X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmatita%2FmatitaMathView.ml;h=e2eb22d5b8f05371ac9f456597360b35668f2c74;hb=f28480139ee72d092a9405619c3bdf6d4ff155ee;hp=d485ac02588c66e31510ed7a6d6fed2935122bb6;hpb=ac813b7e251e4bac1a8a16befa628203775771ca;p=helm.git

diff --git a/helm/matita/matitaMathView.ml b/helm/matita/matitaMathView.ml
index d485ac025..e2eb22d5b 100644
--- a/helm/matita/matitaMathView.ml
+++ b/helm/matita/matitaMathView.ml
@@ -1,4 +1,4 @@
-(* Copyright (C) 2000-2002, HELM Team.
+(* Copyright (C) 2004-2005, HELM Team.
  * 
  * This file is part of HELM, an Hypertextual, Electronic
  * Library of Mathematics, developed at the Computer Science
@@ -23,281 +23,1085 @@
  * http://cs.unibo.it/helm/.
  *)
 
+(* $Id$ *)
+
 open Printf
 
-open MatitaCicMisc
-open MatitaTypes
+open GrafiteTypes
+open MatitaGtkMisc
+open MatitaGuiTypes
 
-(* List utility functions *)
-exception Skip
+module Stack = Continuationals.Stack
 
-let list_map_fail f =
- let rec aux =
-  function
-     [] -> []
-   | he::tl ->
-      try
-       let he' = f he in
-        he'::(aux tl)
-      with Skip ->
-       (aux tl)
- in
-  aux
-
-let choose_selection mmlwidget (element : Gdome.element option) =
-  let rec aux element =
-    if element#hasAttributeNS
-       ~namespaceURI:Misc.helmns
-       ~localName:(Gdome.domString "xref")
-    then
-      mmlwidget#set_selection (Some element)
-    else
-      try
-        match element#get_parentNode with
-        | None -> assert false
-        | Some p -> aux (new Gdome.element_of_node p)
-      with GdomeInit.DOMCastException _ ->
-        debug_print "trying to select above the document root"
+(** inherit from this class if you want to access current script *)
+class scriptAccessor =
+object (self)
+  method private script = MatitaScript.current ()
+end
+
+let cicBrowsers = ref []
+let gui_instance = ref None
+let set_gui gui = gui_instance := Some gui
+let get_gui () =
+  match !gui_instance with
+  | None -> assert false
+  | Some gui -> gui
+
+let default_font_size () =
+  Helm_registry.get_opt_default Helm_registry.int
+    ~default:BuildTimeConf.default_font_size "matita.font_size"
+let current_font_size = ref ~-1
+let increase_font_size () = incr current_font_size
+let decrease_font_size () = decr current_font_size
+let reset_font_size () = current_font_size := default_font_size ()
+
+  (* is there any lablgtk2 constant corresponding to the various mouse
+   * buttons??? *)
+let left_button = 1
+let middle_button = 2
+let right_button = 3
+
+let near (x1, y1) (x2, y2) =
+  let distance = sqrt (((x2 -. x1) ** 2.) +. ((y2 -. y1) ** 2.)) in
+  (distance < 4.)
+
+let xlink_ns = Gdome.domString "http://www.w3.org/1999/xlink"
+let helm_ns = Gdome.domString "http://www.cs.unibo.it/helm"
+let href_ds = Gdome.domString "href"
+let xref_ds = Gdome.domString "xref"
+
+let domImpl = Gdome.domImplementation ()
+
+  (** Gdome.element of a MathML document whose rendering should be blank. Used
+  * by cicBrowser to render "about:blank" document *)
+let empty_mathml = lazy (
+  domImpl#createDocument ~namespaceURI:(Some DomMisc.mathml_ns)
+    ~qualifiedName:(Gdome.domString "math") ~doctype:None)
+
+let empty_boxml = lazy (
+  domImpl#createDocument ~namespaceURI:(Some DomMisc.boxml_ns) 
+    ~qualifiedName:(Gdome.domString "box") ~doctype:None)
+
+  (** shown for goals closed by side effects *)
+let closed_goal_mathml = lazy (
+  domImpl#createDocumentFromURI ~uri:BuildTimeConf.closed_xml ())
+
+(* ids_to_terms should not be passed here, is just for debugging *)
+let find_root_id annobj id ids_to_father_ids ids_to_terms ids_to_inner_types =
+  let find_parent id ids =
+    let rec aux id =
+(*       (prerr_endline (sprintf "id %s = %s" id
+        (try
+          CicPp.ppterm (Hashtbl.find ids_to_terms id)
+        with Not_found -> "NONE"))); *)
+      if List.mem id ids then Some id
+      else
+        (match
+          (try Hashtbl.find ids_to_father_ids id with Not_found -> None)
+        with
+        | None -> None
+        | Some id' -> aux id')
+    in
+    aux id
   in
-  match element with
-  | Some x -> aux x
-  | None   -> mmlwidget#set_selection None
+  let return_father id ids =
+    match find_parent id ids with
+    | None -> assert false
+    | Some parent_id -> parent_id
+  in
+  let mk_ids terms = List.map CicUtil.id_of_annterm terms in
+  let inner_types =
+   Hashtbl.fold
+    (fun _ types acc ->
+      match types.Cic2acic.annexpected with
+         None -> types.Cic2acic.annsynthesized :: acc
+       | Some ty -> ty :: types.Cic2acic.annsynthesized :: acc
+    ) ids_to_inner_types [] in
+  match annobj with
+  | Cic.AConstant (_, _, _, Some bo, ty, _, _)
+  | Cic.AVariable (_, _, Some bo, ty, _, _)
+  | Cic.ACurrentProof (_, _, _, _, bo, ty, _, _) ->
+      return_father id (mk_ids (ty :: bo :: inner_types))
+  | Cic.AConstant (_, _, _, None, ty, _, _)
+  | Cic.AVariable (_, _, None, ty, _, _) ->
+      return_father id (mk_ids (ty::inner_types))
+  | Cic.AInductiveDefinition _ ->
+      assert false  (* TODO *)
 
-class proof_viewer obj =
- object(self)
+  (** @return string content of a dom node having a single text child node, e.g.
+   * <m:mi xlink:href="...">bool</m:mi> *)
+let string_of_dom_node node =
+  match node#get_firstChild with
+  | None -> ""
+  | Some node ->
+      (try
+        let text = new Gdome.text_of_node node in
+        text#get_data#to_string
+      with GdomeInit.DOMCastException _ -> "")
 
-  inherit GMathViewAux.single_selection_math_view obj
+let name_of_hypothesis = function
+  | Some (Cic.Name s, _) -> s
+  | _ -> assert false
 
