inkstitch/lib/extensions/commands.py

import os
import sys
import inkex
import simpletransform
import cubicsuperpath
from copy import deepcopy
from shapely import geometry as shgeo

from .base import InkstitchExtension
from ..i18n import _
from ..elements import SatinColumn
from ..utils import get_bundled_dir, cache
from ..svg.tags import SVG_DEFS_TAG, SVG_GROUP_TAG, SVG_USE_TAG, SVG_PATH_TAG, INKSCAPE_GROUPMODE, XLINK_HREF, CONNECTION_START, CONNECTION_END, CONNECTOR_TYPE
from ..svg import get_node_transform


class Commands(InkstitchExtension):
    COMMANDS = ["fill_start", "fill_end", "stop", "trim"]

    def __init__(self, *args, **kwargs):
        InkstitchExtension.__init__(self, *args, **kwargs)
        for command in self.COMMANDS:
            self.OptionParser.add_option("--%s" % command, type="inkbool")

    @property
    def symbols_path(self):
        return os.path.join(get_bundled_dir("symbols"), "inkstitch.svg")

    @property
    @cache
    def symbols_svg(self):
        with open(self.symbols_path) as symbols_file:
            return inkex.etree.parse(symbols_file)

    @property
    @cache
    def symbol_defs(self):
        return self.symbols_svg.find(SVG_DEFS_TAG)

    @property
    @cache
    def defs(self):
        return self.document.find(SVG_DEFS_TAG)

    def ensure_symbol(self, command):
        path = "./*[@id='inkstitch_%s']" % command
        if self.defs.find(path) is None:
            self.defs.append(deepcopy(self.symbol_defs.find(path)))

    def get_correction_transform(self, node):
        # if we want to place our new nodes in the same group as this node,
        # then we'll need to factor in the effects of any transforms set on
        # the parents of this node.

        # we can ignore the transform on the node itself since it won't apply
        # to the objects we add
        transform = get_node_transform(node.getparent())

        # now invert it, so that we can position our objects in absolute
        # coordinates
        transform = simpletransform.invertTransform(transform)

        return simpletransform.formatTransform(transform)

    def add_connector(self, symbol, element):
        # I'd like it if I could position the connector endpoint nicely but inkscape just
        # moves it to the element's center immediately after the extension runs.
        start_pos = (symbol.get('x'), symbol.get('y'))
        end_pos = element.shape.centroid

        path = inkex.etree.Element(SVG_PATH_TAG,
            {
                "id": self.uniqueId("connector"),
                "d": "M %s,%s %s,%s" % (start_pos[0], start_pos[1], end_pos.x, end_pos.y),
                "style": "stroke:#000000;stroke-width:1px;fill:none;",
                "transform": self.get_correction_transform(symbol),
                CONNECTION_START: "#%s" % symbol.get('id'),
                CONNECTION_END: "#%s" % element.node.get('id'),
                CONNECTOR_TYPE: "polyline",
            }
        )

        symbol.getparent().insert(symbol.getparent().index(symbol), path)

    def get_command_pos(self, element, index, total):
        # Put command symbols 30 pixels out from the shape, spaced evenly around it.
        outline = element.shape.buffer(30).exterior
        return outline.interpolate(index / float(total), normalized=True)

    def add_command(self, element, commands):
        for i, command in enumerate(commands):
            pos = self.get_command_pos(element, i, len(commands))

            symbol = inkex.etree.SubElement(element.node.getparent(), SVG_USE_TAG,
                {
                    "id": self.uniqueId("use"),
                    XLINK_HREF: "#inkstitch_%s" % command,
                    "height": "100%",
                    "width": "100%",
                    "x": str(pos.x),
                    "y": str(pos.y),
                    "transform": self.get_correction_transform(element.node)
                }
            )

            self.add_connector(symbol, element)

    def effect(self):
        if not self.get_elements():
            return

        if not self.selected:
            inkex.errormsg(_("Please select one or more objects to which to attach commands."))
            return

        self.svg = self.document.getroot()

        commands = [command for command in self.COMMANDS if getattr(self.options, command)]

        if not commands:
            inkex.errormsg(_("Please choose one or more commands to attach."))
            return

        for command in commands:
            self.ensure_symbol(command)

        for element in self.elements:
                self.add_command(element, commands)