- Qt 5.5
- Qt Widgets
- Text Codecs Example
- previewform.cpp Example File
- Qt 5.5.1 Reference Documentation

# previewform.cpp Example File

tools/codecs/previewform.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
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    **   * Redistributions of source code must retain the above copyright
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    **     from this software without specific prior written permission.
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    #include <QtWidgets>

    #include "previewform.h"

    PreviewForm::PreviewForm(QWidget *parent)
        : QDialog(parent)
    {
        encodingComboBox = new QComboBox;

        encodingLabel = new QLabel(tr("&Encoding:"));
        encodingLabel->setBuddy(encodingComboBox);

        textEdit = new QTextEdit;
        textEdit->setLineWrapMode(QTextEdit::NoWrap);
        textEdit->setReadOnly(true);

        buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok
                                        | QDialogButtonBox::Cancel);

        connect(encodingComboBox, SIGNAL(activated(int)),
                this, SLOT(updateTextEdit()));
        connect(buttonBox, SIGNAL(accepted()), this, SLOT(accept()));
        connect(buttonBox, SIGNAL(rejected()), this, SLOT(reject()));

        QGridLayout *mainLayout = new QGridLayout;
        mainLayout->addWidget(encodingLabel, 0, 0);
        mainLayout->addWidget(encodingComboBox, 0, 1);
        mainLayout->addWidget(textEdit, 1, 0, 1, 2);
        mainLayout->addWidget(buttonBox, 2, 0, 1, 2);
        setLayout(mainLayout);

        setWindowTitle(tr("Choose Encoding"));
        resize(400, 300);
    }

    void PreviewForm::setCodecList(const QList<QTextCodec *> &list)
    {
        encodingComboBox->clear();
        foreach (QTextCodec *codec, list)
            encodingComboBox->addItem(codec->name(), codec->mibEnum());
    }

    void PreviewForm::setEncodedData(const QByteArray &data)
    {
        encodedData = data;
        updateTextEdit();
    }

    void PreviewForm::updateTextEdit()
    {
        int mib = encodingComboBox->itemData(
                          encodingComboBox->currentIndex()).toInt();
        QTextCodec *codec = QTextCodec::codecForMib(mib);

        QTextStream in(&encodedData);
        in.setAutoDetectUnicode(false);
        in.setCodec(codec);
        decodedStr = in.readAll();

        textEdit->setPlainText(decodedStr);
    }