a #GdkWindow
the property to change
the new type for the property. If @mode is %GDK_PROP_MODE_PREPEND or %GDK_PROP_MODE_APPEND, then this must match the existing type or an error will occur.
the new format for the property. If @mode is %GDK_PROP_MODE_PREPEND or %GDK_PROP_MODE_APPEND, then this must match the existing format or an error will occur.
a value describing how the new data is to be combined with the current data.
the data (a guchar * gushort *, or gulong *, depending on @format), cast to a guchar *.
Changes the contents of a property on a window.