FindGTK2: Better handling of include directories

Add a method _GTK2_ADD_TARGET_INCLUDE_DIRS to handle it.

Modules/FindGTK2.cmake

@@ -466,6 +466,15 @@ function(_GTK2_ADD_TARGET_DEPENDS _var)
     endforeach()
 endfunction()
 
+function(_GTK2_ADD_TARGET_INCLUDE_DIRS _var)
+    string(REGEX REPLACE "GTK2_" "" _basename "${_var}")
+    string(TOLOWER "${_basename}" _basename)
+    if(TARGET GTK2::${_basename})
+        foreach(_include ${ARGN})
+            set_property(TARGET GTK2::${_basename} APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${_include}")
+        endforeach()
+    endif()
+endfunction()
 
 #=============================================================
 
@@ -626,9 +635,7 @@ foreach(_GTK2_component ${GTK2_FIND_COMPONENTS})
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GTHREAD glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GMODULE glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GDK_PIXBUF gobject glib)
-        #_GTK2_ADD_TARGET_DEPENDS(GTK2_CAIRO)
-        set_property(TARGET GTK2::cairo APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${FREETYPE_INCLUDE_DIRS}")
-        set_property(TARGET GTK2::cairo APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${GTK2_FONTCONFIG_INCLUDE_DIRS}")
+        _GTK2_ADD_TARGET_INCLUDE_DIRS(GTK2_CAIRO ${FREETYPE_INCLUDE_DIRS} ${GTK2_FONTCONFIG_INCLUDE_DIRS})
         _GTK2_ADD_TARGET_DEPENDS(GTK2_PANGO gobject glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_PANGOCAIRO pango cairo gobject glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GDK pangocairo pango cairo gdk_pixbuf gobject glib)
@@ -675,18 +682,15 @@ foreach(_GTK2_component ${GTK2_FIND_COMPONENTS})
         _GTK2_FIND_LIBRARY    (GTK2_SIGC++ sigc true true)
         _GTK2_ADJUST_LIB_VARS (GTK2_SIGC++)
 
-        #_GTK2_ADD_TARGET_DEPENDS(GTK2_SIGC++)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GLIBMM gobject sigc glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GIOMM gio glibmm gobject sigc glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_ATKMM atk glibmm gobject sigc glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_CAIROMM cairo sigc++)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_PANGOMM glibmm cairomm pangocairo sigc++ pango cairo gobject glib)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GDKMM giomm pangomm gtk glibmm cairomm sigc++ gdk atk gio pangoft2 pangocairo gdk_pixbuf cairo pango gobject glib)
-        set_property(TARGET GTK2::gtkmm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${FREETYPE_INCLUDE_DIRS}")
-        set_property(TARGET GTK2::gtkmm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${GTK2_FONTCONFIG_INCLUDE_DIRS}")
+        _GTK2_ADD_TARGET_INCLUDE_DIRS(GTK2_GDKMM ${FREETYPE_INCLUDE_DIRS} ${GTK2_FONTCONFIG_INCLUDE_DIRS})
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GTKMM atkmm gdkmm giomm pangomm gtk glibmm cairomm sigc++ gdk atk gio pangoft2 pangocairo gdk_pixbuf cairo pango gthread gobject glib)
-        set_property(TARGET GTK2::gtkmm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${FREETYPE_INCLUDE_DIRS}")
-        set_property(TARGET GTK2::gtkmm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${GTK2_FONTCONFIG_INCLUDE_DIRS}")
+        _GTK2_ADD_TARGET_INCLUDE_DIRS(GTK2_GTKMM ${FREETYPE_INCLUDE_DIRS} ${GTK2_FONTCONFIG_INCLUDE_DIRS})
 
     elseif(_GTK2_component STREQUAL "glade")
 
@@ -694,8 +698,7 @@ foreach(_GTK2_component ${GTK2_FIND_COMPONENTS})
         _GTK2_FIND_LIBRARY    (GTK2_GLADE glade false true)
         _GTK2_ADJUST_LIB_VARS (GTK2_GLADE)
         _GTK2_ADD_TARGET_DEPENDS(GTK2_GLADE gtk gdk atk gio pangoft2 pangocairo gdk_pixbuf cairo pango gobject glib)
-        set_property(TARGET GTK2::glade APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${FREETYPE_INCLUDE_DIRS}")
-        set_property(TARGET GTK2::glade APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${GTK2_FONTCONFIG_INCLUDE_DIRS}")
+        _GTK2_ADD_TARGET_INCLUDE_DIRS(GTK2_GLADE ${FREETYPE_INCLUDE_DIRS} ${GTK2_FONTCONFIG_INCLUDE_DIRS})
 
     elseif(_GTK2_component STREQUAL "glademm")
 
@@ -703,9 +706,8 @@ foreach(_GTK2_component ${GTK2_FIND_COMPONENTS})
         _GTK2_FIND_INCLUDE_DIR(GTK2_GLADEMMCONFIG libglademmconfig.h)
         _GTK2_FIND_LIBRARY    (GTK2_GLADEMM glademm true true)
         _GTK2_ADJUST_LIB_VARS (GTK2_GLADEMM)
-        _GTK2_ADD_TARGET_DEPENDS(GLADEMM gtkmm glade atkmm gdkmm giomm pangomm glibmm cairomm sigc++ gtk gdk atk gio pangoft pangocairo gdk_pixbuf cairo pango gthread gobject glib)
-        set_property(TARGET GTK2::glademm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${FREETYPE_INCLUDE_DIRS}")
-        set_property(TARGET GTK2::glademm APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${GTK2_FONTCONFIG_INCLUDE_DIRS}")
+        _GTK2_ADD_TARGET_DEPENDS(GTK2_GLADEMM gtkmm glade atkmm gdkmm giomm pangomm glibmm cairomm sigc++ gtk gdk atk gio pangoft pangocairo gdk_pixbuf cairo pango gthread gobject glib)
+        _GTK2_ADD_TARGET_INCLUDE_DIRS(GTK2_GLADEMM ${FREETYPE_INCLUDE_DIRS} ${GTK2_FONTCONFIG_INCLUDE_DIRS})
 
     else()
         message(FATAL_ERROR "Unknown GTK2 component ${_component}")