Simplify and fix spectrum build structure

It is not obvious why the example did go to quite a length to
make ffpeg a separate dynamic library. Just build it always
as a static library. The code is LGPLv2.1, but that is compatible
with the BSD-3-Clause license of the example.

Also move the actual application out of the sub-app directory
into the top level directory. This is much more intuitive to use.

Pick-to: 6.2
Change-Id: Ib6173ce21dab78d02190fb0b38c90629b41d26cd
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

35 files changed, 79 insertions, 177 deletions

diff --git a/examples/multimedia/spectrum/3rdparty/fftreal/CMakeLists.txt b/examples/multimedia/spectrum/3rdparty/fftreal/CMakeLists.txt
index e04fdc5fa..d348dde65 100644
--- a/examples/multimedia/spectrum/3rdparty/fftreal/CMakeLists.txt
+++ b/examples/multimedia/spectrum/3rdparty/fftreal/CMakeLists.txt
@@ -1,12 +1,6 @@
-# Generated from fftreal.pro.
+find_package(Qt6 COMPONENTS Core REQUIRED)
 
-#####################################################################
-## fftreal Generic Library:
-#####################################################################
-
-qt_internal_add_cmake_library(fftreal
-    INSTALL_DIRECTORY "${INSTALL_EXAMPLESDIR}/multimedia/spectrum"
-    SOURCES
+add_library(fftreal STATIC
         Array.h Array.hpp
         DynArray.h DynArray.hpp
         FFTRealFixLen.h FFTRealFixLen.hpp
@@ -18,55 +12,16 @@ qt_internal_add_cmake_library(fftreal
         OscSinCos.h OscSinCos.hpp
         def.h
         fftreal_wrapper.cpp fftreal_wrapper.h
-    DEFINES
-        FFTREAL_LIBRARY
-        LOG_ENGINE
-        LOG_SPECTRUMANALYSER
-        SPECTRUM_ANALYSER_SEPARATE_THREAD
-        SUPERIMPOSE_PROGRESS_ON_WAVEFORM
-    PUBLIC_LIBRARIES
-        Qt::Core
-        Qt::Gui
-)
-
-#### Keys ignored in scope 1:.:.:fftreal.pro:<TRUE>:
-# EXAMPLE_FILES = "bwins/fftreal.def" "eabi/fftreal.def" "readme.txt" "license.txt"
-# INSTALLS = "target"
-# TEMPLATE = "lib"
-# target.path = "$$[QT_INSTALL_EXAMPLES]/multimedia/spectrum"
-
-## Scopes:
-#####################################################################
-
-qt_internal_extend_target(fftreal CONDITION static
-    DEFINES
-        DISABLE_FFT
 )
 
-#### Keys ignored in scope 4:.:.:fftreal.pro:else:
-# DESTDIR = "../..$${spectrum_build_dir}"
-
-qt_internal_extend_target(fftreal CONDITION WIN32
-    DEFINES
-        _CRT_SECURE_NO_WARNINGS
+target_compile_definitions(fftreal PRIVATE
+    FFTREAL_LIBRARY
+    LOG_ENGINE
+    LOG_SPECTRUMANALYSER
+    SPECTRUM_ANALYSER_SEPARATE_THREAD
+    SUPERIMPOSE_PROGRESS_ON_WAVEFORM
 )
 
-#### Keys ignored in scope 10:.:../..:../../spectrum.pri:CONFIG(release,release OR debug):
-# spectrum_build_dir = "/release"
-
-#### Keys ignored in scope 11:.:../..:../../spectrum.pri:CONFIG(debug,release OR debug):
-# spectrum_build_dir = "/debug"
-
-# special case begin
-if(NOT DEFINED INSTALL_EXAMPLESDIR)
-  set(INSTALL_EXAMPLESDIR "examples")
-endif()
+target_link_libraries(fftreal PRIVATE Qt6::Core)
 
