.12.10 Reference Documentation

# mainwindow.cpp Example File

richtext/syntaxhighlighter/mainwindow.cpp

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     #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()));
     }