diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,25 +1,686 @@
-The following license covers this documentation, and the source code, except
-where otherwise indicated.
+Copyright (C) 2011-2014 Ian-Woo Kim
 
-Copyright 2011-2013, Ian-Woo Kim. All rights reserved.
+Hoodle is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
 
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
+Hoodle is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
 
-* Redistributions of source code must retain the above copyright notice, this
-  list of conditions and the following disclaimer.
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
 
-* Redistributions in binary form must reproduce the above copyright notice,
-  this list of conditions and the following disclaimer in the documentation
-  and/or other materials provided with the distribution.
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
 
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+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/hoodle-render.cabal b/hoodle-render.cabal
--- a/hoodle-render.cabal
+++ b/hoodle-render.cabal
@@ -1,8 +1,8 @@
 Name:		hoodle-render
-Version:	0.3.2
+Version:	0.4
 Synopsis:       Hoodle file renderer
 Description: 	Rendering library using cairo for hoodle file format
-License: 	BSD3
+License: 	GPL-3
 License-file:	LICENSE
 Author:		Ian-Woo Kim
 Maintainer: 	Ian-Woo Kim <ianwookim@gmail.com>
@@ -19,23 +19,28 @@
   ghc-options: 	-Wall -fno-warn-orphans -funbox-strict-fields -fno-warn-unused-do-bind
   ghc-prof-options: -caf-all -auto-all
 
-  Build-Depends: base == 4.*, 
-                 mtl == 2.*, 
-                 filepath, 
-                 directory, 
-                 containers >= 0.4, 
-                 cairo == 0.12.*, 
-                 svgcairo == 0.12.*,
-                 strict >= 0.3, 
-                 bytestring >= 0.9,
+  Build-Depends: 
+                 base == 4.*, 
                  base64-bytestring >= 0.1, 
+                 bytestring >= 0.9,
+                 cairo >= 0.12, 
+                 containers >= 0.4, 
+                 directory, 
+                 filepath, 
+                 gd >= 3000.7,  
+                 gtk >= 0.12,
+                 hoodle-types >= 0.3,
                  lens >= 2.5, 
-                 hoodle-types >= 0.2.1,
-                 gd >= 3000.7, 
-                 unix >= 2.5,
-                 uuid >= 1.2, 
                  monad-loops >= 0.3,  
-                 poppler >= 0.12.2.2
+                 mtl == 2.*, 
+                 poppler >= 0.12.2.2,
+                 stm,
+                 strict >= 0.3, 
+                 svgcairo >= 0.12,
+                 transformers >= 0.3,
+                 unix >= 2.5,
+                 unordered-containers, 
+                 uuid >= 1.2 
 
 
   Exposed-Modules: 
@@ -51,6 +56,8 @@
                    Graphics.Hoodle.Render.Type.HitTest
                    Graphics.Hoodle.Render.Type.Hoodle
                    Graphics.Hoodle.Render.Type.Item
+                   Graphics.Hoodle.Render.Type.RenderCache
+                   Graphics.Hoodle.Render.Type.Renderer
                    Graphics.Hoodle.Render.Type.Select
                    Graphics.Hoodle.Render.Util
                    Graphics.Hoodle.Render.Util.HitTest
diff --git a/src/Graphics/Hoodle/Render.hs b/src/Graphics/Hoodle/Render.hs
--- a/src/Graphics/Hoodle/Render.hs
+++ b/src/Graphics/Hoodle/Render.hs
@@ -1,12 +1,13 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
 
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -15,17 +16,16 @@
 --
 -----------------------------------------------------------------------------
 
-
 module Graphics.Hoodle.Render 
 (      
+-- * xform 
+  Xform4Page(..) 
 -- * simple rendering using non-R-structure   
-  renderStrk
+, renderStrk
 , renderImg
 , renderBkg
 , renderItem 
 , renderPage
--- * render in bbox using non R-structure 
--- , renderBkg_InBBox
 -- * simple rendering using R-structure 
 , renderRBkg
 , renderRItem 
@@ -46,76 +46,85 @@
 , cnstrctRHoodle  
 ) where
 
+import           Control.Concurrent (putMVar)
+import           Control.Concurrent.STM
 import           Control.Lens (view,set)
 import           Control.Monad.Identity (runIdentity)
 import           Control.Monad.State hiding (mapM,mapM_)
+import           Control.Monad.Trans.Reader
 import qualified Data.ByteString.Char8 as C
 import           Data.Foldable
+import qualified Data.HashMap.Strict as HM
+import           Data.Sequence ( (|>))
+import qualified Data.Sequence as Seq (null)
 import           Data.Traversable (mapM)
--- import qualified Data.Map as M
--- import           Data.Monoid
-import           Graphics.Rendering.Cairo
+import           Data.UUID.V4
+import qualified Graphics.Rendering.Cairo as Cairo
+import qualified Graphics.Rendering.Cairo.SVG as RSVG
+import qualified Graphics.UI.Gtk.Poppler.Page as PopplerPage
 -- from hoodle-platform 
 import           Data.Hoodle.Generic
 import           Data.Hoodle.Simple
 import           Data.Hoodle.BBox
-import           Data.Hoodle.Predefined 
-import           Data.Hoodle.Zipper hiding (moveTo) 
-import qualified Graphics.UI.Gtk.Poppler.Page as PopplerPage
-import qualified Graphics.Rendering.Cairo.SVG as RSVG
+import           Data.Hoodle.Predefined
+import           Data.Hoodle.Zipper
 -- from this package
--- import Graphics.Hoodle.Render.Simple 
-import Graphics.Hoodle.Render.Background 
-import Graphics.Hoodle.Render.Item 
-import Graphics.Hoodle.Render.Primitive
-import Graphics.Hoodle.Render.Type 
-import Graphics.Hoodle.Render.Type.HitTest
-import Graphics.Hoodle.Render.Util 
-import Graphics.Hoodle.Render.Util.HitTest 
+import           Graphics.Hoodle.Render.Background
+-- import Graphics.Hoodle.Render.Highlight
+import           Graphics.Hoodle.Render.Item
+import           Graphics.Hoodle.Render.Primitive
+import           Graphics.Hoodle.Render.Type
+import           Graphics.Hoodle.Render.Type.HitTest
+import           Graphics.Hoodle.Render.Util
+import           Graphics.Hoodle.Render.Util.HitTest
 -- 
-import Prelude hiding (curry,uncurry,mapM,mapM_,concatMap)
-
+import           Prelude hiding (curry,uncurry,mapM,mapM_,concatMap)
 
+data Xform4Page = Xform4Page { transx :: Double
+                                                 , transy :: Double 
+                                                 , scalex :: Double
+                                                 , scaley :: Double } 
+                          deriving (Show)
 
------
--- simple 
---- 
+------------
+-- simple --
+------------
 
 -- | render stroke 
-renderStrk :: Stroke -> Render ()
+renderStrk :: Stroke -> Cairo.Render ()
 renderStrk s@(Stroke _ _ w d) = do 
     let opacity = if stroke_tool s == "highlighter" 
                   then predefined_highlighter_opacity
                   else 1.0
     case getPenColor (stroke_color s) of 
-      Just (r,g,b,a) -> setSourceRGBA r g b (a*opacity) 
-      Nothing -> setSourceRGBA 0.5 0.5 0.5 1
-    setLineWidth w
-    setLineCap LineCapRound
-    setLineJoin LineJoinRound
+      Just (r,g,b,a) -> Cairo.setSourceRGBA r g b (a*opacity) 
+      Nothing -> Cairo.setSourceRGBA 0.5 0.5 0.5 1
+    Cairo.setLineWidth w
+    Cairo.setLineCap Cairo.LineCapRound
+    Cairo.setLineJoin Cairo.LineJoinRound
     drawStrokeCurve d
-    stroke 
+    Cairo.stroke 
 renderStrk s@(VWStroke _ _ d) = do 
     let opacity = if stroke_tool s == "highlighter" 
                   then predefined_highlighter_opacity
                   else 1.0
     case getPenColor (stroke_color s) of
-      Just (r,g,b,a) -> setSourceRGBA r g b (a*opacity) 
-      Nothing -> setSourceRGBA 0.5 0.5 0.5 1
-    setFillRule FillRuleWinding
+      Just (r,g,b,a) -> Cairo.setSourceRGBA r g b (a*opacity) 
+      Nothing -> Cairo.setSourceRGBA 0.5 0.5 0.5 1
+    Cairo.setFillRule Cairo.FillRuleWinding
     drawVWStrokeCurve d
-    fill 
+    Cairo.fill 
 
 -- | render image : not fully implemented 
-renderImg :: Image -> Render () 
+renderImg :: Image -> Cairo.Render () 
 renderImg (Image _ (x,y) (Dim w h)) = do  
-      setSourceRGBA 0 0 0 1
-      setLineWidth 10
-      rectangle x y w h
-      stroke
+      Cairo.setSourceRGBA 0 0 0 1
+      Cairo.setLineWidth 10
+      Cairo.rectangle x y w h
+      Cairo.stroke
 
 -- | render svg  
-renderSVG :: SVG -> Render () 
+renderSVG :: SVG -> Cairo.Render () 
 renderSVG svg@(SVG _ _ bstr _ _) = do  
     let str = C.unpack bstr 
     RSVG.withSvgFromString str $ \rsvg -> do 
@@ -125,390 +134,358 @@
           (ix',iy') = RSVG.svgGetSize rsvg
           ix = fromIntegral ix' 
           iy = fromIntegral iy'
-      -- clipBBox (Just (getBBox svgbbx))
-      save 
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
+      Cairo.save 
+      Cairo.translate x y 
+      Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
       RSVG.svgRender rsvg 
-      restore
-      -- resetClip 
+      Cairo.restore
       return () 
 
 -- | render svg  
-renderLink :: Link -> Render () 
-renderLink lnk = do  
+renderLink :: Link -> Cairo.Render () 
+renderLink lnk = 
     let bstr = link_render lnk 
-    let str = C.unpack bstr 
-    RSVG.withSvgFromString str $ \rsvg -> do 
-      let lnkbbx = runIdentity (makeBBoxed lnk)
-      let (x,y) = (link_pos . bbxed_content) lnkbbx
-          BBox (x1,y1) (x2,y2) = getBBox lnkbbx
-          (ix',iy') = RSVG.svgGetSize rsvg
-          ix = fromIntegral ix' 
-          iy = fromIntegral iy'
-      clipBBox (Just (getBBox lnkbbx))
-      save 
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      RSVG.svgRender rsvg 
-      restore
-      resetClip 
-      return () 
+    in if C.null bstr 
+       then do
+         let lnkbbx = runIdentity (makeBBoxed lnk)
+             bbox@(BBox (x0,y0) (x1,y1)) = getBBox lnkbbx
+         clipBBox (Just bbox)
+         Cairo.setSourceRGBA 0 1 0 1 
+         Cairo.rectangle x0 y0 (x1-x0) (y1-y0)
+         Cairo.fill
+         Cairo.resetClip
+         return ()
+       else do
+         let str = C.unpack bstr 
+         RSVG.withSvgFromString str $ \rsvg -> do 
+           let lnkbbx = runIdentity (makeBBoxed lnk)
+           let (x,y) = (link_pos . bbxed_content) lnkbbx
+               BBox (x1,y1) (x2,y2) = getBBox lnkbbx
+               (ix',iy') = RSVG.svgGetSize rsvg
+               ix = fromIntegral ix' 
+               iy = fromIntegral iy'
+           clipBBox (Just (getBBox lnkbbx))
+           Cairo.save 
+           Cairo.translate x y 
+           Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+           RSVG.svgRender rsvg 
+           Cairo.restore
+           Cairo.resetClip 
+           return () 
+-- renderLink lnk@LinkAnchor {..} = do
+--    let lnkbbx = runIdentity (makeBBoxed lnk)
+--        bbox@(BBox (x0,y0) (x1,y1)) = getBBox lnkbbx
+--    clipBBox (Just bbox)
+--    Cairo.setSourceRGBA 0 1 0 1 
+--    Cairo.rectangle x0 y0 (x1-x0) (y1-y0)
+--    Cairo.fill
+--    Cairo.resetClip
+--    return ()
 
