source: trunk/src/gui/util/qundoview.cpp@ 878

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#include "qundostack.h"
#include "qundoview.h"

#ifndef QT_NO_UNDOVIEW

#include "qundogroup.h"
#include <QtCore/qabstractitemmodel.h>
#include <QtCore/qpointer.h>
#include <QtGui/qicon.h>
#include <private/qlistview_p.h>

QT_BEGIN_NAMESPACE

class QUndoModel : public QAbstractItemModel
{
    Q_OBJECT
public:
    QUndoModel(QObject *parent = 0);

    QUndoStack *stack() const;

    virtual QModelIndex index(int row, int column,
                const QModelIndex &parent = QModelIndex()) const;
    virtual QModelIndex parent(const QModelIndex &child) const;
    virtual int rowCount(const QModelIndex &parent = QModelIndex()) const;
    virtual int columnCount(const QModelIndex &parent = QModelIndex()) const;
    virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;

    QModelIndex selectedIndex() const;
    QItemSelectionModel *selectionModel() const;

    QString emptyLabel() const;
    void setEmptyLabel(const QString &label);

    void setCleanIcon(const QIcon &icon);
    QIcon cleanIcon() const;

public slots:
    void setStack(QUndoStack *stack);

private slots:
    void stackChanged();
    void stackDestroyed(QObject *obj);
    void setStackCurrentIndex(const QModelIndex &index);

private:
    QUndoStack *m_stack;
    QItemSelectionModel *m_sel_model;
    QString m_emty_label;
    QIcon m_clean_icon;
};

QUndoModel::QUndoModel(QObject *parent)
    : QAbstractItemModel(parent)
{
    m_stack = 0;
    m_sel_model = new QItemSelectionModel(this, this);
    connect(m_sel_model, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
            this, SLOT(setStackCurrentIndex(QModelIndex)));
    m_emty_label = tr("<empty>");
}

QItemSelectionModel *QUndoModel::selectionModel() const
{
    return m_sel_model;
}

QUndoStack *QUndoModel::stack() const
{
    return m_stack;
}

void QUndoModel::setStack(QUndoStack *stack)
{
    if (m_stack == stack)
        return;

    if (m_stack != 0) {
        disconnect(m_stack, SIGNAL(cleanChanged(bool)), this, SLOT(stackChanged()));
        disconnect(m_stack, SIGNAL(indexChanged(int)), this, SLOT(stackChanged()));
        disconnect(m_stack, SIGNAL(destroyed(QObject*)), this, SLOT(stackDestroyed(QObject*)));
    }
    m_stack = stack;
    if (m_stack != 0) {
        connect(m_stack, SIGNAL(cleanChanged(bool)), this, SLOT(stackChanged()));
        connect(m_stack, SIGNAL(indexChanged(int)), this, SLOT(stackChanged()));
        connect(m_stack, SIGNAL(destroyed(QObject*)), this, SLOT(stackDestroyed(QObject*)));
    }

    stackChanged();
}

void QUndoModel::stackDestroyed(QObject *obj)
{
    if (obj != m_stack)
        return;
    m_stack = 0;

    stackChanged();
}

void QUndoModel::stackChanged()
{
    reset();
    m_sel_model->setCurrentIndex(selectedIndex(), QItemSelectionModel::ClearAndSelect);
}

void QUndoModel::setStackCurrentIndex(const QModelIndex &index)
{
    if (m_stack == 0)
        return;

    if (index == selectedIndex())
        return;

    if (index.column() != 0)
        return;

    m_stack->setIndex(index.row());
}

QModelIndex QUndoModel::selectedIndex() const
{
    return m_stack == 0 ? QModelIndex() : createIndex(m_stack->index(), 0);
}

QModelIndex QUndoModel::index(int row, int column, const QModelIndex &parent) const
{
    if (m_stack == 0)
        return QModelIndex();

    if (parent.isValid())
        return QModelIndex();

    if (column != 0)
        return QModelIndex();

    if (row < 0 || row > m_stack->count())
        return QModelIndex();

    return createIndex(row, column);
}

QModelIndex QUndoModel::parent(const QModelIndex&) const
{
    return QModelIndex();
}

int QUndoModel::rowCount(const QModelIndex &parent) const
{
    if (m_stack == 0)
        return 0;

    if (parent.isValid())
        return 0;

    return m_stack->count() + 1;
}

int QUndoModel::columnCount(const QModelIndex&) const
{
    return 1;
}

QVariant QUndoModel::data(const QModelIndex &index, int role) const
{
    if (m_stack == 0)
        return QVariant();

    if (index.column() != 0)
        return QVariant();

    if (index.row() < 0 || index.row() > m_stack->count())
        return QVariant();

    if (role == Qt::DisplayRole) {
        if (index.row() == 0)
            return m_emty_label;
        return m_stack->text(index.row() - 1);
    } else if (role == Qt::DecorationRole) {
        if (index.row() == m_stack->cleanIndex() && !m_clean_icon.isNull())
            return m_clean_icon;
        return QVariant();
    }

    return QVariant();
}

QString QUndoModel::emptyLabel() const
{
    return m_emty_label;
}

void QUndoModel::setEmptyLabel(const QString &label)
{
    m_emty_label = label;
    stackChanged();
}

void QUndoModel::setCleanIcon(const QIcon &icon)
{
    m_clean_icon = icon;
    stackChanged();
}

QIcon QUndoModel::cleanIcon() const
{
    return m_clean_icon;
}

/*!
    \class QUndoView
    \brief The QUndoView class displays the contents of a QUndoStack.
    \since 4.2

    \ingroup advanced

    QUndoView is a QListView which displays the list of commands pushed on an undo stack.
    The most recently executed command is always selected. Selecting a different command
    results in a call to QUndoStack::setIndex(), rolling the state of the document
    backwards or forward to the new command.

    The stack can be set explicitly with setStack(). Alternatively, a QUndoGroup object can
    be set with setGroup(). The view will then update itself automatically whenever the
    active stack of the group changes.

    \image qundoview.png
*/

class QUndoViewPrivate : public QListViewPrivate
{
    Q_DECLARE_PUBLIC(QUndoView)
public:
    QUndoViewPrivate() :
#ifndef QT_NO_UNDOGROUP
        group(0),
#endif
        model(0) {}

#ifndef QT_NO_UNDOGROUP
    QPointer<QUndoGroup> group;
#endif
    QUndoModel *model;

    void init();
};

void QUndoViewPrivate::init()
{
    Q_Q(QUndoView);

    model = new QUndoModel(q);
    q->setModel(model);