-static const char *kKeyDrawingName = "drawing_name";
-static const char *kKeyDrawingArea = "drawing_area";
-static const char *kKeyDrawingRect = "drawing_rect";
-static const char *kKeyX = "x";
-static const char *kKeyY = "y";
-static const char *kKeyWidth = "width";
-static const char *kKeyHeight = "height";
-static const char *kKeyWidthPixel = "width_pixel";
-static const char *kKeyHeightPixel = "height_pixel";
-static const char *kKeyWidthMm = "width_mm";
-static const char *kKeyHeightMm = "height_mm";
-
+extern const char kKeyDrawingName[];
+extern const char kKeyDrawingArea[];
+extern const char kKeyDrawingRect[];
+extern const char kKeyX[];
+extern const char kKeyY[];
+extern const char kKeyWidth[];
+extern const char kKeyHeigh[];
+extern const char kKeyWidthPixel[];
+extern const char kKeyHeightPixel[];
+extern const char kKeyWidthMm[];
+extern const char kKeyHeightMm[];