textedit.cpp Example File
^{demos/textedit/textedit.cpp}

    /****************************************************************************
    **
    ** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved.
    **
    ** This file is part of the documentation of the Qt Toolkit.
    **
    ** This file may be used under the terms of the GNU General Public
    ** License version 2.0 as published by the Free Software Foundation
    ** and appearing in the file LICENSE.GPL included in the packaging of
    ** this file.  Please review the following information to ensure GNU
    ** General Public Licensing requirements will be met:
    ** http://www.trolltech.com/products/qt/opensource.html
    **
    ** If you are unsure which license is appropriate for your use, please
    ** review the following information:
    ** http://www.trolltech.com/products/qt/licensing.html or contact the
    ** sales department at sales@trolltech.com.
    **
    ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
    ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
    **
    ****************************************************************************/

    #include "textedit.h"

    #include <QAction>
    #include <QApplication>
    #include <QClipboard>
    #include <QColorDialog>
    #include <QComboBox>
    #include <QFile>
    #include <QFileDialog>
    #include <QFileInfo>
    #include <QFontDatabase>
    #include <QMenu>
    #include <QMenuBar>
    #include <QPrintDialog>
    #include <QPrinter>
    #include <QTextCodec>
    #include <QTextEdit>
    #include <QToolBar>
    #include <QTextCursor>
    #include <QTextList>
    #include <QtDebug>
    #include <QCloseEvent>
    #include <QMessageBox>

    #ifdef Q_WS_MAC
    const QString rsrcPath = ":/images/mac";
    #else
    const QString rsrcPath = ":/images/win";
    #endif

    TextEdit::TextEdit(QWidget *parent)
        : QMainWindow(parent)
    {
        setupFileActions();
        setupEditActions();
        setupTextActions();

        textEdit = new QTextEdit(this);
        connect(textEdit, SIGNAL(currentCharFormatChanged(const QTextCharFormat &)),
                this, SLOT(currentCharFormatChanged(const QTextCharFormat &)));

        setCentralWidget(textEdit);
        textEdit->setFocus();
        setCurrentFileName(QString());

        fontChanged(textEdit->font());
        colorChanged(textEdit->textColor());
        alignmentChanged(textEdit->alignment());

        connect(textEdit->document(), SIGNAL(modificationChanged(bool)),
                actionSave, SLOT(setEnabled(bool)));
        connect(textEdit->document(), SIGNAL(modificationChanged(bool)),
                this, SLOT(setWindowModified(bool)));
        connect(textEdit->document(), SIGNAL(undoAvailable(bool)),
                actionUndo, SLOT(setEnabled(bool)));
        connect(textEdit->document(), SIGNAL(redoAvailable(bool)),
                actionRedo, SLOT(setEnabled(bool)));

        setWindowModified(textEdit->document()->isModified());
        actionSave->setEnabled(textEdit->document()->isModified());
        actionUndo->setEnabled(textEdit->document()->isUndoAvailable());
        actionRedo->setEnabled(textEdit->document()->isRedoAvailable());

        connect(actionUndo, SIGNAL(triggered()), textEdit, SLOT(undo()));
        connect(actionRedo, SIGNAL(triggered()), textEdit, SLOT(redo()));

        actionCut->setEnabled(false);
        actionCopy->setEnabled(false);

        connect(actionCut, SIGNAL(triggered()), textEdit, SLOT(cut()));
        connect(actionCopy, SIGNAL(triggered()), textEdit, SLOT(copy()));
        connect(actionPaste, SIGNAL(triggered()), textEdit, SLOT(paste()));

        connect(textEdit, SIGNAL(copyAvailable(bool)), actionCut, SLOT(setEnabled(bool)));
        connect(textEdit, SIGNAL(copyAvailable(bool)), actionCopy, SLOT(setEnabled(bool)));

        connect(QApplication::clipboard(), SIGNAL(dataChanged()), this, SLOT(clipboardDataChanged()));

