# -*- encoding: utf-8 -*-
#
#
# Copyright (C) 2002-2012, 2022, 2025 Jörg Lehmann <joerg@pyx-project.org>
# Copyright (C) 2003-2011 Michael Schindler <m-schindler@users.sourceforge.net>
# Copyright (C) 2002-2012, 2022, 2024, 2025 André Wobst <wobsta@pyx-project.org>
#
# This file is part of PyX (https://pyx-project.org/).
#
# PyX is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PyX is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with PyX; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

import functools, logging, math
from pyx import attr, unit, text, utils
from pyx.graph.axis import painter, parter, positioner, rater, texter, tick

logger = logging.getLogger("pyx")
class _marker: pass


class axisdata:
    """axis data storage class

    Instances of this class are used to store axis data local to the
    graph. It will always contain an axispos instance provided by the
    graph during initialization."""

    def __init__(self, **kwargs):
        for key, value in list(kwargs.items()):
            setattr(self, key, value)


class _axis:
    """axis"""

    def createlinked(self, data, positioner, graphtextengine, errorname, linkpainter):
        canvas = painter.axiscanvas(self.painter, graphtextengine)
        if linkpainter is not None:
            linkpainter.paint(canvas, data, self, positioner)
        return canvas


class NoValidPartitionError(RuntimeError):

    pass


class _regularaxis(_axis):
    """base implementation a regular axis

    Regular axis have a continuous variable like linear axes,
    logarithmic axes, time axes etc."""

    def __init__(self, min=None, max=None, reverse=0, divisor=None, title=None,
                       painter=painter.regular(), texter=texter.default(), linkpainter=painter.linked(),
                       maxworse=2, manualticks=[], fallbackrange=None, **kwargs):

        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["painter", "texter", "linkpainter"])
        if rest_kwargs:
            raise ValueError("Invalid split kwargs: %s" % rest_kwargs)

        if "painter" in split_kwargs: painter = painter(**split_kwargs["painter"])
        if "texter" in split_kwargs: texter = texter(**split_kwargs["texter"])
        if "linkpainter" in split_kwargs: linkpainter = linkpainter(**split_kwargs["linkpainter"])

        if min is not None and max is not None and min > max:
            min, max, reverse = max, min, not reverse
        self.min = min
        self.max = max
        self.reverse = reverse
        self.divisor = divisor
        self.title = title
        self.painter = painter
        self.texter = texter
        self.linkpainter = linkpainter
        self.maxworse = maxworse
        self.manualticks = self.checkfraclist(manualticks)
        self.fallbackrange = fallbackrange

    def createdata(self, errorname):
        return axisdata(min=self.min, max=self.max)

    zero = 0.0

    def adjustaxis(self, data, columndata, graphtextengine, errorname):
        if self.min is None or self.max is None:
            for value in columndata:
                try:
                    value = value + self.zero
                except Exception:
                    pass
                else:
                    if self.min is None and (data.min is None or value < data.min):
                        data.min = value
                    if self.max is None and (data.max is None or value > data.max):
                        data.max = value

    def checkfraclist(self, fracs):
        "orders a list of fracs, equal entries are not allowed"
        if not len(fracs): return []
        sorted = list(fracs)
        sorted.sort()
        last = sorted[0]
        for item in sorted[1:]:
            if last == item:
                raise ValueError("duplicate entry found")
            last = item
        return sorted

    def _create(self, data, positioner, graphtextengine, parter, rater, errorname):
        errorname = " for axis %s" % errorname
        if data.min is None or data.max is None:
            raise RuntimeError("incomplete axis range%s" % errorname)
        if data.max == data.min:
            if self.fallbackrange is not None:
                try:
                    data.min, data.max = data.min - 0.5*self.fallbackrange, data.min + 0.5*self.fallbackrange
                except TypeError:
                    data.min, data.max = self.fallbackrange[0], self.fallbackrange[1]
            else:
                raise RuntimeError("zero axis range%s" % errorname)

        if self.divisor is not None:
            rational_divisor = tick.rational(self.divisor)
            convert_tick = lambda x: float(x)*self.divisor
        else:
            convert_tick = lambda x: x

        def layout(data):
            if data.ticks:
                self.adjustaxis(data, [convert_tick(data.ticks[0]), convert_tick(data.ticks[-1])], graphtextengine, errorname)
            self.texter.labels(data.ticks)
            if self.divisor:
                for t in data.ticks:
                    t *= rational_divisor
            canvas = painter.axiscanvas(self.painter, graphtextengine)
            if self.painter is not None:
                self.painter.paint(canvas, data, self, positioner)
            return canvas

        if parter is None:
            data.ticks = self.manualticks
            return layout(data)

