Add the QIdentityProxyModel.

Older commit history is in KDE svn:
http://websvn.kde.org/trunk/KDE/kdelibs/kdeui/itemviews/kidentityproxymodel.cpp?view=log

Ammended to update the license headers.

Merge-request: 900
Reviewed-by: Gabriel de Dietrich <gabriel.dietrich-de@nokia.com>

4 files changed, 700 insertions, 1 deletions

diff --git a/src/gui/itemviews/itemviews.pri b/src/gui/itemviews/itemviews.pri
index bbc1e98..149bfd6 100644
--- a/src/gui/itemviews/itemviews.pri
+++ b/src/gui/itemviews/itemviews.pri
@@ -4,6 +4,7 @@ HEADERS += \
 	itemviews/qabstractitemview.h \
     itemviews/qabstractitemview_p.h \
 	itemviews/qheaderview.h \
+	itemviews/qidentityproxymodel.h \
 	itemviews/qlistview.h \
 	itemviews/qlistview_p.h \
 	itemviews/qbsptree_p.h \
@@ -44,6 +45,7 @@ HEADERS += \
 SOURCES += \
 	itemviews/qabstractitemview.cpp \
 	itemviews/qheaderview.cpp \
+	itemviews/qidentityproxymodel.cpp \
 	itemviews/qlistview.cpp \
 	itemviews/qbsptree.cpp \
 	itemviews/qtableview.cpp \
diff --git a/src/gui/itemviews/qidentityproxymodel.cpp b/src/gui/itemviews/qidentityproxymodel.cpp
new file mode 100644
index 0000000..9396e61
--- /dev/null
+++ b/src/gui/itemviews/qidentityproxymodel.cpp
@@ -0,0 +1,582 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Klarälvdalens Datakonsult AB,
+**        a KDAB Group company, info@kdab.com,
+**        author Stephen Kelly <stephen.kelly@kdab.com>
+** All rights reserved.
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 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 the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+****************************************************************************/
+
+#include "qidentityproxymodel.h"
+
+#ifndef QT_NO_IDENTITYPROXYMODEL
+
+#include "qitemselectionmodel.h"
+#include <private/qabstractproxymodel_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QIdentityProxyModelPrivate : public QAbstractProxyModelPrivate
+{
+  QIdentityProxyModelPrivate()
+    : ignoreNextLayoutAboutToBeChanged(false),
+      ignoreNextLayoutChanged(false)
+  {
+
+  }
+
+  Q_DECLARE_PUBLIC(QIdentityProxyModel)
+
+  bool ignoreNextLayoutAboutToBeChanged;
+  bool ignoreNextLayoutChanged;
+  QList<QPersistentModelIndex> layoutChangePersistentIndexes;
+  QModelIndexList proxyIndexes;
+
+  void _q_sourceRowsAboutToBeInserted(const QModelIndex &parent, int start, int end);
+  void _q_sourceRowsInserted(const QModelIndex &parent, int start, int end);
+  void _q_sourceRowsAboutToBeRemoved(const QModelIndex &parent, int start, int end);
+  void _q_sourceRowsRemoved(const QModelIndex &parent, int start, int end);
+  void _q_sourceRowsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest);
+  void _q_sourceRowsMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest);
+
+  void _q_sourceColumnsAboutToBeInserted(const QModelIndex &parent, int start, int end);
+  void _q_sourceColumnsInserted(const QModelIndex &parent, int start, int end);
+  void _q_sourceColumnsAboutToBeRemoved(const QModelIndex &parent, int start, int end);
+  void _q_sourceColumnsRemoved(const QModelIndex &parent, int start, int end);
+  void _q_sourceColumnsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest);
+  void _q_sourceColumnsMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest);
+
+  void _q_sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight);
+  void _q_sourceHeaderDataChanged(Qt::Orientation orientation, int first, int last);
+
+  void _q_sourceLayoutAboutToBeChanged();
+  void _q_sourceLayoutChanged();
+  void _q_sourceModelAboutToBeReset();
+  void _q_sourceModelReset();
+
+};
+
+/*!