        QString initialFile = ":/example.html";
        const QStringList args = QCoreApplication::arguments();
        if (args.count() == 2)
            initialFile = args.at(1);

        if (!load(initialFile))
            fileNew();
    }

    void TextEdit::closeEvent(QCloseEvent *e)
    {
        if (maybeSave())
            e->accept();
        else
            e->ignore();
    }

    void TextEdit::setupFileActions()
    {
        QToolBar *tb = new QToolBar(this);
        tb->setWindowTitle(tr("File Actions"));
        addToolBar(tb);

        QMenu *menu = new QMenu(tr("&File"), this);
        menuBar()->addMenu(menu);

        QAction *a;

        a = new QAction(QIcon(rsrcPath + "/filenew.png"), tr("&New"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_N);
        connect(a, SIGNAL(triggered()), this, SLOT(fileNew()));
        tb->addAction(a);
        menu->addAction(a);

        a = new QAction(QIcon(rsrcPath + "/fileopen.png"), tr("&Open..."), this);
        a->setShortcut(Qt::CTRL + Qt::Key_O);
        connect(a, SIGNAL(triggered()), this, SLOT(fileOpen()));
        tb->addAction(a);
        menu->addAction(a);

        menu->addSeparator();

        actionSave = a = new QAction(QIcon(rsrcPath + "/filesave.png"), tr("&Save"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_S);
        connect(a, SIGNAL(triggered()), this, SLOT(fileSave()));
        a->setEnabled(false);
        tb->addAction(a);
        menu->addAction(a);

        a = new QAction(tr("Save &As..."), this);
        connect(a, SIGNAL(triggered()), this, SLOT(fileSaveAs()));
        menu->addAction(a);
        menu->addSeparator();

        a = new QAction(QIcon(rsrcPath + "/fileprint.png"), tr("&Print..."), this);
        a->setShortcut(Qt::CTRL + Qt::Key_P);
        connect(a, SIGNAL(triggered()), this, SLOT(filePrint()));
        tb->addAction(a);
        menu->addAction(a);

        a = new QAction(QIcon(rsrcPath + "/exportpdf.png"), tr("&Export PDF..."), this);
        a->setShortcut(Qt::CTRL + Qt::Key_D);
        connect(a, SIGNAL(triggered()), this, SLOT(filePrintPdf()));
        tb->addAction(a);
        menu->addAction(a);

        menu->addSeparator();

        a = new QAction(tr("&Quit"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_Q);
        connect(a, SIGNAL(triggered()), this, SLOT(close()));
        menu->addAction(a);
    }

    void TextEdit::setupEditActions()
    {
        QToolBar *tb = new QToolBar(this);
        tb->setWindowTitle(tr("Edit Actions"));
        addToolBar(tb);

        QMenu *menu = new QMenu(tr("&Edit"), this);
        menuBar()->addMenu(menu);

        QAction *a;
        a = actionUndo = new QAction(QIcon(rsrcPath + "/editundo.png"), tr("&Undo"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_Z);
        tb->addAction(a);
        menu->addAction(a);
        a = actionRedo = new QAction(QIcon(rsrcPath + "/editredo.png"), tr("&Redo"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_Y);
        tb->addAction(a);
        menu->addAction(a);
        menu->addSeparator();
        a = actionCut = new QAction(QIcon(rsrcPath + "/editcut.png"), tr("Cu&t"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_X);
        tb->addAction(a);
        menu->addAction(a);
        a = actionCopy = new QAction(QIcon(rsrcPath + "/editcopy.png"), tr("&Copy"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_C);
        tb->addAction(a);
        menu->addAction(a);
        a = actionPaste = new QAction(QIcon(rsrcPath + "/editpaste.png"), tr("&Paste"), this);
        a->setShortcut(Qt::CTRL + Qt::Key_V);
        tb->addAction(a);
        menu->addAction(a);
        actionPaste->setEnabled(!QApplication::clipboard()->text().isEmpty());
    }

    void TextEdit::setupTextActions()
    {
        QToolBar *tb = new QToolBar(this);
        tb->setWindowTitle(tr("Format Actions"));
        addToolBar(tb);

