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.h

@@ -0,0 +1,63 @@
+/***************************************************************************
+**
+** 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/>.
+**
+***************************************************************************/
+
+#ifndef FFTREAL_WRAPPER_H
+#define FFTREAL_WRAPPER_H
+
+#include <QtCore/QtGlobal>
+
+#if defined(FFTREAL_LIBRARY)
+#  define FFTREAL_EXPORT Q_DECL_EXPORT
+#else
+#  define FFTREAL_EXPORT Q_DECL_IMPORT
+#endif
+
+class FFTRealWrapperPrivate;
+
+// Each pass of the FFT processes 2^X samples, where X is the
+// number below.
+static const int FFTLengthPowerOfTwo = 12;
+
+/**
+ * Wrapper around the FFTRealFixLen template provided by the FFTReal
+ * library
+ *
+ * This class instantiates a single instance of FFTRealFixLen, using
+ * FFTLengthPowerOfTwo as the template parameter.  It then exposes
+ * FFTRealFixLen<FFTLengthPowerOfTwo>::do_fft via the calculateFFT
+ * function, thereby allowing an application to dynamically link
+ * against the FFTReal implementation.
+ *
+ * See http://ldesoras.free.fr/prod.html
+ */
+class FFTREAL_EXPORT FFTRealWrapper
+{
+public:
+    FFTRealWrapper();
+    ~FFTRealWrapper();
+
+    typedef float DataType;
+    void calculateFFT(DataType in[], const DataType out[]);
+
+private:
+    FFTRealWrapperPrivate*  m_private;
+};
+
+#endif // FFTREAL_WRAPPER_H
+