+    \since 4.8
+    \class QIdentityProxyModel
+    \brief The QIdentityProxyModel class proxies its source model unmodified
+
+    \ingroup model-view
+
+    QIdentityProxyModel can be used to forward the structure of a source model exactly, with no sorting, filtering or other transformation.
+    This is similar in concept to an identity matrix where A.I = A.
+
+    Because it does no sorting or filtering, this class is most suitable to proxy models which transform the data() of the source model.
+    For example, a proxy model could be created to define the font used, or the background colour, or the tooltip etc. This removes the
+    need to implement all data handling in the same class that creates the structure of the model, and can also be used to create
+    re-usable components.
+
+    This also provides a way to change the data in the case where a source model is supplied by a third party which can not be modified.
+
+    \snippet doc/src/snippets/code/src_gui_itemviews_qidentityproxymodel.cpp 0
+
+    \sa QAbstractProxyModel, {Model/View Programming}, QAbstractItemModel
+
+*/
+
+/*!
+    Constructs an identity model with the given \a parent.
+*/
+QIdentityProxyModel::QIdentityProxyModel(QObject* parent)
+  : QAbstractProxyModel(*new QIdentityProxyModelPrivate, parent)
+{
+
+}
+
+/*! \internal
+ */
+QIdentityProxyModel::QIdentityProxyModel(QIdentityProxyModelPrivate &dd, QObject* parent)
+  : QAbstractProxyModel(dd, parent)
+{
+
+}
+
+/*!
+    Destroys this identity model.
+*/
+QIdentityProxyModel::~QIdentityProxyModel()
+{
+}
+
+/*!
+    \reimp
+ */
+int QIdentityProxyModel::columnCount(const QModelIndex& parent) const
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(const QIdentityProxyModel);
+    return d->model->columnCount(mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+bool QIdentityProxyModel::dropMimeData(const QMimeData* data, Qt::DropAction action, int row, int column, const QModelIndex& parent)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(QIdentityProxyModel);
+    return d->model->dropMimeData(data, action, row, column, mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+QModelIndex QIdentityProxyModel::index(int row, int column, const QModelIndex& parent) const
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(const QIdentityProxyModel);
+    if (!hasIndex(row, column, parent))
+        return QModelIndex();
+    const QModelIndex sourceParent = mapToSource(parent);
+    const QModelIndex sourceIndex = d->model->index(row, column, sourceParent);
+    Q_ASSERT(sourceIndex.isValid());
+    return mapFromSource(sourceIndex);
+}
+
+/*!
+    \reimp
+ */
+bool QIdentityProxyModel::insertColumns(int column, int count, const QModelIndex& parent)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(QIdentityProxyModel);
+    return d->model->insertColumns(column, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+bool QIdentityProxyModel::insertRows(int row, int count, const QModelIndex& parent)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(QIdentityProxyModel);
+    return d->model->insertRows(row, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+QModelIndex QIdentityProxyModel::mapFromSource(const QModelIndex& sourceIndex) const
+{
+    Q_D(const QIdentityProxyModel);
+    if (!d->model || !sourceIndex.isValid())
+        return QModelIndex();
+
+    Q_ASSERT(sourceIndex.model() == d->model);
+    return createIndex(sourceIndex.row(), sourceIndex.column(), sourceIndex.internalPointer());
+}
+
+/*!
+    \reimp
+ */
+QItemSelection QIdentityProxyModel::mapSelectionFromSource(const QItemSelection& selection) const
+{
+    Q_D(const QIdentityProxyModel);
+    QItemSelection proxySelection;
+
+    if (!d->model)
+        return proxySelection;
+
+    QItemSelection::const_iterator it = selection.constBegin();
+    const QItemSelection::const_iterator end = selection.constEnd();
+    for ( ; it != end; ++it) {
+        Q_ASSERT(it->model() == d->model);
+        const QItemSelectionRange range(mapFromSource(it->topLeft()), mapFromSource(it->bottomRight()));
+        proxySelection.append(range);
+    }
+
+    return proxySelection;
+}
+
+/*!