        QMenu *menu = new QMenu(tr("F&ormat"), this);
        menuBar()->addMenu(menu);

        actionTextBold = new QAction(QIcon(rsrcPath + "/textbold.png"), tr("&Bold"), this);
        actionTextBold->setShortcut(Qt::CTRL + Qt::Key_B);
        QFont bold;
        bold.setBold(true);
        actionTextBold->setFont(bold);
        connect(actionTextBold, SIGNAL(triggered()), this, SLOT(textBold()));
        tb->addAction(actionTextBold);
        menu->addAction(actionTextBold);
        actionTextBold->setCheckable(true);

        actionTextItalic = new QAction(QIcon(rsrcPath + "/textitalic.png"), tr("&Italic"), this);
        actionTextItalic->setShortcut(Qt::CTRL + Qt::Key_I);
        QFont italic;
        italic.setItalic(true);
        actionTextItalic->setFont(italic);
        connect(actionTextItalic, SIGNAL(triggered()), this, SLOT(textItalic()));
        tb->addAction(actionTextItalic);
        menu->addAction(actionTextItalic);
        actionTextItalic->setCheckable(true);

        actionTextUnderline = new QAction(QIcon(rsrcPath + "/textunder.png"), tr("&Underline"), this);
        actionTextUnderline->setShortcut(Qt::CTRL + Qt::Key_U);
        QFont underline;
        underline.setUnderline(true);
        actionTextUnderline->setFont(underline);
        connect(actionTextUnderline, SIGNAL(triggered()), this, SLOT(textUnderline()));
        tb->addAction(actionTextUnderline);
        menu->addAction(actionTextUnderline);
        actionTextUnderline->setCheckable(true);

        menu->addSeparator();

        QActionGroup *grp = new QActionGroup(this);
        connect(grp, SIGNAL(triggered(QAction *)), this, SLOT(textAlign(QAction *)));

        actionAlignLeft = new QAction(QIcon(rsrcPath + "/textleft.png"), tr("&Left"), grp);
        actionAlignLeft->setShortcut(Qt::CTRL + Qt::Key_L);
        actionAlignLeft->setCheckable(true);
        actionAlignCenter = new QAction(QIcon(rsrcPath + "/textcenter.png"), tr("C&enter"), grp);
        actionAlignCenter->setShortcut(Qt::CTRL + Qt::Key_E);
        actionAlignCenter->setCheckable(true);
        actionAlignRight = new QAction(QIcon(rsrcPath + "/textright.png"), tr("&Right"), grp);
        actionAlignRight->setShortcut(Qt::CTRL + Qt::Key_R);
        actionAlignRight->setCheckable(true);
        actionAlignJustify = new QAction(QIcon(rsrcPath + "/textjustify.png"), tr("&Justify"), grp);
        actionAlignJustify->setShortcut(Qt::CTRL + Qt::Key_J);
        actionAlignJustify->setCheckable(true);

        tb->addActions(grp->actions());
        menu->addActions(grp->actions());

        menu->addSeparator();

        QPixmap pix(16, 16);
        pix.fill(Qt::black);
        actionTextColor = new QAction(pix, tr("&Color..."), this);
        connect(actionTextColor, SIGNAL(triggered()), this, SLOT(textColor()));
        tb->addAction(actionTextColor);
        menu->addAction(actionTextColor);

        tb = new QToolBar(this);
        tb->setAllowedAreas(Qt::TopToolBarArea | Qt::BottomToolBarArea);
        tb->setWindowTitle(tr("Format Actions"));
        addToolBarBreak(Qt::TopToolBarArea);
        addToolBar(tb);

        comboStyle = new QComboBox(tb);
        tb->addWidget(comboStyle);
        comboStyle->addItem("Standard");
        comboStyle->addItem("Bullet List (Disc)");
        comboStyle->addItem("Bullet List (Circle)");
        comboStyle->addItem("Bullet List (Square)");
        comboStyle->addItem("Ordered List (Decimal)");
        comboStyle->addItem("Ordered List (Alpha lower)");
        comboStyle->addItem("Ordered List (Alpha upper)");
        connect(comboStyle, SIGNAL(activated(int)),
                this, SLOT(textStyle(int)));

        comboFont = new QComboBox(tb);
        tb->addWidget(comboFont);
        comboFont->setEditable(true);
        QFontDatabase db;
        comboFont->addItems(db.families());
        connect(comboFont, SIGNAL(activated(const QString &)),
                this, SLOT(textFamily(const QString &)));
        comboFont->setCurrentIndex(comboFont->findText(QApplication::font().family()));