 
+-- | 
+renderAnchor :: Anchor -> Cairo.Render ()
+renderAnchor anc = 
+    let bstr = anchor_render anc
+    in if C.null bstr 
+       then do
+         let ancbbx = runIdentity (makeBBoxed anc)
+             bbox@(BBox (x0,y0) (x1,y1)) = getBBox ancbbx
+         clipBBox (Just bbox)
+         Cairo.setSourceRGBA 1 0 0 1 
+         Cairo.rectangle x0 y0 (x1-x0) (y1-y0)
+         Cairo.fill
+         Cairo.resetClip
+         return ()
+       else do
+         let str = C.unpack bstr 
+         RSVG.withSvgFromString str $ \rsvg -> do 
+           let ancbbx = runIdentity (makeBBoxed anc)
+           let (x,y) = (anchor_pos . bbxed_content) ancbbx
+               BBox (x1,y1) (x2,y2) = getBBox ancbbx
+               (ix',iy') = RSVG.svgGetSize rsvg
+               ix = fromIntegral ix' 
+               iy = fromIntegral iy'
+           clipBBox (Just (getBBox ancbbx))
+           Cairo.save 
+           Cairo.translate x y 
+           Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+           RSVG.svgRender rsvg 
+           Cairo.restore
+           Cairo.resetClip 
+           return () 
+
+
 -- | render item 
-renderItem :: Item -> Render () 
+renderItem :: Item -> Cairo.Render () 
 renderItem (ItemStroke strk) = renderStrk strk
 renderItem (ItemImage img) = renderImg img
 renderItem (ItemSVG svg) = renderSVG svg
 renderItem (ItemLink lnk) = renderLink lnk
+renderItem (ItemAnchor anc) = renderAnchor anc 
 
 -- |
-renderPage :: Page -> Render ()
+renderPage :: Page -> Cairo.Render ()
 renderPage page = do 
   renderBkg (view background page,view dimension page)
-  setLineCap LineCapRound
-  setLineJoin LineJoinRound
+  Cairo.setLineCap Cairo.LineCapRound
+  Cairo.setLineJoin Cairo.LineJoinRound
   mapM_ (mapM renderItem . view items) . view layers $ page
-  stroke
-
+  Cairo.stroke
 
 -----
 -- R-structure 
 ----
 
-drawFallBackBkg :: Dimension -> Render () 
+drawFallBackBkg :: Dimension -> Cairo.Render () 
 drawFallBackBkg (Dim w h) = do 
-  setSourceRGBA 1 1 1 1 
-  rectangle 0 0 w h 
-  fill 
-  setSourceRGBA 0 0 0 1 
-  setLineWidth 5
-  moveTo 0 0
-  lineTo w h 
-  stroke 
-  moveTo w 0 
-  lineTo 0 h
-  stroke
+  Cairo.setSourceRGBA 1 1 1 1 
+  Cairo.rectangle 0 0 w h 
+  Cairo.fill 
+  Cairo.setSourceRGBA 0 0 0 1 
+  Cairo.setLineWidth 5
+  Cairo.moveTo 0 0
+  Cairo.lineTo w h 
+  Cairo.stroke 
+  Cairo.moveTo w 0 
+  Cairo.lineTo 0 h
+  Cairo.stroke
   
 
 -- | 
-renderRBkg :: (RBackground,Dimension) -> Render (RBackground,Dimension)
-renderRBkg (r,dim) = 
+renderRBkg :: RenderCache 
+           -> (RBackground,Dimension, Maybe Xform4Page) 
+           -> Cairo.Render (RBackground,Dimension, Maybe Xform4Page)
+renderRBkg cache (r,dim,mx) = 
     case r of 
-      (RBkgSmpl _ _ _) -> 
-        drawBkgAndRecord (renderBkg (rbkg2Bkg r,dim))
-        -- renderBkg (rbkg2Bkg r,dim) >> return (r,dim)
-      (RBkgPDF _ _ _ p _) -> 
-        maybe (drawFallBackBkg dim >> return (r,dim)) 
-              (\pg -> drawBkgAndRecord (bkgPdfRender pg)) p
-      (RBkgEmbedPDF _ p _) -> 
-        maybe (drawFallBackBkg dim >> return (r,dim)) 
-              (\pg -> drawBkgAndRecord (bkgPdfRender pg)) p 
-  where 
-    drawBkgAndRecord rdr = do 
-      rdr 
-      case rbkg_cairosurface r of
-        Nothing -> return ()
-        Just sfc -> liftIO $ renderWith sfc rdr
-      return (r,dim)
-    bkgPdfRender pg = do 
-      let Dim w h = dim 
-      setSourceRGBA 1 1 1 1
-      rectangle 0 0 w h 
-      fill
-      PopplerPage.pageRender pg
-
-
+      (RBkgSmpl _ _ _)     ->  renderBkg (rbkg2Bkg r,dim) >> return (r,dim,mx)
+      (RBkgPDF _ _ _ _ _)  -> renderRBkg_Buf cache (r,dim,mx)
+      (RBkgEmbedPDF _ _ _) -> renderRBkg_Buf cache (r,dim,mx)
 
 -- |
-renderRItem :: RItem -> Render RItem  
-renderRItem itm@(RItemStroke strk) = renderStrk (bbxed_content strk) >> return itm
-renderRItem itm@(RItemImage img msfc) = do  
-  case msfc of
-    Nothing -> renderImg (bbxed_content img)
-    Just sfc -> do 
-      let (x,y) = (img_pos . bbxed_content) img
-          BBox (x1,y1) (x2,y2) = getBBox img
-      ix <- liftM fromIntegral (imageSurfaceGetWidth sfc)
-      iy <- liftM fromIntegral (imageSurfaceGetHeight sfc)
-      save 
-      -- setAntialias AntialiasNone      
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      setSourceSurface sfc 0 0 
-      paint 
-      restore
-  return itm 
-renderRItem itm@(RItemSVG svgbbx mrsvg) = do 
-  case mrsvg of
-    Nothing -> renderSVG (bbxed_content svgbbx)
-    Just rsvg -> do 
-      let (x,y) = (svg_pos . bbxed_content) svgbbx
-          BBox (x1,y1) (x2,y2) = getBBox svgbbx
-          (ix',iy') = RSVG.svgGetSize rsvg
-          ix = fromIntegral ix' 
-          iy = fromIntegral iy'
-      --  clipBBox (Just (getBBox svgbbx))
-      save 
-      -- setAntialias AntialiasNone
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      RSVG.svgRender rsvg 
-      restore
-      -- resetClip 
-      return () 
-  return itm 
-renderRItem itm@(RItemLink lnkbbx mrsvg) = do 
-  case mrsvg of
-    Nothing -> renderLink (bbxed_content lnkbbx)
-    Just rsvg -> do 
-      let (x,y) = (link_pos . bbxed_content) lnkbbx
-          BBox (x1,y1) (x2,y2) = getBBox lnkbbx
-          (ix',iy') = RSVG.svgGetSize rsvg
-          ix = fromIntegral ix' 
-          iy = fromIntegral iy'
-      -- clipBBox (Just (getBBox lnkbbx))
-      save 
-      -- setAntialias AntialiasNone
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      RSVG.svgRender rsvg 
-      restore
-      -- resetClip 
-      return () 
-  return itm 
-
+renderRItem :: RenderCache -> RItem -> Cairo.Render RItem  
+renderRItem _ itm@(RItemStroke strk) = renderStrk (bbxed_content strk) >> return itm
+renderRItem cache itm@(RItemImage img msfc {- uuid -} ) = do
+    -- let mssfc = HM.lookup uuid cache
+    case msfc of
+      Nothing -> renderImg (bbxed_content img)
+      Just sfc -> do 
+	let (x,y) = (img_pos . bbxed_content) img
+	    BBox (x1,y1) (x2,y2) = getBBox img
+	ix <- liftM fromIntegral (Cairo.imageSurfaceGetWidth sfc)
+	iy <- liftM fromIntegral (Cairo.imageSurfaceGetHeight sfc)
+	Cairo.save 
+	Cairo.translate x y 
+        Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+	-- Cairo.scale ((x2-x1)/ix/s) ((y2-y1)/iy/s)
+	Cairo.setSourceSurface sfc 0 0 
+	Cairo.paint 
+	Cairo.restore
+    return itm 
+renderRItem _ itm@(RItemSVG svgbbx mrsvg) = do 
+    case mrsvg of
+      Nothing -> renderSVG (bbxed_content svgbbx)
+      Just rsvg -> do 
+	let (x,y) = (svg_pos . bbxed_content) svgbbx
+	    BBox (x1,y1) (x2,y2) = getBBox svgbbx
+	    (ix',iy') = RSVG.svgGetSize rsvg
+	    ix = fromIntegral ix' 
+	    iy = fromIntegral iy'
+	Cairo.save 
+	Cairo.translate x y 
+	Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+	RSVG.svgRender rsvg 
+	Cairo.restore
+	return () 
+    return itm 
+renderRItem _ itm@(RItemLink lnkbbx mrsvg) = do 
+    case mrsvg of
+      Nothing -> renderLink (bbxed_content lnkbbx)
+      Just rsvg -> do 
+	let (x,y) = (link_pos . bbxed_content) lnkbbx
+	    BBox (x1,y1) (x2,y2) = getBBox lnkbbx
+	    (ix',iy') = RSVG.svgGetSize rsvg
+	    ix = fromIntegral ix' 
+	    iy = fromIntegral iy'
+	Cairo.save 
+	Cairo.translate x y 
+	Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+	RSVG.svgRender rsvg 
+	Cairo.restore
+	return () 
+    return itm 
+renderRItem _ itm@(RItemAnchor ancbbx mrsvg) = do
+    case mrsvg of
+      Nothing -> renderAnchor (bbxed_content ancbbx)
+      Just rsvg -> do 
+	let (x,y) = (anchor_pos . bbxed_content) ancbbx
+	    BBox (x1,y1) (x2,y2) = getBBox ancbbx
+	    (ix',iy') = RSVG.svgGetSize rsvg
+	    ix = fromIntegral ix' 
+	    iy = fromIntegral iy'
+	Cairo.save 
+	Cairo.translate x y 
+	Cairo.scale ((x2-x1)/ix) ((y2-y1)/iy)
+	RSVG.svgRender rsvg 
+	Cairo.restore
+	return () 
+    return itm 
 
 
 ------------
 -- InBBox --
 ------------
 
-{-
-renderRItem_InBBox :: Maybe BBox -> RItem -> Render RItem  
-renderRItem_InBBox _ itm@(RItemStroke strk) = renderStrk (bbxed_content strk) >> return itm
-renderRItem_InBBox mbbox itm@(RItemImage img msfc) = do  
-  case msfc of
-    Nothing -> renderImg (bbxed_content img)
-    Just sfc -> do 
-      let (x,y) = (img_pos . bbxed_content) img
-          BBox (x1,y1) (x2,y2) = getBBox img
-      ix <- liftM fromIntegral (imageSurfaceGetWidth sfc)
-      iy <- liftM fromIntegral (imageSurfaceGetHeight sfc)
-      save 
-      clipBBox (fmap (flip inflate 1) mbbox) 
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      setSourceSurface sfc 0 0 
-      paint 
-      resetClip 
-      restore
-  return itm 
-renderRItem_InBBox mbbox itm@(RItemSVG svgbbx mrsvg) = do 
-  case mrsvg of
-    Nothing -> renderSVG (bbxed_content svgbbx)
-    Just rsvg -> do 
-      let (x,y) = (svg_pos . bbxed_content) svgbbx
-          BBox (x1,y1) (x2,y2) = getBBox svgbbx
-          (ix',iy') = RSVG.svgGetSize rsvg
-          ix = fromIntegral ix' 
-          iy = fromIntegral iy'
-      clipBBox (fmap (flip inflate 0.5) mbbox)
-      save 
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      RSVG.svgRender rsvg 
-      resetClip 
-      restore
-      return () 
-  return itm 
-renderRItem_InBBox mbbox itm@(RItemLink lnkbbx mrsvg) = do 
-  case mrsvg of
-    Nothing -> renderLink (bbxed_content lnkbbx)
-    Just rsvg -> do 
-      let (x,y) = (link_pos . bbxed_content) lnkbbx
-          BBox (x1,y1) (x2,y2) = getBBox lnkbbx
-          (ix',iy') = RSVG.svgGetSize rsvg
-          ix = fromIntegral ix' 
-          iy = fromIntegral iy'
-      save 
-      clipBBox (fmap (flip inflate 0.5) mbbox)
-      translate x y 
-      scale ((x2-x1)/ix) ((y2-y1)/iy)
-      RSVG.svgRender rsvg 
-      resetClip 
-      restore
-      return () 
-  return itm 
--}
-
-
 -- | background drawing in bbox 
-renderRBkg_InBBox :: Maybe BBox 
-                  -> (RBackground,Dimension) 
-                  -> Render (RBackground,Dimension)
-renderRBkg_InBBox mbbox (b,dim) = do 
+renderRBkg_InBBox :: RenderCache 
+                  -> Maybe BBox 
+                  -> (RBackground,Dimension,Maybe Xform4Page) 
+                  -> Cairo.Render (RBackground,Dimension, Maybe Xform4Page)
+renderRBkg_InBBox cache mbbox (b,dim,mx) = do 
     clipBBox (fmap (flip inflate 1) mbbox)
-    -- clipBBox mbbox
-    renderRBkg_Buf (b,dim)
-    resetClip
-    return (b,dim)
+    renderRBkg_Buf cache (b,dim,mx)
+    Cairo.resetClip
+    return (b,dim,mx)
 