-  val mutable current_infos = None
-  val mutable current_mathml = None
+let id_of_node (node: Gdome.element) =
+  let xref_attr =
+    node#getAttributeNS ~namespaceURI:helm_ns ~localName:xref_ds in
+  try
+    List.hd (HExtlib.split ~sep:' ' xref_attr#to_string)
+  with Failure _ -> assert false
+
+type selected_term =
+  | SelTerm of Cic.term * string option (* term, parent hypothesis (if any) *)
+  | SelHyp of string * Cic.context (* hypothesis, context *)
+
+class clickableMathView obj =
+let text_width = 80 in
+object (self)
+  inherit GMathViewAux.multi_selection_math_view obj
+
+  val mutable href_callback: (string -> unit) option = None
+  method set_href_callback f = href_callback <- f
+
+  val mutable _cic_info = None
+  method private set_cic_info info = _cic_info <- info
+  method private cic_info = _cic_info
 
   initializer
-    ignore (self#connect#click (fun (gdome_elt, _, _, _) ->
-      match gdome_elt with
-      | Some gdome_elt ->
-          prerr_endline (gdome_elt#get_nodeName#to_string);
-          ignore (self#action_toggle gdome_elt)
-      | None -> ()));
-    ignore (self#connect#selection_changed (choose_selection self))
-
-  method load_proof ((uri_opt, _, _, _) as proof, (goal_opt: int option)) =
-    let (annobj, ids_to_terms, ids_to_father_ids, ids_to_inner_sorts,
-        ids_to_inner_types, ids_to_conjectures, ids_to_hypotheses) =
-      Cic2acic.acic_object_of_cic_object (cicCurrentProof proof)
+    self#set_font_size !current_font_size;
+    ignore (self#connect#selection_changed self#choose_selection_cb);
+    ignore (self#event#connect#button_press self#button_press_cb);
+    ignore (self#event#connect#button_release self#button_release_cb);
+    ignore (self#event#connect#selection_clear self#selection_clear_cb);
+    ignore (self#coerce#misc#connect#selection_get self#selection_get_cb)
+
+  val mutable button_press_x = -1.
+  val mutable button_press_y = -1.
+  val mutable selection_changed = false
+
+  method private selection_get_cb ctxt ~info ~time =
+    let text =
+      match ctxt#target with
+      | "PATTERN" -> self#text_of_selection `Pattern
+      | "TERM" | _ -> self#text_of_selection `Term
+    in
+    match text with
+    | None -> ()
+    | Some s -> ctxt#return s
+
+  method private text_of_selection fmt =
+    match self#get_selections with
+    | [] -> None
+    | node :: _ -> Some (self#string_of_node ~paste_kind:fmt node)
+
+  method private selection_clear_cb sel_event =
+    self#remove_selections;
+    (GData.clipboard Gdk.Atom.clipboard)#clear ();
+    false
+
+  method private button_press_cb gdk_button =
+    let button = GdkEvent.Button.button gdk_button in
+    if  button = left_button then begin
+      button_press_x <- GdkEvent.Button.x gdk_button;
+      button_press_y <- GdkEvent.Button.y gdk_button;
+      selection_changed <- false
+    end else if button = right_button then
+      self#popup_contextual_menu (GdkEvent.Button.time gdk_button);
+    false
+
+    (** @return a pattern structure which contains pretty printed terms *)
+  method private tactic_text_pattern_of_selection =
+    match self#get_selections with
+    | [] -> assert false (* this method is invoked only if there's a sel. *)
+    | node :: _ ->
+        let id = id_of_node node in
+        let cic_info, unsh_sequent = self#get_cic_info id in
+        match self#get_term_by_id cic_info id with
+        | SelTerm (t, father_hyp) ->
+            let sequent = self#sequent_of_id ~paste_kind:`Pattern id in
+            let text = self#string_of_cic_sequent sequent in
+            (match father_hyp with
+            | None -> None, [], Some text
+            | Some hyp_name -> None, [ hyp_name, text ], None)
+        | SelHyp (hyp_name, _ctxt) -> None, [ hyp_name, "%" ], None
+
+  method private popup_contextual_menu time =
+    let menu = GMenu.menu () in
+    let add_menu_item ?(menu = menu) ?stock ?label () =
+      GMenu.image_menu_item ?stock ?label ~packing:menu#append () in
+    let check = add_menu_item ~label:"Check" () in
+    let reductions_menu_item = GMenu.menu_item ~label:"βδιζ-reduce" () in
+    menu#append reductions_menu_item;
+    let reductions = GMenu.menu () in
+    reductions_menu_item#set_submenu reductions;
+    let normalize = add_menu_item ~menu:reductions ~label:"Normalize" () in
+    let reduce = add_menu_item ~menu:reductions ~label:"Reduce" () in
+    let simplify = add_menu_item ~menu:reductions ~label:"Simplify" () in
+    let whd = add_menu_item ~menu:reductions ~label:"Weak head" () in
+    menu#append (GMenu.separator_item ());
+    let copy = add_menu_item ~stock:`COPY () in
+    let gui = get_gui () in
+    List.iter (fun item -> item#misc#set_sensitive gui#canCopy)
+      [ copy; check; normalize; reduce; simplify; whd ];
+    let reduction_action kind () =
+      let pat = self#tactic_text_pattern_of_selection in
+      let statement =
+        let loc = HExtlib.dummy_floc in
+        "\n" ^
+        GrafiteAstPp.pp_executable ~term_pp:(fun s -> s)
+          ~lazy_term_pp:(fun _ -> assert false) ~obj_pp:(fun _ -> assert false)
+          (GrafiteAst.Tactical (loc,
+            GrafiteAst.Tactic (loc, GrafiteAst.Reduce (loc, kind, pat)),
+            Some (GrafiteAst.Semicolon loc))) in
+      (MatitaScript.current ())#advance ~statement () in
+    connect_menu_item copy gui#copy;
+    connect_menu_item normalize (reduction_action `Normalize);
+    connect_menu_item reduce (reduction_action `Reduce);
+    connect_menu_item simplify (reduction_action `Simpl);
+    connect_menu_item whd (reduction_action `Whd);
+    menu#popup ~button:right_button ~time
+
+  method private button_release_cb gdk_button =
+    if GdkEvent.Button.button gdk_button = left_button then begin
+      let button_release_x = GdkEvent.Button.x gdk_button in
+      let button_release_y = GdkEvent.Button.y gdk_button in
+      if selection_changed then
+        ()
+      else  (* selection _not_ changed *)
+        if near (button_press_x, button_press_y)
+          (button_release_x, button_release_y)
+        then
+          let x = int_of_float button_press_x in
+          let y = int_of_float button_press_y in
+          (match self#get_element_at x y with
+          | None -> ()
+          | Some elt ->
+              let localName = href_ds in
+              if elt#hasAttributeNS ~namespaceURI:xlink_ns ~localName then
+                self#invoke_href_callback
+                  (elt#getAttributeNS ~namespaceURI:xlink_ns
+                    ~localName)#to_string
+                  gdk_button
+              else
+                ignore (self#action_toggle elt));
+    end;
+    false
+
+  method private invoke_href_callback href_value gdk_button =
+    let button = GdkEvent.Button.button gdk_button in
+    if button = left_button then
+      let time = GdkEvent.Button.time gdk_button in
+      match href_callback with
+      | None -> ()
+      | Some f ->
+          (match HExtlib.split href_value with
+          | [ uri ] ->  f uri
+          | uris ->
+              let menu = GMenu.menu () in
+              List.iter
+                (fun uri ->
+                  let menu_item =
+                    GMenu.menu_item ~label:uri ~packing:menu#append () in
+                  connect_menu_item menu_item (fun () -> f uri))
+                uris;
+              menu#popup ~button ~time)
+
+  method private choose_selection_cb gdome_elt =
+    let set_selection elt =
+      let misc = self#coerce#misc in
+      self#set_selection (Some elt);
+      misc#add_selection_target ~target:"STRING" Gdk.Atom.primary;
+      ignore (misc#grab_selection Gdk.Atom.primary);
     in
-    current_infos <- Some (ids_to_terms, ids_to_father_ids, ids_to_conjectures,
-      ids_to_hypotheses);
-    let mathml =
-      ApplyTransformation.mml_of_cic_object ~explode_all:true
-        (unopt_uri uri_opt) annobj ids_to_inner_sorts ids_to_inner_types
+    let rec aux elt =
+      if (elt#getAttributeNS ~namespaceURI:helm_ns
+            ~localName:xref_ds)#to_string <> ""
+      then
+        set_selection elt
+      else
+        try
+          (match elt#get_parentNode with
+          | None -> assert false
+          | Some p -> aux (new Gdome.element_of_node p))
+        with GdomeInit.DOMCastException _ -> ()
     in
-    debug_print "load_proof: dumping MathML to ./proof";
-    ignore (Misc.domImpl#saveDocumentToFile ~name:"./proof" ~doc:mathml ());
-    match current_mathml with
-    |  None ->
-        self#load_root ~root:mathml#get_documentElement ;
-        current_mathml <- Some mathml
-    | Some current_mathml ->
-        self#freeze;
-        XmlDiff.update_dom ~from:current_mathml mathml ;
-        self#thaw
-  end
+    (match gdome_elt with
+    | Some elt when (elt#getAttributeNS ~namespaceURI:xlink_ns
+        ~localName:href_ds)#to_string <> "" ->
+          set_selection elt
+    | Some elt -> aux elt
+    | None -> self#set_selection None);
+    selection_changed <- true
 
