Support for Interrupt Monitor

Support Interrupt Monitor for JPEG and PNG Conversion

This document explains how to support an interrupt for conversion of JPEG and PNG image using Aspose.Imaging. This example uses the Interrupt class to produce an interrupt during conversion.

import aspose.pycore as aspycore
from aspose.imaging import *
from aspose.imaging.brushes import *
from aspose.imaging.fileformats.jpeg import *
from aspose.imaging.fileformats.png import *
from aspose.imaging.imageoptions import *
from aspose.imaging.multithreading import *
from aspose.imaging.sources import *
import os
import time
from datetime import datetime
from threading import Thread

if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder


# Tries to convert image from one format to another. Handles interruption.
def thread_proc(input_path, output_path, save_options, monitor):
	print("Work thread")
	with Image.load(input_path) as image:
		InterruptMonitor.set_thread_local_instance(monitor)
		try:
			image.save(output_path, save_options)
			print("Finished correctly")
		except RuntimeError as e:
			if "OperationInterruptedException" in str(e):
				print("The save thread #{0} finishes at {1}".format(thread.native_id, datetime.now()))
			# print(e)
		finally:
			InterruptMonitor.set_thread_local_instance(None)


save_options = PngOptions()
monitor = InterruptMonitor()
thread = Thread(target=thread_proc, args=(os.path.join(data_dir, "template.jpg"), os.path.join(data_dir, "result.png"), save_options, monitor))
try:
	thread.start()
	# The timeout should be less than the time required for full image conversion (without interruption).
	time.sleep(0.1)
	# Interrupt the process
	monitor.interrupt()
	print("Interrupting the save thread #{0} at {1}".format(thread.native_id, datetime.now()))
	# Wait for interruption...
	thread.join()
finally:
	# If the file to be deleted does not exist, no exception is thrown.
	if delete_output:
		os.remove(os.path.join(data_dir, "result.png"))