-set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/multimedia/spectrum")
-
-install(TARGETS fftreal
-    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
-    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
-    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
-)
-# special case end
+target_include_directories(fftreal INTERFACE .)
diff --git a/examples/multimedia/spectrum/3rdparty/fftreal/fftreal_wrapper.h b/examples/multimedia/spectrum/3rdparty/fftreal/fftreal_wrapper.h
index 2da3147ac..1b92d8e65 100644
--- a/examples/multimedia/spectrum/3rdparty/fftreal/fftreal_wrapper.h
+++ b/examples/multimedia/spectrum/3rdparty/fftreal/fftreal_wrapper.h
@@ -22,12 +22,6 @@
 
 #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
@@ -46,7 +40,7 @@ static const int FFTLengthPowerOfTwo = 12;
  *
  * See http://ldesoras.free.fr/prod.html
  */
-class FFTREAL_EXPORT FFTRealWrapper
+class FFTRealWrapper
 {
 public:
     FFTRealWrapper();
diff --git a/examples/multimedia/spectrum/CMakeLists.txt b/examples/multimedia/spectrum/CMakeLists.txt
index 5e0d8c45b..25b17dfb2 100644
--- a/examples/multimedia/spectrum/CMakeLists.txt
+++ b/examples/multimedia/spectrum/CMakeLists.txt
@@ -1,6 +1,67 @@
-# Generated from spectrum.pro.
+cmake_minimum_required(VERSION 3.14)
+project(spectrum LANGUAGES CXX)
 
-add_subdirectory(app)
-if(BUILD_SHARED_LIBS) # special case
-    add_subdirectory(3rdparty/fftreal)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+  set(INSTALL_EXAMPLESDIR "examples")
 endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/multimedia/spectrum")
+
+find_package(Qt6 COMPONENTS Multimedia Widgets REQUIRED)
+
+add_subdirectory(3rdparty/fftreal)
+
+qt_add_executable(spectrum
+    engine.cpp engine.h
+    frequencyspectrum.cpp frequencyspectrum.h
+    levelmeter.cpp levelmeter.h
+    main.cpp
+    mainwidget.cpp mainwidget.h
+    progressbar.cpp progressbar.h
+    settingsdialog.cpp settingsdialog.h
+    spectrograph.cpp spectrograph.h
+    spectrum.h
+    spectrumanalyser.cpp spectrumanalyser.h
+    tonegenerator.cpp tonegenerator.h
+    tonegeneratordialog.cpp tonegeneratordialog.h
+    utils.cpp utils.h
+    waveform.cpp waveform.h
+)
+
+set_target_properties(spectrum PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_compile_definitions(spectrum PRIVATE
+    LOG_ENGINE
+    LOG_SPECTRUMANALYSER
+    SPECTRUM_ANALYSER_SEPARATE_THREAD
+    SUPERIMPOSE_PROGRESS_ON_WAVEFORM
+)
+
+target_link_libraries(spectrum PRIVATE
+    Qt6::Multimedia
+    Qt6::Widgets
+    fftreal
+)
+
+qt_add_resources(spectrum "spectrum"
+    PREFIX
+        "/"
+    FILES
+        "images/record.png"
+        "images/settings.png"
+)
+
+install(TARGETS spectrum
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/examples/multimedia/spectrum/app/.gitignore b/examples/multimedia/spectrum/app/.gitignore
deleted file mode 100644
index 82cf2a28f..000000000
--- a/examples/multimedia/spectrum/app/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-spectrum
