qt5base-lts/examples/widgets/tutorials/notepad/notepad.cpp

// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

#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);

    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, &QWidget::close);
#if QT_CONFIG(clipboard)
    connect(ui->textEdit, &QTextEdit::copyAvailable, ui->actionCopy, &QAction::setEnabled);
    connect(ui->actionCopy, &QAction::triggered, ui->textEdit, &QTextEdit::copy);
    connect(ui->actionCut, &QAction::triggered, ui->textEdit, &QTextEdit::cut);
    connect(ui->actionPaste, &QAction::triggered, ui->textEdit, &QTextEdit::paste);
#endif
    connect(ui->textEdit, &QTextEdit::undoAvailable, ui->actionUndo, &QAction::setEnabled);
    connect(ui->actionUndo, &QAction::triggered, ui->textEdit, &QTextEdit::undo);
    connect(ui->textEdit, &QTextEdit::redoAvailable, ui->actionRedo, &QAction::setEnabled);
    connect(ui->actionRedo, &QAction::triggered, ui->textEdit, &QTextEdit::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 !defined(QT_PRINTSUPPORT_LIB) || !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");
    if (fileName.isEmpty())
        return;
    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");
        if (fileName.isEmpty())
            return;
        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");
    if (fileName.isEmpty())
        return;
    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 defined(QT_PRINTSUPPORT_LIB) && 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::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 Notepad"),
                       tr("The <b>Notepad</b> example demonstrates how to code a basic "
                          "text editor using QtWidgets"));
}