Provides to use the system wxWidgets install

The default is to use the system one if found.  If the
WXWIN environment variable is set and points to a valid
wxWidgets tree, that will be used.  Otherwise, it will
search the platform specific locations.

You can use a local library instead with:

   cmake -Duse_system_wxwigets=no ...

In this case it will look for the WXWIN environment variable
and use that or it will download the Audacity specific wxWidgets
source.  In both cases, wxWidgets will be built as part of the
Audacity project.

cmake-proxies/libid3tag/CMakeLists.txt

@@ -25,6 +25,7 @@ list( APPEND SOURCES
 list( APPEND INCLUDES
    PRIVATE
       ${CMAKE_CURRENT_BINARY_DIR}/private
+      $<$<PLATFORM_ID:Windows>:$ENV{WXWIN}/src/zlib>
    PUBLIC
       ${TARGET_ROOT}
 )

cmake-proxies/wxwidgets/CMakeLists.txt

@@ -3,96 +3,137 @@ add_library( ${TARGET} INTERFACE )
 
 def_vars()
 
-set( WXWIN $ENV{WXWIN} )
-if( "${WXWIN}" STREQUAL "" )
-   set( WXWIN "${_INTDIR}/wxwidgets" )
-   # XXX: Look into importing instead of adding to this project
+option( use_system_wxwidgets "Prefer wxWidgets system library if available" ON )
+if( use_system_wxwidgets )
+   find_package(wxWidgets)
 endif()
 
-if( NOT EXISTS "${WXWIN}" )
-   find_package( Git )
-   if( NOT GIT_FOUND )
-      message( FATAL_ERROR "Git is needed to clone wxWidgets" )
+if( wxWidgets_FOUND )
+   #include(${wxWidgets_USE_FILE})
+
+   if( wxWidgets_INCLUDE_DIRS_NO_SYSTEM )
+      set( INCLUDES
+         INTERFACE
+            ${wxWidgets_INCLUDE_DIRS}
+      )
+   else()
+      set( INCLUDES
+         SYSTEM
+            ${wxWidgets_INCLUDE_DIRS}
+      )
    endif() 
 
-   execute_process(
-      COMMAND
-         ${GIT_EXECUTABLE} clone
-                           --depth 1
-                           --single-branch
-                           --recurse-submodules
-                           https://github.com/audacity/wxwidgets
-                           "${WXWIN}"
+   set( DEFINES
+      INTERFACE
+         ${wxWidgets_DEFINITIONS}
+         ${wxWidgets_DEFINITIONS_DEBUG}
    )
+
+   set( LIBRARIES
+      INTERFACE
+         ${wxWidgets_LIBRARIES}
+         $<$<NOT:$<PLATFORM_ID:Windows>>:z>
+   )
+
+   set( toolkit "${wxWidgets_LIBRARIES}" )
+else()
+   set( use_system_wxwidgets OFF CACHE BOOL "Prefer wxWidgets system library if available" FORCE )
+
+   set( WXWIN $ENV{WXWIN} )
+   if( "${WXWIN}" STREQUAL "" )
+      # XXX: Look into importing instead of adding to this project
+      set( WXWIN "${_INTDIR}/wxwidgets" )
+   endif()
+
+   if( NOT EXISTS "${WXWIN}" )
+      find_package( Git )
+      if( NOT GIT_FOUND )
+         message( FATAL_ERROR "Git is needed to clone wxWidgets" )
+      endif()
+
+      execute_process(
+         COMMAND
+            ${GIT_EXECUTABLE} clone
+                              --depth 1
+                              --single-branch
+                              --recurse-submodules
+                              https://github.com/audacity/wxwidgets
+                              "${WXWIN}"
+      )
+   endif()
+
+   if( CMAKE_SYSTEM_NAME MATCHES "Windows" )
+      # Want accessibility
+      set( wxUSE_ACCESSIBILITY YES )
+
+      # Windows requires it due to missing "#include" directives
+      set( wxBUILD_PRECOMP YES )
+   elseif( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
+      # Want accessibility
+      set( wxUSE_ACCESSIBILITY YES )
+
+      # Causes problems on OSX, so turn it off
+      set( wxBUILD_PRECOMP NO )
+   elseif( CMAKE_SYSTEM_NAME MATCHES "Linux" )
+      # Doesn't yet have accessbility
+      set( wxUSE_ACCESSIBILITY NO )
+
+      # Linux can go either way, so might as well use it
+      set( wxBUILD_PRECOMP YES )
+   endif()
+
+   # Just to be consistent with Audacity
+   set( wxBUILD_CXX_STANDARD "14" )
+
+   # Pull in wxWidgets
+   add_subdirectory( ${WXWIN} ${WXWIN} )
+
+   # And rearrange the folder structure
+   set_dir_folder( ${WXWIN} "wxWidgets" )
+
+   set( INCLUDES
+      $<$<STREQUAL:"${wxUSE_ZLIB}","builtin">:${WXWIN}/src/zlib>
+   )
+
+   set( DEFINES
+      WXUSINGDLL
+   )
+
+   set( LIBRARIES
+      adv
+      base
+      core
+      html
+      net
+      qa
+      xml
+      $<$<STREQUAL:"${wxUSE_EXPAT}","builtin">:wxexpat>
+      $<$<STREQUAL:"${wxUSE_LIBJPEG}","builtin">:wxjpeg>
+      $<$<STREQUAL:"${wxUSE_LIBPNG}","builtin">:wxpng>
+      $<$<STREQUAL:"${wxUSE_LIBTIFF}","builtin">:wxtiff>
+      $<$<STREQUAL:"${wxUSE_REGEX}","builtin">:wxregex>
+      $<$<STREQUAL:"${wxUSE_ZLIB}","builtin">:wxzlib>
+   )
+
+   if( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
+      # When accessibility is enabled, the build will fail in "wx/chkconf.h"
+      # since wxRegex compile defines do not include __WXOSX_COCOA__.  So,
+      # add it here.
+      target_compile_definitions( wxregex PRIVATE "__WXOSX_COCOA__" )
+   elseif( CMAKE_SYSTEM_NAME MATCHES "Linux" )
+      set( toolkit "${wxBUILD_TOOLKIT}" )
+   endif()
 endif()
 
