centralize and fixup example sources install targets

This follows suit with aeb036e in qtbase.

Change-Id: Ie8580d0a1f38ab9858b0e44c9f99bdc552a1752a
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: hjk <qthjk@ovi.com>

examples/multimedia/spectrum/3rdparty/fftreal/fftreal_wrapper.cpp

@@ -0,0 +1,54 @@
+/***************************************************************************
+**
+** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** This program is free software: you can redistribute it and/or modify
+** it under the terms of the GNU Lesser General Public License as
+** published by the Free Software Foundation, either version 2.1. This
+** program is distributed in the hope that it will be useful, but WITHOUT
+** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+** for more details. You should have received a copy of the GNU General
+** Public License along with this program. If not, see
+** <http://www.gnu.org/licenses/>.
+**
+***************************************************************************/
+
+#include "fftreal_wrapper.h"
+
+// FFTReal code generates quite a lot of 'unused parameter' compiler warnings,
+// which we suppress here in order to get a clean build output.
+#if defined Q_CC_MSVC
+#    pragma warning(disable:4100)
+#elif defined Q_CC_GNU
+#    pragma GCC diagnostic ignored "-Wunused-parameter"
+#elif defined Q_CC_MWERKS
+#    pragma warning off (10182)
+#endif
+
+#include "FFTRealFixLen.h"
+
+class FFTRealWrapperPrivate {
+public:
+    FFTRealFixLen<FFTLengthPowerOfTwo> m_fft;
+};
+
+
+FFTRealWrapper::FFTRealWrapper()
+    :   m_private(new FFTRealWrapperPrivate)
+{
+
+}
+
+FFTRealWrapper::~FFTRealWrapper()
+{
+    delete m_private;
+}
+
+void FFTRealWrapper::calculateFFT(DataType in[], const DataType out[])
+{
+    m_private->m_fft.do_fft(in, out);
+}