diff options
Diffstat (limited to 'tex/context/base/mkiv/supp-box.lua')
| -rw-r--r-- | tex/context/base/mkiv/supp-box.lua | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/supp-box.lua b/tex/context/base/mkiv/supp-box.lua index f2da9155b..323274bea 100644 --- a/tex/context/base/mkiv/supp-box.lua +++ b/tex/context/base/mkiv/supp-box.lua @@ -26,6 +26,7 @@ local disc_code = nodecodes.disc local hlist_code = nodecodes.hlist local vlist_code = nodecodes.vlist local glue_code = nodecodes.glue +local penalty_code = nodecodes.penalty local glyph_code = nodecodes.glyph local nuts = nodes.nuts @@ -49,6 +50,7 @@ local takebox = nuts.takebox local setlink = nuts.setlink local setboth = nuts.setboth local setnext = nuts.setnext +local setprev = nuts.setprev local setbox = nuts.setbox local setlist = nuts.setlist local setdisc = nuts.setdisc @@ -56,6 +58,8 @@ local setwidth = nuts.setwidth local setheight = nuts.setheight local setdepth = nuts.setdepth local setshift = nuts.setshift +local setsplit = nuts.setsplit +local setattrlist = nuts.setattrlist local flush_node = nuts.flush_node local flush_list = nuts.flush_list @@ -64,6 +68,9 @@ local copy_list = nuts.copy_list local find_tail = nuts.tail local getdimensions = nuts.dimensions local hpack = nuts.hpack +local traverse_id = nuts.traverse_id +local free = nuts.free +local findtail = nuts.tail local nextdisc = nuts.traversers.disc local nextdir = nuts.traversers.dir @@ -648,3 +655,162 @@ implement { texsetdimen("givendepth", t.depth or 0) end, } + +local function stripglue(list) + local done = false + local first = list + while first do + local id = getid(first) + if id == glue_code or id == penalty_code then + first = getnext(first) + else + break + end + end + if first and first ~= list then + -- we have discardables + setsplit(getprev(first),first) + flush_list(list) + list = first + done = true + end + if list then + local tail = findtail(list) + local last = tail + while last do + local id = getid(last) + if id == glue_code or id == penalty_code then + last = getprev(last) + else + break + end + end + if last ~= tail then + -- we have discardables + flush_list(getnext(last)) + setnext(last) + done = true + end + end + return list, done +end + +local function limitate(t) + local text = t.text + if text then + text = tonut(text) + else + return + end + local sentinel = t.sentinel + if sentinel then + sentinel = tonut(sentinel) + local s = getlist(sentinel) + setlist(sentinel) + free(sentinel) + sentinel = s + else + return tonode(text) + end + local list = getlist(text) + local width = getwidth(text) + local done = false + if t.strip then + list, done = stripglue(list) + if not list then + setlist(text) + setwidth(text,0) + return text + elseif done then + width = getdimensions(list) + setlist(text,list) + end + end + local left = t.left or 0 + local right = t.right or 0 + if left + right >= width then + if done then + setwidth(text,width) + end + return tonode(text) + end + local last = nil + local first = nil + local maxleft = left + local maxright = right + local swidth = getwidth(sentinel) + if maxright > 0 then + maxleft = maxleft - swidth/2 + maxright = maxright - swidth/2 + else + maxleft = maxleft - swidth + end + for n in traverse_id(glue_code,list) do + local width = getdimensions(list,n) + if width > maxleft then + if not last then + last = n + end + break + else + last = n + end + end + if last and maxright > 0 then + for n in traverse_id(glue_code,last) do + local width = getdimensions(n) + if width < maxright then + first = n + break + else + first = n + end + end + end + if last then + local rest = getnext(last) + if rest then + local tail = findtail(sentinel) + if first and getid(first) == glue_code and getid(tail) == glue_code then + setwidth(first,0) + end + if last and getid(last) == glue_code and getid(sentinel) == glue_code then + setwidth(last,0) + end + if first and first ~= last then + local prev = getprev(first) + if prev then + setnext(prev) + end + setlink(tail,first) + end + setlink(last,sentinel) + setprev(rest) + flush_list(rest) + end + end + local result = hpack(list) + setattrlist(result,text) + setlist(text) + free(text) + return tonode(result) +end + +interfaces.implement { + name = "limitated", + public = true, + protected = true, + arguments = { + { + { "left", "dimension" }, + { "right", "dimension" }, + { "text", "hbox" }, + { "sentinel", "hbox" }, + { "strip", "boolean" }, + } + }, + actions = function(t) + context.dontleavehmode() + context(limitate(t)) + end, +} |