Sets the pixel size to use for named icons. If the pixel size is set to a value != -1, it is used instead of the icon size set by gtk_image_set_from_icon_name(). Since 2.6
the new pixel size
See Implementation
Sets the pixel size to use for named icons. If the pixel size is set to a value != -1, it is used instead of the icon size set by gtk_image_set_from_icon_name(). Since 2.6