-class sequent_viewer obj =
- object(self)
+  method update_font_size = self#set_font_size !current_font_size
 
-  inherit GMathViewAux.multi_selection_math_view obj
+    (** find a term by id from stored CIC infos @return either `Hyp if the id
+     * correspond to an hypothesis or `Term (cic, hyp) if the id correspond to a
+     * term. In the latter case hyp is either None (if the term is a subterm of
+     * the sequent conclusion) or Some hyp_name if the term belongs to an
+     * hypothesis *)
+  method private get_term_by_id cic_info id =
+    let unsh_item, ids_to_terms, ids_to_hypotheses, ids_to_father_ids, _, _ =
+      cic_info in
+    let rec find_father_hyp id =
+      if Hashtbl.mem ids_to_hypotheses id
+      then Some (name_of_hypothesis (Hashtbl.find ids_to_hypotheses id))
+      else
+        let father_id =
+          try Hashtbl.find ids_to_father_ids id
+          with Not_found -> assert false in
+        match father_id with
+        | Some id -> find_father_hyp id
+        | None -> None
+    in
+    try
+      let term = Hashtbl.find ids_to_terms id in
+      let father_hyp = find_father_hyp id in
+      SelTerm (term, father_hyp)
+    with Not_found ->
+      try
+        let hyp = Hashtbl.find ids_to_hypotheses id in
+        let _, context, _ =
+          match unsh_item with Some seq -> seq | None -> assert false in
+        let context' = MatitaMisc.list_tl_at hyp context in
+        SelHyp (name_of_hypothesis hyp, context')
+      with Not_found -> assert false
+    
+  method private find_obj_conclusion id =
+    match self#cic_info with
+    | None
+    | Some (_, _, _, _, _, None) -> assert false
+    | Some (_, ids_to_terms, _, ids_to_father_ids, ids_to_inner_types, Some annobj) ->
+        let id =
+         find_root_id annobj id ids_to_father_ids ids_to_terms ids_to_inner_types
+        in
+         (try Hashtbl.find ids_to_terms id with Not_found -> assert false)
+
+  method private string_of_node ~(paste_kind:paste_kind) node =
+    if node#hasAttributeNS ~namespaceURI:helm_ns ~localName:xref_ds
+    then
+      let id = id_of_node node in
+      self#string_of_cic_sequent (self#sequent_of_id ~paste_kind id)
+    else string_of_dom_node node
+
+  method private string_of_cic_sequent cic_sequent =
+    let script = MatitaScript.current () in
+    let metasenv =
+      if script#onGoingProof () then script#proofMetasenv else [] in
+    let _, (acic_sequent, _, _, ids_to_inner_sorts, _) =
+      Cic2acic.asequent_of_sequent metasenv cic_sequent in
+    let _, _, _, annterm = acic_sequent in
+    let ast, ids_to_uris =
+      TermAcicContent.ast_of_acic ids_to_inner_sorts annterm in
+    let pped_ast = TermContentPres.pp_ast ast in
+    let markup = CicNotationPres.render ids_to_uris pped_ast in
+    BoxPp.render_to_string text_width markup
+
+  method private pattern_of term context unsh_sequent =
+    let context_len = List.length context in
+    let _, unsh_context, conclusion = unsh_sequent in
+    try
+      (match
+        List.nth unsh_context (List.length unsh_context - context_len - 1)
+      with
+      | None -> assert false (* can't select a restricted hypothesis *)
+      | Some (name, Cic.Decl ty) ->
+          ProofEngineHelpers.pattern_of ~term:ty [term]
+      | Some (name, Cic.Def (bo, _)) ->
+          ProofEngineHelpers.pattern_of ~term:bo [term])
+    with Failure _ | Invalid_argument _ ->
+      ProofEngineHelpers.pattern_of ~term:conclusion [term]
+
+  method private get_cic_info id =
+    match self#cic_info with
+    | Some ((Some unsh_sequent, _, _, _, _, _) as info) -> info, unsh_sequent
+    | Some ((None, _, _, _, _, _) as info) ->
+        let t = self#find_obj_conclusion id in
+        info, (~-1, [], t) (* dummy sequent for obj *)
+    | None -> assert false
+
+  method private sequent_of_id ~(paste_kind:paste_kind) id =
+    let cic_info, unsh_sequent = self#get_cic_info id in
+    let cic_sequent =
+      match self#get_term_by_id cic_info id with
+      | SelTerm (t, _father_hyp) ->
+          let occurrences =
+            ProofEngineHelpers.locate_in_conjecture t unsh_sequent in
+          (match occurrences with
+          | [ context, _t ] ->
+              (match paste_kind with
+              | `Term -> ~-1, context, t
+              | `Pattern -> ~-1, [], self#pattern_of t context unsh_sequent)
+          | _ ->
+              HLog.error (sprintf "found %d occurrences while 1 was expected"
+                (List.length occurrences));
+              assert false) (* since it uses physical equality *)
+      | SelHyp (_name, context) -> ~-1, context, Cic.Rel 1 in
+    cic_sequent
+
+  method private string_of_selection ~(paste_kind:paste_kind) =
+    match self#get_selections with
+    | [] -> None
+    | node :: _ -> Some (self#string_of_node ~paste_kind node)
+
+  method has_selection = self#get_selections <> []
+
+    (** @return an associative list format -> string with all possible selection
+     * formats. Rationale: in order to convert the selection to TERM or PATTERN
+     * format we need the sequent, the metasenv, ... keeping all of them in a
+     * closure would be more expensive than keeping their already converted
+     * forms *)
+  method strings_of_selection =
+    try
+      let misc = self#coerce#misc in
+      List.iter
+        (fun target -> misc#add_selection_target ~target Gdk.Atom.clipboard)
+        [ "TERM"; "PATTERN"; "STRING" ];
+      ignore (misc#grab_selection Gdk.Atom.clipboard);
+      List.map
+        (fun paste_kind ->
+          paste_kind, HExtlib.unopt (self#string_of_selection ~paste_kind))
+        [ `Term; `Pattern ]
+    with Failure _ -> failwith "no selection"
+
+end
+
+let clickableMathView ?hadjustment ?vadjustment ?font_size ?log_verbosity =
+  GtkBase.Widget.size_params
+    ~cont:(OgtkMathViewProps.pack_return (fun p ->
+      OgtkMathViewProps.set_params
+        (new clickableMathView (GtkMathViewProps.MathView_GMetaDOM.create p))
+        ~font_size:None ~log_verbosity:None))
+    []
+
+class cicMathView obj =
+object (self)
+  inherit clickableMathView obj
+
+  val mutable current_mathml = None
 
