ImGui 1.71 needs to link to ApplicationServices on macOS

[AboudFayad]

I am trying to build the magnum integration with imgui on mac, but the build always fails with the following error:

Undefined symbols for architecture x86_64:
  "_CFArrayGetCount", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_CFDataCreate", referenced from:
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
  "_CFDataGetBytes", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_CFDataGetLength", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_CFRelease", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
  "_PasteboardClear", referenced from:
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
  "_PasteboardCopyItemFlavorData", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_PasteboardCopyItemFlavors", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_PasteboardCreate", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
  "_PasteboardGetItemCount", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_PasteboardGetItemIdentifier", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "_PasteboardPutItemFlavor", referenced from:
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
  "_PasteboardSynchronize", referenced from:
      GetClipboardTextFn_DefaultImpl(void*) in imgui.cpp.o
  "___CFConstantStringClassReference", referenced from:
      CFString in imgui.cpp.o
      CFString in imgui.cpp.o
  "_kCFAllocatorDefault", referenced from:
      SetClipboardTextFn_DefaultImpl(void*, char const*) in imgui.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [src/Magnum/ImGuiIntegration/libMagnumImGuiIntegration.2.2.dylib] Error 1
make[1]: *** [src/Magnum/ImGuiIntegration/CMakeFiles/MagnumImGuiIntegration.dir/all] Error 2
make: *** [all] Error 2

which are windows specific functions, I tried building it on windows the same way I did on mac and it worked. So I believe it is a mac specific issue.

Anyway to overcome this issue?

[mosra]

Hi, sorry about this. The integration code was not yet upgraded to work with latest ImGui versions and this seems to be caused by new macOS clipboard support in 1.71 (ocornut/imgui#2546). Until I fix this and link the missing framework, can you build with an older version of ImGui? The code was tested extensively with 1.69, 1.70 could work too.

[AboudFayad]

Thanks a lot, 1.69 works just fine.

[Melix19]

If there is a need to use the latest version of imgui you can add the Carbon library to your CMakeLists and that should fix the error:

if(APPLE)
    find_library(CARBON_LIBRARY Carbon)
endif()

# Add ${CARBON_LIBRARY} to your target_link_libraries()

EDIT:
Or even better: just add "-framework ApplicationServices" to target_link_libraries()

[mosra]

Should be fixed with b157344 -- to make it work, please update the FindImGui.cmake copy in your projects.

[ocornut]

Note as as-per ocornut/imgui@29d9394 and ocornut/imgui#2546 (comment) I have reverted this change. It is possible to explicitely enabled the default cocoa handler by using IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS, as a facility for custom engine writers on the Mac.

[ocornut]

....That wasn't explicit in the message above, but it means you may revert linking to ApplicationServices... Magnum probably has its own clipboard handler anyway.

[mosra]

@ocornut thanks a lot for taking the time to comment! 💚

I'll keep it around for now so people using 1.71 don't run into the same issue again, will remove it a few releases later.