 
 -- | render RLayer within BBox after hittest items
-renderRLayer_InBBox :: Maybe BBox -> RLayer -> Render RLayer
-renderRLayer_InBBox mbbox layer = do  
+renderRLayer_InBBox :: RenderCache -> Maybe BBox -> RLayer -> Cairo.Render RLayer
+renderRLayer_InBBox cache mbbox layer = do  
   clipBBox (fmap (flip inflate 2) mbbox)  -- temporary
-  -- clipBBox mbbox 
   let hittestbbox = case mbbox of 
         Nothing -> NotHitted [] 
                    :- Hitted (view gitems layer) 
                    :- Empty 
         Just bbox -> (hltHittedByBBox bbox . view gitems) layer
-  (mapM_ renderRItem . concatMap unHitted  . getB) hittestbbox
-  resetClip  
+  (mapM_ (renderRItem cache) . concatMap unHitted  . getB) hittestbbox
+  Cairo.resetClip  
   -- simply twice rendering if whole redraw happening 
   case view gbuffer layer of 
     LyBuf (Just sfc) -> do 
-      liftIO $ renderWith sfc $ do 
+      liftIO $ Cairo.renderWith sfc $ do 
         clipBBox (fmap (flip inflate 2) mbbox ) -- temporary
-        -- clipBBox mbbox 
-        -- setAntialias AntialiasNone
-        setSourceRGBA 0 0 0 0 
-        setOperator OperatorSource
-        paint
-        setOperator OperatorOver
-        (mapM_ renderRItem . concatMap unHitted  . getB) hittestbbox
-        resetClip 
+        Cairo.setSourceRGBA 0 0 0 0 
+        Cairo.setOperator Cairo.OperatorSource
+        Cairo.paint
+        Cairo.setOperator Cairo.OperatorOver
+        (mapM_ (renderRItem cache) . concatMap unHitted  . getB) hittestbbox
+        Cairo.resetClip 
         return layer 
     _ -> return layer 
 
-  
-
-
-
 -----------------------
 -- draw using buffer -- 
 -----------------------
 
 -- | Background rendering using buffer
-renderRBkg_Buf :: (RBackground,Dimension) 
-               -> Render (RBackground,Dimension)
-renderRBkg_Buf (b,dim) = do 
-    case b of 
-      RBkgSmpl _ _ msfc  -> do  
-        case msfc of 
-          Nothing -> renderRBkg (b,dim) >> return ()
-          Just sfc -> do 
-            save
-            -- setAntialias AntialiasNone
-            setSourceSurface sfc 0 0 
-            paint 
-            restore
-      RBkgPDF _ _ _n _ msfc -> do 
-        case msfc of 
-          Nothing -> renderRBkg (b,dim) >> return ()
-          Just sfc -> do 
-            save
-            -- setAntialias AntialiasNone            
-            setSourceSurface sfc 0 0 
-            paint 
-            restore
-      RBkgEmbedPDF _ _ msfc -> do 
-        case msfc of 
-          Nothing -> renderRBkg (b,dim) >> return ()
-          Just sfc -> do 
-            save
-            -- setAntialias AntialiasNone            
-            setSourceSurface sfc 0 0 
-            paint 
-            restore
-    return (b,dim)
+renderRBkg_Buf :: RenderCache
+               -> (RBackground,Dimension,Maybe Xform4Page) 
+               -> Cairo.Render (RBackground,Dimension,Maybe Xform4Page)
+renderRBkg_Buf cache (b,dim,mx) = do 
+    case HM.lookup (rbkg_uuid b) cache of
+      Nothing -> drawFallBackBkg dim >> return ()
+      Just (s,sfc) -> do 
+        -- liftIO $ print mx
+        -- liftIO $ print (1/s)
+        Cairo.save
+        case mx of 
+          Nothing -> Cairo.scale (1/s) (1/s) 
+          Just xform -> if (scalex xform /s > 0.999 && scalex xform /s < 1.001) 
+                          then do Cairo.identityMatrix
+                                  Cairo.translate (transx xform) (transy xform)
+                                  Cairo.setAntialias Cairo.AntialiasNone
+                          else Cairo.scale (1/s) (1/s)
+        Cairo.setSourceSurface sfc 0 0 
+        Cairo.paint 
+        Cairo.restore
+    return (b,dim,mx)
 
 -- | 
-renderRLayer_InBBoxBuf :: Maybe BBox -> RLayer -> Render RLayer 
-renderRLayer_InBBoxBuf mbbox lyr = do
+renderRLayer_InBBoxBuf :: RenderCache 
+                       -> Maybe BBox -> RLayer -> Cairo.Render RLayer 
+renderRLayer_InBBoxBuf cache mbbox lyr = do
     case view gbuffer lyr of 
       LyBuf (Just sfc) -> do 
         clipBBox mbbox
-        setSourceSurface sfc 0 0 
-        paint 
-        resetClip 
+        Cairo.setSourceSurface sfc 0 0 
+        Cairo.paint 
+        Cairo.resetClip 
         return lyr 
       _ -> do 
-        renderRLayer_InBBox mbbox lyr         
-        -- return lyr 
+        renderRLayer_InBBox cache mbbox lyr         
 
 -------------------
 -- update buffer
 -------------------
 
 -- | 
-updateLayerBuf :: Dimension -> Maybe BBox -> RLayer -> IO RLayer
-updateLayerBuf (Dim w h) mbbox lyr = do 
+updateLayerBuf :: RenderCache -> Dimension -> Maybe BBox -> RLayer -> IO RLayer
+updateLayerBuf cache (Dim w h) mbbox lyr = do 
   case view gbuffer lyr of 
     LyBuf (Just sfc) -> do 
-      renderWith sfc $ do 
-        renderRLayer_InBBox mbbox lyr 
+      Cairo.renderWith sfc $ do 
+        renderRLayer_InBBox cache mbbox lyr 
       return lyr
     LyBuf Nothing -> do 
-      -- return lyr 
-      sfc <- createImageSurface FormatARGB32 (floor w) (floor h)
-      renderWith sfc $ do 
-        renderRLayer_InBBox Nothing lyr
+      sfc <- Cairo.createImageSurface Cairo.FormatARGB32 (floor w) (floor h)
+      Cairo.renderWith sfc $ do 
+        renderRLayer_InBBox cache Nothing lyr
       return (set gbuffer (LyBuf (Just sfc)) lyr) 
       
 -- | 
-updatePageBuf :: RPage -> IO RPage 
-updatePageBuf pg = do 
+updatePageBuf :: RenderCache -> RPage -> IO RPage 
+updatePageBuf cache pg = do 
   let dim = view gdimension pg
       mbbox = Just . dimToBBox $ dim 
-  nlyrs <- mapM (updateLayerBuf dim mbbox) . view glayers $ pg 
+  nlyrs <- mapM (updateLayerBuf cache dim mbbox) . view glayers $ pg 
   return (set glayers nlyrs pg)
 
 -- | 
-updateHoodleBuf :: RHoodle -> IO RHoodle 
-updateHoodleBuf hdl = do 
+updateHoodleBuf :: RenderCache -> RHoodle -> IO RHoodle 
+updateHoodleBuf cache hdl = do 
   let pgs = view gpages hdl 
-  npgs <- mapM updatePageBuf pgs
+  npgs <- mapM (updatePageBuf cache) pgs
   return . set gpages npgs $ hdl
 
 -------
 -- smart constructor for R hoodle structures
 -------
-
-
+ 
 -- |
-cnstrctRHoodle :: Hoodle -> IO RHoodle
+cnstrctRHoodle :: Hoodle -> Renderer RHoodle
 cnstrctRHoodle hdl = do 
   let hid = view hoodleID hdl 
       ttl = view title hdl 
       revs = view revisions hdl 
       pgs = view pages hdl
-      embeddedsrc = view embeddedPdf hdl 
-  mdoc <- maybe (return Nothing) (\src -> liftIO $ popplerGetDocFromDataURI src)
-            embeddedsrc
-  npgs <- evalStateT (mapM cnstrctRPage_StateT pgs) (Just (Context "" "" Nothing mdoc)) 
-  return $ GHoodle hid ttl revs embeddedsrc (fromList npgs)          
-   
+      pdf = view embeddedPdf hdl 
+      txt = view embeddedText hdl
+  (_,qvar) <- ask
+  mdoc <- maybe (return Nothing) (\src -> liftIO $ do
+            uuid <- nextRandom
+            docvar <- atomically newEmptyTMVar
+            atomically $ sendPDFCommand uuid qvar (GetDocFromDataURI src docvar)
+            atomically $ takeTMVar docvar 
+          ) pdf
 
+  npgs <- evalStateT (mapM cnstrctRPage_StateT pgs) 
+                     (Just (Context "" "" Nothing mdoc)) 
+  return $ GHoodle hid ttl revs pdf txt (fromList npgs)          
+   
 -- |
-cnstrctRPage_StateT :: Page -> StateT (Maybe Context) IO RPage
+cnstrctRPage_StateT :: Page -> StateT (Maybe Context) Renderer RPage
 cnstrctRPage_StateT pg = do  
   let bkg = view background pg
       dim = view dimension pg 
       lyrs = view layers pg
-  nlyrs_lst <- liftIO $ mapM cnstrctRLayer lyrs
+  nlyrs_lst <- lift (mapM cnstrctRLayer lyrs)
   let nlyrs_nonemptylst = if null nlyrs_lst then (emptyRLayer,[]) else (head nlyrs_lst,tail nlyrs_lst) 
       nlyrs = fromNonEmptyList nlyrs_nonemptylst 
   nbkg <- cnstrctRBkg_StateT dim bkg
   return $ GPage dim nbkg nlyrs 
     