-  initializer
-    ignore (self#connect#selection_changed (choose_selection self))
-
-  val mutable current_infos = None
-
-  method get_selected_terms =
-   let selections = self#get_selections in
-    list_map_fail
-     (function node ->
-       let xpath =
-        ((node : Gdome.element)#getAttributeNS
-          ~namespaceURI:Misc.helmns
-          ~localName:(Gdome.domString "xref"))#to_string
-       in
-        if xpath = "" then assert false (* "ERROR: No xref found!!!" *)
-        else
-         match current_infos with
-            Some (ids_to_terms,_,_) ->
-             let id = xpath in
-              (try
-                Hashtbl.find ids_to_terms id
-               with _ -> raise Skip)
-          | None -> assert false (* "ERROR: No current term!!!" *)
-     ) selections
-
-  method get_selected_hypotheses =
-   let selections = self#get_selections in
-    list_map_fail
-     (function node ->
-       let xpath =
-        ((node : Gdome.element)#getAttributeNS
-          ~namespaceURI:Misc.helmns
-          ~localName:(Gdome.domString "xref"))#to_string
-       in
-        if xpath = "" then assert false (* "ERROR: No xref found!!!" *)
-        else
-         match current_infos with
-            Some (_,_,ids_to_hypotheses) ->
-             let id = xpath in
-              (try
-                Hashtbl.find ids_to_hypotheses id
-               with _ -> raise Skip)
-          | None -> assert false (* "ERROR: No current term!!!" *)
-     ) selections
-  
   method load_sequent metasenv metano =
-(*
-    let (annconjecture, ids_to_terms, ids_to_father_ids, ids_to_inner_sorts,
-        ids_to_hypotheses) =
-      Cic2acic.asequent_of_sequent metasenv conjecture
-    in
-*)
     let sequent = CicUtil.lookup_meta metano metasenv in
-    let (mathml, (ids_to_terms, ids_to_father_ids, ids_to_hypotheses)) =
+    let (mathml, unsh_sequent,
+      (_, (ids_to_terms, ids_to_father_ids, ids_to_hypotheses,_ )))
+    =
       ApplyTransformation.mml_of_cic_sequent metasenv sequent
     in
-    current_infos <- Some (ids_to_terms, ids_to_father_ids, ids_to_hypotheses);
-    debug_print "load_sequent: dumping MathML to ./prova";
-    ignore (Misc.domImpl#saveDocumentToFile ~name:"./prova" ~doc:mathml ());
+    self#set_cic_info
+      (Some (Some unsh_sequent,
+        ids_to_terms, ids_to_hypotheses, ids_to_father_ids,
+        Hashtbl.create 1, None));
+    if BuildTimeConf.debug then begin
+      let name = "sequent_viewer.xml" in
+      HLog.debug ("load_sequent: dumping MathML to ./" ^ name);
+      ignore (domImpl#saveDocumentToFile ~name ~doc:mathml ())
+    end;
     self#load_root ~root:mathml#get_documentElement
- end
 
+  method load_object obj =
+    let use_diff = false in (* ZACK TODO use XmlDiff when re-rendering? *)
+    let (mathml,
+      (annobj, (ids_to_terms, ids_to_father_ids, _, ids_to_hypotheses, _, ids_to_inner_types)))
+    =
+      ApplyTransformation.mml_of_cic_object obj
+    in
+    self#set_cic_info
+      (Some (None, ids_to_terms, ids_to_hypotheses, ids_to_father_ids, ids_to_inner_types, Some annobj));
+    (match current_mathml with
+    | Some current_mathml when use_diff ->
+        self#freeze;
+        XmlDiff.update_dom ~from:current_mathml mathml;
+        self#thaw
+    |  _ ->
+        if BuildTimeConf.debug then begin
+          let name = "cic_browser.xml" in
+          HLog.debug ("cic_browser: dumping MathML to ./" ^ name);
+          ignore (domImpl#saveDocumentToFile ~name ~doc:mathml ())
+        end;
+        self#load_root ~root:mathml#get_documentElement;
+        current_mathml <- Some mathml);
+end
 
