/****************************************************************************+
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**+
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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).+
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** All rights reserved.+
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** Contact: Nokia Corporation (qt-info@nokia.com)+
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**+
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** This file is part of the QtGui module of the Qt Toolkit.+
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**+
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** $QT_BEGIN_LICENSE:LGPL$+
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** No Commercial Usage+
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** This file contains pre-release code and may not be distributed.+
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** You may use this file in accordance with the terms and conditions+
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** contained in the Technology Preview License Agreement accompanying+
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** this package.+
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**+
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** GNU Lesser General Public License Usage+
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** Alternatively, this file may be used under the terms of the GNU Lesser+
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** General Public License version 2.1 as published by the Free Software+
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** Foundation and appearing in the file LICENSE.LGPL included in the+
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** packaging of this file.  Please review the following information to+
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** ensure the GNU Lesser General Public License version 2.1 requirements+
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** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.+
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**+
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** In addition, as a special exception, Nokia gives you certain additional+
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** rights.  These rights are described in the Nokia Qt LGPL Exception+
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** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.+
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**+
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** If you have questions regarding the use of this file, please contact+
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** Nokia at qt-info@nokia.com.+
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**+
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**+
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**+
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**+
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**+
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**+
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**+
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**+
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** $QT_END_LICENSE$+
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**+
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****************************************************************************/+
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+
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#include "qundogroup.h"+
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#include "qundostack.h"+
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#include "qundostack_p.h"+
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+
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#ifndef QT_NO_UNDOGROUP+
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+
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QT_BEGIN_NAMESPACE+
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+
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class QUndoGroupPrivate : public QObjectPrivate+
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{+
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    Q_DECLARE_PUBLIC(QUndoGroup)+
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public:+
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    QUndoGroupPrivate() : active(0) {}+
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+
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    QUndoStack *active;+
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    QList<QUndoStack*> stack_list;+
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};+
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+
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/*!+
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    \class QUndoGroup+
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    \brief The QUndoGroup class is a group of QUndoStack objects.+
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    \since 4.2+
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+
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    For an overview of the Qt's undo framework, see the+
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    \link qundo.html overview\endlink.+
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+
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    An application often has multiple undo stacks, one for each opened document. At the+
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    same time, an application usually has one undo action and one redo action, which+
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    triggers undo or redo in the active document.+
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+
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    QUndoGroup is a group of QUndoStack objects, one of which may be active. It has+
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    an undo() and redo() slot, which calls QUndoStack::undo() and QUndoStack::redo()+
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    for the active stack. It also has the functions createUndoAction() and createRedoAction().+
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    The actions returned by these functions behave in the same way as those returned by+
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    QUndoStack::createUndoAction() and QUndoStack::createRedoAction() of the active+
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    stack.+
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+
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    Stacks are added to a group with addStack() and removed with removeStack(). A stack+
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    is implicitly added to a group when it is created with the group as its parent+
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    QObject.+
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+
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    It is the programmer's responsibility to specify which stack is active by+
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    calling QUndoStack::setActive(), usually when the associated document window receives focus.+
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    The active stack may also be set with setActiveStack(), and is returned by activeStack().+
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+
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    When a stack is added to a group using addStack(), the group does not take ownership+
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    of the stack. This means the stack has to be deleted separately from the group. When+
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    a stack is deleted, it is automatically removed from a group. A stack may belong to+
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    only one group. Adding it to another group will cause it to be removed from the previous+
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    group.+
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+
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    A QUndoGroup is also useful in conjunction with QUndoView. If a QUndoView is+
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    set to watch a group using QUndoView::setGroup(), it will update itself to display+
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    the active stack.+
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*/+
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+
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/*!+
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    Creates an empty QUndoGroup object with parent \a parent.+
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+
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    \sa addStack()+
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*/+
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+
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QUndoGroup::QUndoGroup(QObject *parent)+
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    : QObject(*new QUndoGroupPrivate(), parent)+
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{+
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}+
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+
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/*!+
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    Destroys the QUndoGroup.+
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*/+
