1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
module Rubyvis
# Alias for Rubyvis::Line
def self.Line
Rubyvis::Line
end
# Provides methods pertinents to line like marks.
module LinePrototype # :nodoc:
include AreaPrototype
def line_anchor(name)
anchor=area_anchor(name).text_align(lambda {|d|
{'left'=>'right', 'bottom'=>'center', 'top'=>'center', 'center'=>'center','right'=>'left'}[self.name()]
}).text_baseline(lambda{|d|
{'top'=>'bottom', 'right'=>'middle', 'left'=>'middle','center'=>'middle', 'bottom'=>'top'}[self.name()]
})
anchor
end
end
# Represents a series of connected line segments, or <i>polyline</i>,
# that can be stroked with a configurable color and thickness. Each
# articulation point in the line corresponds to a datum; for <i>n</i> points,
# <i>n</i>-1 connected line segments are drawn. The point is positioned using
# the box model. Arbitrary paths are also possible, allowing radar plots and
# other custom visualizations.
#
# <p>Like areas, lines can be stroked and filled with arbitrary colors. In most
# cases, lines are only stroked, but the fill style can be used to construct
# arbitrary polygons.
class Line < Mark
include AreaPrototype
include LinePrototype
@properties=Mark.properties.dup
##
# :attr: line_width
# The width of stroked lines, in pixels; used in conjunction with
# +stroke_style+ to stroke the line.
##
# :attr: stroke_style
# The style of stroked lines; used in conjunction with <tt>lineWidth</tt> to
# stroke the line. The default value of this property is a categorical color.
##
# :attr: line_join
# The type of corners where two lines meet. Accepted values are "bevel",
# "round" and "miter". The default value is "miter".
#
# <p>For segmented lines, only "miter" joins and "linear" interpolation are
# currently supported. Any other value, including nil, will disable joins,
# producing disjoint line segments. Note that the miter joins must be computed
# manually (at least in the current SVG renderer); since this calculation may
# be expensive and unnecessary for small lines, specifying nil can improve
# performance significantly.
#
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
##
# :attr: fill_style
# The line fill style; if non-nil, the interior of the line is closed and
# filled with the specified color. The default value of this property is a
# nil, meaning that lines are not filled by default.
#
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
##
# :attr: segmented
# Whether the line is segmented; whether variations in stroke style, line width and the other properties are treated as fixed. Rendering segmented lines is noticeably slower than non-segmented lines.
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
##
# :attr: stroke_dasharray
# Whether the line is dashed using the strokeDasharray SVG property.
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
##
# :attr: interpolate
# How to interpolate between values. Linear interpolation ("linear") is the
# default, producing a straight line between points. For piecewise constant
# functions (i.e., step functions), either "step-before" or "step-after"
# can be specified. To draw a clockwise circular arc between points,
# specify "polar"; to draw a counterclockwise circular arc between points,
# specify "polar-reverse". To draw open uniform b-splines, specify "basis". # To draw cardinal splines, specify "cardinal"; see also Line.tension()
#
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
##
# :attr: eccentricity
# The eccentricity of polar line segments; used in conjunction with
# interpolate("polar"). The default value of 0 means that line segments are
# drawn as circular arcs. A value of 1 draws a straight line. A value between 0
# and 1 draws an elliptical arc with the given eccentricity.
##
# :attr: tension
# The tension of cardinal splines; used in conjunction with
# interpolate("cardinal"). A value between 0 and 1 draws cardinal splines with
# the given tension. In some sense, the tension can be interpreted as the
# "length" of the tangent; a tension of 1 will yield all zero tangents (i.e.,
# linear interpolation), and a tension of 0 yields a Catmull-Rom spline. The
# default value is 0.7.
#
# <p>This property is <i>fixed</i>. See Rubyvis.Mark
attr_accessor_dsl :line_width, :line_join, [:stroke_style, lambda {|d| Rubyvis.color(d)}], [:fill_style, lambda {|d| Rubyvis.color(d)}], :stroke_dasharray, :segmented, :interpolate, :eccentricity, :tension
# Type of line
def type
"line"
end
# Constructs a new line anchor with default properties. Lines support five
# different anchors:<ul>
#
# <li>top
# <li>left
# <li>center
# <li>bottom
# <li>right
#
# </ul>In addition to positioning properties (left, right, top bottom), the
# anchors support text rendering properties (text-align, text-baseline). Text is
# rendered to appear outside the line. Note that this behavior is different
# from other mark anchors, which default to rendering text <i>inside</i> the
# mark.
#
# <p>For consistency with the other mark types, the anchor positions are
# defined in terms of their opposite edge. For example, the top anchor defines
# the bottom property, such that a bar added to the top anchor grows upward.
def anchor(name)
line_anchor(name)
end
# Reuse Area's implementation for segmented bind & build.
def bind(*args) # :nodoc:
area_bind(*args)
end
# Reuse Area's implementation for segmented bind & build.
def build_instance(*args) # :nodoc:
area_build_instance(*args)
end
# Default properties for lines. By default, there is no fill and the stroke
# style is a categorical color. The default interpolation is linear.
def self.defaults
a=Rubyvis::Colors.category10()
Line.new.mark_extend(Mark.defaults).
line_join('miter').
line_width(1.5).
stroke_style( lambda { a.scale(parent.index)}).
stroke_dasharray('').
interpolate('linear').
eccentricity(0).
tension(0.7)
end
end
end
|