-class sequents_viewer ~(notebook:GPack.notebook)
-  ~(sequent_viewer:sequent_viewer) ~set_goal ()
-=
-  let tab_label metano =
-    (GMisc.label ~text:(sprintf "?%d" metano) ~show:true ())#coerce
+let tab_label meta_markup =
+  let rec aux =
+    function
+    | `Current m -> sprintf "<b>%s</b>" (aux m)
+    | `Closed m -> sprintf "<s>%s</s>" (aux m)
+    | `Shift (pos, m) -> sprintf "|<sub>%d</sub>: %s" pos (aux m)
+    | `Meta n -> sprintf "?%d" n
   in
+  let markup = aux meta_markup in
+  (GMisc.label ~markup ~show:true ())#coerce
+
+let goal_of_switch = function Stack.Open g | Stack.Closed g -> g
+
+class sequentsViewer ~(notebook:GPack.notebook) ~(cicMathView:cicMathView) () =
   object (self)
+    inherit scriptAccessor
+
     val mutable pages = 0
     val mutable switch_page_callback = None
     val mutable page2goal = []  (* associative list: page no -> goal no *)
     val mutable goal2page = []  (* the other way round *)
     val mutable goal2win = []   (* associative list: goal no -> scrolled win *)
     val mutable _metasenv = []
+    val mutable scrolledWin: GBin.scrolled_window option = None
+      (* scrolled window to which the sequentViewer is currently attached *)
+    val logo = (GMisc.image
+      ~file:(MatitaMisc.image_path "matita_medium.png") ()
+      :> GObj.widget)
+            
+    val logo_with_qed = (GMisc.image
+      ~file:(MatitaMisc.image_path "matita_small.png") ()
+      :> GObj.widget)
+
+    method load_logo =
+     notebook#set_show_tabs false;
+     notebook#append_page logo
+
+    method load_logo_with_qed =
+     notebook#set_show_tabs false;
+     notebook#append_page logo_with_qed
 
     method reset =
-      for i = 1 to pages do notebook#remove_page 0 done;
-      pages <- 0;
-      page2goal <- [];
-      goal2page <- [];
-      goal2win <- [];
-      _metasenv <- [];
+      cicMathView#remove_selections;
+      (match scrolledWin with
+      | Some w ->
+          (* removing page from the notebook will destroy all contained widget,
+          * we do not want the cicMathView to be destroyed as well *)
+          w#remove cicMathView#coerce;
+          scrolledWin <- None
+      | None -> ());
       (match switch_page_callback with
       | Some id ->
           GtkSignal.disconnect notebook#as_widget id;
           switch_page_callback <- None
-      | None -> ())
+      | None -> ());
+      for i = 0 to pages do notebook#remove_page 0 done; 
+      notebook#set_show_tabs true;
+      pages <- 0;
+      page2goal <- [];
+      goal2page <- [];
+      goal2win <- [];
+      _metasenv <- []; 
+      self#script#setGoal None
 
-    method load_sequents metasenv =
-      let sequents_no = List.length metasenv in
+    method load_sequents { proof = (_,metasenv,_,_) as proof; stack = stack } =
       _metasenv <- metasenv;
-      pages <- sequents_no;
-      let win metano =
+      pages <- 0;
+      let win goal_switch =
         let w =
-          GBin.scrolled_window ~hpolicy:`AUTOMATIC ~vpolicy:`AUTOMATIC
+          GBin.scrolled_window ~hpolicy:`AUTOMATIC ~vpolicy:`ALWAYS
             ~shadow_type:`IN ~show:true ()
         in
         let reparent () =
-          match sequent_viewer#misc#parent with
-          | None -> w#add sequent_viewer#coerce
-          | Some _ -> sequent_viewer#misc#reparent w#coerce
+          scrolledWin <- Some w;
+          match cicMathView#misc#parent with
+          | None -> w#add cicMathView#coerce
+          | Some parent ->
+             let parent =
+              match cicMathView#misc#parent with
+                 None -> assert false
+               | Some p -> GContainer.cast_container p
+             in
+              parent#remove cicMathView#coerce;
+              w#add cicMathView#coerce
         in
-        goal2win <- (metano, reparent) :: goal2win;
+        goal2win <- (goal_switch, reparent) :: goal2win;
         w#coerce
       in
+      assert (
+        let stack_goals = Stack.open_goals stack in
+        let proof_goals = ProofEngineTypes.goals_of_proof proof in
+        if
+          HExtlib.list_uniq (List.sort Pervasives.compare stack_goals)
+          <> List.sort Pervasives.compare proof_goals
+        then begin
+          prerr_endline ("STACK GOALS = " ^ String.concat " " (List.map string_of_int stack_goals));
+          prerr_endline ("PROOF GOALS = " ^ String.concat " " (List.map string_of_int proof_goals));
+          false
+        end
+        else true
+      );
+      let render_switch =
+        function Stack.Open i ->`Meta i | Stack.Closed i ->`Closed (`Meta i)
+      in
       let page = ref 0 in
-      List.iter
-        (fun (metano, _, _) ->
-          page2goal <- (!page, metano) :: page2goal;
-          goal2page <- (metano, !page) :: goal2page;
+      let added_goals = ref [] in
+        (* goals can be duplicated on the tack due to focus, but we should avoid
+         * multiple labels in the user interface *)
+      let add_tab markup goal_switch =
+        let goal = Stack.goal_of_switch goal_switch in
+        if not (List.mem goal !added_goals) then begin
+          notebook#append_page ~tab_label:(tab_label markup) (win goal_switch);
+          page2goal <- (!page, goal_switch) :: page2goal;
+          goal2page <- (goal_switch, !page) :: goal2page;
           incr page;
-          notebook#append_page ~tab_label:(tab_label metano) (win metano))
-        metasenv;
+          pages <- pages + 1;
+          added_goals := goal :: !added_goals
+        end
+      in
+      let add_switch _ _ (_, sw) = add_tab (render_switch sw) sw in
+      Stack.iter  (** populate notebook with tabs *)
+        ~env:(fun depth tag (pos, sw) ->
+          let markup =
+            match depth, pos with
+            | 0, _ -> `Current (render_switch sw)
+            | 1, pos when Stack.head_tag stack = `BranchTag ->
+                `Shift (pos, render_switch sw)
+            | _ -> render_switch sw
+          in
+          add_tab markup sw)
+        ~cont:add_switch ~todo:add_switch
+        stack;
       switch_page_callback <-
         Some (notebook#connect#switch_page ~callback:(fun page ->
-          let goal =
-            try
-              List.assoc page page2goal
-            with Not_found -> assert false
+          let goal_switch =
+            try List.assoc page page2goal with Not_found -> assert false
           in
-          set_goal goal;
-          self#render_page ~page ~goal))
+          self#script#setGoal (Some (goal_of_switch goal_switch));
+          self#render_page ~page ~goal_switch))
 