-spectrum.exe
diff --git a/examples/multimedia/spectrum/app/CMakeLists.txt b/examples/multimedia/spectrum/app/CMakeLists.txt
deleted file mode 100644
index 40ea37f2e..000000000
--- a/examples/multimedia/spectrum/app/CMakeLists.txt
+++ /dev/null
@@ -1,107 +0,0 @@
-# Generated from app.pro.
-
-cmake_minimum_required(VERSION 3.14)
-project(spectrum LANGUAGES CXX)
-
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-
-set(CMAKE_AUTOMOC ON)
-set(CMAKE_AUTORCC ON)
-set(CMAKE_AUTOUIC ON)
-
-if(NOT DEFINED INSTALL_EXAMPLESDIR)
-  set(INSTALL_EXAMPLESDIR "examples")
-endif()
-
-set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/multimedia/spectrum")
-
-find_package(Qt6 COMPONENTS Core)
-find_package(Qt6 COMPONENTS Gui)
-find_package(Qt6 COMPONENTS Multimedia)
-find_package(Qt6 COMPONENTS Widgets)
-
-qt_add_executable(spectrum
-    engine.cpp engine.h
-    frequencyspectrum.cpp frequencyspectrum.h
-    levelmeter.cpp levelmeter.h
-    main.cpp
-    mainwidget.cpp mainwidget.h
-    progressbar.cpp progressbar.h
-    settingsdialog.cpp settingsdialog.h
-    spectrograph.cpp spectrograph.h
-    spectrum.h
-    spectrumanalyser.cpp spectrumanalyser.h
-    tonegenerator.cpp tonegenerator.h
-    tonegeneratordialog.cpp tonegeneratordialog.h
-    utils.cpp utils.h
-    waveform.cpp waveform.h
-)
-set_target_properties(spectrum PROPERTIES
-    WIN32_EXECUTABLE TRUE
-    MACOSX_BUNDLE TRUE
-)
-target_include_directories(spectrum PUBLIC
-    ../3rdparty/fftreal
-    ../../shared
-)
-
-target_compile_definitions(spectrum PUBLIC
-    LOG_ENGINE
-    LOG_SPECTRUMANALYSER
-    SPECTRUM_ANALYSER_SEPARATE_THREAD
-    SUPERIMPOSE_PROGRESS_ON_WAVEFORM
-)
-
-target_link_libraries(spectrum PUBLIC
-    Qt::Core
-    Qt::Gui
-    Qt::Multimedia
-    Qt::Widgets
-)
-
-
-# Resources:
-set(spectrum_resource_files
-    "images/record.png"
-    "images/settings.png"
-)
-
-qt6_add_resources(spectrum "spectrum"
-    PREFIX
-        "/"
-    FILES
-        ${spectrum_resource_files}
-)
-
-if(MACOS AND BUILD_SHARED_LIBS) # special case
-    target_link_libraries(spectrum PUBLIC
-        fftreal # special case
-        # Remove: F
-    )
-endif()
-
-
-if(BUILD_SHARED_LIBS AND NOT MACOS) # special case
-    target_link_libraries(spectrum PUBLIC
-        # Remove: L..
-        fftreal
-    )
-endif()
-
-if(static)
-    target_compile_definitions(spectrum PUBLIC
-        DISABLE_FFT
-    )
-endif()
-
-if(WIN32)
-    target_compile_definitions(spectrum PUBLIC
-        _CRT_SECURE_NO_WARNINGS
-    )
-endif()
-
-install(TARGETS spectrum
-    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
-    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
-    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
-)
diff --git a/examples/multimedia/spectrum/doc/src/spectrum.qdoc b/examples/multimedia/spectrum/doc/src/spectrum.qdoc
index ad0ec984f..6db616219 100644
--- a/examples/multimedia/spectrum/doc/src/spectrum.qdoc
+++ b/examples/multimedia/spectrum/doc/src/spectrum.qdoc
@@ -58,8 +58,9 @@
 