        # a variant is a data copy with local modifications to test several partitions
        @functools.total_ordering
        class variant:
            def __init__(self, data, **kwargs):
                self.data = data
                for key, value in list(kwargs.items()):
                    setattr(self, key, value)

            def __getattr__(self, key):
                return getattr(data, key)

            def __lt__(self, other):
                # we can also sort variants by their rate
                return self.rate < other.rate

            def __eq__(self, other):
                # we can also sort variants by their rate
                return self.rate == other.rate

        # build a list of variants
        bestrate = None
        if self.divisor is not None:
            if data.min is not None:
                data_min_divided = data.min/self.divisor
            else:
                data_min_divided = None
            if data.max is not None:
                data_max_divided = data.max/self.divisor
            else:
                data_max_divided = None
            partfunctions = parter.partfunctions(data_min_divided, data_max_divided,
                                                 self.min is None, self.max is None)
        else:
            partfunctions = parter.partfunctions(data.min, data.max,
                                                 self.min is None, self.max is None)
        variants = []
        for partfunction in partfunctions:
            worse = 0
            while worse < self.maxworse:
                worse += 1
                ticks = partfunction()
                if ticks is None:
                    break
                ticks = tick.mergeticklists(self.manualticks, ticks, mergeequal=0)
                if ticks:
                    rate = rater.rateticks(self, ticks)
                    if rate is not None:
                        if self.reverse:
                            rate += rater.raterange(self.convert(data, convert_tick(ticks[0])) -
                                                    self.convert(data, convert_tick(ticks[-1])), 1)
                        else:
                            rate += rater.raterange(self.convert(data, convert_tick(ticks[-1])) -
                                                    self.convert(data, convert_tick(ticks[0])), 1)
                        if bestrate is None or rate < bestrate:
                            bestrate = rate
                            worse = 0
                        variants.append(variant(data, rate=rate, ticks=ticks))

        if not variants:
            raise RuntimeError("no axis partitioning found%s" % errorname)

        if len(variants) == 1 or self.painter is None:
            # When the painter is None, we could sort the variants here by their rating.
            # However, we didn't did this so far and there is no real reason to change that.
            data.ticks = variants[0].ticks
            return layout(data)

        # build the layout for best variants
        for variant in variants:
            variant.storedcanvas = None
        variants.sort()
        while not variants[0].storedcanvas:
            variants[0].storedcanvas = layout(variants[0])
            ratelayout = rater.ratelayout(variants[0].storedcanvas)
            if ratelayout is None:
                del variants[0]
                if not variants:
                    raise NoValidPartitionError("no valid axis partitioning found%s" % errorname)
            else:
                variants[0].rate += ratelayout
            variants.sort()
        self.adjustaxis(data, variants[0].ticks, graphtextengine, errorname)
        data.ticks = variants[0].ticks
        return variants[0].storedcanvas


class linear(_regularaxis):
    """linear axis"""

    def __init__(self, parter=parter.autolinear(), rater=rater.linear(), density=None, **kwargs):
        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["parter", "rater"])