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QUndoGroup::~QUndoGroup()+
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{+
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    // Ensure all QUndoStacks no longer refer to this group.+
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    Q_D(QUndoGroup);+
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    QList<QUndoStack *>::iterator it = d->stack_list.begin();+
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    QList<QUndoStack *>::iterator end = d->stack_list.end();+
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    while (it != end) {+
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        (*it)->d_func()->group = 0;+
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        ++it;+
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    }+
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}+
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+
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/*!+
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    Adds \a stack to this group. The group does not take ownership of the stack. Another+
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    way of adding a stack to a group is by specifying the group as the stack's parent+
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    QObject in QUndoStack::QUndoStack(). In this case, the stack is deleted when the+
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    group is deleted, in the usual manner of QObjects.+
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+
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    \sa removeStack() stacks() QUndoStack::QUndoStack()+
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*/+
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+
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void QUndoGroup::addStack(QUndoStack *stack)+
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{+
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    Q_D(QUndoGroup);+
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+
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    if (d->stack_list.contains(stack))+
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        return;+
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    d->stack_list.append(stack);+
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+
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    if (QUndoGroup *other = stack->d_func()->group)+
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        other->removeStack(stack);+
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    stack->d_func()->group = this;+
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}+
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+
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/*!+
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    Removes \a stack from this group. If the stack was the active stack in the group,+
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    the active stack becomes 0.+
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+
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    \sa addStack() stacks() QUndoStack::~QUndoStack()+
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*/+
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+
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void QUndoGroup::removeStack(QUndoStack *stack)+
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{+
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    Q_D(QUndoGroup);+
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+
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    if (d->stack_list.removeAll(stack) == 0)+
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        return;+
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    if (stack == d->active)+
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        setActiveStack(0);+
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    stack->d_func()->group = 0;+
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}+
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+
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/*!+
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    Returns a list of stacks in this group.+
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+
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    \sa addStack() removeStack()+
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*/+
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+
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QList<QUndoStack*> QUndoGroup::stacks() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->stack_list;+
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}+
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+
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/*!+
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    Sets the active stack of this group to \a stack.+
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+
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    If the stack is not a member of this group, this function does nothing.+
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+
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    Synonymous with calling QUndoStack::setActive() on \a stack.+
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+
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    The actions returned by createUndoAction() and createRedoAction() will now behave+
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    in the same way as those returned by \a stack's QUndoStack::createUndoAction()+
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    and QUndoStack::createRedoAction().+
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+
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    \sa QUndoStack::setActive() activeStack()+
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*/+
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+
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void QUndoGroup::setActiveStack(QUndoStack *stack)+
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{+
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    Q_D(QUndoGroup);+
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    if (d->active == stack)+
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        return;+
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+
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    if (d->active != 0) {+
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        disconnect(d->active, SIGNAL(canUndoChanged(bool)),+
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                    this, SIGNAL(canUndoChanged(bool)));+
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        disconnect(d->active, SIGNAL(undoTextChanged(QString)),+
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                    this, SIGNAL(undoTextChanged(QString)));+
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        disconnect(d->active, SIGNAL(canRedoChanged(bool)),+
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                    this, SIGNAL(canRedoChanged(bool)));+
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        disconnect(d->active, SIGNAL(redoTextChanged(QString)),+
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                    this, SIGNAL(redoTextChanged(QString)));+
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        disconnect(d->active, SIGNAL(indexChanged(int)),+
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                    this, SIGNAL(indexChanged(int)));+
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        disconnect(d->active, SIGNAL(cleanChanged(bool)),+
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                    this, SIGNAL(cleanChanged(bool)));+
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    }+
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+
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    d->active = stack;+
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+
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    if (d->active == 0) {+
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        emit canUndoChanged(false);+
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        emit undoTextChanged(QString());+
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        emit canRedoChanged(false);+
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        emit redoTextChanged(QString());+
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        emit cleanChanged(true);+
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        emit indexChanged(0);+
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    } else {+
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        connect(d->active, SIGNAL(canUndoChanged(bool)),+
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                this, SIGNAL(canUndoChanged(bool)));+
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        connect(d->active, SIGNAL(undoTextChanged(QString)),+
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                this, SIGNAL(undoTextChanged(QString)));+
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        connect(d->active, SIGNAL(canRedoChanged(bool)),+
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                this, SIGNAL(canRedoChanged(bool)));+
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        connect(d->active, SIGNAL(redoTextChanged(QString)),+
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                this, SIGNAL(redoTextChanged(QString)));+