        comboSize = new QComboBox(tb);
        comboSize->setObjectName("comboSize");
        tb->addWidget(comboSize);
        comboSize->setEditable(true);

        foreach(int size, db.standardSizes())
            comboSize->addItem(QString::number(size));

        connect(comboSize, SIGNAL(activated(const QString &)),
                this, SLOT(textSize(const QString &)));
        comboSize->setCurrentIndex(comboSize->findText(QString::number(QApplication::font()
                                                                       .pointSize())));
    }

    bool TextEdit::load(const QString &f)
    {
        if (!QFile::exists(f))
            return false;
        QFile file(f);
        if (!file.open(QFile::ReadOnly))
            return false;

        QByteArray data = file.readAll();
        QTextCodec *codec = Qt::codecForHtml(data);
        QString str = codec->toUnicode(data);
        if (Qt::mightBeRichText(str)) {
            textEdit->setHtml(str);
        } else {
            str = QString::fromLocal8Bit(data);
            textEdit->setPlainText(str);
        }

        setCurrentFileName(f);
        return true;
    }

    bool TextEdit::maybeSave()
    {
        if (!textEdit->document()->isModified())
            return true;
        if (fileName.startsWith(QLatin1String(":/")))
            return true;
        int ret = QMessageBox::warning(this, tr("Application"),
                                       tr("The document has been modified.\n"
                                          "Do you want to save your changes?"),
                                       QMessageBox::Yes | QMessageBox::Default,
                                       QMessageBox::No,
                                       QMessageBox::Cancel | QMessageBox::Escape);
        if (ret == QMessageBox::Yes)
            return fileSave();
        else if (ret == QMessageBox::Cancel)
            return false;
        return true;
    }

    void TextEdit::setCurrentFileName(const QString &fileName)
    {
        this->fileName = fileName;
        textEdit->document()->setModified(false);

        QString shownName;
        if (fileName.isEmpty())
            shownName = "untitled.txt";
        else
            shownName = QFileInfo(fileName).fileName();

        setWindowTitle(tr("%1[*] - %2").arg(shownName).arg(tr("Rich Text")));
        setWindowModified(false);
    }

    void TextEdit::fileNew()
    {
        if (maybeSave()) {
            textEdit->clear();
            setCurrentFileName(QString());
        }
    }

    void TextEdit::fileOpen()
    {
        QString fn = QFileDialog::getOpenFileName(this, tr("Open File..."),
                                                  QString(), tr("HTML-Files (*.htm *.html);;All Files (*)"));
        if (!fn.isEmpty())
            load(fn);
    }

    bool TextEdit::fileSave()
    {
        if (fileName.isEmpty())
            return fileSaveAs();

        QFile file(fileName);
        if (!file.open(QFile::WriteOnly))
            return false;
        QTextStream ts(&file);
        ts.setCodec(QTextCodec::codecForName("UTF-8"));
        ts << textEdit->document()->toHtml("UTF-8");
        textEdit->document()->setModified(false);
        return true;
    }

    bool TextEdit::fileSaveAs()
    {
        QString fn = QFileDialog::getSaveFileName(this, tr("Save as..."),
                                                  QString(), tr("HTML-Files (*.htm *.html);;All Files (*)"));
        if (fn.isEmpty())
            return false;
        setCurrentFileName(fn);
        return fileSave();
    }

    void TextEdit::filePrint()
    {
    #ifndef QT_NO_PRINTER
        QPrinter printer(QPrinter::HighResolution);
        printer.setFullPage(true);
        QPrintDialog *dlg = new QPrintDialog(&printer, this);
        if (dlg->exec() == QDialog::Accepted) {
            textEdit->document()->print(&printer);
        }
        delete dlg;
    #endif
    }

    void TextEdit::filePrintPdf()
    {
    #ifndef QT_NO_PRINTER
        QString fileName = QFileDialog::getSaveFileName(this, "Export PDF", QString(), "*.pdf");
        if (fileName.isEmpty())
            return;
        QPrinter printer(QPrinter::HighResolution);
        printer.setOutputFormat(QPrinter::PdfFormat);
        printer.setOutputFileName(fileName);
        textEdit->document()->print(&printer);
    #endif
    }

