Qt 5.11 | Qt Widgets | Getting Started Programming with Qt Widgets | notepad.cpp Example File

Qt 5.11.3 Reference Documentation

# notepad.cpp Example File

tutorials/notepad/notepad.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the documentation 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 <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);

      // 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::on_actionNew_triggered()
      {
          currentFile.clear();
          ui->textEdit->setText(QString());
      }

      void Notepad::on_actionOpen_triggered()
      {
          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::on_actionSave_triggered()
      {
          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::on_actionSave_as_triggered()
      {
          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::on_actionPrint_triggered()
      {
      #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::on_actionExit_triggered()
      {
          QCoreApplication::quit();
      }

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

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

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

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

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

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

      void Notepad::on_actionUnderline_triggered()
      {
          ui->textEdit->setFontUnderline(ui->actionUnderline->isChecked());
      }

      void Notepad::on_actionItalic_triggered()
      {
          ui->textEdit->setFontItalic(ui->actionItalic->isChecked());
      }

      void Notepad::on_actionBold_triggered()
      {
          ui->actionBold->isChecked() ? ui->textEdit->setFontWeight(QFont::Bold) :
                                        ui->textEdit->setFontWeight(QFont::Normal);
      }

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

      }