CairoWriteFunc: CairoWriteFunc
Description
A callback used by cairo for outputting graphics data in formats
like svg and png.Signature
CairoWriteFunc(data, length, user_data)
:
The type of function which is called when a backend needs to write
data to an output stream. It is passed the closure which was specified
by the user at the time the write function was registered, the data to
write and the length of the data in bytes. The write function should
return CAIRO_STATUS_SUCCESS
if all the data was successfully
written, CAIRO_STATUS_WRITE_ERROR
otherwise.
data
- [raw] the buffer containing the data to write
length
- [numeric] the amount of data to write
user_data
- [R object] user-supplied data