#!/usr/bin/env python # -*- coding: utf-8 -*- """ This is a web service to print labels on Brother QL label printers. """ import sys, logging, random, json, argparse from io import BytesIO from bottle import run, route, get, post, response, request, jinja2_view as view, static_file, redirect from PIL import Image, ImageDraw, ImageFont from brother_ql.devicedependent import models, label_type_specs, label_sizes from brother_ql.devicedependent import ENDLESS_LABEL, DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL from brother_ql import BrotherQLRaster, create_label from brother_ql.backends import backend_factory, guess_backend from font_helpers import get_fonts logger = logging.getLogger(__name__) LABEL_SIZES = [ (name, label_type_specs[name]['name']) for name in label_sizes] PRINTERS = {} try: with open('config.json') as fh: CONFIG = json.load(fh) except FileNotFoundError as e: with open('config.example.json') as fh: CONFIG = json.load(fh) @route('/') def index(): redirect('/labeldesigner') @route('/static/') def serve_static(filename): return static_file(filename, root='./static') @route('/labeldesigner') @view('labeldesigner.jinja2') def labeldesigner(): font_family_names = sorted(list(FONTS.keys())) return {'font_family_names': font_family_names, 'fonts': FONTS, 'label_sizes': LABEL_SIZES, 'website': CONFIG['WEBSITE'], 'label': CONFIG['LABEL'], 'printers': PRINTERS } def get_label_context(request): """ might raise LookupError() """ d = request.params.decode() # UTF-8 decoded form data font_family = d.get('font_family').rpartition('(')[0].strip() font_style = d.get('font_family').rpartition('(')[2].rstrip(')') context = { 'text': d.get('text', None), 'font_size': int(d.get('font_size', 100)), 'font_family': font_family, 'font_style': font_style, 'label_size': d.get('label_size', "62"), 'kind': label_type_specs[d.get('label_size', "62")]['kind'], 'margin': int(d.get('margin', 10)), 'threshold': int(d.get('threshold', 70)), 'align': d.get('align', 'center'), 'orientation': d.get('orientation', 'standard'), 'margin_top': float(d.get('margin_top', 24))/100., 'margin_bottom': float(d.get('margin_bottom', 45))/100., 'margin_left': float(d.get('margin_left', 35))/100., 'margin_right': float(d.get('margin_right', 35))/100., 'printer_name': d.get('printer_name', None), } context['margin_top'] = int(context['font_size']*context['margin_top']) context['margin_bottom'] = int(context['font_size']*context['margin_bottom']) context['margin_left'] = int(context['font_size']*context['margin_left']) context['margin_right'] = int(context['font_size']*context['margin_right']) def get_font_path(font_family_name, font_style_name): try: if font_family_name is None or font_style_name is None: font_family_name = CONFIG['LABEL']['DEFAULT_FONTS']['family'] font_style_name = CONFIG['LABEL']['DEFAULT_FONTS']['style'] font_path = FONTS[font_family_name][font_style_name] except KeyError: raise LookupError("Couln't find the font & style") return font_path context['font_path'] = get_font_path(context['font_family'], context['font_style']) def get_label_dimensions(label_size): try: ls = label_type_specs[context['label_size']] except KeyError: raise LookupError("Unknown label_size") return ls['dots_printable'] width, height = get_label_dimensions(context['label_size']) if height > width: width, height = height, width if context['orientation'] == 'rotated': height, width = width, height context['width'], context['height'] = width, height return context def create_label_im(text, **kwargs): label_type = kwargs['kind'] im_font = ImageFont.truetype(kwargs['font_path'], kwargs['font_size']) im = Image.new('L', (20, 20), 'white') draw = ImageDraw.Draw(im) # workaround for a bug in multiline_textsize() # when there are empty lines in the text: lines = [] for line in text.split('\n'): if line == '': line = ' ' lines.append(line) text = '\n'.join(lines) linesize = im_font.getsize(text) textsize = draw.multiline_textsize(text, font=im_font) width, height = kwargs['width'], kwargs['height'] if kwargs['orientation'] == 'standard': if label_type in (ENDLESS_LABEL,): height = textsize[1] + kwargs['margin_top'] + kwargs['margin_bottom'] elif kwargs['orientation'] == 'rotated': if label_type in (ENDLESS_LABEL,): width = textsize[0] + kwargs['margin_left'] + kwargs['margin_right'] im = Image.new('L', (width, height), 'white') draw = ImageDraw.Draw(im) if kwargs['orientation'] == 'standard': if label_type in (DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL): vertical_offset = (height - textsize[1])//2 vertical_offset += (kwargs['margin_top'] - kwargs['margin_bottom'])//2 else: vertical_offset = kwargs['margin_top'] horizontal_offset = max((width - textsize[0])//2, 0) elif kwargs['orientation'] == 'rotated': vertical_offset = (height - textsize[1])//2 vertical_offset += (kwargs['margin_top'] - kwargs['margin_bottom'])//2 if label_type in (DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL): horizontal_offset = max((width - textsize[0])//2, 0) else: horizontal_offset = kwargs['margin_left'] offset = horizontal_offset, vertical_offset draw.multiline_text(offset, text, (0), font=im_font, align=kwargs['align']) return im @get('/api/preview/text') @post('/api/preview/text') def get_preview_image(): context = get_label_context(request) im = create_label_im(**context) return_format = request.query.get('return_format', 'png') if return_format == 'base64': import base64 response.set_header('Content-type', 'text/plain') return base64.b64encode(image_to_png_bytes(im)) else: response.set_header('Content-type', 'image/png') return image_to_png_bytes(im) def image_to_png_bytes(im): image_buffer = BytesIO() im.save(image_buffer, format="PNG") image_buffer.seek(0) return image_buffer.read() @post('/api/print/text') @get('/api/print/text') def print_text(): """ API to print a label returns: JSON Ideas for additional URL parameters: - alignment """ return_dict = {'success': False} try: context = get_label_context(request) except LookupError as e: return_dict['message'] = e.msg return return_dict if not context['text'] or context['text'] is None: return_dict['message'] = 'Please provide the text for the label' return return_dict if not context['printer_name'] or context['printer_name'] is None: return_dict['message'] = 'Please select a printer' return return_dict im = create_label_im(**context) if DEBUG: im.save('sample-out.png') if context['kind'] == ENDLESS_LABEL: rotate = 0 if context['orientation'] == 'standard' else 90 elif context['kind'] in (ROUND_DIE_CUT_LABEL, DIE_CUT_LABEL): rotate = 'auto' qlr = BrotherQLRaster(PRINTERS[context['printer_name']]["MODEL"]) create_label(qlr, im, context['label_size'], threshold=context['threshold'], cut=True, rotate=rotate) try: selected_backend = guess_backend(PRINTERS[context['printer_name']]["LOCATION"]) except Exception as e: return_dict['message'] = str(e) return return_dict BACKEND_CLASS = backend_factory(selected_backend)['backend_class'] if not DEBUG: try: be = BACKEND_CLASS(PRINTERS[context['printer_name']]["LOCATION"]) be.write(qlr.data) be.dispose() del be except Exception as e: return_dict['message'] = str(e) logger.warning('Exception happened: %s', e) return return_dict return_dict['success'] = True if DEBUG: return_dict['data'] = str(qlr.data) return return_dict def main(): global DEBUG, FONTS, BACKEND_CLASS, CONFIG parser = argparse.ArgumentParser(description=__doc__) parser.add_argument('--port', default=False) parser.add_argument('--loglevel', type=lambda x: getattr(logging, x.upper()), default=False) parser.add_argument('--font-folder', default=False, help='folder for additional .ttf/.otf fonts') parser.add_argument('--default-label-size', default=False, help='Label size inserted in your printer. Defaults to 62.') parser.add_argument('--default-orientation', default=False, choices=('standard', 'rotated'), help='Label orientation, defaults to "standard". To turn your text by 90 degrees, state "rotated".') parser.add_argument('--model', default=False, choices=models, help='The model of your printer (default: QL-500)') parser.add_argument('printer', nargs='?', default=False, help='String descriptor for the printer to use (like tcp://192.168.0.23:9100 or file:///dev/usb/lp0)') args = parser.parse_args() if args.printer: CONFIG['PRINTERS']['PRINTER'] = args.printer if args.port: PORT = args.port else: PORT = CONFIG['SERVER']['PORT'] if args.loglevel: LOGLEVEL = args.loglevel else: LOGLEVEL = CONFIG['SERVER']['LOGLEVEL'] if LOGLEVEL == 'DEBUG': DEBUG = True else: DEBUG = False if args.model: CONFIG['PRINTERS']['MODEL'] = args.model if args.default_label_size: CONFIG['LABEL']['DEFAULT_SIZE'] = args.default_label_size if args.default_orientation: CONFIG['LABEL']['DEFAULT_ORIENTATION'] = args.default_orientation if args.font_folder: ADDITIONAL_FONT_FOLDER = args.font_folder else: ADDITIONAL_FONT_FOLDER = CONFIG['SERVER']['ADDITIONAL_FONT_FOLDER'] logging.basicConfig(level=LOGLEVEL) if CONFIG['LABEL']['DEFAULT_SIZE'] not in label_sizes: parser.error("Invalid --default-label-size. Please choose on of the following:\n:" + " ".join(label_sizes)) FONTS = get_fonts() if ADDITIONAL_FONT_FOLDER: FONTS.update(get_fonts(ADDITIONAL_FONT_FOLDER)) if not FONTS: sys.stderr.write("Not a single font was found on your system. Please install some or use the \"--font-folder\" argument.\n") sys.exit(2) for font in CONFIG['LABEL']['DEFAULT_FONTS']: try: FONTS[font['family']][font['style']] CONFIG['LABEL']['DEFAULT_FONTS'] = font logger.debug("Selected the following default font: {}".format(font)) break except: pass if CONFIG['LABEL']['DEFAULT_FONTS'] is None: sys.stderr.write('Could not find any of the default fonts. Choosing a random one.\n') family = random.choice(list(FONTS.keys())) style = random.choice(list(FONTS[family].keys())) CONFIG['LABEL']['DEFAULT_FONTS'] = {'family': family, 'style': style} sys.stderr.write('The default font is now set to: {family} ({style})\n'.format(**CONFIG['LABEL']['DEFAULT_FONTS'])) for printer in CONFIG['PRINTERS']: PRINTERS[printer["NAME"]] = printer run(host=CONFIG['SERVER']['HOST'], port=PORT, debug=DEBUG) if __name__ == "__main__": main()