2016-01-12 16:26:00

1 files changed, 157 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/scrn-hlp.lua b/tex/context/base/mkiv/scrn-hlp.lua
new file mode 100644
index 000000000..99c0565a8
--- /dev/null
+++ b/tex/context/base/mkiv/scrn-hlp.lua
@@ -0,0 +1,157 @@
+if not modules then modules = { } end modules ['scrn-hlp'] = {
+    version   = 1.001,
+    comment   = "companion to scrn-hlp.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local tonumber = tonumber
+
+local help           = { }
+interactions.help    = help
+
+local context        = context
+local implement      = interfaces.implement
+
+local formatters     = string.formatters
+
+local a_help         = attributes.private("help")
+
+local copy_nodelist  = node.copy_list
+local hpack_nodelist = node.hpack
+
+local register_list  = nodes.pool.register
+
+local texgetbox      = tex.getbox
+
+local nodecodes      = nodes.nodecodes
+
+local hlist_code     = nodecodes.hlist
+local vlist_code     = nodecodes.vlist
+
+local data, references = { }, { }
+
+local helpscript = [[
+    function Hide_All_Help(prefix) {
+        var n = 0
+        while (true) {
+            n += 1 ;
+            v = this.getField(prefix + n) ;
+            if (v) {
+                v.hidden = true ;
+                this.dirty = false ;
+            } else {
+                return ;
+            }
+        }
+    }
+]]
+
+local template = "javascript(Hide_All_Help{help:}),action(show{help:%s})"
+
+local function register(specification)
+    local number = specification.number
+    local name   = specification.name
+    local box    = specification.box
+    if number and name and box then
+        if helpscript then
+            interactions.javascripts.setpreamble("HelpTexts",helpscript)
+            helpscript = false
+        end
+        local b = copy_nodelist(texgetbox(box))
+        register_list(b)
+        data[number] = b
+        if name and name ~= "" then
+            references[name] = number
+            structures.references.define("",name,formatters[template](number))
+        end
+    end
+end
+
+local function collectused(head,used)
+    while head do
+        local id = head.id
+        if id == hlist_code then
+            local a = head[a_help]
+            if a then
+                if not used then
+                    used = { a }
+                else
+                    used[#used+1] = a
+                end
+            else
+                used = collectused(head.list,used)
+            end
+        elseif id == vlist_code then
+            used = collectused(head.list,used)
+        end
+        head = head.next
+    end
+    return used
+end
+
+local function collect(box)
+    if next(data) then
+        return collectused(texgetbox(box).list)
+    end
+end
+
+local function reference(name)
+    return references[name] or tonumber(name) or 0
+end
+
+help.register  = register
+help.collect   = collect
+help.reference = reference
+
+implement {
+    name    = "registerhelp",
+    actions = register,
+    arguments = {
+        {
+            { "number", "integer" },
+            { "name" },
+            { "box" , "integer" }
+        }
+    }
+}
+
+implement {
+    name      = "collecthelp",
+    arguments = "integer",
+    actions   = function(box)
+        local used = collect(box)
+        if used then
+            local done = { }
+            context.startoverlay()
+            for i=1,#used do
+                local d = data[used[i]]
+                if d and not done[d] then
+                    local box = hpack_nodelist(copy_nodelist(d))
+                    context(false,box)
+                    done[d] = true
+                else
+                    -- error
+                end
+            end
+            context.stopoverlay()
+        end
+    end
+}
+
+implement {
+    name      = "helpreference",
+    arguments = "string",
+    actions   = function(name)
+        context(reference(name))
+    end
+}
+
+implement {
+    name      = "helpaction",
+    arguments = "string",
+    actions   = function(name)
+        context(template,reference(name))
+    end
+}