-    method private render_page ~page ~goal =
-      sequent_viewer#load_sequent _metasenv goal;
-      try
-        List.assoc goal goal2win ();
-        sequent_viewer#set_selection None
-      with Not_found -> assert false
+    method private render_page ~page ~goal_switch =
+      (match goal_switch with
+      | Stack.Open goal -> cicMathView#load_sequent _metasenv goal
+      | Stack.Closed goal ->
+          let doc = Lazy.force closed_goal_mathml in
+          cicMathView#load_root ~root:doc#get_documentElement);
+      (try
+        cicMathView#set_selection None;
+        List.assoc goal_switch goal2win ()
+      with Not_found -> assert false)
 
     method goto_sequent goal =
-      let page =
+      let goal_switch, page =
         try
-          List.assoc goal goal2page
+          List.find
+            (function Stack.Open g, _ | Stack.Closed g, _ -> g = goal)
+            goal2page
         with Not_found -> assert false
       in
       notebook#goto_page page;
-      self#render_page page goal;
+      self#render_page page goal_switch
 
   end
 
  (** constructors *)
 
-let sequent_viewer ?hadjustment ?vadjustment ?font_size ?log_verbosity =
-  GtkBase.Widget.size_params
-    ~cont:(OgtkMathViewProps.pack_return (fun p ->
-      OgtkMathViewProps.set_params
-        (new sequent_viewer (GtkMathViewProps.MathView_GMetaDOM.create p))
-        ~font_size ~log_verbosity))
-    []
+type 'widget constructor =
+  ?hadjustment:GData.adjustment ->
+  ?vadjustment:GData.adjustment ->
+  ?font_size:int ->
+  ?log_verbosity:int ->
+  ?width:int ->
+  ?height:int ->
+  ?packing:(GObj.widget -> unit) ->
+  ?show:bool ->
+  unit ->
+    'widget
 
-let proof_viewer ?hadjustment ?vadjustment ?font_size ?log_verbosity =
+let cicMathView ?hadjustment ?vadjustment ?font_size ?log_verbosity =
   GtkBase.Widget.size_params
     ~cont:(OgtkMathViewProps.pack_return (fun p ->
       OgtkMathViewProps.set_params
-        (new proof_viewer (GtkMathViewProps.MathView_GMetaDOM.create p))
+        (new cicMathView (GtkMathViewProps.MathView_GMetaDOM.create p))
         ~font_size ~log_verbosity))
     []
 
-let proof_viewer_instance =
-  let instance = lazy (
-    let gui = MatitaGui.instance () in
-    proof_viewer ~show:true ~packing:gui#proof#scrolledProof#add ()
-  ) in
-  fun () -> Lazy.force instance
+let blank_uri = BuildTimeConf.blank_uri
+let current_proof_uri = BuildTimeConf.current_proof_uri
 
