Export icons according to XDG icon spec on unix

Signed-off-by: Matthew J. Milner <[email protected]>

avogadro/CMakeLists.txt

@@ -175,7 +175,17 @@ if(APPLE)
 elseif(UNIX)
   install(FILES "icons/org.openchemistry.Avogadro2.desktop" DESTINATION "${INSTALL_XDG_APPS_DIR}")
   install(FILES "icons/org.openchemistry.Avogadro2.metainfo.xml" DESTINATION "${CMAKE_INSTALL_PREFIX}/share/metainfo")
-  install(FILES "icons/avogadro.png" DESTINATION "${INSTALL_XDG_ICON_DIR}"
+  install(FILES "icons/avogadro.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/32x32/apps"
+    RENAME "org.openchemistry.Avogadro2.png")
+  install(FILES "icons/avogadro.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/16x16@2/apps"
+    RENAME "org.openchemistry.Avogadro2.png")
+  install(FILES "icons/avogadro2_64.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/64x64/apps"
+    RENAME "org.openchemistry.Avogadro2.png")
+  install(FILES "icons/avogadro2_64.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/32x32@2/apps"
+    RENAME "org.openchemistry.Avogadro2.png")
+  install(FILES "icons/avogadro2_128.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/128x128/apps"
+    RENAME "org.openchemistry.Avogadro2.png")
+  install(FILES "icons/avogadro2_256.png" DESTINATION "${INSTALL_XDG_ICON_DIR}/hicolor/256x256/apps"
     RENAME "org.openchemistry.Avogadro2.png")
 elseif(WIN32)
   list(APPEND avogadro_srcs icons/avogadro.rc)

cmake/InstallLocation.cmake

@@ -33,7 +33,7 @@ if(UNIX AND NOT APPLE)
     set(INSTALL_XDG_APPS_DIR "${INSTALL_DATA_DIR}/applications")
   endif()
   if(NOT INSTALL_XDG_ICON_DIR)
-    set(INSTALL_XDG_ICON_DIR "${INSTALL_DATA_DIR}/pixmaps")
+    set(INSTALL_XDG_ICON_DIR "${INSTALL_DATA_DIR}/icons")
   endif()
 endif()