MODULAR_MATTER/output_module/print_or_preview.py

import time
import os # library to use bash commands
import keyboard




def preview_output(preview_button_count, last_module):

    #open last_module.ps, read its content and save it as print.ps
    fileInput = open(last_module +  ".ps", "rt") # rt = read text mode
    #output file to write the result to
    fileOutput = open("print.ps", "wt") # wt = write text mode

    # read the input file, search for a patterns, replace it with new patterns (that take the values from the input sensor)
    # uses regular expressions library (re)
    content = fileInput.read()

    # write the new text to the output file
    fileOutput.write(content)
    #close input and output files
    fileInput.close()
    fileOutput.close()

    #on first button press: open preview
    if preview_button_count == 1:
        print("start preview of print.ps")
        os.system("gv -fullscreen print.ps &") # open file in ghostscript viewer in fullscreen mode

    #on additional button press: refresh preview
    elif preview_button_count >= 2:
        print("refresh preview of print.ps")
        keyboard.send(".") # refresh file that is open in ghostscript viewer



def print_output(last_module):

    #open last_module.ps, read its content and save it as print.ps
    fileInput = open(last_module +  ".ps", "rt") # rt = read text mode
    #output file to write the result to
    fileOutput = open("print.ps", "wt") # wt = write text mode

    # read the input file, search for a patterns, replace it with new patterns (that take the values from the input sensor)
    # uses regular expressions library (re)
    content = fileInput.read()

    # write the new text to the output file
    fileOutput.write(content)
    #close input and output files
    fileInput.close()
    fileOutput.close()

    #on button press: send to printer
    print("send print.ps to printer")
    os.system("lp print.ps") # lp is the bash print command