importsvg

src/c3nav/mapdata/management/commands/importsvg.py

@@ -0,0 +1,182 @@
+import argparse
+import logging
+import re
+from xml.etree import ElementTree
+
+from django.core.management.base import BaseCommand, CommandError
+from django.utils.translation import ugettext_lazy as _
+from shapely.affinity import scale, translate
+from shapely.geometry import Polygon
+
+from c3nav.mapdata.models import Area, MapUpdate, Obstacle, Space
+from c3nav.mapdata.utils.cache.changes import changed_geometries
+
+
+class Command(BaseCommand):
+    help = 'render the map'
+
+    @staticmethod
+    def space_value(value):
+        try:
+            space = Space.objects.get(pk=value)
+        except Space.DoesNotExist:
+            raise argparse.ArgumentTypeError(
+                _('unknown space')
+            )
+        return space
+
+    def add_arguments(self, parser):
+        parser.add_argument('svgfile', type=argparse.FileType('r'), help=_('svg file to import'))
+        parser.add_argument('name', type=str, help=_('name of the import'))
+        parser.add_argument('--type', type=str, required=True, choices=('areas', 'obstacles'),
+                            help=_('type of objects to create'))
+        parser.add_argument('--space', type=self.space_value, required=True,
+                            help=_('space to add the objects to'))
+        parser.add_argument('--minx', type=float, required=True,
+                            help=_('minimum x coordinate, everthing left of it will be cropped'))
+        parser.add_argument('--miny', type=float, required=True,
+                            help=_('minimum y coordinate, everthing below it will be cropped'))
+        parser.add_argument('--maxx', type=float, required=True,
+                            help=_('maximum x coordinate, everthing right of it will be cropped'))
+        parser.add_argument('--maxy', type=float, required=True,
+                            help=_('maximum y coordinate, everthing above it will be cropped'))
+
+    @staticmethod
+    def parse_svg_data(data):
+        first = False
+
+        last_point = (0, 0)
+        last_end_point = None
+
+        done_subpaths = []
+        current_subpath = []
+        while data:
+            data = data.lstrip().replace(',', ' ')
+            command = data[0]
+            if first and command not in 'Mm':
+                raise ValueError('path data has to start with moveto command.')
+            data = data[1:].lstrip()
+            first = False
+
+            numbers = []
+            while True:
+                match = re.match('^-?[0-9]+(\.[0-9]+)?(e-?[0-9]+)?', data)
+                if match is None:
+                    break
+                numbers.append(float(match.group(0)))
+                data = data[len(match.group(0)):].lstrip()
+
+            relative = command.islower()
+            if command in 'Mm':
+                if not len(numbers) or len(numbers) % 2:
+                    raise ValueError('Invalid number of arguments for moveto command!')
+                numbers = iter(numbers)
+                first = True
+                for x, y in zip(numbers, numbers):
+                    if relative:
+                        x, y = last_point[0] + x, last_point[1] + y
+                    if first:
+                        first = False
+                        if current_subpath:
+                            done_subpaths.append(current_subpath)
+                            last_end_point = current_subpath[-1]
+                            current_subpath = []
+                    current_subpath.append((x, y))
+                    last_point = (x, y)
+
+            elif command in 'Ll':
+                if not len(numbers) or len(numbers) % 2:
+                    raise ValueError('Invalid number of arguments for lineto command!')
+                numbers = iter(numbers)
+                for x, y in zip(numbers, numbers):
+                    if relative:
+                        x, y = last_point[0] + x, last_point[1] + y
+                    if not current_subpath:
+                        current_subpath.append(last_end_point)
+                    current_subpath.append((x, y))
+                    last_point = (x, y)
+
+            elif command in 'Hh':
+                if not len(numbers):
+                    raise ValueError('Invalid number of arguments for horizontal lineto command!')
+                y = last_point[1]
+                for x in numbers:
+                    if relative:
+                        x = last_point[0] + x
+                    if not current_subpath:
+                        current_subpath.append(last_end_point)
+                    current_subpath.append((x, y))
+                    last_point = (x, y)
+
+            elif command in 'Vv':
+                if not len(numbers):
+                    raise ValueError('Invalid number of arguments for vertical lineto command!')
+                x = last_point[0]
+                for y in numbers:
+                    if relative:
+                        y = last_point[1] + y
+                    if not current_subpath:
+                        current_subpath.append(last_end_point)
+                    current_subpath.append((x, y))
+                    last_point = (x, y)
+
+            elif command in 'Zz':
+                if numbers:
+                    raise ValueError('Invalid number of arguments for closepath command!')
+                current_subpath.append(current_subpath[0])
+                done_subpaths.append(current_subpath)
+                last_end_point = current_subpath[-1]
+                current_subpath = []
+
+            else:
+                raise ValueError('unknown svg command: ' + command)
+
+        if current_subpath:
+            done_subpaths.append(current_subpath)
+        return done_subpaths
+
+    def handle(self, *args, **options):
+        minx = options['minx']
+        miny = options['miny']
+        maxx = options['maxx']
+        maxy = options['maxy']
+
+        if minx >= maxx:
+            raise CommandError(_('minx has to be lower than maxx'))
+        if miny >= maxy:
+            raise CommandError(_('miny has to be lower than maxy'))
+
+        width = maxx-minx
+        height = maxy-miny
+
+        model = {'areas': Area, 'obstacles': Obstacle}[options['type']]
+
+        namespaces = {'svg': 'http://www.w3.org/2000/svg'}
+
+        svg = ElementTree.fromstring(options['svgfile'].read())
+        svg_width = float(svg.attrib['width'])
+        svg_height = float(svg.attrib['height'])
+
+        for element in svg.findall('.//svg:clipPath/..', namespaces):
+            for clippath in element.findall('./svg:clipPath', namespaces):
+                element.remove(clippath)
+
+        if svg.findall('.//*[@transform]'):
+            raise CommandError(_('svg contains transform attributes. Use inkscape apply transforms!'))
+
+        with MapUpdate.lock():
+            changed_geometries.reset()
+            for path in svg.findall('.//svg:path', namespaces):
+                for polygon in self.parse_svg_data(path.attrib['d']):
+                    polygon = Polygon(polygon)
+                    polygon = scale(polygon, xfact=width / svg_width, yfact=height / svg_height, origin=(0, 0))
+                    polygon = translate(polygon, xoff=minx, yoff=miny)
+                    obj = model(geometry=polygon, space=options['space'], import_tag=options['name'])
+                    obj.save()
+            MapUpdate.objects.create(type='importsvg')
+
+        logger = logging.getLogger('c3nav')
+        logger.info('Imported, map update created.')
+        logger.info('Next step: go into the shell and edit them using '
+                    '%s.objects.filter(space_id=%r, import_tag=%r)' %
+                    (model.__name__, options['space'].pk, options['name']))