API description

Printer API

 There are three layers of printer API, the lower layer is C, the device provid C interface, and the third app to write their own JNI source by calling the C interface.
 The middle layer is JNI interface, wizarPOS write JNI source and generate the device so files, so the third app just use the JNIInterface to finish the calling.
 The upper layer is Java interface, wizarPOS provide Java interface for the third app, the third app only need to import the .aar pakcage to their libs.

C interface

Functions

The calling sequence is open>query_status>begin>write>end>close.

open

 int printer_open()

Open the printer device.This operation should be used before other operations.

Parameters

Returns

The result code, >= 0, success; <0 error code.

begin

 int printer_begin()

Prepare to print, the app should print data after this funciton.

Parameters

Returns

The result code, >= 0, success; <0 error code.

end

 int printer_end()

End to print,the begin and end apis are pair operations.

Parameters

Returns

The result code, >= 0, success; <0 error code.

close

 int printer_close()

Close the device.The open and close apis are pair operations. If you don’t want to use the device, you should call close to release the device.

Parameters

Returns

The result code, >= 0, success; <0 error code.

query_status

 int printer_query_status()

Query the status of the printer.This api should be used inner open and close, but not inner begin and end.

Parameters

Returns

The result code, == 1, has paper; == 0, success; <0 error code.

write

 int printer_write(unsigned char* pData, int nDataLength)

Write data to the device. The data can be String, Bitmap data or ESC command.

Parameters

pData	data or ESC command
nDataLength	Length of data

Returns

The result code, >= 0, success; <0 error code.