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        connect(d->active, SIGNAL(indexChanged(int)),+
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                this, SIGNAL(indexChanged(int)));+
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        connect(d->active, SIGNAL(cleanChanged(bool)),+
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                this, SIGNAL(cleanChanged(bool)));+
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        emit canUndoChanged(d->active->canUndo());+
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        emit undoTextChanged(d->active->undoText());+
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        emit canRedoChanged(d->active->canRedo());+
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        emit redoTextChanged(d->active->redoText());+
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        emit cleanChanged(d->active->isClean());+
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        emit indexChanged(d->active->index());+
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    }+
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+
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    emit activeStackChanged(d->active);+
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}+
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+
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/*!+
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    Returns the active stack of this group.+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns 0.+
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+
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    \sa setActiveStack() QUndoStack::setActive()+
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*/+
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+
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QUndoStack *QUndoGroup::activeStack() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active;+
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}+
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+
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/*!+
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    Calls QUndoStack::undo() on the active stack.+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    does nothing.+
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+
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    \sa redo() canUndo() setActiveStack()+
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*/+
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+
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void QUndoGroup::undo()+
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{+
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    Q_D(QUndoGroup);+
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    if (d->active != 0)+
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        d->active->undo();+
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}+
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+
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/*!+
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    Calls QUndoStack::redo() on the active stack.+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    does nothing.+
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+
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    \sa undo() canRedo() setActiveStack()+
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*/+
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+
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+
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void QUndoGroup::redo()+
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{+
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    Q_D(QUndoGroup);+
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    if (d->active != 0)+
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        d->active->redo();+
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}+
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+
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/*!+
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    Returns the value of the active stack's QUndoStack::canUndo().+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns false.+
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+
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    \sa canRedo() setActiveStack()+
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*/+
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+
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bool QUndoGroup::canUndo() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active != 0 && d->active->canUndo();+
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}+
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+
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/*!+
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    Returns the value of the active stack's QUndoStack::canRedo().+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns false.+
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+
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    \sa canUndo() setActiveStack()+
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*/+
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+
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bool QUndoGroup::canRedo() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active != 0 && d->active->canRedo();+
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}+
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+
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/*!+
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    Returns the value of the active stack's QUndoStack::undoText().+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns an empty string.+
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+
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    \sa redoText() setActiveStack()+
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*/+
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+
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QString QUndoGroup::undoText() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active == 0 ? QString() : d->active->undoText();+
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}+
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+
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/*!+
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    Returns the value of the active stack's QUndoStack::redoText().+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns an empty string.+
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+
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    \sa undoText() setActiveStack()+
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*/+
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+
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QString QUndoGroup::redoText() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active == 0 ? QString() : d->active->redoText();+
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}+
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+
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/*!+
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    Returns the value of the active stack's QUndoStack::isClean().+
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+
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    If none of the stacks are active, or if the group is empty, this function+
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    returns true.+
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+
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    \sa setActiveStack()+
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*/+
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+
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bool QUndoGroup::isClean() const+
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{+
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    Q_D(const QUndoGroup);+
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    return d->active == 0 || d->active->isClean();+
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}+
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+
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#ifndef QT_NO_ACTION+
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+
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/*!+
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    Creates an undo QAction object with parent \a parent.+
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+
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    Triggering this action will cause a call to QUndoStack::undo() on the active stack.+
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    The text of this action will always be the text of the command which will be undone+
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    in the next call to undo(), prefixed by \a prefix. If there is no command available+
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    for undo, if the group is empty or if none of the stacks are active, this action will+
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    be disabled.+
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+
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    If \a prefix is empty, the default prefix "Undo" is used.+
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+
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    \sa createRedoAction() canUndo() QUndoCommand::text()+