+    \reimp
+ */
+QItemSelection QIdentityProxyModel::mapSelectionToSource(const QItemSelection& selection) const
+{
+    Q_D(const QIdentityProxyModel);
+    QItemSelection sourceSelection;
+
+    if (!d->model)
+        return sourceSelection;
+
+    QItemSelection::const_iterator it = selection.constBegin();
+    const QItemSelection::const_iterator end = selection.constEnd();
+    for ( ; it != end; ++it) {
+        Q_ASSERT(it->model() == this);
+        const QItemSelectionRange range(mapToSource(it->topLeft()), mapToSource(it->bottomRight()));
+        sourceSelection.append(range);
+    }
+
+    return sourceSelection;
+}
+
+/*!
+    \reimp
+ */
+QModelIndex QIdentityProxyModel::mapToSource(const QModelIndex& proxyIndex) const
+{
+    Q_D(const QIdentityProxyModel);
+    if (!d->model || !proxyIndex.isValid())
+        return QModelIndex();
+    Q_ASSERT(proxyIndex.model() == this);
+    return d->model->createIndex(proxyIndex.row(), proxyIndex.column(), proxyIndex.internalPointer());
+}
+
+/*!
+    \reimp
+ */
+QModelIndexList QIdentityProxyModel::match(const QModelIndex& start, int role, const QVariant& value, int hits, Qt::MatchFlags flags) const
+{
+    Q_D(const QIdentityProxyModel);
+    Q_ASSERT(start.isValid() ? start.model() == this : true);
+    if (!d->model)
+        return QModelIndexList();
+
+    const QModelIndexList sourceList = d->model->match(mapToSource(start), role, value, hits, flags);
+    QModelIndexList::const_iterator it = sourceList.constBegin();
+    const QModelIndexList::const_iterator end = sourceList.constEnd();
+    QModelIndexList proxyList;
+    for ( ; it != end; ++it)
+        proxyList.append(mapFromSource(*it));
+    return proxyList;
+}
+
+/*!
+    \reimp
+ */
+QModelIndex QIdentityProxyModel::parent(const QModelIndex& child) const
+{
+    Q_ASSERT(child.isValid() ? child.model() == this : true);
+    const QModelIndex sourceIndex = mapToSource(child);
+    const QModelIndex sourceParent = sourceIndex.parent();
+    return mapFromSource(sourceParent);
+}
+
+/*!
+    \reimp
+ */
+bool QIdentityProxyModel::removeColumns(int column, int count, const QModelIndex& parent)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(QIdentityProxyModel);
+    return d->model->removeColumns(column, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+bool QIdentityProxyModel::removeRows(int row, int count, const QModelIndex& parent)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(QIdentityProxyModel);
+    return d->model->removeRows(row, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+int QIdentityProxyModel::rowCount(const QModelIndex& parent) const
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == this : true);
+    Q_D(const QIdentityProxyModel);
+    return d->model->rowCount(mapToSource(parent));
+}
+
+/*!