     Spectrum analysis is performed by calculating the Fast Fourier Transform
     (FFT) of a segment of audio data.  An open-source library,
-    \l{http://ldesoras.free.fr/prod.html}{FFTReal}, against which the
-    application is dynamically linked, is used to compute the transform.
+    \l{http://ldesoras.free.fr/prod.html}{FFTReal} is used to compute the
+    transform. FFTReal is available under the GNU Library General Public License
+    2.0 or later.
 
     \include examples-run.qdocinc
 */
diff --git a/examples/multimedia/spectrum/app/engine.cpp b/examples/multimedia/spectrum/engine.cpp
index 2a6a50168..2a6a50168 100644
--- a/examples/multimedia/spectrum/app/engine.cpp
+++ b/examples/multimedia/spectrum/engine.cpp
diff --git a/examples/multimedia/spectrum/app/engine.h b/examples/multimedia/spectrum/engine.h
index 449884251..449884251 100644
--- a/examples/multimedia/spectrum/app/engine.h
+++ b/examples/multimedia/spectrum/engine.h
diff --git a/examples/multimedia/spectrum/app/frequencyspectrum.cpp b/examples/multimedia/spectrum/frequencyspectrum.cpp
index abec65d23..abec65d23 100644
--- a/examples/multimedia/spectrum/app/frequencyspectrum.cpp
+++ b/examples/multimedia/spectrum/frequencyspectrum.cpp
diff --git a/examples/multimedia/spectrum/app/frequencyspectrum.h b/examples/multimedia/spectrum/frequencyspectrum.h
index 4b13cbb99..4b13cbb99 100644
--- a/examples/multimedia/spectrum/app/frequencyspectrum.h
+++ b/examples/multimedia/spectrum/frequencyspectrum.h
diff --git a/examples/multimedia/spectrum/app/images/record.png b/examples/multimedia/spectrum/images/record.png
index 184fce809..184fce809 100644
--- a/examples/multimedia/spectrum/app/images/record.png
+++ b/examples/multimedia/spectrum/images/record.png
diff --git a/examples/multimedia/spectrum/app/images/settings.png b/examples/multimedia/spectrum/images/settings.png
index 12179dc9a..12179dc9a 100644
--- a/examples/multimedia/spectrum/app/images/settings.png
+++ b/examples/multimedia/spectrum/images/settings.png
diff --git a/examples/multimedia/spectrum/app/levelmeter.cpp b/examples/multimedia/spectrum/levelmeter.cpp
index f3bd619cd..f3bd619cd 100644
--- a/examples/multimedia/spectrum/app/levelmeter.cpp
+++ b/examples/multimedia/spectrum/levelmeter.cpp
diff --git a/examples/multimedia/spectrum/app/levelmeter.h b/examples/multimedia/spectrum/levelmeter.h
index 987f90e8f..987f90e8f 100644
--- a/examples/multimedia/spectrum/app/levelmeter.h
+++ b/examples/multimedia/spectrum/levelmeter.h
diff --git a/examples/multimedia/spectrum/app/main.cpp b/examples/multimedia/spectrum/main.cpp
index 7eeb94949..7eeb94949 100644
--- a/examples/multimedia/spectrum/app/main.cpp
+++ b/examples/multimedia/spectrum/main.cpp
diff --git a/examples/multimedia/spectrum/app/mainwidget.cpp b/examples/multimedia/spectrum/mainwidget.cpp
index 2dbfda9ab..2dbfda9ab 100644
--- a/examples/multimedia/spectrum/app/mainwidget.cpp
+++ b/examples/multimedia/spectrum/mainwidget.cpp
diff --git a/examples/multimedia/spectrum/app/mainwidget.h b/examples/multimedia/spectrum/mainwidget.h
index d2340daae..d2340daae 100644
--- a/examples/multimedia/spectrum/app/mainwidget.h
+++ b/examples/multimedia/spectrum/mainwidget.h
diff --git a/examples/multimedia/spectrum/app/progressbar.cpp b/examples/multimedia/spectrum/progressbar.cpp
index 4ac34b866..4ac34b866 100644
--- a/examples/multimedia/spectrum/app/progressbar.cpp
+++ b/examples/multimedia/spectrum/progressbar.cpp
diff --git a/examples/multimedia/spectrum/app/progressbar.h b/examples/multimedia/spectrum/progressbar.h
index 601900efb..601900efb 100644
--- a/examples/multimedia/spectrum/app/progressbar.h
+++ b/examples/multimedia/spectrum/progressbar.h
diff --git a/examples/multimedia/spectrum/app/settingsdialog.cpp b/examples/multimedia/spectrum/settingsdialog.cpp
index 3ec9c6956..3ec9c6956 100644