        _regularaxis.__init__(self, **rest_kwargs)

        if "parter" in split_kwargs: parter = parter(**split_kwargs["parter"])
        if "rater" in split_kwargs or density:
            rater_kwargs = split_kwargs.get("rater", {})
            if density:
                if "density" in rater_kwargs:
                    raise ValueError("duplicate density in rater and depricated setting")
                logger.warning("density should be passed to rater instead of axis")
                rater_kwargs["density"] = density
            rater = rater(**rater_kwargs)

        self.parter = parter
        self.rater = rater
        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return linear(**utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["parter", "rater"]))

    def convert(self, data, value):
        """axis coordinates -> graph coordinates"""
        if self.reverse:
            return (data.max - float(value)) / (data.max - data.min)
        else:
            return (float(value) - data.min) / (data.max - data.min)

    def create(self, data, positioner, graphtextengine, errorname):
        return _regularaxis._create(self, data, positioner, graphtextengine, self.parter, self.rater, errorname)

lin = linear


class logarithmic(_regularaxis):
    """logarithmic axis"""

    def __init__(self, parter=parter.autologarithmic(), rater=rater.logarithmic(),
                       linearparter=parter.autolinear(extendtick=None), density=None, **kwargs):
        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["parter", "rater", "linearparter"])

        _regularaxis.__init__(self, **rest_kwargs)

        if "parter" in split_kwargs: parter = parter(**split_kwargs["parter"])
        if "rater" in split_kwargs or density:
            rater_kwargs = split_kwargs.get("rater", {})
            if density:
                if "density" in rater_kwargs:
                    raise ValueError("duplicate density in rater and depricated setting")
                logger.warning("density should be passed to rater instead of axis")
                rater_kwargs["density"] = density
            rater = rater(**rater_kwargs)
        if "linearparter" in split_kwargs: linearparter = linearparter(**split_kwargs["linearparter"])

        self.parter = parter
        self.rater = rater
        self.linearparter = linearparter
        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return linear(**utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["parter", "rater", "linearparter"]))

    def convert(self, data, value):
        """axis coordinates -> graph coordinates"""
        # TODO: store log(data.min) and log(data.max)
        if data.max < 0:
            if self.reverse:
                return (math.log(-data.max) - math.log(-float(value))) / (math.log(-data.max) - math.log(-data.min))
            else:
                return (math.log(-float(value)) - math.log(-data.min)) / (math.log(-data.max) - math.log(-data.min))
        else:
            if self.reverse:
                return (math.log(data.max) - math.log(float(value))) / (math.log(data.max) - math.log(data.min))
            else:
                return (math.log(float(value)) - math.log(data.min)) / (math.log(data.max) - math.log(data.min))

    def create(self, data, positioner, graphtextengine, errorname):
        try:
            return _regularaxis._create(self, data, positioner, graphtextengine, self.parter, self.rater, errorname)
        except NoValidPartitionError:
            if self.linearparter:
                logger.warning("no valid logarithmic partitioning found for axis %s, switch to linear partitioning" % errorname)
                return _regularaxis._create(self, data, positioner, graphtextengine, self.linearparter, self.rater, errorname)
            raise

log = logarithmic


class subaxispositioner(positioner._positioner):
    """a subaxis positioner"""

    def __init__(self, basepositioner, subaxis):
        self.basepositioner = basepositioner
        self.vmin = subaxis.vmin
        self.vmax = subaxis.vmax
        self.vminover = subaxis.vminover
        self.vmaxover = subaxis.vmaxover

    def vbasepath(self, v1=None, v2=None):
        if v1 is not None:
            v1 = self.vmin+v1*(self.vmax-self.vmin)
        else:
            v1 = self.vminover
        if v2 is not None:
            v2 = self.vmin+v2*(self.vmax-self.vmin)
        else:
            v2 = self.vmaxover
        return self.basepositioner.vbasepath(v1, v2)

    def vgridpath(self, v):
        return self.basepositioner.vgridpath(self.vmin+v*(self.vmax-self.vmin))

    def vtickpoint_pt(self, v, axis=None):
        return self.basepositioner.vtickpoint_pt(self.vmin+v*(self.vmax-self.vmin))

    def vtickdirection(self, v, axis=None):
        return self.basepositioner.vtickdirection(self.vmin+v*(self.vmax-self.vmin))


class bar(_axis):

    def __init__(self, subaxes=None, defaultsubaxis=linear(painter=None, linkpainter=None, parter=None),
                       dist=0.5, firstdist=None, lastdist=None, title=None, reverse=0, epsilon=1e-10,
                       painter=painter.bar(), linkpainter=painter.linkedbar(), **kwargs):
        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["defaultsubaxis", "painter", "linkpainter"], allow_only_split=True)