+    \reimp
+ */
+void QIdentityProxyModel::setSourceModel(QAbstractItemModel* sourceModel)
+{
+    beginResetModel();
+
+    if (sourceModel) {
+        disconnect(sourceModel, SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceRowsAboutToBeInserted(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(rowsInserted(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceRowsInserted(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceRowsAboutToBeRemoved(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceRowsRemoved(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(rowsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                   this, SLOT(_q_sourceRowsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        disconnect(sourceModel, SIGNAL(rowsMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                   this, SLOT(_q_sourceRowsMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        disconnect(sourceModel, SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceColumnsAboutToBeInserted(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(columnsInserted(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceColumnsInserted(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(columnsAboutToBeRemoved(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceColumnsAboutToBeRemoved(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
+                   this, SLOT(_q_sourceColumnsRemoved(const QModelIndex &, int, int)));
+        disconnect(sourceModel, SIGNAL(columnsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                   this, SLOT(_q_sourceColumnsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        disconnect(sourceModel, SIGNAL(columnsMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                   this, SLOT(_q_sourceColumnsMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        disconnect(sourceModel, SIGNAL(modelAboutToBeReset()),
+                   this, SLOT(_q_sourceModelAboutToBeReset()));
+        disconnect(sourceModel, SIGNAL(modelReset()),
+                   this, SLOT(_q_sourceModelReset()));
+        disconnect(sourceModel, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
+                   this, SLOT(_q_sourceDataChanged(const QModelIndex &, const QModelIndex &)));
+        disconnect(sourceModel, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
+                   this, SLOT(_q_sourceHeaderDataChanged(Qt::Orientation,int,int)));
+        disconnect(sourceModel, SIGNAL(layoutAboutToBeChanged()),
+                   this, SLOT(_q_sourceLayoutAboutToBeChanged()));
+        disconnect(sourceModel, SIGNAL(layoutChanged()),
+                   this, SLOT(_q_sourceLayoutChanged()));
+    }
+
+    QAbstractProxyModel::setSourceModel(sourceModel);
+
+    if (sourceModel) {
+        connect(sourceModel, SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
+                SLOT(_q_sourceRowsAboutToBeInserted(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(rowsInserted(const QModelIndex &, int, int)),
+                SLOT(_q_sourceRowsInserted(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(rowsAboutToBeRemoved(const QModelIndex &, int, int)),
+                SLOT(_q_sourceRowsAboutToBeRemoved(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(rowsRemoved(const QModelIndex &, int, int)),
+                SLOT(_q_sourceRowsRemoved(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(rowsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                SLOT(_q_sourceRowsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        connect(sourceModel, SIGNAL(rowsMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                SLOT(_q_sourceRowsMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        connect(sourceModel, SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
+                SLOT(_q_sourceColumnsAboutToBeInserted(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(columnsInserted(const QModelIndex &, int, int)),
+                SLOT(_q_sourceColumnsInserted(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(columnsAboutToBeRemoved(const QModelIndex &, int, int)),
+                SLOT(_q_sourceColumnsAboutToBeRemoved(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(columnsRemoved(const QModelIndex &, int, int)),
+                SLOT(_q_sourceColumnsRemoved(const QModelIndex &, int, int)));
+        connect(sourceModel, SIGNAL(columnsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                SLOT(_q_sourceColumnsAboutToBeMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        connect(sourceModel, SIGNAL(columnsMoved(const QModelIndex &, int, int, const QModelIndex &, int)),
+                SLOT(_q_sourceColumnsMoved(const QModelIndex &, int, int, const QModelIndex &, int)));
+        connect(sourceModel, SIGNAL(modelAboutToBeReset()),
+                SLOT(_q_sourceModelAboutToBeReset()));
+        connect(sourceModel, SIGNAL(modelReset()),
+                SLOT(_q_sourceModelReset()));
+        connect(sourceModel, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
+                SLOT(_q_sourceDataChanged(const QModelIndex &, const QModelIndex &)));
+        connect(sourceModel, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
+                SLOT(_q_sourceHeaderDataChanged(Qt::Orientation,int,int)));
+        connect(sourceModel, SIGNAL(layoutAboutToBeChanged()),
