notepad.cpp Example File | Qt Widgets 5.12.6

Qt 5.12 | Qt Widgets | Getting Started Programming with Qt Widgets | notepad.cpp Example File

Qt 5.12.6 Reference Documentation

# notepad.cpp Example File

tutorials/notepad/notepad.cpp

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      #include <QFile>
      #include <QFileDialog>
      #include <QTextStream>
      #include <QMessageBox>
      #if defined(QT_PRINTSUPPORT_LIB)
      #include <QtPrintSupport/qtprintsupportglobal.h>
      #if QT_CONFIG(printer)
      #if QT_CONFIG(printdialog)
      #include <QPrintDialog>
      #endif // QT_CONFIG(printdialog)
      #include <QPrinter>
      #endif // QT_CONFIG(printer)
      #endif // QT_PRINTSUPPORT_LIB
      #include <QFont>
      #include <QFontDialog>

      #include "notepad.h"
      #include "ui_notepad.h"

      Notepad::Notepad(QWidget *parent) :
          QMainWindow(parent),
          ui(new Ui::Notepad)
      {
          ui->setupUi(this);
          this->setCentralWidget(ui->textEdit);

          connect(ui->actionNew, &QAction::triggered, this, &Notepad::newDocument);
          connect(ui->actionOpen, &QAction::triggered, this, &Notepad::open);
          connect(ui->actionSave, &QAction::triggered, this, &Notepad::save);
          connect(ui->actionSave_as, &QAction::triggered, this, &Notepad::saveAs);
          connect(ui->actionPrint, &QAction::triggered, this, &Notepad::print);
          connect(ui->actionExit, &QAction::triggered, this, &Notepad::exit);
          connect(ui->actionCopy, &QAction::triggered, this, &Notepad::copy);
          connect(ui->actionCut, &QAction::triggered, this, &Notepad::cut);
          connect(ui->actionPaste, &QAction::triggered, this, &Notepad::paste);
          connect(ui->actionUndo, &QAction::triggered, this, &Notepad::undo);
          connect(ui->actionRedo, &QAction::triggered, this, &Notepad::redo);
          connect(ui->actionFont, &QAction::triggered, this, &Notepad::selectFont);
          connect(ui->actionBold, &QAction::triggered, this, &Notepad::setFontBold);
          connect(ui->actionUnderline, &QAction::triggered, this, &Notepad::setFontUnderline);
          connect(ui->actionItalic, &QAction::triggered, this, &Notepad::setFontItalic);
          connect(ui->actionAbout, &QAction::triggered, this, &Notepad::about);

      // Disable menu actions for unavailable features
      #if !QT_CONFIG(printer)
          ui->actionPrint->setEnabled(false);
      #endif

      #if !QT_CONFIG(clipboard)
          ui->actionCut->setEnabled(false);
          ui->actionCopy->setEnabled(false);
          ui->actionPaste->setEnabled(false);
      #endif
      }

      Notepad::~Notepad()
      {
          delete ui;
      }

      void Notepad::newDocument()
      {
          currentFile.clear();
          ui->textEdit->setText(QString());
      }

      void Notepad::open()
      {
          QString fileName = QFileDialog::getOpenFileName(this, "Open the file");
          QFile file(fileName);
          currentFile = fileName;
          if (!file.open(QIODevice::ReadOnly | QFile::Text)) {
              QMessageBox::warning(this, "Warning", "Cannot open file: " + file.errorString());
              return;
          }
          setWindowTitle(fileName);
          QTextStream in(&file);
          QString text = in.readAll();
          ui->textEdit->setText(text);
          file.close();
      }

      void Notepad::save()
      {
          QString fileName;
          // If we don't have a filename from before, get one.
          if (currentFile.isEmpty()) {
              fileName = QFileDialog::getSaveFileName(this, "Save");
              currentFile = fileName;
          } else {
              fileName = currentFile;
          }
          QFile file(fileName);
          if (!file.open(QIODevice::WriteOnly | QFile::Text)) {
              QMessageBox::warning(this, "Warning", "Cannot save file: " + file.errorString());
              return;
          }
          setWindowTitle(fileName);
          QTextStream out(&file);
          QString text = ui->textEdit->toPlainText();
          out << text;
          file.close();
      }

      void Notepad::saveAs()
      {
          QString fileName = QFileDialog::getSaveFileName(this, "Save as");
          QFile file(fileName);

          if (!file.open(QFile::WriteOnly | QFile::Text)) {
              QMessageBox::warning(this, "Warning", "Cannot save file: " + file.errorString());
              return;
          }
          currentFile = fileName;
          setWindowTitle(fileName);
          QTextStream out(&file);
          QString text = ui->textEdit->toPlainText();
          out << text;
          file.close();
      }

      void Notepad::print()
      {
      #if QT_CONFIG(printer)
          QPrinter printDev;
      #if QT_CONFIG(printdialog)
          QPrintDialog dialog(&printDev, this);
          if (dialog.exec() == QDialog::Rejected)
              return;
      #endif // QT_CONFIG(printdialog)
          ui->textEdit->print(&printDev);
      #endif // QT_CONFIG(printer)
      }

      void Notepad::exit()
      {
          QCoreApplication::quit();
      }

      void Notepad::copy()
      {
      #if QT_CONFIG(clipboard)
          ui->textEdit->copy();
      #endif
      }

      void Notepad::cut()
      {
      #if QT_CONFIG(clipboard)
          ui->textEdit->cut();
      #endif
      }

      void Notepad::paste()
      {
      #if QT_CONFIG(clipboard)
          ui->textEdit->paste();
      #endif
      }

      void Notepad::undo()
      {
           ui->textEdit->undo();
      }

      void Notepad::redo()
      {
          ui->textEdit->redo();
      }

      void Notepad::selectFont()
      {
          bool fontSelected;
          QFont font = QFontDialog::getFont(&fontSelected, this);
          if (fontSelected)
              ui->textEdit->setFont(font);
      }

      void Notepad::setFontUnderline(bool underline)
      {
          ui->textEdit->setFontUnderline(underline);
      }

      void Notepad::setFontItalic(bool italic)
      {
          ui->textEdit->setFontItalic(italic);
      }

      void Notepad::setFontBold(bool bold)
      {
          bold ? ui->textEdit->setFontWeight(QFont::Bold) :
                 ui->textEdit->setFontWeight(QFont::Normal);
      }

      void Notepad::about()
      {
         QMessageBox::about(this, tr("About MDI"),
                      tr("The <b>Notepad</b> example demonstrates how to code a basic "
                         "text editor using QtWidgets"));

      }