 -- |
-cnstrctRLayer :: Layer -> IO RLayer 
+cnstrctRLayer :: Layer -> Renderer RLayer 
 cnstrctRLayer lyr = do 
   nitms <- (mapM cnstrctRItem . view items) lyr 
   return (set gitems nitms emptyRLayer)
-
-                 
diff --git a/src/Graphics/Hoodle/Render/Background.hs b/src/Graphics/Hoodle/Render/Background.hs
--- a/src/Graphics/Hoodle/Render/Background.hs
+++ b/src/Graphics/Hoodle/Render/Background.hs
@@ -4,9 +4,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.PDFBackground 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -15,16 +15,20 @@
 
 module Graphics.Hoodle.Render.Background where
 
+import           Control.Concurrent
+import           Control.Concurrent.STM
 import           Control.Monad.State hiding (mapM_)
+import           Control.Monad.Trans.Maybe
+import           Control.Monad.Trans.Reader (ask)
 import           Data.ByteString hiding (putStrLn,filter)
 import           Data.Foldable (mapM_)
-import           Graphics.Rendering.Cairo
---
 import qualified Data.Map as M
 import           Data.ByteString.Base64 
 import qualified Data.ByteString.Char8 as C
 import           Data.Monoid
 import           Data.UUID.V4 (nextRandom)
+import qualified Graphics.Rendering.Cairo as Cairo
+import           Graphics.UI.Gtk (postGUIAsync)
 import qualified Graphics.UI.Gtk.Poppler.Document as Poppler
 import qualified Graphics.UI.Gtk.Poppler.Page as PopplerPage
 import           System.Directory
@@ -35,6 +39,7 @@
 import           Data.Hoodle.Simple
 --
 import           Graphics.Hoodle.Render.Type.Background
+import           Graphics.Hoodle.Render.Type.Renderer
 -- 
 import Prelude hiding (mapM_)
 
@@ -70,33 +75,26 @@
 -- |
 popplerGetPageFromDoc :: Poppler.Document 
                       -> Int -- ^ page number 
-                      -> IO (Maybe Poppler.Page, Maybe Surface)
+                      -> IO (Maybe Poppler.Page)
 popplerGetPageFromDoc doc pn = do   
   n <- Poppler.documentGetNPages doc 
   if pn > n 
-    then return (Nothing, Nothing)
+    then return Nothing
     else do 
       pg <- Poppler.documentGetPage doc (pn-1) 
-      (w,h) <- PopplerPage.pageGetSize pg
-      sfc <- createImageSurface FormatARGB32 (floor w) (floor h)
-      renderWith sfc $ do   
-        setSourceRGBA 1 1 1 1
-        rectangle 0 0 w h 
-        fill
-        PopplerPage.pageRender pg
-      return (Just pg, Just sfc)
+      return (Just pg)
 
 -- | draw ruling all 
-drawRuling :: Double -> Double -> ByteString -> Render () 
+drawRuling :: Double -> Double -> ByteString -> Cairo.Render () 
 drawRuling w h style = do
   let drawHorizRules = do 
       let (r,g,b,a) = predefined_RULING_COLOR         
-      setSourceRGBA r g b a 
-      setLineWidth predefined_RULING_THICKNESS
+      Cairo.setSourceRGBA r g b a 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
       let drawonerule y = do 
-            moveTo 0 y 
-            lineTo w y
-            stroke  
+            Cairo.moveTo 0 y 
+            Cairo.lineTo w y
+            Cairo.stroke  
       mapM_ drawonerule [ predefined_RULING_TOPMARGIN 
                         , predefined_RULING_TOPMARGIN+predefined_RULING_SPACING
                         .. 
@@ -106,24 +104,24 @@
     "lined" -> do 
       drawHorizRules
       let (r2,g2,b2,a2) = predefined_RULING_MARGIN_COLOR
-      setSourceRGBA r2 g2 b2 a2 
-      setLineWidth predefined_RULING_THICKNESS
-      moveTo predefined_RULING_LEFTMARGIN 0 
-      lineTo predefined_RULING_LEFTMARGIN h
-      stroke
+      Cairo.setSourceRGBA r2 g2 b2 a2 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
+      Cairo.moveTo predefined_RULING_LEFTMARGIN 0 
+      Cairo.lineTo predefined_RULING_LEFTMARGIN h
+      Cairo.stroke
     "ruled" -> drawHorizRules 
     "graph" -> do 
       let (r3,g3,b3,a3) = predefined_RULING_COLOR 
-      setSourceRGBA r3 g3 b3 a3 
-      setLineWidth predefined_RULING_THICKNESS
+      Cairo.setSourceRGBA r3 g3 b3 a3 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
       let drawonegraphvert x = do 
-            moveTo x 0 
-            lineTo x h
-            stroke  
+            Cairo.moveTo x 0 
+            Cairo.lineTo x h
+            Cairo.stroke  
       let drawonegraphhoriz y = do 
-            moveTo 0 y
-            lineTo w y
-            stroke
+            Cairo.moveTo 0 y
+            Cairo.lineTo w y
+            Cairo.stroke
       mapM_ drawonegraphvert  [0,predefined_RULING_GRAPHSPACING..w-1] 
       mapM_ drawonegraphhoriz [0,predefined_RULING_GRAPHSPACING..h-1]
     _ -> return ()     
@@ -131,20 +129,20 @@
 
 
 -- | draw ruling  in bbox 
-drawRuling_InBBox :: BBox -> Double -> Double -> ByteString -> Render () 
+drawRuling_InBBox :: BBox -> Double -> Double -> ByteString -> Cairo.Render () 
 drawRuling_InBBox (BBox (x1,y1) (x2,y2)) w h style = do
   let drawonerule y = do 
-        moveTo x1 y 
-        lineTo x2 y
-        stroke  
+        Cairo.moveTo x1 y 
+        Cairo.lineTo x2 y
+        Cairo.stroke  
   let drawonegraphvert x = do 
-        moveTo x y1 
-        lineTo x y2
-        stroke  
+        Cairo.moveTo x y1 
+        Cairo.lineTo x y2
+        Cairo.stroke  
   let drawonegraphhoriz y = do 
-        moveTo x1 y
-        lineTo x2 y
-        stroke
+        Cairo.moveTo x1 y
+        Cairo.lineTo x2 y
+        Cairo.stroke
       fullRuleYs = [ predefined_RULING_TOPMARGIN 
                    , predefined_RULING_TOPMARGIN+predefined_RULING_SPACING
                    .. 
@@ -156,88 +154,95 @@
       graphYs = filter (\y->(y<=y2)&&(y>=y1)) fullGraphYs 
   let drawHorizRules = do 
       let (r,g,b,a) = predefined_RULING_COLOR         
-      setSourceRGBA r g b a 
-      setLineWidth predefined_RULING_THICKNESS
+      Cairo.setSourceRGBA r g b a 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
       mapM_ drawonerule ruleYs
   case style of 
     "plain" -> return () 
     "lined" -> do 
       drawHorizRules
       let (r2,g2,b2,a2) = predefined_RULING_MARGIN_COLOR
-      setSourceRGBA r2 g2 b2 a2 
-      setLineWidth predefined_RULING_THICKNESS
-      moveTo predefined_RULING_LEFTMARGIN 0 
-      lineTo predefined_RULING_LEFTMARGIN h
-      stroke
+      Cairo.setSourceRGBA r2 g2 b2 a2 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
+      Cairo.moveTo predefined_RULING_LEFTMARGIN 0 
+      Cairo.lineTo predefined_RULING_LEFTMARGIN h
+      Cairo.stroke
     "ruled" -> drawHorizRules 
     "graph" -> do 
       let (r3,g3,b3,a3) = predefined_RULING_COLOR 
-      setSourceRGBA r3 g3 b3 a3 
-      setLineWidth predefined_RULING_THICKNESS
+      Cairo.setSourceRGBA r3 g3 b3 a3 
+      Cairo.setLineWidth predefined_RULING_THICKNESS
       mapM_ drawonegraphvert  graphXs 
       mapM_ drawonegraphhoriz graphYs
     _ -> return ()     
 
 
 -- | render background without any constraint 
-renderBkg :: (Background,Dimension) -> Render () 
+renderBkg :: (Background,Dimension) -> Cairo.Render () 
 renderBkg (Background _typ col sty,Dim w h) = do 
     let c = M.lookup col predefined_bkgcolor  
     case c of 
-      Just (r,g,b,_a) -> setSourceRGB r g b 
-      Nothing        -> setSourceRGB 1 1 1 
-    rectangle 0 0 w h 
-    fill
+      Just (r,g,b,_a) -> Cairo.setSourceRGB r g b 
+      Nothing         -> Cairo.setSourceRGB 1 1 1 
+    Cairo.rectangle 0 0 w h 
+    Cairo.fill
     drawRuling w h sty
 renderBkg (BackgroundPdf _ _ _ _,Dim w h) = do 
-    setSourceRGBA 1 1 1 1
-    rectangle 0 0 w h 
-    fill
+    Cairo.setSourceRGBA 1 1 1 1
+    Cairo.rectangle 0 0 w h 
+    Cairo.fill
 renderBkg (BackgroundEmbedPdf _ _,Dim w h) = do 
-    setSourceRGBA 1 1 1 1
-    rectangle 0 0 w h 
-    fill
+    Cairo.setSourceRGBA 1 1 1 1
+    Cairo.rectangle 0 0 w h 
+    Cairo.fill
 
 
 
 -- | this has some bugs. need to fix 
-cnstrctRBkg_StateT :: Dimension -> Background 
-                   -> StateT (Maybe Context) IO RBackground
+cnstrctRBkg_StateT :: Dimension 
+                   -> Background 
+                   -> StateT (Maybe Context) Renderer RBackground
 cnstrctRBkg_StateT dim@(Dim w h) bkg = do  
+  (handler,qvar) <- lift ask
+  uuid <- liftIO nextRandom
   case bkg of 
-    Background _t c s -> do 
-      sfc <- liftIO $ createImageSurface FormatARGB32 (floor w) (floor h)
-      renderWith sfc $ renderBkg (bkg,dim) 
-      return (RBkgSmpl c s (Just sfc))
+    Background _t c s -> return (RBkgSmpl c s uuid) 
     BackgroundPdf _t md mf pn -> do 
-      case (md,mf) of 
-        (Just d, Just f) -> do 
-           mdoc <- liftIO $ popplerGetDocFromFile f
-           put $ Just (Context d f mdoc Nothing)
-           case mdoc of 
-             Just doc -> do  
-               (mpg,msfc) <- liftIO $ popplerGetPageFromDoc doc pn 
-               return (RBkgPDF md f pn mpg msfc)
-             Nothing -> error "error1 in cnstrctRBkg_StateT"
-        _ -> do 
-          mctxt <- get
-          case mctxt of  
-            Just (Context oldd oldf olddoc _) -> do 
-              (mpage,msfc) <- case olddoc of 
-                Just doc -> do 
-                  liftIO $ popplerGetPageFromDoc doc pn
-                Nothing -> error "error2 in cnstrctRBkg_StateT" 
-              maybe (liftIO $ putStrLn ( "pn = " ++ show pn )) (const (return ())) mpage 
-              return (RBkgPDF (Just oldd) oldf pn mpage msfc)
-            Nothing -> error "error3 in cnstrctRBkg_StateT" 
+      r <- runMaybeT $ do
+        (pg,rbkg) <- case (md,mf) of 
+          (Just d, Just f) -> do 
+            uuiddoc <- liftIO nextRandom
+            docvar <- liftIO (atomically newEmptyTMVar)
+            liftIO . atomically $ sendPDFCommand uuiddoc qvar (GetDocFromFile f docvar)
+            doc <- MaybeT . liftIO $ atomically $ takeTMVar docvar 
+            lift . put $ Just (Context d f (Just doc) Nothing)
+            --
+            uuidpg <- liftIO nextRandom
+            pgvar <- liftIO (atomically newEmptyTMVar)
+            liftIO . atomically $ sendPDFCommand uuidpg qvar (GetPageFromDoc doc pn pgvar)
+            pg <- MaybeT . liftIO $ atomically $ takeTMVar pgvar        
+            return (pg, RBkgPDF md f pn (Just pg) uuid)
+          _ -> do 
+            Context oldd oldf olddoc _ <- MaybeT get
+            doc <- MaybeT . return $ olddoc  
+            uuidpg <- liftIO nextRandom
+            pgvar <- liftIO (atomically newEmptyTMVar)
+            liftIO . atomically $ sendPDFCommand uuidpg qvar (GetPageFromDoc doc pn pgvar)
+            pg <- MaybeT . liftIO $ atomically $ takeTMVar pgvar        
+            return (pg, RBkgPDF (Just oldd) oldf pn (Just pg) uuid)
+        return rbkg
+      case r of
+        Nothing -> error "error in cnstrctRBkg_StateT"
+        Just x -> return x
     BackgroundEmbedPdf _ pn -> do 
-      mctxt <- get
-      case mctxt of  
-        Just (Context _ _ _ mdoc) -> do 
-          (mpage,msfc) <- case mdoc of 
-            Just doc -> do 
-              liftIO $ popplerGetPageFromDoc doc pn
-            Nothing -> error "error4 in cnstrctRBkg_StateT" 
-          return (RBkgEmbedPDF pn mpage msfc)
-        Nothing -> error "error5 in cnstrctRBkg_StateT" 
-
+      r <- runMaybeT $ do 
+        Context _ _ _ mdoc <- MaybeT get
+        doc <- (MaybeT . return) mdoc 
+        uuidpg <- liftIO nextRandom
+        pgvar <- liftIO (atomically newEmptyTMVar)
+        liftIO . atomically $ sendPDFCommand uuidpg qvar (GetPageFromDoc doc pn pgvar)
+        pg <- MaybeT . liftIO $ atomically $ takeTMVar pgvar        
+        return (RBkgEmbedPDF pn (Just pg) uuid)
+      case r of 
+        Nothing -> error "error in cnstrctRBkg_StateT"
+        Just x -> return x
diff --git a/src/Graphics/Hoodle/Render/Debug.hs b/src/Graphics/Hoodle/Render/Debug.hs
--- a/src/Graphics/Hoodle/Render/Debug.hs
+++ b/src/Graphics/Hoodle/Render/Debug.hs
@@ -4,7 +4,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Debug
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -20,8 +20,6 @@
 (      
 -- * dummy rendering 
   renderRBkg_Dummy  
--- * render in bbox using non R-structure 
--- , renderBkg_InBBox
 -- * nopdf
 , renderRBkg_NoPDF
 -- * render only bbox (for debug purpose)
@@ -39,15 +37,16 @@
 import           Control.Monad.State hiding (mapM,mapM_)
 import           Data.Foldable
 import qualified Data.Map as M
-import           Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 -- from hoodle-platform 
-import Data.Hoodle.Generic
-import Data.Hoodle.Simple
-import Data.Hoodle.BBox
-import Data.Hoodle.Predefined 
+import           Data.Hoodle.Generic
+import           Data.Hoodle.Simple
+import           Data.Hoodle.BBox
+import           Data.Hoodle.Predefined 
 -- from this package
-import Graphics.Hoodle.Render
-import Graphics.Hoodle.Render.Type 
+import           Graphics.Hoodle.Render
+import           Graphics.Hoodle.Render.Highlight
+import           Graphics.Hoodle.Render.Type 
 -- 
 import Prelude hiding (curry,uncurry,mapM,mapM_,concatMap)
 