+                SLOT(_q_sourceLayoutAboutToBeChanged()));
+        connect(sourceModel, SIGNAL(layoutChanged()),
+                SLOT(_q_sourceLayoutChanged()));
+    }
+
+    endResetModel();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsAboutToBeInserted(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginInsertColumns(q->mapFromSource(parent), start, end);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest)
+{
+    Q_ASSERT(sourceParent.isValid() ? sourceParent.model() == model : true);
+    Q_ASSERT(destParent.isValid() ? destParent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginMoveColumns(q->mapFromSource(sourceParent), sourceStart, sourceEnd, q->mapFromSource(destParent), dest);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginRemoveColumns(q->mapFromSource(parent), start, end);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsInserted(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(parent)
+    Q_UNUSED(start)
+    Q_UNUSED(end)
+    q->endInsertColumns();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest)
+{
+    Q_ASSERT(sourceParent.isValid() ? sourceParent.model() == model : true);
+    Q_ASSERT(destParent.isValid() ? destParent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(sourceParent)
+    Q_UNUSED(sourceStart)
+    Q_UNUSED(sourceEnd)
+    Q_UNUSED(destParent)
+    Q_UNUSED(dest)
+    q->endMoveColumns();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceColumnsRemoved(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(parent)
+    Q_UNUSED(start)
+    Q_UNUSED(end)
+    q->endRemoveColumns();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
+{
+    Q_ASSERT(topLeft.isValid() ? topLeft.model() == model : true);
+    Q_ASSERT(bottomRight.isValid() ? bottomRight.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->dataChanged(q->mapFromSource(topLeft), q->mapFromSource(bottomRight));
+}
+
+void QIdentityProxyModelPrivate::_q_sourceHeaderDataChanged(Qt::Orientation orientation, int first, int last)
+{
+    Q_Q(QIdentityProxyModel);
+    q->headerDataChanged(orientation, first, last);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceLayoutAboutToBeChanged()
+{
+    if (ignoreNextLayoutAboutToBeChanged)
+        return;
+
+    Q_Q(QIdentityProxyModel);
+
+    foreach(const QPersistentModelIndex &proxyPersistentIndex, q->persistentIndexList()) {
+        proxyIndexes << proxyPersistentIndex;
+        Q_ASSERT(proxyPersistentIndex.isValid());
+        const QPersistentModelIndex srcPersistentIndex = q->mapToSource(proxyPersistentIndex);
+        Q_ASSERT(srcPersistentIndex.isValid());
+        layoutChangePersistentIndexes << srcPersistentIndex;
+    }
+
+    q->layoutAboutToBeChanged();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceLayoutChanged()
+{
+    if (ignoreNextLayoutChanged)
+        return;
+
+    Q_Q(QIdentityProxyModel);
+
+    for (int i = 0; i < proxyIndexes.size(); ++i) {
+        q->changePersistentIndex(proxyIndexes.at(i), q->mapFromSource(layoutChangePersistentIndexes.at(i)));
+    }
+
+    layoutChangePersistentIndexes.clear();
+    proxyIndexes.clear();
+
+    q->layoutChanged();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceModelAboutToBeReset()
+{
+    Q_Q(QIdentityProxyModel);
+    q->beginResetModel();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceModelReset()
+{
+    Q_Q(QIdentityProxyModel);
+    q->endResetModel();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsAboutToBeInserted(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginInsertRows(q->mapFromSource(parent), start, end);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest)
+{
+    Q_ASSERT(sourceParent.isValid() ? sourceParent.model() == model : true);
+    Q_ASSERT(destParent.isValid() ? destParent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginMoveRows(q->mapFromSource(sourceParent), sourceStart, sourceEnd, q->mapFromSource(destParent), dest);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    q->beginRemoveRows(q->mapFromSource(parent), start, end);
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsInserted(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(parent)
+    Q_UNUSED(start)
+    Q_UNUSED(end)
+    q->endInsertRows();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destParent, int dest)
+{
+    Q_ASSERT(sourceParent.isValid() ? sourceParent.model() == model : true);
+    Q_ASSERT(destParent.isValid() ? destParent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(sourceParent)
+    Q_UNUSED(sourceStart)
+    Q_UNUSED(sourceEnd)
+    Q_UNUSED(destParent)
+    Q_UNUSED(dest)
+    q->endMoveRows();
+}
+
+void QIdentityProxyModelPrivate::_q_sourceRowsRemoved(const QModelIndex &parent, int start, int end)
+{
+    Q_ASSERT(parent.isValid() ? parent.model() == model : true);
+    Q_Q(QIdentityProxyModel);
+    Q_UNUSED(parent)
+    Q_UNUSED(start)
+    Q_UNUSED(end)
+    q->endRemoveRows();
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qidentityproxymodel.cpp"
+
+#endif // QT_NO_IDENTITYPROXYMODEL
diff --git a/src/gui/itemviews/qidentityproxymodel.h b/src/gui/itemviews/qidentityproxymodel.h
new file mode 100644
index 0000000..b60aa0b
--- /dev/null
+++ b/src/gui/itemviews/qidentityproxymodel.h
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Klarälvdalens Datakonsult AB,
+**        a KDAB Group company, info@kdab.com,
+**        author Stephen Kelly <stephen.kelly@kdab.com>
+** All rights reserved.
