single slicer instance

check for other instances during startup
send message with command line arguments if found and terminate
listen for those messages and load objects from paths in messages from them

src/slic3r/CMakeLists.txt

@@ -161,6 +161,8 @@ set(SLIC3R_GUI_SOURCES
     GUI/DoubleSlider.hpp
     GUI/ObjectDataViewModel.cpp
     GUI/ObjectDataViewModel.hpp
+    GUI/InstanceCheck.cpp
+    GUI/InstanceCheck.hpp
     Utils/Http.cpp
     Utils/Http.hpp
     Utils/FixModelByWin10.cpp
@@ -195,6 +197,8 @@ if (APPLE)
             GUI/RemovableDriveManagerMM.mm
             GUI/RemovableDriveManagerMM.h
             GUI/Mouse3DHandlerMac.mm
+            GUI/InstanceCheckMac.mm
+            GUI/InstanceCheckMac.h
         )
     FIND_LIBRARY(DISKARBITRATION_LIBRARY DiskArbitration)
 
@@ -206,6 +210,10 @@ encoding_check(libslic3r_gui)
 
 target_link_libraries(libslic3r_gui libslic3r avrdude cereal imgui GLEW::GLEW OpenGL::GL OpenGL::GLU hidapi libcurl ${wxWidgets_LIBRARIES})
 
+if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    target_link_libraries(libslic3r_gui ${DBUS_LIBRARIES}) 
+endif()
+
 if(APPLE)
     target_link_libraries(libslic3r_gui ${DISKARBITRATION_LIBRARY})
 endif()