1#!/usr/bin/env python
2#coding:utf-8
3# Author:  mozman --<mozman@gmx.at>
4# Purpose: mixins
5# Created: 19.10.2010
6# Copyright (C) 2010, Manfred Moitzi
7# License: MIT License
8
9from svgwrite.utils import strlist
10from svgwrite.utils import is_string
11
12_horiz = {'center': 'xMid', 'left': 'xMin', 'right': 'xMax'}
13_vert  = {'middle': 'YMid', 'top': 'YMin', 'bottom':'YMax'}
14
15class ViewBox(object):
16    """ The **ViewBox** mixin provides the ability to specify that a
17    given set of graphics stretch to fit a particular container element.
18
19    The value of the **viewBox** attribute is a list of four numbers
20    **min-x**, **min-y**, **width** and **height**, separated by whitespace
21    and/or a comma, which specify a rectangle in **user space** which should
22    be mapped to the bounds of the viewport established by the given element,
23    taking into account attribute **preserveAspectRatio**.
24
25    """
26    def viewbox(self, minx=0, miny=0, width=0, height=0):
27        """ Specify a rectangle in **user space** (no units allowed) which
28        should be mapped to the bounds of the viewport established by the
29        given element.
30
31        :param number minx: left border of the viewBox
32        :param number miny: top border of the viewBox
33        :param number width: width of the viewBox
34        :param number height: height of the viewBox
35
36        """
37        self['viewBox'] = strlist( [minx, miny, width, height] )
38
39    def stretch(self):
40        """ Stretch viewBox in x and y direction to fill viewport, does not
41        preserve aspect ratio.
42        """
43        self['preserveAspectRatio'] = 'none'
44
45    def fit(self, horiz="center", vert="middle", scale="meet"):
46        """ Set the **preserveAspectRatio** attribute.
47
48        :param string horiz: horizontal alignment ``'left | center | right'``
49        :param string vert: vertical alignment ``'top | middle | bottom'``
50        :param string scale: scale method ``'meet | slice'``
51
52        ============= =======================================================
53        Scale methods Description
54        ============= =======================================================
55        ``'meet'``    preserve aspect ration and zoom to limits of viewBox
56        ``'slice'``   preserve aspect ration and viewBox touch viewport on
57                      all bounds, viewBox will extend beyond the bounds of
58                      the viewport
59        ============= =======================================================
60
61        """
62        if self.debug and scale not in ('meet', 'slice'):
63            raise ValueError("Invalid scale parameter '%s'" % scale)
64        self['preserveAspectRatio'] = "%s%s %s" % (_horiz[horiz],_vert[vert], scale)
65
66class Transform(object):
67    """ The **Transform** mixin operates on the **transform** attribute.
68    The value of the **transform** attribute is a `<transform-list>`, which
69    is defined as a list of transform definitions, which are applied in the
70    order provided. The individual transform definitions are separated by
71    whitespace and/or a comma. All coordinates are **user
72    space coordinates**.
73
74    """
75    transformname = 'transform'
76    def translate(self, tx, ty=None):
77        """
78        Specifies a translation by **tx** and **ty**. If **ty** is not provided,
79        it is assumed to be zero.
80
81        :param number tx: user coordinate - no units allowed
82        :param number ty: user coordinate - no units allowed
83        """
84        self._add_transformation("translate(%s)" % strlist( [tx, ty] ))
85
86    def rotate(self, angle, center=None):
87        """
88        Specifies a rotation by **angle** degrees about a given point.
89        If optional parameter **center** are not supplied, the rotate is
90        about the origin of the current user coordinate system.
91
92        :param number angle: rotate-angle in degrees
93        :param 2-tuple center: rotate-center as user coordinate - no units allowed
94
95        """
96        self._add_transformation("rotate(%s)" % strlist( [angle, center] ))
97
98    def scale(self, sx, sy=None):
99        """
100        Specifies a scale operation by **sx** and **sy**. If **sy** is not
101        provided, it is assumed to be equal to **sx**.
102
103        :param number sx: scalar factor x-axis, no units allowed
104        :param number sy: scalar factor y-axis, no units allowed
105
106        """
107        self._add_transformation("scale(%s)" % strlist([sx, sy]))
108
109    def skewX(self, angle):
110        """ Specifies a skew transformation along the x-axis.
111
112        :param number angle: skew-angle in degrees, no units allowed
113
114        """
115        self._add_transformation("skewX(%s)" % angle)
116
117    def skewY(self, angle):
118        """ Specifies a skew transformation along the y-axis.
119
120        :param number angle: skew-angle in degrees, no units allowed
121
122        """
123        self._add_transformation("skewY(%s)" % angle)
124
125    def matrix(self, a, b, c, d, e, f):
126        self._add_transformation("matrix(%s)" % strlist( [a, b, c, d, e, f] ))
127
128    def _add_transformation(self, new_transform):
129        old_transform = self.attribs.get(self.transformname, '')
130        self[self.transformname] = ("%s %s" % (old_transform, new_transform)).strip()
131
132
133class XLink(object):
134    """ XLink mixin """
135    def set_href(self, element):
136        """
137        Create a reference to **element**.
138
139        :param element: if element is a `string` its the **id** name of the
140          referenced element, if element is a **BaseElement** class the **id**
141          SVG Attribute is used to create the reference.
142
143        """
144        self.href = element
145        self.update_id()
146
147    def set_xlink(self, title=None, show=None, role=None, arcrole=None):
148        """ Set XLink attributes (for `href` use :meth:`set_href`).
