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
|
if not modules then modules = { } end modules ['attr-eff'] = {
version = 1.001,
comment = "companion to attr-eff.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local attributes, nodes, backends, utilities = attributes, nodes, backends, utilities
local tex = tex
local states = attributes.states
local enableaction = nodes.tasks.enableaction
local nodeinjections = backends.nodeinjections
local texsetattribute = tex.setattribute
local allocate = utilities.storage.allocate
local setmetatableindex = table.setmetatableindex
local interfaces = interfaces
local implement = interfaces.implement
attributes.alternates = attributes.alternates or { }
local alternates = attributes.alternates
local a_alternate = attributes.private('alternate')
alternates.data = allocate()
alternates.values = alternates.values or { }
alternates.registered = alternates.registered or { }
alternates.attribute = a_alternate
local data = alternates.data
local registered = alternates.registered
local values = alternates.values
storage.register("attributes/alternates/registered", registered, "attributes.alternates.registered")
storage.register("attributes/alternates/values", values, "attributes.alternates.values")
local function extender(alternates,key)
if key == "none" then
local d = nodeinjections.stopalternate()
alternates.none = d
return d
end
end
local function reviver(data,n)
local d = values[n] and nodeinjections.startalternate(values[n]) or nodeinjections.stopalternate()
data[n] = d
return d
end
setmetatableindex(alternates, extender)
setmetatableindex(alternates.data, reviver)
alternates.handler = nodes.installattributehandler {
name = "alternate",
namespace = alternates,
initializer = states.initialize,
finalizer = states.finalize,
processor = states.simple,
}
local function register(specification)
local text = specification.text or "unknown"
local n = registered[text]
if not n then
n = #values + 1
values[n] = text
registered[text] = n
end
return n
end
local enabled = false
local function enable()
if not enabled then
enableaction("shipouts","attributes.alternates.handler")
enabled = true
end
end
alternates.register = register
alternates.enable = enable
-- interface
implement {
name = "setalternate",
actions = function(specification)
if not enabled then
enable()
end
texsetattribute(a_alternate,register(specification))
end,
arguments = {
{
{ "text", "string" },
}
}
}
implement {
name = "resetalternate",
actions = function()
if enabled then
texsetattribute(a_alternate)
end
end
}
|