1 files changed, 105 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/page-pst.lua b/tex/context/base/mkiv/page-pst.lua
new file mode 100644
index 000000000..472bdbabe
--- /dev/null
+++ b/tex/context/base/mkiv/page-pst.lua
@@ -0,0 +1,105 @@
+if not modules then modules = { } end modules ['page-pst'] = {
+    version   = 1.001,
+    comment   = "companion to page-pst.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- todo: adapt message
+
+local tonumber, next, type = tonumber, next, type
+local find, validstring = string.find, string.valid
+
+local context     = context
+local implement   = interfaces.implement
+
+local texgetcount = tex.getcount
+local texsetcount = tex.setcount
+
+local sortedkeys   = table.sortedkeys
+local formatters   = string.formatters
+
+local cache = { }
+
+local function flush(page)
+    local c = cache[page]
+    if c then
+        for i=1,#c do
+         -- characters.showstring(c[i])
+            context.viafile(c[i],formatters["page.%s"](validstring(page,"nopage")))
+        end
+        cache[page] = nil
+    end
+end
+
+local function setnextpage()
+    local n = next(cache) and sortedkeys(cache)[1]
+    if not n then
+        n = 0           -- nothing in the cache
+    elseif n == 0 then
+        n = -1          -- generic buffer (0)
+    elseif n > 0 then
+                        -- upcoming page (realpageno)
+    end
+    texsetcount("global","c_page_postponed_blocks_next_page",n)
+end
+
+local function flushpostponedblocks(specification)
+    -- we need to flush previously pending pages as well and the zero
+    -- slot is the generic one so that one is always flushed
+    local t = sortedkeys(cache)
+    local p = tonumber(specification.page) or texgetcount("realpageno") or 0
+    for i=1,#t do
+        local ti = t[i]
+        if ti <= p then
+            flush(ti)
+        else
+            break
+        end
+    end
+    setnextpage()
+end
+
+implement {
+    name      = "flushpostponedblocks",
+    actions   = flushpostponedblocks,
+    arguments = {
+        {
+            { "page" }
+        }
+    }
+}
+
+local function registerpostponedblock(page)
+    if type(page) == "string" then
+        if find(page,"^+") then
+            page = texgetcount("realpageno") + (tonumber(page) or 1) -- future delta page
+        else
+            page = tonumber(page) or 0 -- preferred page or otherwise first possible occasion
+        end
+    end
+    if not page then
+        page = 0
+    end
+    local c = cache[page]
+    if not c then
+        c = { }
+        cache[page] = c
+    end
+    c[#c+1] = buffers.raw("postponedblock")
+    buffers.erase("postponedblock")
+    if page == 0 then
+        interfaces.showmessage("layouts",3,#c)
+    else
+        interfaces.showmessage("layouts",3,formatters["%s (realpage: %s)"](#c,page))
+    end
+    setnextpage()
+end
+
+implement {
+    name      = "registerpostponedblock",
+    actions   = registerpostponedblock,
+    arguments = "string"
+}
+