stable 2010-05-24 13:10

1 files changed, 221 insertions, 0 deletions

diff --git a/tex/context/base/page-str.lua b/tex/context/base/page-str.lua
new file mode 100644
index 000000000..c4d1957c3
--- /dev/null
+++ b/tex/context/base/page-str.lua
@@ -0,0 +1,221 @@
+if not modules then modules = { } end modules ['page-str'] = {
+    version   = 1.001,
+    comment   = "companion to page-str.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- work in progresss .. unfinished
+
+local concat = table.concat
+
+local find_tail, write_node, free_node, copy_nodelist = node.slide, node.write, node.free, node.copy_list
+local vpack_nodelist, hpack_nodelist = node.vpack, node.hpack
+local texdimen, texbox = tex.dimen, tex.box
+
+local new_kern  = nodes.kern
+local new_glyph = nodes.glyph
+
+local trace_collecting = false  trackers.register("streams.collecting", function(v) trace_collecting = v end)
+local trace_flushing   = false  trackers.register("streams.flushing",   function(v) trace_flushing   = v end)
+
+streams = streams or { }
+
+local data, name, stack = { }, nil, { }
+
+function streams.enable(newname)
+    if newname == "default" then
+        name = nil
+    else
+        name = newname
+    end
+end
+
+function streams.disable()
+    name = stack[#stack]
+end
+
+function streams.start(newname)
+    table.insert(stack,name)
+    name = newname
+end
+
+function streams.stop(newname)
+    name = table.remove(stack)
+end
+
+function streams.collect(head,where)
+    if name and head and name ~= "default" then
+        local tail = node.slide(head)
+        local dana = data[name]
+        if not dana then
+            dana = { }
+            data[name] = dana
+        end
+        local last = dana[#dana]
+        if last then
+            local tail = find_tail(last)
+            tail.next, head.prev = head, tail
+        elseif last == false then
+            dana[#dana] = head
+        else
+            dana[1] = head
+        end
+        if trace_collecting then
+            logs.report("streams","appending snippet '%s' to slot %s",name,#dana)
+        end
+        return nil, true
+    else
+        return head, false
+    end
+end
+
+function streams.push(thename)
+    if not thename or thename == "" then
+        thename = name
+    end
+    if thename and thename ~= "" then
+        local dana = data[thename]
+        if dana then
+            dana[#dana+1] = false
+            if trace_collecting then
+                logs.report("streams","pushing snippet '%s'",thename)
+            end
+        end
+    end
+end
+
+function streams.flush(name,copy) -- problem: we need to migrate afterwards
+    local dana = data[name]
+    if dana then
+        local dn = #dana
+        if dn == 0 then
+            -- nothing to flush
+        elseif copy then
+            if trace_flushing then
+                logs.report("streams","flushing copies of %s slots of '%s'",dn,name)
+            end
+            for i=1,dn do
+                local di = dana[i]
+                if di then
+                    write_node(copy_nodelist(di.list)) -- list, will be option
+                end
+            end
+            if copy then
+                data[name] = nil
+            end
+        else
+            if trace_flushing then
+                logs.report("streams","flushing %s slots of '%s'",dn,name)
+            end
+            for i=1,dn do
+                local di = dana[i]
+                if di then
+                    write_node(di.list) -- list, will be option
+                    di.list = nil
+                    free_node(di)
+                end
+            end
+        end
+    end
+end
+
+function streams.synchronize(list) -- this is an experiment !
+    -- we don't optimize this as we want to trace in detail
+    list = aux.settings_to_array(list)
+    local max = 0
+    if trace_flushing then
+        logs.report("streams","synchronizing list: %s",concat(list," "))
+    end
+    for i=1,#list do
+        local dana = data[list[i]]
+        if dana then
+            local n = #dana
+            if n > max then
+                max = n
+            end
+        end
+    end
+    if trace_flushing then
+        logs.report("streams","maximum number of slots: %s",max)
+    end
+    for m=1,max do
+        local height, depth = 0, 0
+        for i=1,#list do
+            local name = list[i]
+            local dana = data[name]
+            local slot = dana[m]
+            if slot then
+                local vbox = vpack_nodelist(slot)
+                local ht, dp = vbox.height, vbox.depth
+                if ht > height then
+                    height = ht
+                end
+                if dp > depth then
+                    depth = dp
+                end
+                dana[m] = vbox
+                if trace_flushing then
+                    logs.report("streams","slot %s of '%s' is packed to height %s and depth %s",m,name,ht,dp)
+                end
+            end
+        end
+        if trace_flushing then
+            logs.report("streams","slot %s has max height %s and max depth %s",m,height,depth)
+        end
+        local strutht, strutdp = texdimen.globalbodyfontstrutheight, texdimen.globalbodyfontstrutdepth
+        local struthtdp = strutht + strutdp
+        for i=1,#list do
+            local name = list[i]
+            local dana = data[name]
+            local vbox = dana[m]
+            if vbox then
+                local delta_height = height - vbox.height
+                local delta_depth  = depth  - vbox.depth
+                if delta_height > 0 or delta_depth > 0 then
+                    if false then
+                        -- actually we need to add glue and repack
+                        vbox.height, vbox.depth = height, depth
+                        if trace_flushing then
+                            logs.report("streams","slot %s of '%s' with delta (%s,%s) is compensated",m,i,delta_height,delta_depth)
+                        end
+                    else
+                        -- this is not yet ok as we also need to keep an eye on vertical spacing
+                        -- so we might need to do some splitting or whatever
+                        local tail = vbox.list and find_tail(vbox.list)
+                        local n, delta = 0, delta_height -- for tracing
+                        while delta > 0 do
+                            -- we need to add some interline penalties
+                            local line = copy_nodelist(tex.box.strutbox)
+                            line.height, line.depth = strutht, strutdp
+                            if tail then
+                                tail.next, line.prev = line, tail
+                            end
+                            tail = line
+                            n, delta = n +1, delta - struthtdp
+                        end
+                        dana[m] = vpack_nodelist(vbox.list)
+                        vbox.list = nil
+                        free_node(vbox)
+                        if trace_flushing then
+                            logs.report("streams","slot %s:%s with delta (%s,%s) is compensated by %s lines",m,i,delta_height,delta_depth,n)
+                        end
+                    end
+                end
+            else
+                -- make dummy
+            end
+        end
+    end
+end
+
+tasks.appendaction("mvlbuilders", "normalizers", "streams.collect")
+
+tasks.disableaction("mvlbuilders", "streams.collect")
+
+function streams.initialize()
+    tasks.enableaction ("mvlbuilders", "streams.collect")
+end
+
+-- todo: remove empty last { }'s