Automatically print other documents when print Packing Slip

Base on the setup in SalesJournalAutoSummary of the customer I want to print extra documents after I print the PackingSlip.

For Example

On a specific customer both ‘Packing Slip’, ‘Picking list’ and ‘Invoice’ is checked (AutoSummary = true) in the SalesJournalAutoSummary table.

I create a new Sales order for this customer.

Do all the necessary things so I can create the packing slip.

When I print the packing slip, the Invoice and Picking list must be printed automatically.

Which classes can I use, and how do I change them to automatically print all the documents?