--- a/examples/multimedia/spectrum/app/settingsdialog.cpp
+++ b/examples/multimedia/spectrum/settingsdialog.cpp
diff --git a/examples/multimedia/spectrum/app/settingsdialog.h b/examples/multimedia/spectrum/settingsdialog.h
index e6563b6ce..e6563b6ce 100644
--- a/examples/multimedia/spectrum/app/settingsdialog.h
+++ b/examples/multimedia/spectrum/settingsdialog.h
diff --git a/examples/multimedia/spectrum/app/spectrograph.cpp b/examples/multimedia/spectrum/spectrograph.cpp
index 2ab1127d7..2ab1127d7 100644
--- a/examples/multimedia/spectrum/app/spectrograph.cpp
+++ b/examples/multimedia/spectrum/spectrograph.cpp
diff --git a/examples/multimedia/spectrum/app/spectrograph.h b/examples/multimedia/spectrum/spectrograph.h
index 0e7b11717..0e7b11717 100644
--- a/examples/multimedia/spectrum/app/spectrograph.h
+++ b/examples/multimedia/spectrum/spectrograph.h
diff --git a/examples/multimedia/spectrum/app/spectrum.h b/examples/multimedia/spectrum/spectrum.h
index aea9ce7c5..aea9ce7c5 100644
--- a/examples/multimedia/spectrum/app/spectrum.h
+++ b/examples/multimedia/spectrum/spectrum.h
diff --git a/examples/multimedia/spectrum/app/spectrum.qrc b/examples/multimedia/spectrum/spectrum.qrc
index 61004791b..61004791b 100644
--- a/examples/multimedia/spectrum/app/spectrum.qrc
+++ b/examples/multimedia/spectrum/spectrum.qrc
diff --git a/examples/multimedia/spectrum/app/spectrumanalyser.cpp b/examples/multimedia/spectrum/spectrumanalyser.cpp
index 4a7b06809..4a7b06809 100644
--- a/examples/multimedia/spectrum/app/spectrumanalyser.cpp
+++ b/examples/multimedia/spectrum/spectrumanalyser.cpp
diff --git a/examples/multimedia/spectrum/app/spectrumanalyser.h b/examples/multimedia/spectrum/spectrumanalyser.h
index 799143489..799143489 100644
--- a/examples/multimedia/spectrum/app/spectrumanalyser.h
+++ b/examples/multimedia/spectrum/spectrumanalyser.h
diff --git a/examples/multimedia/spectrum/app/tonegenerator.cpp b/examples/multimedia/spectrum/tonegenerator.cpp
index 3e70180fd..3e70180fd 100644
--- a/examples/multimedia/spectrum/app/tonegenerator.cpp
+++ b/examples/multimedia/spectrum/tonegenerator.cpp
diff --git a/examples/multimedia/spectrum/app/tonegenerator.h b/examples/multimedia/spectrum/tonegenerator.h
index af6efade2..af6efade2 100644
--- a/examples/multimedia/spectrum/app/tonegenerator.h
+++ b/examples/multimedia/spectrum/tonegenerator.h
diff --git a/examples/multimedia/spectrum/app/tonegeneratordialog.cpp b/examples/multimedia/spectrum/tonegeneratordialog.cpp
index 086eba758..086eba758 100644
--- a/examples/multimedia/spectrum/app/tonegeneratordialog.cpp
+++ b/examples/multimedia/spectrum/tonegeneratordialog.cpp
diff --git a/examples/multimedia/spectrum/app/tonegeneratordialog.h b/examples/multimedia/spectrum/tonegeneratordialog.h
index 5095cbb7d..5095cbb7d 100644
--- a/examples/multimedia/spectrum/app/tonegeneratordialog.h
+++ b/examples/multimedia/spectrum/tonegeneratordialog.h
diff --git a/examples/multimedia/spectrum/app/utils.cpp b/examples/multimedia/spectrum/utils.cpp
index 2a6b2a33e..2a6b2a33e 100644
--- a/examples/multimedia/spectrum/app/utils.cpp
+++ b/examples/multimedia/spectrum/utils.cpp
diff --git a/examples/multimedia/spectrum/app/utils.h b/examples/multimedia/spectrum/utils.h
index d143a83f7..d143a83f7 100644
--- a/examples/multimedia/spectrum/app/utils.h
+++ b/examples/multimedia/spectrum/utils.h
diff --git a/examples/multimedia/spectrum/app/waveform.cpp b/examples/multimedia/spectrum/waveform.cpp
index 5f9563a8d..5f9563a8d 100644
--- a/examples/multimedia/spectrum/app/waveform.cpp
+++ b/examples/multimedia/spectrum/waveform.cpp
diff --git a/examples/multimedia/spectrum/app/waveform.h b/examples/multimedia/spectrum/waveform.h
index 8c26e99b2..8c26e99b2 100644
--- a/examples/multimedia/spectrum/app/waveform.h
+++ b/examples/multimedia/spectrum/waveform.h