1if not modules then modules = { } end modules ['attr-eff'] = {
2 version = 1.001,
3 comment = "companion to attr-eff.mkiv",
4 author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
5 copyright = "PRAGMA ADE / ConTeXt Development Team",
6 license = "see context related readme files"
7}
8
9local attributes, nodes, backends, utilities = attributes, nodes, backends, utilities
10local tex = tex
11
12local states = attributes.states
13local enableaction = nodes.tasks.enableaction
14local nodeinjections = backends.nodeinjections
15local texsetattribute = tex.setattribute
16local allocate = utilities.storage.allocate
17local setmetatableindex = table.setmetatableindex
18local formatters = string.formatters
19
20local interfaces = interfaces
21local implement = interfaces.implement
22
23local variables = interfaces.variables
24local v_normal = variables.normal
25
26attributes.effects = attributes.effects or { }
27local effects = attributes.effects
28
29local a_effect = attributes.private('effect')
30
31effects.data = allocate()
32effects.values = effects.values or { }
33effects.registered = effects.registered or { }
34effects.attribute = a_effect
35
36local data = effects.data
37local registered = effects.registered
38local values = effects.values
39
40local f_stamp = formatters["%s:%s:%s"]
41
42storage.register("attributes/effects/registered", registered, "attributes.effects.registered")
43storage.register("attributes/effects/values", values, "attributes.effects.values")
44
45
46
47local function effect(...) effect = nodeinjections.effect return effect(...) end
48
49local function extender(effects,key)
50 if key == "none" then
51 local d = effect(0,0,0)
52 effects.none = d
53 return d
54 end
55end
56
57local function reviver(data,n)
58 local e = values[n]
59 local d = effect(e[1],e[2],e[3])
60 data[n] = d
61 return d
62end
63
64setmetatableindex(effects, extender)
65setmetatableindex(effects.data, reviver)
66
67effects.handler = nodes.installattributehandler {
68 name = "effect",
69 namespace = effects,
70 initializer = states.initialize,
71 finalizer = states.finalize,
72 processor = states.process,
73}
74
75local function register(specification)
76 local alternative, stretch, rulethickness
77 if specification then
78 alternative = specification.alternative or v_normal
79 stretch = specification.stretch or 0
80 rulethickness = specification.rulethickness or 0
81 else
82 alternative = v_normal
83 stretch = 0
84 rulethickness = 0
85 end
86 local stamp = f_stamp(alternative,stretch,rulethickness)
87 local n = registered[stamp]
88 if not n then
89 n = #values + 1
90 values[n] = { alternative, stretch, rulethickness }
91 registered[stamp] = n
92 end
93 return n
94end
95
96local enabled = false
97
98local function enable()
99 if not enabled then
100 enableaction("shipouts","attributes.effects.handler")
101 enabled = true
102 end
103end
104
105effects.register = register
106effects.enable = enable
107
108
109
110implement {
111 name = "seteffect",
112 actions = function(specification)
113 if not enabled then
114 enable()
115 end
116 texsetattribute(a_effect,register(specification))
117 end,
118 arguments = {
119 {
120 { "alternative", "string" },
121 { "stretch", "integer" },
122 { "rulethickness", "dimen" }
123 }
124 }
125}
126
127implement {
128 name = "reseteffect",
129 actions = function()
130 if enabled then
131 texsetattribute(a_effect,register())
132 end
133 end
134}
135 |
