cairoSetUserData: cairoSetUserData
Description
Attach user data to cr. To remove user data from a surface,
call this function with the key that was used to set it and NULL
for data.Usage
cairoSetUserData(cr, key, user.data)
Value
[CairoStatus] CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY if a
slot could not be allocated for the user data.