@@ -55,87 +54,85 @@
 -- Dummy (for testing) 
 -----
 
-renderRBkg_Dummy :: (RBackground,Dimension) -> Render () 
-renderRBkg_Dummy (_,Dim w h) = do 
-    setSourceRGBA 1 1 1 1
-    rectangle 0 0 w h 
-    fill 
+renderRBkg_Dummy :: RenderCache -> (RBackground,Dimension,Maybe Xform4Page) -> Cairo.Render ()
+renderRBkg_Dummy _ (_,Dim w h,_) = do 
+    Cairo.setSourceRGBA 1 1 1 1
+    Cairo.rectangle 0 0 w h 
+    Cairo.fill 
 
 -----------
 -- NoPDF -- 
 -----------
 
 -- | render background without pdf 
-renderRBkg_NoPDF :: (RBackground,Dimension) -> Render ()
-renderRBkg_NoPDF r@(RBkgSmpl _ _ _,_) = renderRBkg r >> return ()
-renderRBkg_NoPDF (RBkgPDF _ _ _ _ _,_) = return ()
-renderRBkg_NoPDF (RBkgEmbedPDF _ _ _,_) = return ()
+renderRBkg_NoPDF :: RenderCache -> (RBackground,Dimension,Maybe Xform4Page) -> Cairo.Render ()
+renderRBkg_NoPDF cache r@(RBkgSmpl _ _ _,_,_) = renderRBkg cache r >> return ()
+renderRBkg_NoPDF _ (RBkgPDF _ _ _ _ _,_,_) = return ()
+renderRBkg_NoPDF _ (RBkgEmbedPDF _ _ _,_,_) = return ()
 
 --------------
 -- BBoxOnly --
 --------------
 
 -- | render only bounding box of a StrokeBBox      
-renderStrkBBx_BBoxOnly :: BBoxed Stroke -> Render () 
+renderStrkBBx_BBoxOnly :: BBoxed Stroke -> Cairo.Render () 
 renderStrkBBx_BBoxOnly sbbox = do  
     let s = bbxed_content sbbox
     case M.lookup (stroke_color s) predefined_pencolor of 
-      Just (r,g,b,a) -> setSourceRGBA r g b a
-      Nothing -> setSourceRGBA 0 0 0 1 
-    setSourceRGBA 0 0 0 1
-    setLineWidth (stroke_width s) 
+      Just (r,g,b,a) -> Cairo.setSourceRGBA r g b a
+      Nothing -> Cairo.setSourceRGBA 0 0 0 1 
+    Cairo.setSourceRGBA 0 0 0 1
+    Cairo.setLineWidth (stroke_width s) 
     let BBox (x1,y1) (x2,y2) = getBBox sbbox
-    rectangle x1 y1 (x2-x1) (y2-y1)
-    stroke
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.stroke
   
 -- |     
-renderImgBBx_BBoxOnly :: BBoxed Image -> Render () 
+renderImgBBx_BBoxOnly :: BBoxed Image -> Cairo.Render ()
 renderImgBBx_BBoxOnly ibbox = do 
-    setSourceRGBA 0 0 0 1
-    setLineWidth 10
+    Cairo.setSourceRGBA 0 0 0 1
+    Cairo.setLineWidth 10
     let BBox (x1,y1) (x2,y2) = getBBox ibbox
-    rectangle x1 y1 (x2-x1) (y2-y1)
-    stroke
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.stroke
 
-renderSVGBBx_BBoxOnly :: BBoxed SVG -> Render () 
+renderSVGBBx_BBoxOnly :: BBoxed SVG -> Cairo.Render ()
 renderSVGBBx_BBoxOnly svg = do 
-    setSourceRGBA 0 0 0 1
-    setLineWidth 10
+    Cairo.setSourceRGBA 0 0 0 1
+    Cairo.setLineWidth 10
     let BBox (x1,y1) (x2,y2) = getBBox svg
-    rectangle x1 y1 (x2-x1) (y2-y1)
-    stroke
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.stroke
 
-renderLnkBBx_BBoxOnly :: BBoxed Link -> Render () 
+renderLnkBBx_BBoxOnly :: BBoxed Link -> Cairo.Render ()
 renderLnkBBx_BBoxOnly lnk = do 
-    setSourceRGBA 0 0 0 1
-    setLineWidth 10
+    Cairo.setSourceRGBA 0 0 0 1
+    Cairo.setLineWidth 10
     let BBox (x1,y1) (x2,y2) = getBBox lnk
-    rectangle x1 y1 (x2-x1) (y2-y1)
-    stroke
-
-    
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.stroke
 
 -- | 
-renderRItem_BBoxOnly :: RItem -> Render () 
-renderRItem_BBoxOnly (RItemStroke sbbox) = renderStrkBBx_BBoxOnly sbbox
-renderRItem_BBoxOnly (RItemImage ibbox _) = renderImgBBx_BBoxOnly ibbox
-renderRItem_BBoxOnly (RItemSVG svg _) = renderSVGBBx_BBoxOnly svg
-renderRItem_BBoxOnly (RItemLink lnk _) = renderLnkBBx_BBoxOnly lnk
-
+renderRItem_BBoxOnly :: RenderCache -> RItem -> Cairo.Render () 
+renderRItem_BBoxOnly _ (RItemStroke sbbox) = renderStrkBBx_BBoxOnly sbbox
+renderRItem_BBoxOnly _ (RItemImage ibbox _) = renderImgBBx_BBoxOnly ibbox
+renderRItem_BBoxOnly _ (RItemSVG svg _) = renderSVGBBx_BBoxOnly svg
+renderRItem_BBoxOnly _ (RItemLink lnk _) = renderLnkBBx_BBoxOnly lnk
+renderRItem_BBoxOnly _ itm@(RItemAnchor anc _) = (renderHltBBox . getBBox) anc
 
 -- | 
-renderRLayer_BBoxOnly :: RLayer -> Render ()
-renderRLayer_BBoxOnly = mapM_  renderRItem_BBoxOnly . view gitems
+renderRLayer_BBoxOnly :: RenderCache -> RLayer -> Cairo.Render ()
+renderRLayer_BBoxOnly cache = mapM_  (renderRItem_BBoxOnly cache) . view gitems
 
 
   
 -- | render only bounding box of a StrokeBBox      
-renderRPage_BBoxOnly :: RPage -> Render ()  
-renderRPage_BBoxOnly page = do
+renderRPage_BBoxOnly :: RenderCache -> RPage -> Cairo.Render ()  
+renderRPage_BBoxOnly cache page = do
     let dim = view gdimension page
         bkg = view gbackground page 
         lyrs =  view glayers page
-    renderRBkg_NoPDF (bkg,dim)
-    mapM_ renderRLayer_BBoxOnly lyrs
+    renderRBkg_NoPDF cache (bkg,dim,Nothing)
+    mapM_ (renderRLayer_BBoxOnly cache) lyrs
 
 
diff --git a/src/Graphics/Hoodle/Render/Generic.hs b/src/Graphics/Hoodle/Render/Generic.hs
--- a/src/Graphics/Hoodle/Render/Generic.hs
+++ b/src/Graphics/Hoodle/Render/Generic.hs
@@ -3,9 +3,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Generic 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -19,7 +19,7 @@
 import Control.Monad hiding (mapM_,mapM)
 import Data.Foldable
 import Data.Traversable 
-import Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 -- from hoodle-platform
 import Data.Hoodle.BBox
 import Data.Hoodle.Generic
@@ -35,30 +35,31 @@
 passarg :: (Monad m) => (a -> m ()) -> a -> m a
 passarg f a = f a >> return a
 
+
 -- | 
 class Renderable a where 
-  cairoRender :: a -> Render a
+  cairoRender :: RenderCache -> a -> Cairo.Render a
                  
 -- | 
 instance Renderable (Background,Dimension) where
-  cairoRender = passarg renderBkg 
+  cairoRender = const (passarg renderBkg) 
 
 -- | 
 instance Renderable Stroke where 
-  cairoRender = passarg renderStrk 
+  cairoRender = const (passarg renderStrk)
 
 -- | 
 instance Renderable (BBoxed Stroke) where
-  cairoRender = passarg (renderStrk . bbxed_content)
+  cairoRender =const (passarg (renderStrk . bbxed_content))
   
 -- | 
 instance Renderable RLayer where
-  cairoRender = renderRLayer_InBBox Nothing 
+  cairoRender cache = renderRLayer_InBBox cache Nothing 
   
 -- | 
 class RenderOptionable a where   
   type RenderOption a :: *
-  cairoRenderOption :: RenderOption a -> a -> Render a
+  cairoRenderOption :: RenderOption a -> RenderCache -> a -> Cairo.Render a
 
 -- | 
 instance RenderOptionable (Background,Dimension) where
@@ -77,70 +78,68 @@
 instance RenderOptionable (BBoxed Stroke) where
   type RenderOption (BBoxed Stroke) = StrokeBBoxOption
   cairoRenderOption DrawFull = cairoRender 
-  cairoRenderOption DrawBoxOnly = passarg renderStrkBBx_BBoxOnly
+  cairoRenderOption DrawBoxOnly = const (passarg renderStrkBBx_BBoxOnly)
   
