From 9ed9bdd5f158f092114c2d98c2537a9396d6a8d7 Mon Sep 17 00:00:00 2001
From: Stefano Zacchiroli <zack@upsilon.cc>
Date: Wed, 19 Jul 2006 17:28:20 +0000
Subject: [PATCH] - pipe graphviz markup to tred before generating png/map
 output to get rid of   transitive dependencies - added method center_on_href
 to clamp viewport so that a given node is visible   (actually it is not a
 real "center"ing ...)

---
 matita/lablGraphviz.ml  | 43 +++++++++++++++++++++++++++++------------
 matita/lablGraphviz.mli |  3 +++
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/matita/lablGraphviz.ml b/matita/lablGraphviz.ml
index 0084c9204..12d302d24 100644
--- a/matita/lablGraphviz.ml
+++ b/matita/lablGraphviz.ml
@@ -31,6 +31,7 @@ type attribute = string * string  (* <key, value> pair *)
 
 let png_flags = "-Tpng"
 let map_flags = "-Tcmapx"
+let tred_cmd = "tred" (* graphviz transitive reduction filter *)
 
 let tempfile () = Filename.temp_file "matita_" ""
 
@@ -39,18 +40,26 @@ class type graphviz_widget =
     method load_graph_from_file: string -> unit
     method connect_href:
       (GdkEvent.Button.t -> (string * string) list -> unit) -> unit
+    method center_on_href: string -> unit
     method as_image: GMisc.image
     method as_viewport: GBin.viewport
   end
 
 class graphviz_impl ?packing gviz_cmd =
   let viewport = GBin.viewport ?packing () in
+  let mk_gviz_cmd flags src_fname dest_fname =
+    sprintf "cat %s | %s | %s %s > %s" src_fname tred_cmd gviz_cmd flags
+      dest_fname in
   let image =
     GMisc.image ~packing:viewport#add ~xalign:0. ~yalign:0. ~xpad:0 ~ypad:0 ()
   in
+  let parse_coords s =
+    match List.map float_of_string (HExtlib.split ~sep:',' s) with
+    | [x1; y1; x2; y2 ] -> x1, y1, x2, y2
+    | _ -> assert false in
   object (self)
     val mutable href_cb = fun _ _ -> ()
-    val mutable map = []
+    val mutable map = []  (* list of associative list attr name -> attr value *)
 
     initializer
       ignore (viewport#event#connect#button_press (fun button ->
@@ -58,20 +67,21 @@ class graphviz_impl ?packing gviz_cmd =
         (* compute coordinates relative to image origin *)
         let x = GdkEvent.Button.x button +. viewport#hadjustment#value in
         let y = GdkEvent.Button.y button +. viewport#vadjustment#value in
-        (try
-          href_cb button (self#find_href x y)
-        with Not_found -> ());
+        (try href_cb button (self#find_href x y) with Not_found -> ());
         false))
 
     method load_graph_from_file fname =
       let tmp_png = tempfile () in
-      ignore (Sys.command (sprintf "%s %s %s > %s"
-        gviz_cmd png_flags fname tmp_png));
+      let rc = Sys.command (mk_gviz_cmd png_flags fname tmp_png) in
+      if rc <> 0 then
+        eprintf
+          ("Graphviz command failed (exit code: %d) on the following graph:\n"
+           ^^ "%s\n%!")
+          rc (HExtlib.input_file fname);
       image#set_file tmp_png;
       HExtlib.safe_remove tmp_png;
       let tmp_map = tempfile () in
-      ignore (Sys.command (sprintf "%s %s %s > %s"
-        gviz_cmd map_flags fname tmp_map));
+      ignore (Sys.command (mk_gviz_cmd map_flags fname tmp_map));
       self#load_map tmp_map;
       HExtlib.safe_remove tmp_map
 
@@ -89,10 +99,6 @@ class graphviz_impl ?packing gviz_cmd =
       map <- !areas
 
     method private find_href x y =
-      let parse_coords s =
-        match List.map float_of_string (HExtlib.split ~sep:',' s) with
-        | [x1; y1; x2; y2 ] -> x1, y1, x2, y2
-        | _ -> assert false in
       List.find
         (fun attrs ->
           let x1, y1, x2, y2 = parse_coords (List.assoc "coords" attrs) in
@@ -104,6 +110,19 @@ class graphviz_impl ?packing gviz_cmd =
     =
       href_cb <- cb
 
+    method center_on_href href =
+      (*eprintf "Centering viewport on uri %s\n%!" href;*)
+      let attrs = 
+        List.find
+          (fun attrs ->
+            try List.assoc "href" attrs = href with Not_found -> false)
+          map in
+      try
+        let x1, y1, x2, y2 = parse_coords (List.assoc "coords" attrs) in
+        viewport#hadjustment#clamp_page ~lower:x1 ~upper:x2;
+        viewport#vadjustment#clamp_page ~lower:y1 ~upper:y2;
+      with Not_found -> ()
+
     method as_image = image
     method as_viewport = viewport
 
diff --git a/matita/lablGraphviz.mli b/matita/lablGraphviz.mli
index 7dcedbf75..d6b7f4f6e 100644
--- a/matita/lablGraphviz.mli
+++ b/matita/lablGraphviz.mli
@@ -49,6 +49,9 @@ class type graphviz_widget =
     method connect_href:
       (GdkEvent.Button.t -> attribute list -> unit) -> unit
 
+    (** Center the viewport on the node having the given href value, if any *)
+    method center_on_href: string -> unit
+
       (** {3 low level access to embedded widgets}
        * Containment hierarchy:
        *  viewport
-- 
2.39.2