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*/+
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+
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QAction *QUndoGroup::createUndoAction(QObject *parent, const QString &prefix) const+
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{+
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    QString pref = prefix.isEmpty() ? tr("Undo") : prefix;+
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    QUndoAction *result = new QUndoAction(pref, parent);+
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    result->setEnabled(canUndo());+
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    result->setPrefixedText(undoText());+
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    connect(this, SIGNAL(canUndoChanged(bool)),+
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            result, SLOT(setEnabled(bool)));+
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    connect(this, SIGNAL(undoTextChanged(QString)),+
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            result, SLOT(setPrefixedText(QString)));+
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    connect(result, SIGNAL(triggered()), this, SLOT(undo()));+
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    return result;+
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}+
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+
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/*!+
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    Creates an redo QAction object with parent \a parent.+
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+
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    Triggering this action will cause a call to QUndoStack::redo() on the active stack.+
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    The text of this action will always be the text of the command which will be redone+
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    in the next call to redo(), prefixed by \a prefix. If there is no command available+
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    for redo, if the group is empty or if none of the stacks are active, this action will+
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    be disabled.+
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+
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    If \a prefix is empty, the default prefix "Undo" is used.+
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+
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    \sa createUndoAction() canRedo() QUndoCommand::text()+
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*/+
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+
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QAction *QUndoGroup::createRedoAction(QObject *parent, const QString &prefix) const+
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{+
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    QString pref = prefix.isEmpty() ? tr("Redo") : prefix;+
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    QUndoAction *result = new QUndoAction(pref, parent);+
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    result->setEnabled(canRedo());+
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    result->setPrefixedText(redoText());+
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    connect(this, SIGNAL(canRedoChanged(bool)),+
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            result, SLOT(setEnabled(bool)));+
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    connect(this, SIGNAL(redoTextChanged(QString)),+
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            result, SLOT(setPrefixedText(QString)));+
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    connect(result, SIGNAL(triggered()), this, SLOT(redo()));+
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    return result;+
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}+
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+
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#endif // QT_NO_ACTION+
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+
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/*! \fn void QUndoGroup::activeStackChanged(QUndoStack *stack)+
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+
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    This signal is emitted whenever the active stack of the group changes. This can happen+
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    when setActiveStack() or QUndoStack::setActive() is called, or when the active stack+
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    is removed form the group. \a stack is the new active stack. If no stack is active,+
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    \a stack is 0.+
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+
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    \sa setActiveStack() QUndoStack::setActive()+
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*/+
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+
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/*! \fn void QUndoGroup::indexChanged(int idx)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::indexChanged()+
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    or the active stack changes.+
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+
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    \a idx is the new current index, or 0 if the active stack is 0.+
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+
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    \sa QUndoStack::indexChanged() setActiveStack()+
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*/+
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+
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/*! \fn void QUndoGroup::cleanChanged(bool clean)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::cleanChanged()+
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    or the active stack changes.+
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+
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    \a clean is the new state, or true if the active stack is 0.+
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+
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    \sa QUndoStack::cleanChanged() setActiveStack()+
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*/+
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+
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/*! \fn void QUndoGroup::canUndoChanged(bool canUndo)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::canUndoChanged()+
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    or the active stack changes.+
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+
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    \a canUndo is the new state, or false if the active stack is 0.+
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+
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    \sa QUndoStack::canUndoChanged() setActiveStack()+
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*/+
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+
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/*! \fn void QUndoGroup::canRedoChanged(bool canRedo)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::canRedoChanged()+
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    or the active stack changes.+
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+
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    \a canRedo is the new state, or false if the active stack is 0.+
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+
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    \sa QUndoStack::canRedoChanged() setActiveStack()+
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*/+
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+
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/*! \fn void QUndoGroup::undoTextChanged(const QString &undoText)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::undoTextChanged()+
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    or the active stack changes.+
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+
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    \a undoText is the new state, or an empty string if the active stack is 0.+
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+
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    \sa QUndoStack::undoTextChanged() setActiveStack()+
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*/+
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+
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/*! \fn void QUndoGroup::redoTextChanged(const QString &redoText)+
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+
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    This signal is emitted whenever the active stack emits QUndoStack::redoTextChanged()+
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    or the active stack changes.+
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+
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    \a redoText is the new state, or an empty string if the active stack is 0.+
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+
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    \sa QUndoStack::redoTextChanged() setActiveStack()+
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*/+
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+
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QT_END_NAMESPACE+
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+
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#endif // QT_NO_UNDOGROUP+
−