 -- | 
-instance RenderOptionable (RBackground,Dimension) where 
-  type RenderOption (RBackground,Dimension) = RBkgOpt 
-  -- cairoRenderOption :: RBkgOpt -> (RBackground,Dimension) -> Render ()
-  cairoRenderOption RBkgDrawPDF = renderRBkg
-  cairoRenderOption RBkgDrawWhite = passarg renderRBkg_Dummy
-  cairoRenderOption RBkgDrawBuffer = renderRBkg_Buf 
-  cairoRenderOption (RBkgDrawPDFInBBox mbbox) = renderRBkg_InBBox mbbox 
+instance RenderOptionable (RBackground,Dimension,Maybe Xform4Page) where 
+  type RenderOption (RBackground,Dimension,Maybe Xform4Page) = RBkgOpt 
+  cairoRenderOption RBkgDrawPDF cache = renderRBkg cache
+  cairoRenderOption RBkgDrawWhite cache = passarg (renderRBkg_Dummy cache)
+  cairoRenderOption RBkgDrawBuffer cache = renderRBkg_Buf cache 
+  cairoRenderOption (RBkgDrawPDFInBBox mbbox) cache = renderRBkg_InBBox cache mbbox 
 
 -- | 
 instance RenderOptionable RLayer where
   type RenderOption RLayer = StrokeBBoxOption 
-  cairoRenderOption DrawFull = cairoRender
-  cairoRenderOption DrawBoxOnly = passarg renderRLayer_BBoxOnly 
+  cairoRenderOption DrawFull cache = cairoRender cache
+  cairoRenderOption DrawBoxOnly cache = passarg (renderRLayer_BBoxOnly cache)
 
 -- | 
 instance RenderOptionable (InBBox RLayer) where
   type RenderOption (InBBox RLayer) = InBBoxOption
-  cairoRenderOption (InBBoxOption mbbox) (InBBox lyr) = 
-    InBBox <$> renderRLayer_InBBoxBuf mbbox lyr
+  cairoRenderOption (InBBoxOption mbbox) cache (InBBox lyr) = 
+    InBBox <$> renderRLayer_InBBoxBuf cache mbbox lyr
     
 -- |
-cairoOptionPage :: ( RenderOptionable (b,Dimension)
+cairoOptionPage :: ( RenderOptionable (b,Dimension,Maybe Xform4Page)
                    , RenderOptionable a
                    , Foldable s) => 
-                   (RenderOption (b,Dimension), RenderOption a) 
-                   -> GPage b s a 
-                   -> Render (GPage b s a)
-cairoOptionPage (optb,opta) p = do 
-    cairoRenderOption optb (view gbackground p, view gdimension p)
-    mapM_ (cairoRenderOption opta) (view glayers p)
-    return p 
+                   (RenderOption (b,Dimension,Maybe Xform4Page), RenderOption a) 
+                   -> RenderCache
+                   -> (GPage b s a, Maybe Xform4Page)
+                   -> Cairo.Render (GPage b s a, Maybe Xform4Page)
+cairoOptionPage (optb,opta) cache (p,mx) = do 
+    cairoRenderOption optb cache (view gbackground p, view gdimension p,mx)
+    mapM_ (cairoRenderOption opta cache) (view glayers p)
+    return (p,mx) 
   
 -- | 
-instance ( RenderOptionable (b,Dimension)
+instance ( RenderOptionable (b,Dimension,Maybe Xform4Page)
          , RenderOptionable a
          , Foldable s) =>
-         RenderOptionable (GPage b s a) where
-  type RenderOption (GPage b s a) = (RenderOption (b,Dimension), RenderOption a)
+         RenderOptionable (GPage b s a,Maybe Xform4Page) where
+  type RenderOption (GPage b s a,Maybe Xform4Page) = (RenderOption (b,Dimension,Maybe Xform4Page), RenderOption a)
   cairoRenderOption = cairoOptionPage
             
 -- | 
-instance RenderOptionable (InBBox RPage) where
-  type RenderOption (InBBox RPage) = InBBoxOption 
-  cairoRenderOption (InBBoxOption mbbox) (InBBox page) = do 
-    cairoRenderOption (RBkgDrawPDFInBBox mbbox) (view gbackground page, view gdimension page) 
-    --  mapM_ (renderRLayer_InBBox mbbox) . view glayers $ page 
+instance RenderOptionable (InBBox RPage,Maybe Xform4Page) where
+  type RenderOption (InBBox RPage,Maybe Xform4Page) = InBBoxOption 
+  cairoRenderOption (InBBoxOption mbbox) cache (InBBox page,mx) = do 
+    cairoRenderOption (RBkgDrawPDFInBBox mbbox) cache (view gbackground page, view gdimension page, mx)
     let lyrs = view glayers page
-    nlyrs <- mapM (liftM unInBBox . cairoRenderOption (InBBoxOption mbbox) . InBBox ) lyrs
+    nlyrs <- mapM (liftM unInBBox . cairoRenderOption (InBBoxOption mbbox) cache . InBBox ) lyrs
     let npage = set glayers nlyrs page
-    return (InBBox npage) 
+    return (InBBox npage,mx) 
 
 -- | 
-instance RenderOptionable (InBBoxBkgBuf RPage) where
-  type RenderOption (InBBoxBkgBuf RPage) = InBBoxOption 
-  cairoRenderOption (InBBoxOption mbbox) (InBBoxBkgBuf page) = do 
-    cairoRenderOption (RBkgDrawPDFInBBox mbbox) (view gbackground page, view gdimension page) 
-    --  mapM_ (renderRLayer_InBBox mbbox) . view glayers $ page 
+instance RenderOptionable (InBBoxBkgBuf RPage,Maybe Xform4Page) where
+  type RenderOption (InBBoxBkgBuf RPage,Maybe Xform4Page) = InBBoxOption 
+  cairoRenderOption (InBBoxOption mbbox) cache (InBBoxBkgBuf page,mx) = do 
+    cairoRenderOption (RBkgDrawPDFInBBox mbbox) cache (view gbackground page, view gdimension page, mx)
     let lyrs = view glayers page
-    nlyrs <- mapM (renderRLayer_InBBox mbbox) lyrs
+    nlyrs <- mapM (renderRLayer_InBBox cache mbbox) lyrs
     let npage = set glayers nlyrs page
-    return (InBBoxBkgBuf npage) 
+    return (InBBoxBkgBuf npage,mx) 
 
 
 
diff --git a/src/Graphics/Hoodle/Render/Highlight.hs b/src/Graphics/Hoodle/Render/Highlight.hs
--- a/src/Graphics/Hoodle/Render/Highlight.hs
+++ b/src/Graphics/Hoodle/Render/Highlight.hs
@@ -3,7 +3,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Highlight
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -18,57 +18,67 @@
 
 -- from others
 import qualified Data.Map as M
-import           Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 -- from hoodle-platform 
-import Data.Hoodle.Simple
-import Data.Hoodle.BBox
-import Data.Hoodle.Predefined 
+import           Data.Hoodle.Simple
+import           Data.Hoodle.BBox
+import           Data.Hoodle.Predefined 
 -- from this package
-import Graphics.Hoodle.Render.Primitive 
-import Graphics.Hoodle.Render.Type.Item 
+import           Graphics.Hoodle.Render.Primitive 
+import           Graphics.Hoodle.Render.Type.Item 
 -- 
 import Prelude hiding (fst,snd,curry,uncurry,mapM_,concatMap)
 
 -- | 
-renderStrkHltd :: BBoxed Stroke -> Render ()
+renderStrkHltd :: BBoxed Stroke -> Cairo.Render ()
 renderStrkHltd sbbox = do 
     let s = bbxed_content sbbox 
     case M.lookup (stroke_color s) predefined_pencolor of 
-      Just (r,g,b,a) -> setSourceRGBA r g b a
-      Nothing -> setSourceRGBA 0 0 0 1 
+      Just (r,g,b,a) -> Cairo.setSourceRGBA r g b a
+      Nothing -> Cairo.setSourceRGBA 0 0 0 1 
     case s of
       Stroke _ _ w d -> do  
-        setLineWidth (w * 4.0) 
-        setLineCap LineCapRound
-        setLineJoin LineJoinRound
+        Cairo.setLineWidth (w * 4.0) 
+        Cairo.setLineCap Cairo.LineCapRound
+        Cairo.setLineJoin Cairo.LineJoinRound
         drawStrokeCurve d
-        stroke
-        setSourceRGBA 1 1 1 1
-        setLineWidth w
+        Cairo.stroke
+        Cairo.setSourceRGBA 1 1 1 1
+        Cairo.setLineWidth w
         drawStrokeCurve . stroke_data $ s 
-        stroke
+        Cairo.stroke
       VWStroke _ _ d -> do  
-        setFillRule FillRuleWinding
+        Cairo.setFillRule Cairo.FillRuleWinding
         drawVWStrokeCurve $ map (\(x,y,z)->(x,y,4*z)) d
-        fill  
-        setSourceRGBA 1 1 1 1
+        Cairo.fill 
+        Cairo.setSourceRGBA 1 1 1 1
         drawVWStrokeCurve d     
-        fill
+        Cairo.fill
     
 
 -- | render items highlighted 
-renderRItemHltd :: RItem -> Render ()
+renderRItemHltd :: RItem -> Cairo.Render ()
 renderRItemHltd (RItemStroke strk) = renderStrkHltd strk
-renderRItemHltd (RItemImage img _) = renderBBoxHltd img
-renderRItemHltd (RItemSVG svg _) = renderBBoxHltd svg 
-renderRItemHltd (RItemLink lnk _) = renderBBoxHltd lnk
+renderRItemHltd (RItemImage img _) = (renderHltBBox . getBBox) img
+renderRItemHltd (RItemSVG svg _) = (renderHltBBox . getBBox) svg 
+renderRItemHltd (RItemLink lnk _) = (renderHltBBox . getBBox) lnk
+renderRItemHltd (RItemAnchor anc _) = (renderHltBBox . getBBox) anc
 
 -- |
-renderBBoxHltd :: (GetBBoxable a) => a -> Render () 
-renderBBoxHltd x = do 
-  setSourceRGBA 0 0 0 1
-  setLineWidth 10 
-  let BBox (x1,y1) (x2,y2) = getBBox x
-  rectangle x1 y1 (x2-x1) (y2-y1)
-  stroke
+renderHltBBox :: BBox -> Cairo.Render ()
+renderHltBBox (BBox (x1,y1) (x2,y2)) = do 
+    Cairo.setSourceRGBA 0 0 0 1
+    Cairo.setLineWidth 10 
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.stroke
 
+{-
+-- |
+renderHighlightedBBoxedItem :: (GetBBoxable a) => a -> Cairo.Render () 
+renderHighlinetedBBoxedItem x = renderHltBBox . getBBox 
+  Cairo.setSourceRGBA 0 0 0 1
+  Cairo.setLineWidth 10 
+  let BBox (x1,y1) (x2,y2) = getBBox x
+  Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+  Cairo.stroke
+-}
diff --git a/src/Graphics/Hoodle/Render/Item.hs b/src/Graphics/Hoodle/Render/Item.hs
--- a/src/Graphics/Hoodle/Render/Item.hs
+++ b/src/Graphics/Hoodle/Render/Item.hs
@@ -3,10 +3,10 @@
 
 -----------------------------------------------------------------------------
 -- |
--- Module      : Graphics.Hoodle.Render.Type.Item 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Module      : Graphics.Hoodle.Render.Item 
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -18,66 +18,119 @@
 module Graphics.Hoodle.Render.Item where
 
 import           Control.Applicative
-import           Control.Monad 
-import           Control.Monad.Identity 
+import           Control.Concurrent (forkIO) 
+import           Control.Monad
+import           Control.Monad.Identity
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans.Reader
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Char8 as C8
 -- import qualified Data.ByteString.Lazy as LB
-import           Data.ByteString.Base64 
+import           Data.ByteString.Base64
+-- import           Data.UUID
+import           Data.UUID.V4
 import           Graphics.GD.ByteString
-import           Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 import qualified Graphics.Rendering.Cairo.SVG as RSVG
+-- import           Graphics.UI.Gtk (postGUIAsync)
 import           System.Directory
-import           System.FilePath 
+import           System.FilePath
 -- from hoodle-platform 
-import           Data.Hoodle.BBox 
+import           Data.Hoodle.BBox
 import           Data.Hoodle.Simple
-import           Hoodle.Util.Process 
+import           Hoodle.Util.Process
 -- from this package
-import Graphics.Hoodle.Render.Type.Item 
+import           Graphics.Hoodle.Render.Type.Item
+import           Graphics.Hoodle.Render.Type.Renderer
 