-if( CMAKE_SYSTEM_NAME MATCHES "Windows" )
-   # Want accessibility
-   set( wxUSE_ACCESSIBILITY YES )
-
-   # Windows requires it due to missing "#include" directives
-   set( wxBUILD_PRECOMP YES )
-elseif( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
-   # Want accessibility
-   set( wxUSE_ACCESSIBILITY YES )
-
-   # Causes problems on OSX, so turn it off
-   set( wxBUILD_PRECOMP NO )
-elseif( CMAKE_SYSTEM_NAME MATCHES "Linux" )
-   # Doesn't yet have accessbility
-   set( wxUSE_ACCESSIBILITY NO )
-
-   # Linux can go either way, so might as well use it
-   set( wxBUILD_PRECOMP YES )
-endif()
-
-# Just to be consistent with Audacity
-set( wxBUILD_CXX_STANDARD "14" )
-
-# Pull in wxWidgets
-add_subdirectory( ${WXWIN} ${WXWIN} )
-
-# And rearrange the folder structure
-set_dir_folder( ${WXWIN} "wxWidgets" )
-
-set( INCLUDES
-   $<$<STREQUAL:"${wxUSE_ZLIB}","builtin">:${WXWIN}/src/zlib>
-)
-
-set( DEFINES
-   WXUSINGDLL
-)
-
-set( LIBRARIES
-   adv
-   base
-   core
-   html
-   net
-   qa
-   xml
-   $<$<STREQUAL:"${wxUSE_EXPAT}","builtin">:wxexpat>
-   $<$<STREQUAL:"${wxUSE_LIBJPEG}","builtin">:wxjpeg>
-   $<$<STREQUAL:"${wxUSE_LIBPNG}","builtin">:wxpng>
-   $<$<STREQUAL:"${wxUSE_LIBTIFF}","builtin">:wxtiff>
-   $<$<STREQUAL:"${wxUSE_REGEX}","builtin">:wxregex>
-   $<$<STREQUAL:"${wxUSE_ZLIB}","builtin">:wxzlib>
-)
-
-if( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
-   # When accessibility is enabled, the build will fail in "wx/chkconf.h"
-   # since wxRegex compile defines do not include __WXOSX_COCOA__.  So,
-   # add it here.
-   target_compile_definitions( wxregex PRIVATE "__WXOSX_COCOA__" )
-elseif( CMAKE_SYSTEM_NAME MATCHES "Linux" )
+if( CMAKE_SYSTEM_NAME MATCHES "Linux" )
    # We need the system GTK/GLIB packages
-   if( "${wxBUILD_TOOLKIT}" STREQUAL "gtk2" )
+   if( "${toolkit}" MATCHES ".*gtk2.*" )
       set( gtk gtk+-2.0 )
       set( glib glib-2.0 )
-   elseif( "${wxBUILD_TOOLKIT}" STREQUAL "gtk3" )
+   elseif( "${toolkit}" MATCHES ".*gtk3.*" )
       set( gtk gtk+-3.0 )
       set( glib glib-2.0 )
-   elseif( "${wxBUILD_TOOLKIT}" STREQUAL "gtk4" )
+   elseif( "${toolkit}" MATCHES ".*gtk4.*" )
       set( gtk gtk+-4.0 )
       set( glib glib-2.0 )
    else()

src/CMakeLists.txt

@@ -1053,6 +1053,12 @@ if( CMAKE_SYSTEM_NAME MATCHES "Windows" )
    configure_file( audacity_config.h.in private/configwin.h )
 
    # Copy over the wxWidgets DLLs
+   if( use_system_wxwidgets )
+      set( wxlibs "$ENV{WXWIN}" )
+   else()
+      set( wxlibs "${CMAKE_BINARY_DIR}" )
+   endif()
+
    file( TO_NATIVE_PATH ${_EXEDIR} exedir )
    add_custom_command(
       TARGET
@@ -1060,7 +1066,7 @@ if( CMAKE_SYSTEM_NAME MATCHES "Windows" )
       COMMAND
          XCOPY "*.dll" ${exedir} /I /R /Y 
       WORKING_DIRECTORY
-         "${CMAKE_BINARY_DIR}/lib/vc_dll" 
+         "${wxlibs}/lib/vc_dll"
       POST_BUILD
    )
 elseif( CMAKE_SYSTEM_NAME MATCHES "Darwin" )