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authorMojca Miklavec <mojca.miklavec@gmail.com>2012-05-14 17:38:55 +0000
committerMojca Miklavec <mojca.miklavec@gmail.com>2012-05-14 17:38:55 +0000
commit15995e10bfc68edf79970c4ea4fbb6678566c46e (patch)
tree2de7ca2a83f2d37ef043ad7429a5cb945bb79ddb /Master/texmf-dist/tex/context/base/typo-pag.lua
parentc9a39f716f1e5ec820ed3aab2c9aef25c5a9d730 (diff)
ConTeXt 2012.05.14 16:00
git-svn-id: svn://tug.org/texlive/trunk@26371 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/tex/context/base/typo-pag.lua')
-rw-r--r--Master/texmf-dist/tex/context/base/typo-pag.lua183
1 files changed, 183 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/context/base/typo-pag.lua b/Master/texmf-dist/tex/context/base/typo-pag.lua
new file mode 100644
index 00000000000..482a3a9f866
--- /dev/null
+++ b/Master/texmf-dist/tex/context/base/typo-pag.lua
@@ -0,0 +1,183 @@
+if not modules then modules = { } end modules ['typo-pag'] = {
+ version = 1.001,
+ comment = "companion to typo-pag.mkiv",
+ author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+ copyright = "PRAGMA ADE / ConTeXt Development Team",
+ license = "see context related readme files"
+}
+
+local nodecodes = nodes.nodecodes
+
+local hlist_code = nodecodes.hlist
+local vlist_code = nodecodes.vlist
+local glue_code = nodecodes.glue
+local kern_code = nodecodes.kern
+local penalty_code = nodecodes.penalty
+
+local insert_node_after = node.insert_after
+local new_penalty = nodes.pool.penalty
+local has_attribute = node.has_attribute
+local unset_attribute = node.unset_attribute
+local set_attribute = node.set_attribute
+
+local points = number.points
+
+local a_keeptogether = attributes.private("keeptogether")
+
+local trace_keeptogether = false
+local report_keeptogether = logs.reporter("parbuilders","keeptogether")
+
+local cache = { }
+local last = 0
+local enabled = false
+
+trackers.register("parbuilders.keeptogether", function(v) trace_keeptogether = v end)
+
+-- todo: also support lines = 3 etc (e.g. dropped caps) but how to set that
+-- when no hlists are there ? ... maybe the local_par
+
+function builders.paragraphs.registertogether(line,specification) -- might change
+ if not enabled then
+ nodes.tasks.enableaction("finalizers","builders.paragraphs.keeptogether")
+ end
+ local a = has_attribute(line,a_keeptogether)
+ local c = a and cache[a]
+ if c then
+ local height = specification.height
+ local depth = specification.depth
+ local slack = specification.slack
+ if height and height > c.height then
+ c.height = height
+ end
+ if depth and depth > c.depth then
+ c.depth = depth
+ end
+ if slack and slack > c.slack then
+ c.slack = slack
+ end
+ else
+ last = last + 1
+ cache[last] = specification
+ if not specification.height then
+ specification.height = 0
+ end
+ if not specification.depth then
+ specification.depth = 0
+ end
+ if not specification.slack then
+ specification.slack = 0
+ end
+ set_attribute(line,a_keeptogether,last)
+ end
+ if trace_keeptogether then
+ local a = a or last
+ local c = cache[a]
+ if trace_keeptogether then
+ local noflines = specification.lineheight
+ local height = c.height
+ local depth = c.depth
+ local slack = c.slack
+ if not noflines or noflines == 0 then
+ noflines = "unknown"
+ else
+ noflines = math.round((height + depth - slack) / noflines)
+ end
+ report_keeptogether("registered, index: %s, height: %s, depth: %s, slack: %s, noflines: %s",
+ a,points(height),points(depth),points(slack),noflines)
+ end
+ end
+end
+
+local function keeptogether(start,a)
+ if start then
+ local specification = cache[a]
+ if a then
+ local current = start.next
+ local previous = start
+ local total = previous.depth
+ local slack = specification.slack
+ local threshold = specification.depth - slack
+ if trace_keeptogether then
+ report_keeptogether("list, index: %s, total: %s, threshold: %s, slack: %s",a,points(total),points(threshold),points(slack))
+ end
+ while current do
+ local id = current.id
+ if id == vlist_code or id == hlist_code then
+ total = total + current.height + current.depth
+ if trace_keeptogether then
+ report_keeptogether("list, index: %s, total: %s, threshold: %s",a,points(total),points(threshold))
+ end
+ if total <= threshold then
+ if previous.id == penalty_code then
+ previous.penalty = 10000
+ else
+ insert_node_after(head,previous,new_penalty(10000))
+ end
+ else
+ break
+ end
+ elseif id == glue_code then
+ -- hm, breakpoint, maybe turn this into kern
+ total = total + current.spec.width
+ if trace_keeptogether then
+ report_keeptogether("glue, index: %s, total: %s, threshold: %s",a,points(total),points(threshold))
+ end
+ if total <= threshold then
+ if previous.id == penalty_code then
+ previous.penalty = 10000
+ else
+ insert_node_after(head,previous,new_penalty(10000))
+ end
+ else
+ break
+ end
+ elseif id == kern_code then
+ total = total + current.kern
+ if trace_keeptogether then
+ report_keeptogether("kern, index: %s, total: %s, threshold: %s",a,points(total),points(threshold))
+ end
+ if total <= threshold then
+ if previous.id == penalty_code then
+ previous.penalty = 10000
+ else
+ insert_node_after(head,previous,new_penalty(10000))
+ end
+ else
+ break
+ end
+ elseif id == penalty_code then
+ if total <= threshold then
+ if previous.id == penalty_code then
+ previous.penalty = 10000
+ end
+ current.penalty = 10000
+ else
+ break
+ end
+ end
+ previous = current
+ current = current.next
+ end
+ end
+ end
+end
+
+-- also look at first non glue/kern node e.g for a dropped caps
+
+function builders.paragraphs.keeptogether(head)
+ local done = false
+ local current = head
+ while current do
+ if current.id == hlist_code then
+ local a = has_attribute(current,a_keeptogether)
+ if a and a > 0 then
+ keeptogether(current,a)
+ unset_attribute(current,a_keeptogether)
+ cache[a] = nil
+ done = true
+ end
+ end
+ current = current.next
+ end
+ return head, done
+end