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 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 the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+****************************************************************************/
+
+
+#ifndef QIDENTITYPROXYMODEL_H
+#define QIDENTITYPROXYMODEL_H
+
+#include <QtGui/qabstractproxymodel.h>
+
+#ifndef QT_NO_IDENTITYPROXYMODEL
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Gui)
+
+class QIdentityProxyModelPrivate;
+
+class Q_GUI_EXPORT QIdentityProxyModel : public QAbstractProxyModel
+{
+    Q_OBJECT
+public:
+    explicit QIdentityProxyModel(QObject* parent = 0);
+    ~QIdentityProxyModel();
+
+    int columnCount(const QModelIndex& parent = QModelIndex()) const;
+    QModelIndex index(int row, int column, const QModelIndex& parent = QModelIndex()) const;
+    QModelIndex mapFromSource(const QModelIndex& sourceIndex) const;
+    QModelIndex mapToSource(const QModelIndex& proxyIndex) const;
+    QModelIndex parent(const QModelIndex& child) const;
+    int rowCount(const QModelIndex& parent = QModelIndex()) const;
+    bool dropMimeData(const QMimeData* data, Qt::DropAction action, int row, int column, const QModelIndex& parent);
+
+    QItemSelection mapSelectionFromSource(const QItemSelection& selection) const;
+    QItemSelection mapSelectionToSource(const QItemSelection& selection) const;
+    QModelIndexList match(const QModelIndex& start, int role, const QVariant& value, int hits = 1, Qt::MatchFlags flags = Qt::MatchFlags(Qt::MatchStartsWith|Qt::MatchWrap)) const;
+    void setSourceModel(QAbstractItemModel* sourceModel);
+
+    bool insertColumns(int column, int count, const QModelIndex& parent = QModelIndex());
+    bool insertRows(int row, int count, const QModelIndex& parent = QModelIndex());
+    bool removeColumns(int column, int count, const QModelIndex& parent = QModelIndex());
+    bool removeRows(int row, int count, const QModelIndex& parent = QModelIndex());
+
+protected:
+    QIdentityProxyModel(QIdentityProxyModelPrivate &dd, QObject* parent);
+
+private:
+    Q_DECLARE_PRIVATE(QIdentityProxyModel)
+    Q_DISABLE_COPY(QIdentityProxyModel)
+
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsAboutToBeInserted(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsInserted(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsAboutToBeRemoved(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsRemoved(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceRowsMoved(QModelIndex,int,int,QModelIndex,int))
+
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsAboutToBeInserted(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsInserted(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsAboutToBeRemoved(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsRemoved(QModelIndex,int,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceColumnsMoved(QModelIndex,int,int,QModelIndex,int))
+
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceDataChanged(QModelIndex,QModelIndex))
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceHeaderDataChanged(Qt::Orientation orientation, int first, int last))
+
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceLayoutAboutToBeChanged())
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceLayoutChanged())
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceModelAboutToBeReset())
+    Q_PRIVATE_SLOT(d_func(), void _q_sourceModelReset())
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QT_NO_IDENTITYPROXYMODEL
+
+#endif // QIDENTITYPROXYMODEL_H
+
diff --git a/src/gui/itemviews/qsortfilterproxymodel.cpp b/src/gui/itemviews/qsortfilterproxymodel.cpp
index eb56f56..f73607b 100644
--- a/src/gui/itemviews/qsortfilterproxymodel.cpp
+++ b/src/gui/itemviews/qsortfilterproxymodel.cpp
@@ -1502,7 +1502,7 @@ void QSortFilterProxyModelPrivate::_q_sourceColumnsRemoved(
     \l{Model Subclassing Reference}.
 
     \sa QAbstractProxyModel, QAbstractItemModel, {Model/View Programming},
-    {Basic Sort/Filter Model Example}, {Custom Sort/Filter Model Example}
+    {Basic Sort/Filter Model Example}, {Custom Sort/Filter Model Example}, QIdentityProxyModel
 */
 
 /*!