    void TextEdit::textBold()
    {
        textEdit->setFontWeight(actionTextBold->isChecked() ? QFont::Bold : QFont::Normal);
    }

    void TextEdit::textUnderline()
    {
        textEdit->setFontUnderline(actionTextUnderline->isChecked());
    }

    void TextEdit::textItalic()
    {
        textEdit->setFontItalic(actionTextItalic->isChecked());
    }

    void TextEdit::textFamily(const QString &f)
    {
        textEdit->setFontFamily(f);
    }

    void TextEdit::textSize(const QString &p)
    {
        textEdit->setFontPointSize(p.toFloat());
    }

    void TextEdit::textStyle(int styleIndex)
    {
        QTextCursor cursor = textEdit->textCursor();

        if (styleIndex != 0) {
            QTextListFormat::Style style = QTextListFormat::ListDisc;

            switch (styleIndex) {
                default:
                case 1:
                    style = QTextListFormat::ListDisc;
                    break;
                case 2:
                    style = QTextListFormat::ListCircle;
                    break;
                case 3:
                    style = QTextListFormat::ListSquare;
                    break;
                case 4:
                    style = QTextListFormat::ListDecimal;
                    break;
                case 5:
                    style = QTextListFormat::ListLowerAlpha;
                    break;
                case 6:
                    style = QTextListFormat::ListUpperAlpha;
                    break;
            }

            cursor.beginEditBlock();

            QTextBlockFormat blockFmt = cursor.blockFormat();

            QTextListFormat listFmt;

            if (cursor.currentList()) {
                listFmt = cursor.currentList()->format();
            } else {
                listFmt.setIndent(blockFmt.indent() + 1);
                blockFmt.setIndent(0);
                cursor.setBlockFormat(blockFmt);
            }

            listFmt.setStyle(style);

            cursor.createList(listFmt);

            cursor.endEditBlock();
        } else {
            // ####
            QTextBlockFormat bfmt;
            bfmt.setObjectIndex(-1);
            cursor.mergeBlockFormat(bfmt);
        }
    }

    void TextEdit::textColor()
    {
        QColor col = QColorDialog::getColor(textEdit->textColor(), this);
        if (!col.isValid())
            return;
        textEdit->setTextColor(col);
        colorChanged(col);
    }

    void TextEdit::textAlign(QAction *a)
    {
        if (a == actionAlignLeft)
            textEdit->setAlignment(Qt::AlignLeft);
        else if (a == actionAlignCenter)
            textEdit->setAlignment(Qt::AlignHCenter);
        else if (a == actionAlignRight)
            textEdit->setAlignment(Qt::AlignRight);
        else if (a == actionAlignJustify)
            textEdit->setAlignment(Qt::AlignJustify);
    }

    void TextEdit::currentCharFormatChanged(const QTextCharFormat &format)
    {
        fontChanged(format.font());
        colorChanged(format.foreground().color());
        alignmentChanged(textEdit->alignment());
    }

    void TextEdit::clipboardDataChanged()
    {
        actionPaste->setEnabled(!QApplication::clipboard()->text().isEmpty());
    }

    void TextEdit::fontChanged(const QFont &f)
    {
        comboFont->setCurrentIndex(comboFont->findText(f.family()));
        comboSize->setCurrentIndex(comboSize->findText(QString::number(f.pointSize())));
        actionTextBold->setChecked(f.bold());
        actionTextItalic->setChecked(f.italic());
        actionTextUnderline->setChecked(f.underline());
    }

    void TextEdit::colorChanged(const QColor &c)
    {
        QPixmap pix(16, 16);
        pix.fill(c);
        actionTextColor->setIcon(pix);
    }

    void TextEdit::alignmentChanged(Qt::Alignment a)
    {
        if (a & Qt::AlignLeft)
            actionAlignLeft->setChecked(true);
        else if (a & Qt::AlignHCenter)
            actionAlignCenter->setChecked(true);
        else if (a & Qt::AlignRight)
            actionAlignRight->setChecked(true);
        else if (a & Qt::AlignJustify)
            actionAlignJustify->setChecked(true);
    }