        if "defaultsubaxis" in split_kwargs: defaultsubaxis = linear(**split_kwargs["defaultsubaxis"])
        if "painter" in split_kwargs: painter = painter.bar(**split_kwargs["painter"])
        if "linkpainter" in split_kwargs: linkpainter = painter.linkedbar(**split_kwargs["linkpainter"])

        self.subaxes = subaxes
        self.defaultsubaxis = defaultsubaxis
        self.dist = dist
        if firstdist is not None:
            self.firstdist = firstdist
        else:
            self.firstdist = 0.5 * dist
        if lastdist is not None:
            self.lastdist = lastdist
        else:
            self.lastdist = 0.5 * dist
        self.title = title
        self.reverse = reverse
        self.painter = painter
        self.linkpainter = linkpainter
        self.epsilon = epsilon
        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return bar(**utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["defaultsubaxis", "painter", "linkpainter"]))

    def createdata(self, errorname):
        data = axisdata(size=self.firstdist+self.lastdist-self.dist, subaxes={}, names=[])
        return data

    def addsubaxis(self, data, name, subaxis, graphtextengine, errorname):
        subaxis = anchoredaxis(subaxis, graphtextengine, "%s, subaxis %s" % (errorname, name))
        subaxis.setcreatecall(lambda: None)
        subaxis.sized = hasattr(subaxis.data, "size")
        if subaxis.sized:
            data.size += subaxis.data.size
        else:
            data.size += 1
        data.size += self.dist
        data.subaxes[name] = subaxis
        if self.reverse:
            data.names.insert(0, name)
        else:
            data.names.append(name)

    def adjustaxis(self, data, columndata, graphtextengine, errorname):
        for value in columndata:

            # some checks and error messages
            try:
                len(value)
            except Exception:
                raise ValueError("tuple expected by bar axis '%s'" % errorname)
            try:
                value + ""
            except Exception:
                pass
            else:
                raise ValueError("tuple expected by bar axis '%s'" % errorname)
            assert len(value) == 2, "tuple of size two expected by bar axis '%s'" % errorname

            name = value[0]
            if name is not None and name not in data.names:
                if self.subaxes:
                    if self.subaxes[name] is not None:
                        self.addsubaxis(data, name, self.subaxes[name], graphtextengine, errorname)
                else:
                    self.addsubaxis(data, name, self.defaultsubaxis, graphtextengine, errorname)
        for name in data.names:
            subaxis = data.subaxes[name]
            if subaxis.sized:
                data.size -= subaxis.data.size
            subaxis.axis.adjustaxis(subaxis.data,
                                    [value[1] for value in columndata if value[0] == name],
                                    graphtextengine,
                                    "%s, subaxis %s" % (errorname, name))
            if subaxis.sized:
                data.size += subaxis.data.size

    def convert(self, data, value):
        if value[0] is None:
            raise ValueError
        subaxis = data.subaxes[value[0]]
        subvalue = subaxis.convert(value[1])
        if (self.epsilon is not None) and not (-self.epsilon < subvalue < 1+self.epsilon):
            raise ValueError
        return subaxis.vmin + subvalue * (subaxis.vmax - subaxis.vmin)

    def create(self, data, positioner, graphtextengine, errorname):
        canvas = painter.axiscanvas(self.painter, graphtextengine)
        v = 0
        position = self.firstdist
        for name in data.names:
            subaxis = data.subaxes[name]
            subaxis.vmin = position / float(data.size)
            if subaxis.sized:
                position += subaxis.data.size
            else:
                position += 1
            subaxis.vmax = position / float(data.size)
            position += 0.5*self.dist
            subaxis.vminover = v
            if name == data.names[-1]:
                subaxis.vmaxover = 1
            else:
                subaxis.vmaxover = position / float(data.size)
            subaxis.setpositioner(subaxispositioner(positioner, subaxis))
            subaxis.create()
            for layer, subcanvas in list(subaxis.canvas.layers.items()):
                canvas.layer(layer).insert(subcanvas)
            assert len(subaxis.canvas.layers) == len(subaxis.canvas.items)
            if canvas.extent_pt < subaxis.canvas.extent_pt:
                canvas.extent_pt = subaxis.canvas.extent_pt
            position += 0.5*self.dist
            v = subaxis.vmaxover
        if self.painter is not None:
            self.painter.paint(canvas, data, self, positioner)
        return canvas

