mainwindow.cpp Example File

tools/codecs/mainwindow.cpp
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 <QtGui>

#include "mainwindow.h"
#include "previewform.h"

MainWindow::MainWindow()
{
    textEdit = new QTextEdit;
    textEdit->setLineWrapMode(QTextEdit::NoWrap);
    setCentralWidget(textEdit);

    findCodecs();

    previewForm = new PreviewForm(this);
    previewForm->setCodecList(codecs);

    createActions();
    createMenus();

    setWindowTitle(tr("Codecs"));
    resize(500, 400);
}

void MainWindow::open()
{
    QString fileName = QFileDialog::getOpenFileName(this);
    if (!fileName.isEmpty()) {
        QFile file(fileName);
        if (!file.open(QFile::ReadOnly)) {
            QMessageBox::warning(this, tr("Codecs"),
                                 tr("Cannot read file %1:\n%2")
                                 .arg(fileName)
                                 .arg(file.errorString()));
            return;
        }

        QByteArray data = file.readAll();

        previewForm->setEncodedData(data);
        if (previewForm->exec())
            textEdit->setPlainText(previewForm->decodedString());
    }
}

void MainWindow::save()
{
    QString fileName = QFileDialog::getSaveFileName(this);
    if (!fileName.isEmpty()) {
        QFile file(fileName);
        if (!file.open(QFile::WriteOnly | QFile::Text)) {
            QMessageBox::warning(this, tr("Codecs"),
                                 tr("Cannot write file %1:\n%2")
                                 .arg(fileName)
                                 .arg(file.errorString()));
            return;
        }

        QAction *action = qobject_cast<QAction *>(sender());
        QByteArray codecName = action->data().toByteArray();

        QTextStream out(&file);
        out.setCodec(codecName);
        out << textEdit->toPlainText();
    }
}

void MainWindow::about()
{
    QMessageBox::about(this, tr("About Codecs"),
            tr("The <b>Codecs</b> example demonstrates how to read and write "
               "files using various encodings."));
}

void MainWindow::aboutToShowSaveAsMenu()
{
    QString currentText = textEdit->toPlainText();

    foreach (QAction *action, saveAsActs) {
        QByteArray codecName = action->data().toByteArray();
        QTextCodec *codec = QTextCodec::codecForName(codecName);
        action->setVisible(codec && codec->canEncode(currentText));
    }
}

void MainWindow::findCodecs()
{
    QMap<QString, QTextCodec *> codecMap;
    QRegExp iso8859RegExp("ISO[- ]8859-([0-9]+).*");

    foreach (int mib, QTextCodec::availableMibs()) {
        QTextCodec *codec = QTextCodec::codecForMib(mib);

        QString sortKey = codec->name().toUpper();
        int rank;

        if (sortKey.startsWith("UTF-8")) {
            rank = 1;
        } else if (sortKey.startsWith("UTF-16")) {
            rank = 2;
        } else if (iso8859RegExp.exactMatch(sortKey)) {
            if (iso8859RegExp.cap(1).size() == 1)
                rank = 3;
            else
                rank = 4;
        } else {
            rank = 5;
        }
        sortKey.prepend(QChar('0' + rank));

        codecMap.insert(sortKey, codec);
    }
    codecs = codecMap.values();
}

void MainWindow::createActions()
{
    openAct = new QAction(tr("&Open..."), this);
    openAct->setShortcuts(QKeySequence::Open);
    connect(openAct, SIGNAL(triggered()), this, SLOT(open()));

    foreach (QTextCodec *codec, codecs) {
        QString text = tr("%1...").arg(QString(codec->name()));

        QAction *action = new QAction(text, this);
        action->setData(codec->name());
        connect(action, SIGNAL(triggered()), this, SLOT(save()));
        saveAsActs.append(action);
    }

    exitAct = new QAction(tr("E&xit"), this);
    exitAct->setShortcuts(QKeySequence::Quit);
    connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));

    aboutAct = new QAction(tr("&About"), this);
    connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));

    aboutQtAct = new QAction(tr("About &Qt"), this);
    connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
}

void MainWindow::createMenus()
{
    saveAsMenu = new QMenu(tr("&Save As"), this);
    foreach (QAction *action, saveAsActs)
        saveAsMenu->addAction(action);
    connect(saveAsMenu, SIGNAL(aboutToShow()),
            this, SLOT(aboutToShowSaveAsMenu()));

    fileMenu = new QMenu(tr("&File"), this);
    fileMenu->addAction(openAct);
    fileMenu->addMenu(saveAsMenu);
    fileMenu->addSeparator();
    fileMenu->addAction(exitAct);

    helpMenu = new QMenu(tr("&Help"), this);
    helpMenu->addAction(aboutAct);
    helpMenu->addAction(aboutQtAct);

    menuBar()->addMenu(fileMenu);
    menuBar()->addSeparator();
    menuBar()->addMenu(helpMenu);
}

© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.