-let sequents_viewer ~(notebook:GPack.notebook)
-  ~(sequent_viewer:sequent_viewer) ~set_goal ()
+type term_source =
+  [ `Ast of CicNotationPt.term
+  | `Cic of Cic.term * Cic.metasenv
+  | `String of string
+  ]
+
+class cicBrowser_impl ~(history:MatitaTypes.mathViewer_entry MatitaMisc.history)
+  ()
 =
-  new sequents_viewer ~notebook ~sequent_viewer ~set_goal ()
-
-let check_widget =
-  lazy
-    (let gui = MatitaGui.instance () in
-    sequent_viewer ~show:true ~packing:gui#check#scrolledCheck#add ())
-
-class mathViewer =
-  object
-    method checkTerm sequent metasenv =
-      let (metano, context, expr) = sequent in
-      let widget = Lazy.force check_widget in
-      let gui = MatitaGui.instance () in
-      gui#check#checkWin#show ();
-      gui#main#showCheckMenuItem#set_active true;
-      widget#load_sequent (sequent :: metasenv) metano
-
-    method unload () = (proof_viewer_instance ())#unload
+  let whelp_RE = Pcre.regexp "^\\s*whelp" in
+  let uri_RE =
+    Pcre.regexp
+      "^cic:/([^/]+/)*[^/]+\\.(con|ind|var)(#xpointer\\(\\d+(/\\d+)+\\))?$"
+  in
+  let dir_RE = Pcre.regexp "^cic:((/([^/]+/)*[^/]+(/)?)|/|)$" in
+  let whelp_query_RE = Pcre.regexp "^\\s*whelp\\s+([^\\s]+)\\s+(.*)$" in
+  let is_whelp txt = Pcre.pmatch ~rex:whelp_RE txt in
+  let is_uri txt = Pcre.pmatch ~rex:uri_RE txt in
+  let is_dir txt = Pcre.pmatch ~rex:dir_RE txt in
+  let gui = get_gui () in
+  let (win: MatitaGuiTypes.browserWin) = gui#newBrowserWin () in
+  let queries = ["Locate";"Hint";"Match";"Elim";"Instance"] in
+  let combo,_ = GEdit.combo_box_text ~strings:queries () in
+  let activate_combo_query input q =
+    let q' = String.lowercase q in
+    let rec aux i = function
+      | [] -> failwith ("Whelp query '" ^ q ^ "' not found")
+      | h::_ when String.lowercase h = q' -> i
+      | _::tl -> aux (i+1) tl
+    in
+    combo#set_active (aux 0 queries);
+    win#queryInputText#set_text input
+  in
+  let set_whelp_query txt =
+    let query, arg = 
+      try
+        let q = Pcre.extract ~rex:whelp_query_RE txt in
+        q.(1), q.(2)
+      with Invalid_argument _ -> failwith "Malformed Whelp query"
+    in
+    activate_combo_query arg query
+  in
+  let toplevel = win#toplevel in
+  let mathView = cicMathView ~packing:win#scrolledBrowser#add () in
+  let fail message = 
+    MatitaGtkMisc.report_error ~title:"Cic browser" ~message 
+      ~parent:toplevel ()  
+  in
+  let tags =
+    [ "dir", GdkPixbuf.from_file (MatitaMisc.image_path "matita-folder.png");
+      "obj", GdkPixbuf.from_file (MatitaMisc.image_path "matita-object.png") ]
+  in
+  let handle_error f =
+    try
+      f ()
+    with exn ->
+      if not (Helm_registry.get_bool "matita.debug") then
+        fail (snd (MatitaExcPp.to_string exn))
+      else raise exn
+  in
+  let handle_error' f = (fun () -> handle_error (fun () -> f ())) in
+  let load_easter_egg = lazy (
+    win#easterEggImage#set_file (MatitaMisc.image_path "meegg.png"))
+  in
+  object (self)
+    inherit scriptAccessor
+    
+    (* Whelp bar queries *)
+
+    initializer
+      activate_combo_query "" "locate";
+      win#whelpBarComboVbox#add combo#coerce;
+      let start_query () = 
+        let query = String.lowercase (List.nth queries combo#active) in
+        let input = win#queryInputText#text in
+        let statement = "whelp " ^ query ^ " " ^ input ^ "." in
+        (MatitaScript.current ())#advance ~statement ()
+      in
+      ignore(win#queryInputText#connect#activate ~callback:start_query);
+      ignore(combo#connect#changed ~callback:start_query);
+      win#whelpBarImage#set_file (MatitaMisc.image_path "whelp.png");
+      win#mathOrListNotebook#set_show_tabs false;
+      win#browserForwardButton#misc#set_sensitive false;
+      win#browserBackButton#misc#set_sensitive false;
+      ignore (win#browserUri#entry#connect#activate (handle_error' (fun () ->
+        self#loadInput win#browserUri#entry#text)));
+      ignore (win#browserHomeButton#connect#clicked (handle_error' (fun () ->
+        self#load (`About `Current_proof))));
+      ignore (win#browserRefreshButton#connect#clicked
+        (handle_error' (self#refresh ~force:true)));
+      ignore (win#browserBackButton#connect#clicked (handle_error' self#back));
+      ignore (win#browserForwardButton#connect#clicked
+        (handle_error' self#forward));
+      ignore (win#toplevel#event#connect#delete (fun _ ->
+        let my_id = Oo.id self in
+        cicBrowsers := List.filter (fun b -> Oo.id b <> my_id) !cicBrowsers;
+        if !cicBrowsers = [] &&
+          Helm_registry.get "matita.mode" = "cicbrowser"
+        then
+          GMain.quit ();
+        false));
+      ignore(win#whelpResultTreeview#connect#row_activated 
+        ~callback:(fun _ _ ->
+          handle_error (fun () -> self#loadInput (self#_getSelectedUri ()))));
+      mathView#set_href_callback (Some (fun uri ->
+        handle_error (fun () ->
+          self#load (`Uri (UriManager.uri_of_string uri)))));
+      self#_load (`About `Blank);
+      toplevel#show ()
+
+    val mutable current_entry = `About `Blank 
+
+    val model =
+      new MatitaGtkMisc.taggedStringListModel tags win#whelpResultTreeview
+
+    val mutable lastDir = ""  (* last loaded "directory" *)
+
+    method mathView = (mathView :> MatitaGuiTypes.clickableMathView)
+
+    method private _getSelectedUri () =
+      match model#easy_selection () with
+      | [sel] when is_uri sel -> sel  (* absolute URI selected *)
+(*       | [sel] -> win#browserUri#entry#text ^ sel  |+ relative URI selected +| *)
+      | [sel] -> lastDir ^ sel
+      | _ -> assert false
+
+    (** history RATIONALE 
+     *
+     * All operations about history are done using _historyFoo.
+     * Only toplevel functions (ATM load and loadInput) call _historyAdd.
+     *)
+          
+    method private _historyAdd item = 
+      history#add item;
+      win#browserBackButton#misc#set_sensitive true;
+      win#browserForwardButton#misc#set_sensitive false
+
+    method private _historyPrev () =
+      let item = history#previous in
+      if history#is_begin then win#browserBackButton#misc#set_sensitive false;
+      win#browserForwardButton#misc#set_sensitive true;
+      item
+    
+    method private _historyNext () =
+      let item = history#next in
+      if history#is_end then win#browserForwardButton#misc#set_sensitive false;
+      win#browserBackButton#misc#set_sensitive true;
+      item
+
+    (** notebook RATIONALE 
+     * 
+     * Use only these functions to switch between the tabs
+     *)
+    method private _showMath = win#mathOrListNotebook#goto_page 0
+    method private _showList = win#mathOrListNotebook#goto_page 1
+
+    method private back () =
+      try
+        self#_load (self#_historyPrev ())
+      with MatitaMisc.History_failure -> ()
+
+    method private forward () =
+      try
+        self#_load (self#_historyNext ())
+      with MatitaMisc.History_failure -> ()
+
+      (* loads a uri which can be a cic uri or an about:* uri
+      * @param uri string *)
+    method private _load ?(force=false) entry =
+      handle_error (fun () ->
+       if entry <> current_entry || entry = `About `Current_proof || force then
+        begin
+          (match entry with
+          | `About `Current_proof -> self#home ()
+          | `About `Blank -> self#blank ()
+          | `About `Us -> self#egg ()
+          | `Check term -> self#_loadCheck term
+          | `Cic (term, metasenv) -> self#_loadTermCic term metasenv