 
 -- | construct renderable item 
-cnstrctRItem :: Item -> IO RItem 
+cnstrctRItem :: Item -> Renderer RItem 
 cnstrctRItem (ItemStroke strk) = return (RItemStroke (runIdentity (makeBBoxed strk)))
 cnstrctRItem (ItemImage img) = do 
+    (handler,_) <- ask 
     let imgbbx = runIdentity (makeBBoxed img)
         src = img_src img
-        embed = getByteStringIfEmbeddedPNG src 
-    case embed of         
+    -- uuid <- liftIO $  nextRandom
+
+    -- liftIO . forkIO $ do
+    --   let embed = getByteStringIfEmbeddedPNG src 
+    --   msfc <- case embed of         
+    --     Just bstr -> do 
+    --       sfc <- saveTempPNGToCreateSurface bstr 
+    --       return (Just sfc)
+    --     Nothing -> do
+    --       let filesrc = C8.unpack (img_src img)
+    --           filesrcext = takeExtension filesrc 
+    --           imgaction 
+    --             | filesrcext == ".PNG" || filesrcext == ".png" = do 
+    --                 b <- doesFileExist filesrc 
+    --                 if b then Just <$> Cairo.imageSurfaceCreateFromPNG filesrc
+    --                      else return Nothing 
+    --             | filesrcext == ".JPG" || filesrcext == ".jpg" = do 
+    --                 b <- doesFileExist filesrc 
+    --                 if b then Just <$> getJPGandCreateSurface filesrc 
+    --                      else return Nothing 
+    --             | otherwise = return Nothing 
+    --       imgaction
+    --   maybe (return ()) (\sfc-> handler (uuid, (1.0,sfc))) msfc
+
+
+    let embed = getByteStringIfEmbeddedPNG src 
+    msfc <- liftIO $ case embed of         
       Just bstr -> do 
         sfc <- saveTempPNGToCreateSurface bstr 
-        return (RItemImage imgbbx (Just sfc))
+        return (Just sfc)
       Nothing -> do
-        let filesrc = C8.unpack (img_src img)
-            filesrcext = takeExtension filesrc 
-            imgaction 
-              | filesrcext == ".PNG" || filesrcext == ".png" = do 
-                  b <- doesFileExist filesrc 
-                  if b then Just <$> imageSurfaceCreateFromPNG filesrc
-                       else return Nothing 
-              | filesrcext == ".JPG" || filesrcext == ".jpg" = do 
-                  b <- doesFileExist filesrc 
-                  if b then Just <$> getJPGandCreateSurface filesrc 
-                       else return Nothing 
-              | otherwise = return Nothing 
-        msfc <- imgaction
-        return (RItemImage imgbbx msfc)
+	let filesrc = C8.unpack (img_src img)
+	    filesrcext = takeExtension filesrc 
+	    imgaction 
+	      | filesrcext == ".PNG" || filesrcext == ".png" = do 
+		  b <- doesFileExist filesrc 
+		  if b then Just <$> Cairo.imageSurfaceCreateFromPNG filesrc
+		       else return Nothing 
+	      | filesrcext == ".JPG" || filesrcext == ".jpg" = do 
+		  b <- doesFileExist filesrc 
+		  if b then Just <$> getJPGandCreateSurface filesrc 
+		       else return Nothing 
+	      | otherwise = return Nothing 
+	imgaction
+    -- maybe (return ()) (\sfc-> handler (uuid, (1.0,sfc))) msfc
+
+    return (RItemImage imgbbx msfc)
 cnstrctRItem (ItemSVG svg@(SVG _ _ bstr _ _)) = do 
     let str = C8.unpack bstr 
         svgbbx = runIdentity (makeBBoxed svg)
-    rsvg <- RSVG.svgNewFromString str
+    rsvg <- liftIO (RSVG.svgNewFromString str)
     return (RItemSVG svgbbx (Just rsvg))
 cnstrctRItem (ItemLink lnk@(Link _ _ _ _ _ bstr _ _)) = do 
     let str = C8.unpack bstr 
         lnkbbx = runIdentity (makeBBoxed lnk)
-    rsvg <- RSVG.svgNewFromString str
+    rsvg <- liftIO $ RSVG.svgNewFromString str
     return (RItemLink lnkbbx (Just rsvg))
 cnstrctRItem (ItemLink lnk@(LinkDocID _ _ _ _ _ bstr _ _)) = do 
     let str = C8.unpack bstr 
         lnkbbx = runIdentity (makeBBoxed lnk)
-    rsvg <- RSVG.svgNewFromString str
+    rsvg <- liftIO $ RSVG.svgNewFromString str
     return (RItemLink lnkbbx (Just rsvg))    
+cnstrctRItem (ItemLink lnk@(LinkAnchor _ _ _ _ bstr _ _)) = 
+    if C8.null bstr 
+    then let lnkbbx = runIdentity (makeBBoxed lnk) 
+         in return (RItemLink lnkbbx Nothing) 
+    else do 
+      let str = C8.unpack bstr 
+          lnkbbx = runIdentity (makeBBoxed lnk)
+      rsvg <- liftIO $ RSVG.svgNewFromString str
+      return (RItemLink lnkbbx (Just rsvg))    
+cnstrctRItem (ItemAnchor anc@(Anchor _ bstr _ _)) = 
+    if C8.null bstr 
+    then let ancbbx = runIdentity (makeBBoxed anc) 
+         in return (RItemAnchor ancbbx Nothing)
+    else do 
+      let str = C8.unpack bstr 
+          ancbbx = runIdentity (makeBBoxed anc)
+      rsvg <- liftIO $ RSVG.svgNewFromString str
+      return (RItemAnchor ancbbx (Just rsvg))    
 
 
 -- | get embedded png image. If not, just give me nothing. 
@@ -91,19 +144,14 @@
 
 -- | read JPG file using GD library and create cairo image surface
 --   currently, this uses temporary png file (which is potentially dangerous)
-getJPGandCreateSurface :: FilePath -> IO Surface 
+getJPGandCreateSurface :: FilePath -> IO Cairo.Surface 
 getJPGandCreateSurface fp = do 
     img <- loadJpegFile fp  
     bstr <- savePngByteString img
     saveTempPNGToCreateSurface bstr 
 
 -- | 
-saveTempPNGToCreateSurface :: C8.ByteString -> IO Surface
+saveTempPNGToCreateSurface :: C8.ByteString -> IO Cairo.Surface
 saveTempPNGToCreateSurface bstr = do 
-    pipeActionWith (B.writeFile "/dev/stdout" bstr) imageSurfaceCreateFromPNG 
+    pipeActionWith (B.writeFile "/dev/stdout" bstr) Cairo.imageSurfaceCreateFromPNG 
 
-{-
-    tdir <- getTemporaryDirectory 
-    let tfile = tdir </> "temp.png"
-    imageSurfaceCreateFromPNG tfile 
--}
diff --git a/src/Graphics/Hoodle/Render/Primitive.hs b/src/Graphics/Hoodle/Render/Primitive.hs
--- a/src/Graphics/Hoodle/Render/Primitive.hs
+++ b/src/Graphics/Hoodle/Render/Primitive.hs
@@ -2,7 +2,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Primitive
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -21,7 +21,7 @@
 import           Control.Applicative
 import           Control.Monad 
 import           Data.Strict.Tuple hiding (fst,snd)
-import           Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 -- from hoodle-platform
 import           Data.Hoodle.Predefined 
 -- 
@@ -32,29 +32,29 @@
 ------------------
 
 -- | 
-drawStrokeCurve :: [Pair Double Double] -> Render ()
+drawStrokeCurve :: [Pair Double Double] -> Cairo.Render ()
 drawStrokeCurve ((x0 :!: y0) : xs) = do 
-  x0 `seq` y0 `seq` moveTo x0 y0
+  x0 `seq` y0 `seq` Cairo.moveTo x0 y0
   mapM_ f xs 
-    where f (x :!: y) = x `seq` y `seq` lineTo x y 
+    where f (x :!: y) = x `seq` y `seq` Cairo.lineTo x y 
 drawStrokeCurve [] = return ()
 
 -- | 
-drawVWStrokeCurve :: [(Double,Double,Double)] -> Render ()
+drawVWStrokeCurve :: [(Double,Double,Double)] -> Cairo.Render ()
 drawVWStrokeCurve [] = return ()
 drawVWStrokeCurve (_:[]) = return ()
 drawVWStrokeCurve ((xo,yo,_zo) : xs) = do 
-    moveTo xo yo
+    Cairo.moveTo xo yo
     let ((xlast,ylast,_zlast):rxs) = reverse xs 
     foldM_ forward (xo,yo) xs 
     foldM_ backward (xlast,ylast) rxs 
   where (dx,dy) = (,) <$> fst <*> snd $ predefinedPenShapeAspectXY
         dir (x,y) = x * dy - y * dx
         forward (x0,y0) (x,y,z) = do if (dir (x-x0,y-y0) > 0) 
-                                       then lineTo (x+0.5*dx*z) (y+0.5*dy*z)
-                                       else lineTo (x-0.5*dx*z) (y-0.5*dy*z) 
+                                       then Cairo.lineTo (x+0.5*dx*z) (y+0.5*dy*z)
+                                       else Cairo.lineTo (x-0.5*dx*z) (y-0.5*dy*z) 
                                      return (x,y)       
         backward (x0,y0) (x,y,z) = do if (dir (x-x0,y-y0) < 0) 
-                                        then lineTo (x-0.5*dx*z) (y-0.5*dy*z)
-                                        else lineTo (x+0.5*dx*z) (y+0.5*dy*z)
+                                        then Cairo.lineTo (x-0.5*dx*z) (y-0.5*dy*z)
+                                        else Cairo.lineTo (x+0.5*dx*z) (y+0.5*dy*z)
                                       return (x,y)
diff --git a/src/Graphics/Hoodle/Render/Type.hs b/src/Graphics/Hoodle/Render/Type.hs
--- a/src/Graphics/Hoodle/Render/Type.hs
+++ b/src/Graphics/Hoodle/Render/Type.hs
@@ -3,7 +3,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Type 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -18,10 +18,14 @@
 ( module Graphics.Hoodle.Render.Type.Background
 , module Graphics.Hoodle.Render.Type.Hoodle
 , module Graphics.Hoodle.Render.Type.Item 
+, module Graphics.Hoodle.Render.Type.RenderCache
+, module Graphics.Hoodle.Render.Type.Renderer
 , module Graphics.Hoodle.Render.Type.Select
 ) where
 
 import Graphics.Hoodle.Render.Type.Background
 import Graphics.Hoodle.Render.Type.Hoodle
 import Graphics.Hoodle.Render.Type.Item
+import Graphics.Hoodle.Render.Type.RenderCache
+import Graphics.Hoodle.Render.Type.Renderer
 import Graphics.Hoodle.Render.Type.Select
diff --git a/src/Graphics/Hoodle/Render/Type/Background.hs b/src/Graphics/Hoodle/Render/Type/Background.hs
--- a/src/Graphics/Hoodle/Render/Type/Background.hs
+++ b/src/Graphics/Hoodle/Render/Type/Background.hs
@@ -4,9 +4,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Type.Background 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -16,7 +16,8 @@
 module Graphics.Hoodle.Render.Type.Background where
 
