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>

2 files changed, 73 insertions, 0 deletions

diff --git a/doc/src/frameworks-technologies/model-view-programming.qdoc b/doc/src/frameworks-technologies/model-view-programming.qdoc
index 92067b9..42404b0 100644
--- a/doc/src/frameworks-technologies/model-view-programming.qdoc
+++ b/doc/src/frameworks-technologies/model-view-programming.qdoc
@@ -1934,6 +1934,13 @@
     \l{QSortFilterProxyModel::lessThan()}{lessThan()} function to perform custom
     comparisons.
 
+    \section3 Custom data models
+
+    QIdentityProxyModel instances do not sort or filter the structure of the source model,
+    but provide a base class for creating a data proxy. This could be useful on top of a
+    QFileSystemModel for example to provide different colours for the BackgroundRole for
+    different types of files.
+
     \section1 Model subclassing reference
 
     Model subclasses need to provide implementations of many of the virtual functions
diff --git a/doc/src/snippets/code/src_gui_itemviews_qidentityproxymodel.cpp b/doc/src/snippets/code/src_gui_itemviews_qidentityproxymodel.cpp
new file mode 100644
index 0000000..8bd6520
--- /dev/null
+++ b/doc/src/snippets/code/src_gui_itemviews_qidentityproxymodel.cpp
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** 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 (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
+**     the names of its contributors may be used to endorse or promote
+**     products derived from this software without specific prior written
+**     permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [0]
+class DateFormatProxyModel : public QIdentityProxyModel
+{
+  // ...
+
+  void setDateFormatString(const QString &formatString)
+  {
+    m_formatString = formatString;
+  }
+
+  QVariant data(const QModelIndex &index, int role)
+  {
+    if (role != Qt::DisplayRole)
+      return QIdentityProxyModel::data(index, role);
+
+    const QDateTime dateTime = sourceModel()->data(SourceClass::DateRole).toDateTime();
+
+    return dateTime.toString(m_formatString);
+  }
+
+private:
+  QString m_formatString;
+};
+//! [0]