+          | `Dir dir -> self#_loadDir dir
+          | `Uri uri -> self#_loadUriManagerUri uri
+          | `Whelp (query, results) -> 
+              set_whelp_query query;
+              self#_loadList (List.map (fun r -> "obj",
+                UriManager.string_of_uri r) results));
+          self#setEntry entry
+        end)
+
+    method private blank () =
+      self#_showMath;
+      mathView#load_root (Lazy.force empty_mathml)#get_documentElement
+
+    method private _loadCheck term =
+      failwith "not implemented _loadCheck";
+(*       self#_showMath *)
+
+    method private egg () =
+      win#mathOrListNotebook#goto_page 2;
+      Lazy.force load_easter_egg
+
+    method private home () =
+      self#_showMath;
+      match self#script#grafite_status.proof_status with
+      | Proof  (uri, metasenv, bo, ty) ->
+          let name = UriManager.name_of_uri (HExtlib.unopt uri) in
+          let obj = Cic.CurrentProof (name, metasenv, bo, ty, [], []) in
+          self#_loadObj obj
+      | Incomplete_proof { proof = (uri, metasenv, bo, ty) } ->
+          let name = UriManager.name_of_uri (HExtlib.unopt uri) in
+          let obj = Cic.CurrentProof (name, metasenv, bo, ty, [], []) in
+          self#_loadObj obj
+      | _ -> self#blank ()
+
+      (** loads a cic uri from the environment
+      * @param uri UriManager.uri *)
+    method private _loadUriManagerUri uri =
+      let uri = UriManager.strip_xpointer uri in
+      let (obj, _) = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+      self#_loadObj obj
+      
+    method private _loadDir dir = 
+      let content = Http_getter.ls dir in
+      let l =
+        List.fast_sort
+          Pervasives.compare
+          (List.map
+            (function 
+              | Http_getter_types.Ls_section s -> "dir", s
+              | Http_getter_types.Ls_object o -> "obj", o.Http_getter_types.uri)
+            content)
+      in
+      lastDir <- dir;
+      self#_loadList l
+
+    method private setEntry entry =
+      win#browserUri#entry#set_text (MatitaTypes.string_of_entry entry);
+      current_entry <- entry
+
+    method private _loadObj obj =
+      (* showMath must be done _before_ loading the document, since if the
+       * widget is not mapped (hidden by the notebook) the document is not
+       * rendered *)
+      self#_showMath;
+      mathView#load_object obj
+
+    method private _loadTermCic term metasenv =
+      let context = self#script#proofContext in
+      let dummyno = CicMkImplicit.new_meta metasenv [] in
+      let sequent = (dummyno, context, term) in
+      mathView#load_sequent (sequent :: metasenv) dummyno;
+      self#_showMath
+
+    method private _loadList l =
+      model#list_store#clear ();
+      List.iter (fun (tag, s) -> model#easy_append ~tag s) l;
+      self#_showList
+    
+    (** { public methods, all must call _load!! } *)
+      
+    method load entry =
+      handle_error (fun () -> self#_load entry; self#_historyAdd entry)
+
+    (**  this is what the browser does when you enter a string an hit enter *)
+    method loadInput txt =
+      let txt = HExtlib.trim_blanks txt in
+      let fix_uri txt =
+        UriManager.string_of_uri
+          (UriManager.strip_xpointer (UriManager.uri_of_string txt))
+      in
+      if is_whelp txt then begin
+        set_whelp_query txt;  
+        (MatitaScript.current ())#advance ~statement:(txt ^ ".") ()
+      end else begin
+        let entry =
+          match txt with
+          | txt when is_uri txt -> `Uri (UriManager.uri_of_string (fix_uri txt))
+          | txt when is_dir txt -> `Dir (MatitaMisc.normalize_dir txt)
+          | txt ->
+             (try
+               MatitaTypes.entry_of_string txt
+              with Invalid_argument _ ->
+               raise
+                (GrafiteTypes.Command_error(sprintf "unsupported uri: %s" txt)))
+        in
+        self#_load entry;
+        self#_historyAdd entry
+      end
+
+      (** {2 methods accessing underlying GtkMathView} *)
+
+    method updateFontSize = mathView#set_font_size !current_font_size
+
+      (** {2 methods used by constructor only} *)
+
+    method win = win
+    method history = history
+    method currentEntry = current_entry
+    method refresh ~force () = self#_load ~force current_entry
+
   end
+  
+let sequentsViewer ~(notebook:GPack.notebook) ~(cicMathView:cicMathView) ():
+  MatitaGuiTypes.sequentsViewer
+=
+  new sequentsViewer ~notebook ~cicMathView ()
+
+let cicBrowser () =
+  let size = BuildTimeConf.browser_history_size in
+  let rec aux history =
+    let browser = new cicBrowser_impl ~history () in
+    let win = browser#win in
+    ignore (win#browserNewButton#connect#clicked (fun () ->
+      let history =
+        new MatitaMisc.browser_history ~memento:history#save size
+          (`About `Blank)
+      in
+      let newBrowser = aux history in
+      newBrowser#load browser#currentEntry));
+(*
+      (* attempt (failed) to close windows on CTRL-W ... *)
+    MatitaGtkMisc.connect_key win#browserWinEventBox#event ~modifiers:[`CONTROL]
+      GdkKeysyms._W (fun () -> win#toplevel#destroy ());
+*)
+    cicBrowsers := browser :: !cicBrowsers;
+    (browser :> MatitaGuiTypes.cicBrowser)
+  in
+  let history = new MatitaMisc.browser_history size (`About `Blank) in
+  aux history
+
+let default_cicMathView () = cicMathView ~show:true ()
+let cicMathView_instance = MatitaMisc.singleton default_cicMathView
+
+let default_sequentsViewer () =
+  let gui = get_gui () in
+  let cicMathView = cicMathView_instance () in
+  sequentsViewer ~notebook:gui#main#sequentsNotebook ~cicMathView ()
+let sequentsViewer_instance = MatitaMisc.singleton default_sequentsViewer
+
+let mathViewer () = 
+  object(self)
+    method private get_browser reuse = 
+      if reuse then
+        (match !cicBrowsers with
+        | [] -> cicBrowser ()
+        | b :: _ -> (b :> MatitaGuiTypes.cicBrowser))
+      else
+        (cicBrowser ())
+          
+    method show_entry ?(reuse=false) t = (self#get_browser reuse)#load t
+      
+    method show_uri_list ?(reuse=false) ~entry l =
+      (self#get_browser reuse)#load entry
+  end
+
+let refresh_all_browsers () =
+  List.iter (fun b -> b#refresh ~force:false ()) !cicBrowsers
+
+let update_font_sizes () =
+  List.iter (fun b -> b#updateFontSize) !cicBrowsers;
+  (cicMathView_instance ())#update_font_size
+
+let get_math_views () =
+  ((cicMathView_instance ()) :> MatitaGuiTypes.clickableMathView)
+  :: (List.map (fun b -> b#mathView) !cicBrowsers)
+
+let find_selection_owner () =
+  let rec aux =
+    function
+    | [] -> raise Not_found
+    | mv :: tl ->
+        (match mv#get_selections with
+        | [] -> aux tl
+        | sel :: _ -> mv)
+  in
+  aux (get_math_views ())
+
+let has_selection () =
+  try ignore (find_selection_owner ()); true
+  with Not_found -> false
+
+let math_view_clipboard = ref None (* associative list target -> string *)
+let has_clipboard () = !math_view_clipboard <> None
+let empty_clipboard () = math_view_clipboard := None
+
+let copy_selection () =
+  try
+    math_view_clipboard :=
+      Some ((find_selection_owner ())#strings_of_selection)
+  with Not_found -> failwith "no selection"
 
-let mathViewer () = new mathViewer
+let paste_clipboard paste_kind =
+  match !math_view_clipboard with
+  | None -> failwith "empty clipboard"
+  | Some cb ->
+      (try List.assoc paste_kind cb with Not_found -> assert false)