2016-01-12 16:26:00

1 files changed, 115 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/trac-jus.lua b/tex/context/base/mkiv/trac-jus.lua
new file mode 100644
index 000000000..ad1a098e2
--- /dev/null
+++ b/tex/context/base/mkiv/trac-jus.lua
@@ -0,0 +1,115 @@
+if not modules then modules = { } end modules ['trac-jus'] = {
+    version   = 1.001,
+    comment   = "companion to trac-jus.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local checkers            = typesetters.checkers or { }
+typesetters.checkers      = checkers
+
+----- report_justification = logs.reporter("visualize","justification")
+
+local a_alignstate        = attributes.private("alignstate")
+local a_justification     = attributes.private("justification")
+
+local nuts                = nodes.nuts
+local tonut               = nuts.tonut
+
+local getfield            = nuts.getfield
+local setfield            = nuts.setfield
+local getlist             = nuts.getlist
+local getattr             = nuts.getattr
+local setattr             = nuts.setattr
+local setlist             = nuts.setlist
+
+local traverse_id         = nuts.traverse_id
+local get_list_dimensions = nuts.dimensions
+local linked_nodes        = nuts.linked
+local copy_node           = nuts.copy
+
+local tracedrule          = nodes.tracers.pool.nuts.rule
+
+local nodepool            = nuts.pool
+
+local new_rule            = nodepool.rule
+local new_hlist           = nodepool.hlist
+local new_glue            = nodepool.glue
+local new_kern            = nodepool.kern
+
+local hlist_code          = nodes.nodecodes.hlist
+
+local texsetattribute     = tex.setattribute
+local unsetvalue          = attributes.unsetvalue
+
+local min_threshold = 0
+local max_threshold = 0
+
+local function set(n)
+    nodes.tasks.enableaction("mvlbuilders", "typesetters.checkers.handler")
+    nodes.tasks.enableaction("vboxbuilders","typesetters.checkers.handler")
+    texsetattribute(a_justification,n or 1)
+    function typesetters.checkers.set(n)
+        texsetattribute(a_justification,n or 1)
+    end
+end
+
+local function reset()
+    texsetattribute(a_justification,unsetvalue)
+end
+
+checkers.set   = set
+checkers.reset = reset
+
+interfaces.implement {
+    name    = "showjustification",
+    actions = set
+}
+
+trackers.register("visualizers.justification", function(v)
+    if v then
+        set(1)
+    else
+        reset()
+    end
+end)
+
+function checkers.handler(head)
+    for current in traverse_id(hlist_code,tonut(head)) do
+        if getattr(current,a_justification) == 1 then
+            setattr(current,a_justification,0) -- kind of reset
+            local width = getfield(current,"width")
+            if width > 0 then
+                local list = getlist(current)
+                if list then
+                    local naturalwidth, naturalheight, naturaldepth = get_list_dimensions(list)
+                    local delta = naturalwidth - width
+                    if naturalwidth == 0 or delta == 0 then
+                        -- special box
+                    elseif delta >= max_threshold then
+                        local rule = tracedrule(delta,naturalheight,naturaldepth,getfield(list,"glue_set") == 1 and "trace:dr" or "trace:db")
+                        setlist(current,linked_nodes(list,new_hlist(rule)))
+                    elseif delta <= min_threshold then
+                        local alignstate = getattr(list,a_alignstate)
+                        if alignstate == 1 then
+                            local rule = tracedrule(-delta,naturalheight,naturaldepth,"trace:dc")
+                            setlist(current,linked_nodes(new_hlist(rule),list))
+                        elseif alignstate == 2 then
+                            local lrule = tracedrule(-delta/2,naturalheight,naturaldepth,"trace:dy")
+                            local rrule = copy_node(lrule)
+                            setlist(current,linked_nodes(new_hlist(lrule),list,new_kern(delta/2),new_hlist(rrule)))
+                        elseif alignstate == 3 then
+                            local rule = tracedrule(-delta,naturalheight,naturaldepth,"trace:dm")
+                            setlist(current,linked_nodes(list,new_kern(delta),new_hlist(rule)))
+                        else
+                            local rule = tracedrule(-delta,naturalheight,naturaldepth,"trace:dg")
+                            setlist(current,linked_nodes(list,new_kern(delta),new_hlist(rule)))
+                        end
+                    end
+                end
+            end
+        end
+    end
+    return head
+end