    def createlinked(self, data, positioner, graphtextengine, errorname, linkpainter):
        canvas = painter.axiscanvas(self.painter, graphtextengine)
        for name in data.names:
            subaxis = data.subaxes[name]
            subaxis = linkedaxis(subaxis, name)
            subaxis.setpositioner(subaxispositioner(positioner, data.subaxes[name]))
            subaxis.create()
            for layer, subcanvas in list(subaxis.canvas.layers.items()):
                canvas.layer(layer).insert(subcanvas)
            assert len(subaxis.canvas.layers) == len(subaxis.canvas.items)
            if canvas.extent_pt < subaxis.canvas.extent_pt:
                canvas.extent_pt = subaxis.canvas.extent_pt
        if linkpainter is not None:
            linkpainter.paint(canvas, data, self, positioner)
        return canvas


class nestedbar(bar):

    def __init__(self, defaultsubaxis=bar(dist=0, painter=None, linkpainter=None), **kwargs):
        bar.__init__(self, defaultsubaxis=defaultsubaxis, **kwargs)


class split(bar):

    def __init__(self, defaultsubaxis=linear(),
                       firstdist=0, lastdist=0,
                       painter=painter.split(), linkpainter=painter.linkedsplit(), **kwargs):
        bar.__init__(self, defaultsubaxis=defaultsubaxis,
                           firstdist=firstdist, lastdist=lastdist,
                           painter=painter, linkpainter=linkpainter, **kwargs)


class sizedlinear(linear):

    def __init__(self, size=1, **kwargs):
        linear.__init__(self, **kwargs)
        self.size = size
        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return sizedlinear(**utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["size"]))

    def createdata(self, errorname):
        data = linear.createdata(self, errorname)
        data.size = self.size
        return data

sizedlin = sizedlinear


class autosizedlinear(linear):

    def __init__(self, parter=parter.autolinear(extendtick=None), **kwargs):
        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["parter"])
        if "parter" in split_kwargs: parter = parter.autolinear(**split_kwargs["parter"])

        linear.__init__(self, parter=parter, **rest_kwargs)

        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return autosizedlinear(**utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["parter"]))

    def createdata(self, errorname):
        data = linear.createdata(self, errorname)
        try:
            data.size = data.max - data.min
        except Exception:
            data.size = 0
        return data

    def adjustaxis(self, data, columndata, graphtextengine, errorname):
        linear.adjustaxis(self, data, columndata, graphtextengine, errorname)
        try:
            data.size = data.max - data.min
        except Exception:
            data.size = 0

    def create(self, data, positioner, graphtextengine, errorname):
        min = data.min
        max = data.max
        canvas = linear.create(self, data, positioner, graphtextengine, errorname)
        if min != data.min or max != data.max:
            raise RuntimeError("range change during axis creation of autosized linear axis")
        return canvas

autosizedlin = autosizedlinear


class anchoredaxis:

    def __init__(self, axis, graphtextengine, errorname):
        assert not isinstance(axis, anchoredaxis), errorname
        self.axis = axis
        self.errorname = errorname
        self.graphtextengine = graphtextengine
        self.data = axis.createdata(self.errorname)
        self.canvas = None
        self.positioner = None

    def setcreatecall(self, function, *args, **kwargs):
        self._createfunction = function
        self._createargs = args
        self._createkwargs = kwargs

    def docreate(self):
        if not self.canvas:
            self._createfunction(*self._createargs, **self._createkwargs)

    def setpositioner(self, positioner):
        assert positioner is not None, self.errorname
        assert self.positioner is None, self.errorname
        self.positioner = positioner

    def convert(self, x):
        self.docreate()
        return self.axis.convert(self.data, x)

