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authorJason Barron <jbarron@trolltech.com>2009-06-25 13:49:53 (GMT)
committerJason Barron <jbarron@trolltech.com>2009-06-25 13:49:53 (GMT)
commitdb8f05e257019694f5e8076845626008f2adc3dd (patch)
tree05d3959403cf15ac5f702091439e028af01f343b /examples/tools/contiguouscache/randomlistmodel.cpp
parent8aafaa65a1d16f8b982279f5aceedf1e281ddb5a (diff)
parent796a5a2c7d8c91a46ac761dde18b7da2ec6c177b (diff)
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Merge commit 'qt/master-stable' into 4.6-stable
Bring Qt 4.6 into the Qt-S60 repo. Conflicts: configure.exe mkspecs/features/qttest_p4.prf qmake/generators/makefile.cpp src/corelib/io/qdir.cpp src/corelib/io/qprocess.h src/corelib/kernel/qcoreevent.h src/corelib/kernel/qobject.cpp src/corelib/kernel/qsharedmemory_unix.cpp src/corelib/thread/qthread_p.h src/corelib/tools/qvector.h src/gui/dialogs/qdialog.cpp src/gui/dialogs/qfiledialog.cpp src/gui/dialogs/qfiledialog_p.h src/gui/dialogs/qmessagebox.cpp src/gui/graphicsview/qgraphicsitem.cpp src/gui/graphicsview/qgraphicsview.cpp src/gui/image/qpixmapcache.cpp src/gui/kernel/qapplication.cpp src/gui/kernel/qapplication_p.h src/gui/kernel/qwidget.cpp src/gui/kernel/qwidget_p.h src/gui/painting/qdrawhelper.cpp src/gui/painting/qpaintengine_raster.cpp src/gui/text/qfontengine_qpf.cpp src/gui/widgets/qmenubar.cpp src/network/socket/qlocalserver.cpp src/testlib/qtestcase.cpp src/testlib/testlib.pro tests/auto/qimagereader/tst_qimagereader.cpp tests/auto/qitemdelegate/tst_qitemdelegate.cpp tests/auto/qnetworkreply/tst_qnetworkreply.cpp tests/auto/qpixmap/qpixmap.pro
Diffstat (limited to 'examples/tools/contiguouscache/randomlistmodel.cpp')
-rw-r--r--examples/tools/contiguouscache/randomlistmodel.cpp97
1 files changed, 97 insertions, 0 deletions
diff --git a/examples/tools/contiguouscache/randomlistmodel.cpp b/examples/tools/contiguouscache/randomlistmodel.cpp
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+++ b/examples/tools/contiguouscache/randomlistmodel.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "randomlistmodel.h"
+#include <stdlib.h>
+
+static const int bufferSize(500);
+static const int lookAhead(100);
+static const int halfLookAhead(lookAhead/2);
+
+RandomListModel::RandomListModel(QObject *parent)
+: QAbstractListModel(parent), m_rows(bufferSize), m_count(10000)
+{
+}
+
+RandomListModel::~RandomListModel()
+{
+}
+
+int RandomListModel::rowCount(const QModelIndex &) const
+{
+ return m_count;
+}
+
+//! [0]
+QVariant RandomListModel::data(const QModelIndex &index, int role) const
+{
+ if (role != Qt::DisplayRole)
+ return QVariant();
+
+ int row = index.row();
+
+ if (row > m_rows.lastIndex()) {
+ if (row - m_rows.lastIndex() > lookAhead)
+ cacheRows(row-halfLookAhead, qMin(m_count, row+halfLookAhead));
+ else while (row > m_rows.lastIndex())
+ m_rows.append(fetchRow(m_rows.lastIndex()+1));
+ } else if (row < m_rows.firstIndex()) {
+ if (m_rows.firstIndex() - row > lookAhead)
+ cacheRows(qMax(0, row-halfLookAhead), row+halfLookAhead);
+ else while (row < m_rows.firstIndex())
+ m_rows.prepend(fetchRow(m_rows.firstIndex()-1));
+ }
+
+ return m_rows.at(row);
+}
+
+void RandomListModel::cacheRows(int from, int to) const
+{
+ for (int i = from; i <= to; ++i)
+ m_rows.insert(i, fetchRow(i));
+}
+//![0]
+
+//![1]
+QString RandomListModel::fetchRow(int position) const
+{
+ return QString::number(rand() % ++position);
+}
+//![1]