 import           Data.ByteString 
-import           Graphics.Rendering.Cairo
+import           Data.UUID
+-- import qualified Graphics.Rendering.Cairo as Cairo
 import qualified Graphics.UI.Gtk.Poppler.Document as Poppler
 -- from hoodle-platform
 import           Data.Hoodle.BBox
@@ -39,18 +40,24 @@
 data RBackground = RBkgSmpl 
                    { rbkg_color :: ByteString
                    , rbkg_style :: ByteString
-                   , rbkg_cairosurface :: Maybe Surface }
+                   , rbkg_uuid :: UUID
+                   }
                  | RBkgPDF 
                    { rbkg_domain :: Maybe ByteString
                    , rbkg_filename :: ByteString
                    , rbkg_pageno :: Int 
                    , rbkg_popplerpage :: Maybe Poppler.Page 
-                   , rbkg_cairosurface :: Maybe Surface } 
+                   -- , rbkg_cairosurface :: Maybe Cairo.Surface 
+                   , rbkg_uuid :: UUID
+                   } 
                  | RBkgEmbedPDF
                    { rbkg_pageno :: Int
                    , rbkg_popplerpage :: Maybe Poppler.Page 
-                   , rbkg_cairosurface :: Maybe Surface } 
-
+                   -- , rbkg_cairosurface :: Maybe Cairo.Surface 
+                   , rbkg_uuid :: UUID
+                   } 
+instance Show (RBackground) where
+  show _ = "RBackground"
 
 isRBkgSmpl :: RBackground -> Bool 
 isRBkgSmpl (RBkgSmpl _ _ _) = True 
@@ -66,7 +73,3 @@
 rbkg2Bkg (RBkgSmpl c s _) = Background "solid" c s 
 rbkg2Bkg (RBkgPDF d f n _ _ ) = BackgroundPdf "pdf" d (Just f) n 
 rbkg2Bkg (RBkgEmbedPDF n _ _) = BackgroundEmbedPdf "embedpdf" n
-
-
-
-
diff --git a/src/Graphics/Hoodle/Render/Type/Hoodle.hs b/src/Graphics/Hoodle/Render/Type/Hoodle.hs
--- a/src/Graphics/Hoodle/Render/Type/Hoodle.hs
+++ b/src/Graphics/Hoodle/Render/Type/Hoodle.hs
@@ -1,11 +1,12 @@
-{-# LANGUAGE TypeFamilies, TypeOperators, MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
 
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Type.Hoodle
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
--- License     : BSD3
+-- License     : GPL-3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
 -- Stability   : experimental
 -- Portability : GHC
@@ -20,7 +21,7 @@
 import Control.Lens 
 import Data.Foldable (toList)
 import qualified Data.IntMap as IM
-import Graphics.Rendering.Cairo 
+import qualified Graphics.Rendering.Cairo as Cairo
 -- from hoodle-platform 
 import Data.Hoodle.BBox
 import Data.Hoodle.Generic
@@ -34,7 +35,7 @@
 -- normal state rendering --
 ----------------------------
 
-newtype LyBuf = LyBuf (Maybe Surface)
+newtype LyBuf = LyBuf (Maybe Cairo.Surface)
 
 -- | normal rendering data structure for layer, R for rendering
 --   buffer is Surface, container for item = list 
@@ -51,6 +52,9 @@
 --   page is RPage
 type RHoodle = GHoodle IM.IntMap RPage 
 
+instance Show RHoodle where
+  show _ = "RHoodle"
+
 emptyRLayer :: RLayer 
 emptyRLayer = GLayer (LyBuf Nothing) []
 
@@ -77,6 +81,7 @@
                         <*> view gtitle 
                         <*> view grevisions
                         <*> view gembeddedpdf
+                        <*> view gembeddedtext
                         <*> IM.elems . fmap rPage2Page . view gpages
 
 
diff --git a/src/Graphics/Hoodle/Render/Type/Item.hs b/src/Graphics/Hoodle/Render/Type/Item.hs
--- a/src/Graphics/Hoodle/Render/Type/Item.hs
+++ b/src/Graphics/Hoodle/Render/Type/Item.hs
@@ -3,7 +3,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Type.Item 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -16,28 +16,33 @@
 
 module Graphics.Hoodle.Render.Type.Item where
 
-import Graphics.Rendering.Cairo
+import           Data.UUID
+-- import           Data.UUID.V4
+import qualified Graphics.Rendering.Cairo as Cairo
 import qualified Graphics.Rendering.Cairo.SVG as RSVG
 -- from hoodle-platform 
-import Data.Hoodle.BBox 
-import Data.Hoodle.Simple
+import           Data.Hoodle.BBox 
+import           Data.Hoodle.Simple
 
 data RItem = RItemStroke (BBoxed Stroke)
-           | RItemImage (BBoxed Image) (Maybe Surface)
+           | RItemImage (BBoxed Image) (Maybe Cairo.Surface) -- UUID
            | RItemSVG (BBoxed SVG) (Maybe RSVG.SVG)
            | RItemLink (BBoxed Link) (Maybe RSVG.SVG)
+           | RItemAnchor (BBoxed Anchor) (Maybe RSVG.SVG)
 
 instance GetBBoxable RItem where
   getBBox (RItemStroke strk) = getBBox strk
   getBBox (RItemImage img _) = getBBox img 
   getBBox (RItemSVG svg _) = getBBox svg 
   getBBox (RItemLink lnk _) = getBBox lnk
+  getBBox (RItemAnchor anc _) = getBBox anc
 
 instance Show RItem where
   show (RItemStroke strk) = "RItemStroke " ++ show strk
   show (RItemImage img _) = "RItemImage " ++ show img 
   show (RItemSVG svg _) = "RItemSVG " ++ show svg
   show (RItemLink lnk _) = "RItemLink " ++ show lnk
+  show (RItemAnchor anc _) = "RItemAnchor " ++ show anc
 
 -- | 
 isStrkInRItem :: RItem -> Bool 
@@ -61,6 +66,12 @@
 
 
 -- | 
+isAnchorInRItem :: RItem -> Bool 
+isAnchorInRItem (RItemAnchor _ _) = True 
+isAnchorInRItem _ = False
+
+
+-- | 
 findStrkInRItem :: RItem -> Maybe (BBoxed Stroke)
 findStrkInRItem (RItemStroke strk) = Just strk
 findStrkInRItem _ = Nothing 
@@ -81,14 +92,7 @@
 rItem2Item :: RItem -> Item 
 rItem2Item (RItemStroke strk) = (ItemStroke . bbxed_content) strk
 rItem2Item (RItemImage img _) = (ItemImage . bbxed_content) img
-rItem2Item (RItemSVG svg _) = (ItemSVG . bbxed_content) svg
-rItem2Item (RItemLink lnk _) = (ItemLink . bbxed_content) lnk
-
-
-{-
--- | 
-rItemBBox :: RItem -> BBox 
-rItemBBox (RItemStroke strk) = strkbbx_bbx strk
-rItemBBox (RItemImage img _) = imgbbx_bbx img
+rItem2Item (RItemSVG svg _)   = (ItemSVG . bbxed_content) svg
+rItem2Item (RItemLink lnk _)  = (ItemLink . bbxed_content) lnk
+rItem2Item (RItemAnchor anc _)  = (ItemAnchor . bbxed_content) anc
 
--}
diff --git a/src/Graphics/Hoodle/Render/Type/RenderCache.hs b/src/Graphics/Hoodle/Render/Type/RenderCache.hs
new file mode 100644
--- /dev/null
+++ b/src/Graphics/Hoodle/Render/Type/RenderCache.hs
@@ -0,0 +1,21 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      : Graphics.Hoodle.Render.Type.RenderCache 
+-- Copyright   : (c) 2014 Ian-Woo Kim
+--
+-- License     : BSD3
+-- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
+-- Stability   : experimental
+-- Portability : GHC
+--
+-----------------------------------------------------------------------------
+
+module Graphics.Hoodle.Render.Type.RenderCache where
+
+import qualified Data.HashMap.Strict as HM
+import           Data.UUID
+import qualified Graphics.Rendering.Cairo as Cairo
+
+-- | hashmap: key = UUID, value = (original size, view size, surface)
+type RenderCache = HM.HashMap UUID (Double, Cairo.Surface)
+
diff --git a/src/Graphics/Hoodle/Render/Type/Renderer.hs b/src/Graphics/Hoodle/Render/Type/Renderer.hs
new file mode 100644
--- /dev/null
+++ b/src/Graphics/Hoodle/Render/Type/Renderer.hs
@@ -0,0 +1,54 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      : Graphics.Hoodle.Render.Type.Renderer
+-- Copyright   : (c) 2014 Ian-Woo Kim
+--
+-- License     : GPL-3
+-- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
+-- Stability   : experimental
+-- Portability : GHC
+--
+-----------------------------------------------------------------------------
+
+module Graphics.Hoodle.Render.Type.Renderer where
+
+-- import           Control.Concurrent.MVar
+import           Control.Concurrent.STM
+import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans.Reader
+import qualified Data.ByteString.Char8 as B
+import           Data.Sequence hiding (null,filter)
+import qualified Data.Sequence as Seq (null,filter)
+import           Data.UUID
+import           Data.UUID.V4 (nextRandom)
+import qualified Graphics.Rendering.Cairo as Cairo
+import qualified Graphics.UI.Gtk.Poppler.Document as Poppler
+--
+import           Data.Hoodle.Simple (Dimension(..))
+
+
+data PDFCommand where
+  GetDocFromFile    :: !B.ByteString -> TMVar (Maybe Poppler.Document) -> PDFCommand
+  GetDocFromDataURI :: !B.ByteString -> TMVar (Maybe Poppler.Document) -> PDFCommand 
+  GetPageFromDoc    :: !Poppler.Document -> !Int -> TMVar (Maybe Poppler.Page) -> PDFCommand 
+  RenderPageScaled  :: !Poppler.Page -> !Dimension -> !Dimension -> PDFCommand 
+
+instance Show PDFCommand where
+  show _ = "PDFCommand"
+
+
+type Renderer = ReaderT ((UUID, (Double,Cairo.Surface)) -> IO (), TVar (Seq (UUID, PDFCommand))) IO
+
+
+sendPDFCommand :: UUID -> TVar (Seq (UUID,PDFCommand)) -> PDFCommand -> STM ()
+sendPDFCommand !uuid !queuevar !cmd = do
+    queue <- readTVar queuevar
+    let queue' = Seq.filter ((/=uuid) .fst) queue 
+        nqueue = queue' |> (uuid,cmd)
+    writeTVar queuevar nqueue
+
diff --git a/src/Graphics/Hoodle/Render/Util.hs b/src/Graphics/Hoodle/Render/Util.hs
--- a/src/Graphics/Hoodle/Render/Util.hs
+++ b/src/Graphics/Hoodle/Render/Util.hs
@@ -3,7 +3,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      : Graphics.Hoodle.Render.Util 
--- Copyright   : (c) 2011-2013 Ian-Woo Kim
+-- Copyright   : (c) 2011-2014 Ian-Woo Kim
 --
 -- License     : BSD3
 -- Maintainer  : Ian-Woo Kim <ianwookim@gmail.com>
@@ -16,25 +16,25 @@
 
 module Graphics.Hoodle.Render.Util where
 
-import           Graphics.Rendering.Cairo
+import qualified Graphics.Rendering.Cairo as Cairo
 -- 
 import           Data.Hoodle.BBox
 
 -- | 
-clipBBox :: Maybe BBox -> Render ()
+clipBBox :: Maybe BBox -> Cairo.Render ()
 clipBBox (Just (BBox (x1,y1) (x2,y2))) = do 
-    resetClip 
-    rectangle x1 y1 (x2-x1) (y2-y1)
-    clip
-clipBBox Nothing = resetClip 
+    Cairo.resetClip 
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1)
+    Cairo.clip
+clipBBox Nothing = Cairo.resetClip 
 
 -- | 
-clearBBox :: Maybe BBox -> Render ()        
+clearBBox :: Maybe BBox -> Cairo.Render ()        
 clearBBox Nothing = return ()
 clearBBox (Just (BBox (x1,y1) (x2,y2))) = do 
-    save
-    setSourceRGBA 0 0 0 0
-    setOperator OperatorSource
-    rectangle x1 y1 (x2-x1) (y2-y1) 
-    fill
-    restore
+    Cairo.save
+    Cairo.setSourceRGBA 0 0 0 0
+    Cairo.setOperator Cairo.OperatorSource
+    Cairo.rectangle x1 y1 (x2-x1) (y2-y1) 
+    Cairo.fill
+    Cairo.restore
