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Sourcecode: qt4-x11 version File versions

src.gui.util.qundostack.cpp

//! [0]
00002     class AppendText : public QUndoCommand
    {
    public:
        AppendText(QString *doc, const QString &text)
            : m_document(doc), m_text(text) { setText("append text"); }
00007         virtual void undo()
            { m_document->chop(m_text.length()); }
00009         virtual void redo()
            { m_document->append(m_text); }
    private:
        QString *m_document;
        QString m_text;
    };
//! [0]


//! [1]
    MyCommand *command1 = new MyCommand();
    stack->push(command1);
    MyCommand *command2 = new MyCommand();
    stack->push(command2);

    stack->undo();

    MyCommand *command3 = new MyCommand();
    stack->push(command3); // command2 gets deleted
//! [1]


//! [2]
    QUndoCommand *insertRed = new QUndoCommand(); // an empty command
    insertRed->setText("insert red text");

    new InsertText(document, idx, text, insertRed); // becomes child of insertRed
    new SetColor(document, idx, text.length(), Qt::red, insertRed);

    stack.push(insertRed);
//! [2]


//! [3]
    bool AppendText::mergeWith(const QUndoCommand *other)
    {
        if (other->id() != id()) // make sure other is also an AppendText command
            return false;
        m_text += static_cast<const AppendText*>(other)->m_text;
        return true;
    }
//! [3]


//! [4]
    stack.beginMacro("insert red text");
    stack.push(new InsertText(document, idx, text));
    stack.push(new SetColor(document, idx, text.length(), Qt::red));
    stack.endMacro(); // indexChanged() is emitted
//! [4]


//! [5]
    QUndoCommand *insertRed = new QUndoCommand(); // an empty command
    insertRed->setText("insert red text");

    new InsertText(document, idx, text, insertRed); // becomes child of insertRed
    new SetColor(document, idx, text.length(), Qt::red, insertRed);

    stack.push(insertRed);
//! [5]



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