Implement the callback
Implement the callback based on the signature in the show_screen_extern.h file and pass this as a parameter of the show_screen
call. For more information on how to do this, see Implement callbacks.
Code example
void show_screen_CB(show_screen_response *p, void *echo_struct){
app_context_t * POS = (app_context_t *)echo_struct;
}
Allocate the request structure
Use show_screen_allocate
to allocate, initialize and return a show_screen_request
structure. Populate the request by performing string duplication.
If you want the data for later use, retain it, or it will be released automatically.
Call the show_screen function
Call the show_screen
function to display specific screens prior to the processing the tender or terminals with large screens (MX925, MX915). Use this function to display order items on a virtual receipt.
Parameters
Value | Description |
---|---|
show_tender_request |
Pointer to the show_screen_request struct, this struct contains all the input parameters for this call. |
show_screen_CB |
Pointer to the callback function in the POS that will be called with the results of the show_screen call. |
Code example
The declaration of the call to start a transaction is as follows:
ADYLibraryResult show_screen(show_screen_request * show_screen_request_ptr, void(*callback_function)(show_screen_response *, void *), void * echo_struct);
Handle the callback
The show_screen_CB
returns the immediate response to the call and a pointer to the POS-defined echo struct.
Parameters
Value | Description |
---|---|
show_screen_response |
The immediate response to the show_screen call, which includes the ID and status of the screen, and the result of the call. |
echo_struct |
Pointer to a POS defined struct. Returned in the callback. It can be used to share a POS data struct between the call to the library and the callback from the library in response to the call. |