149        """
150        if role is not None:
151            self['xlink:role'] = role
152        if arcrole is not None:
153            self['xlink:arcrole'] = arcrole
154        if title is not None:
155            self['xlink:title'] = title
156        if show is not None:
157            self['xlink:show'] = show
158
159    def update_id(self):
160        if not hasattr(self, 'href'):
161            return
162        if is_string(self.href):
163            idstr = self.href
164        else:
165            idstr = self.href.get_iri()
166        self.attribs['xlink:href'] = idstr
167
168
169class Presentation(object):
170    """
171    Helper methods to set presentation attributes.
172    """
173    def fill(self, color=None, rule=None, opacity=None):
174        """
175        Set SVG Properties **fill**, **fill-rule** and **fill-opacity**.
176
177        """
178        if color is not None:
179            if is_string(color):
180                self['fill'] = color
181            else:
182                self['fill'] = color.get_paint_server()
183        if rule is not None:
184            self['fill-rule'] = rule
185        if opacity is not None:
186            self['fill-opacity'] = opacity
187        return self
188
189    def stroke(self, color=None, width=None, opacity=None, linecap=None,
190               linejoin=None, miterlimit=None):
191        """
192        Set SVG Properties **stroke**, **stroke-width**, **stroke-opacity**,
193        **stroke-linecap** and **stroke-miterlimit**.
194
195        """
196
197        if color is not None:
198            if is_string(color):
199                self['stroke'] = color
200            else:
201                self['stroke'] = color.get_paint_server()
202        if width is not None:
203            self['stroke-width'] = width
204        if opacity is not None:
205            self['stroke-opacity'] = opacity
206        if linecap is not None:
207            self['stroke-linecap'] = linecap
208        if linejoin is not None:
209            self['stroke-linejoin'] = linejoin
210        if miterlimit is not None:
211            self['stroke-miterlimit'] = miterlimit
212        return self
213
214    def dasharray(self, dasharray=None, offset=None):
215        """
216        Set SVG Properties **stroke-dashoffset** and **stroke-dasharray**.
217
218        Where *dasharray* specify the lengths of alternating dashes and gaps as
219        <list> of <int> or <float> values or a <string> of comma and/or white
220        space separated <lengths> or <percentages>. (e.g. as <list> dasharray=[1, 0.5]
221        or as <string> dasharray='1 0.5')
222        """
223        if dasharray is not None:
224            self['stroke-dasharray'] = strlist(dasharray, ' ')
225        if offset is not None:
226            self['stroke-dashoffset'] = offset
227        return self
228
229
230class MediaGroup(object):
231    """
232    Helper methods to set media group attributes.
233
234    """
235
236    def viewport_fill(self, color=None, opacity=None):
237        """
238        Set SVG Properties **viewport-fill** and **viewport-fill-opacity**.
239
240        """
241        if color is not None:
242            self['viewport-fill'] = color
243        if opacity is not None:
244            self['viewport-fill-opacity'] = opacity
245        return self
246
247
248class Markers(object):
249    """
250    Helper methods to set marker attributes.
251
252    """
253    def set_markers(self, markers):
254        """
255        Set markers for line elements (line, polygon, polyline, path) to
256        values specified by  `markers`.
257
258        * if `markers` is a 3-tuple:
259
260          * attribute 'marker-start' = markers[0]
261          * attribute 'marker-mid' = markers[1]
262          * attribute 'marker-end' = markers[2]
263
264        * `markers` is a `string` or a `Marker` class:
265
266          * attribute 'marker' = `FuncIRI` of markers
267
268        """
269        def get_funciri(value):
270            if is_string(value):
271                # strings has to be a valid reference including the '#'
272                return 'url(%s)' % value
273            else:
274                # else create a reference to the object '#id'
275                return 'url(#%s)' % value['id']
276
277        if is_string(markers):
278            self['marker'] = get_funciri(markers)
279        else:
280            try:
281                start_marker, mid_marker, end_marker = markers
282                if start_marker:
283                    self['marker-start'] = get_funciri(start_marker)
284                if mid_marker:
285                    self['marker-mid'] = get_funciri(mid_marker)
286                if end_marker:
287                    self['marker-end'] = get_funciri(end_marker)
288            except (TypeError, KeyError):
289                self['marker'] = get_funciri(markers)
290
291
292class Clipping(object):
293    def clip_rect(self, top='auto', right='auto', bottom='auto', left='auto'):
294        """
295        Set SVG Property **clip**.
296
297        """
298        self['clip'] = "rect(%s,%s,%s,%s)" % (top, right, bottom, left)
299