    def adjustaxis(self, columndata):
        if self.canvas is None:
            self.axis.adjustaxis(self.data, columndata, self.graphtextengine, self.errorname)
        else:
            logger.warning("ignore axis range adjustment of already created axis '%s'"  % self.errorname)

    def vbasepath(self, v1=None, v2=None):
        return self.positioner.vbasepath(v1=v1, v2=v2)

    def basepath(self, x1=None, x2=None):
        self.docreate()
        if x1 is None:
            if x2 is None:
                return self.positioner.vbasepath()
            else:
                return self.positioner.vbasepath(v2=self.axis.convert(self.data, x2))
        else:
            if x2 is None:
                return self.positioner.vbasepath(v1=self.axis.convert(self.data, x1))
            else:
                return self.positioner.vbasepath(v1=self.axis.convert(self.data, x1),
                                                 v2=self.axis.convert(self.data, x2))

    def vgridpath(self, v):
        return self.positioner.vgridpath(v)

    def gridpath(self, x):
        self.docreate()
        return self.positioner.vgridpath(self.axis.convert(self.data, x))

    def vtickpoint_pt(self, v):
        return self.positioner.vtickpoint_pt(v)

    def vtickpoint(self, v):
        return self.positioner.vtickpoint_pt(v) * unit.t_pt

    def tickpoint_pt(self, x):
        self.docreate()
        return self.positioner.vtickpoint_pt(self.axis.convert(self.data, x))

    def tickpoint(self, x):
        self.docreate()
        x_pt, y_pt = self.positioner.vtickpoint_pt(self.axis.convert(self.data, x))
        return  x_pt * unit.t_pt, y_pt * unit.t_pt

    def vtickdirection(self, v):
        return self.positioner.vtickdirection(v)

    def tickdirection(self, x):
        self.docreate()
        return self.positioner.vtickdirection(self.axis.convert(self.data, x))

    def create(self):
        if self.canvas is None:
            assert self.positioner is not None, self.errorname
            self.canvas = self.axis.create(self.data, self.positioner, self.graphtextengine, self.errorname)
        return self.canvas


class linkedaxis(anchoredaxis):

    def __init__(self, linkedaxis=None, errorname="manual-linked", painter=_marker, **kwargs):
        split_kwargs, rest_kwargs = utils.kwsplit(kwargs, ["painter"])
        if rest_kwargs:
            raise ValueError("Unknown kwargs '%s' to linkedaxis" % rest_kwargs)
        if "painter" in split_kwargs: painter = painter(**split_kwargs["painter"])
        self.painter = painter
        self.linkedto = None
        self.errorname = errorname
        self.canvas = None
        self.positioner = None
        if linkedaxis:
            self.setlinkedaxis(linkedaxis)
        self.kwargs = kwargs

    def __call__(self, **kwargs):
        return linkedaxis(linkedaxis=self.linkedto, errorname=self.errorname, **utils.merge_members_kwargs(self, [self.kwargs, kwargs], ["painter"]))

    def setlinkedaxis(self, linkedaxis):
        assert isinstance(linkedaxis, anchoredaxis), self.errorname
        self.linkedto = linkedaxis
        self.axis = linkedaxis.axis
        self.graphtextengine = self.linkedto.graphtextengine
        self.errorname = "%s (linked to %s)" % (self.errorname, linkedaxis.errorname)
        self.data = linkedaxis.data
        if self.painter is _marker:
            self.painter = linkedaxis.axis.linkpainter

    def create(self):
        assert self.linkedto is not None, self.errorname
        assert self.positioner is not None, self.errorname
        if self.canvas is None:
            self.linkedto.docreate()
            self.canvas = self.axis.createlinked(self.data, self.positioner, self.graphtextengine, self.errorname, self.painter)
        return self.canvas


class anchoredpathaxis(anchoredaxis):
    """an anchored axis along a path"""

    def __init__(self, path, axis, **kwargs):
        anchoredaxis.__init__(self, axis, text.defaulttextengine, "pathaxis")
        self.setpositioner(positioner.pathpositioner(path, **kwargs))
        self.create()

def pathaxis(*args, **kwargs):
    """creates an axiscanvas for an axis along a path"""
    return anchoredpathaxis(*args, **kwargs).canvas

