visualwall now fully working

6 files changed, 613 insertions, 104 deletions

diff --git a/makefile b/makefile
index d502225..dc4cc96 100644
--- a/makefile
+++ b/makefile
@@ -30,8 +30,10 @@ visualwall:
 	ocamlfind opt -g -linkpkg -I ${SOURCEDIR} \
 	-o ${OUTPUTDIR}/visualwall \
 	-package lablgtk2,zarith \
-	${SOURCEDIR}/sequence.mli ${SOURCEDIR}/sequence.ml \
+	${SOURCEDIR}/util.mli ${SOURCEDIR}/util.ml \
 	${SOURCEDIR}/wall.mli ${SOURCEDIR}/wall.ml \
+	${SOURCEDIR}/sequence.mli ${SOURCEDIR}/sequence.ml \
+	${SOURCEDIR}/dialog.mli ${SOURCEDIR}/dialog.ml \
 	${SOURCEDIR}/visualwall.ml
 
 wallgen:
diff --git a/src/dialog.ml b/src/dialog.ml
new file mode 100644
index 0000000..826d280
--- /dev/null
+++ b/src/dialog.ml
@@ -0,0 +1,297 @@
+
+
+(* Programmed by Jedidiah Barber *)
+(* Licensed under the Sunset License v1.0 *)
+
+
+let license_text =
+  "SUNSET LICENSE\n" ^
+  "Version 1.0, June 2017\n" ^
+  "\n" ^
+  "1. You may copy, modify, use, sell, or distribute this work, verbatim or\n" ^
+  "modified, for any purpose.\n" ^
+  "\n" ^
+  "2. If you sell or distribute this work, whether verbatim or modified, you must\n" ^
+  "include a copy of this license, and you must make the source code available for\n" ^
+  "no extra charge.\n" ^
+  "\n" ^
+  "3. A modified version of this work must be clearly labeled as such.\n" ^
+  "\n" ^
+  "4. Derivative works must also be licensed under this license or a license of\n" ^
+  "equivalent terms. As an exception, linking this work with another, whether\n" ^
+  "statically or dynamically, does not impose any license requirements on the\n" ^
+  "other work.\n" ^
+  "\n" ^
+  "5. If a minimum of 15 years have passed since the date of first publishing for\n" ^
+  "a part of this work, then that part is placed into the public domain and you\n" ^
+  "may do whatever you want with it, regardless of all other clauses.\n"
+
+
+
+let new_wall () =
+  let newer =
+    GWindow.dialog
+      ~title:"Create New Wall - Number Wall Viewer" () in
+  let dialog_box =
+    GPack.vbox
+      ~border_width:10
+      ~packing:newer#vbox#add () in
+  let frame =
+    GBin.frame
+      ~label:"New Wall"
+      ~packing:dialog_box#add () in
+  let frame_box =
+    GPack.vbox
+      ~border_width:5
+      ~packing:frame#add () in
+  let seq_box =
+    GPack.hbox
+      ~border_width:5
+      ~packing:frame_box#add () in
+  let _ =
+    GMisc.label
+      ~text:"Sequence : "
+      ~packing:seq_box#add () in
+  let seq_combo =
+    GEdit.combo
+      ~popdown_strings:["Pagoda";"Random"]
+      ~allow_empty:false
+      ~case_sensitive:false
+      ~enable_arrow_keys:true
+      ~packing:seq_box#add () in
+  let adj_box =
+    GPack.hbox
+      ~border_width:5
+      ~packing:frame_box#add () in
+  let x_adj =
+    GData.adjustment
+      ~value:200.0
+      ~lower:10.0
+      ~upper:10000.0
+      ~step_incr:1.0
+      ~page_incr:100.0
+      ~page_size:0.0 () in
+  let y_adj =
+    GData.adjustment
+      ~value:200.0
+      ~lower:10.0
+      ~upper:10000.0
+      ~step_incr:1.0
+      ~page_incr:100.0
+      ~page_size:0.0 () in
+  let _ =
+    GMisc.label
+      ~text:"X : "
+      ~packing:adj_box#add () in
+  let _ =
+    GEdit.spin_button
+      ~adjustment:x_adj
+      ~rate:0.0
+      ~digits:0
+      ~wrap:false
+      ~packing:adj_box#add () in
+  let _ =
+    GMisc.label
+      ~text:"  Y : "
+      ~packing:adj_box#add () in
+  let _ =
+    GEdit.spin_button
+      ~adjustment:y_adj
+      ~rate:0.0
+      ~digits:0
+      ~wrap:false
+      ~packing:adj_box#add () in
+  newer#add_button_stock `CANCEL `CANCEL;
+  newer#add_button_stock `NEW `NEW;
+  let code = newer#run () in
+  let result = (int_of_float x_adj#value, int_of_float y_adj#value, seq_combo#entry#text) in
+  newer#destroy ();
+  if code = `NEW then Some result else None
+
+
+
+let open_file ?(folder = "") () =
+  let chooser =
+    GWindow.file_chooser_dialog
+      ~action:`OPEN
+      ~title:"Open Sequence - Number Wall Viewer" () in
+  chooser#add_button_stock `CANCEL `dialog;
+  chooser#add_select_button_stock `OPEN `filechooser;
+  ignore (chooser#set_current_folder folder);
+  let code = chooser#run () in
+  let maybe_result = chooser#filename in
+  chooser#destroy ();
+  if code <> `filechooser then None else maybe_result
+
+
+
+let overwrite_check ~filename =
+  if not (Sys.file_exists filename) then
+    true
+  else
+   (let asker =
+      GWindow.dialog
+        ~title:"Confirm Overwrite"
+        ~resizable:false
+        ~width:380 ~height:130 () in
+    let box =
+      GPack.hbox
+        ~packing:asker#vbox#add () in
+    ignore (GMisc.image
+        ~stock:`DIALOG_ERROR
+        ~packing:box#add ());
+    let message =
+      GMisc.label
+        ~text:("Error: " ^ filename ^ " already exists.")
+        ~packing:box#add () in
+    message#set_line_wrap true;
+    asker#add_button "Cancel" `dialog;
+    asker#add_button "Overwrite" `filechooser;
+    let code = asker#run () in
+    asker#destroy ();
+    code = `filechooser)
+
+let save_export_file ~title ?(folder = "") ?(name = "") () =
+  let chooser =
+    GWindow.file_chooser_dialog
+      ~action:`SAVE
+      ~title:title () in
+  chooser#add_button_stock `CANCEL `dialog;
+  chooser#add_select_button_stock `SAVE `filechooser;
+  chooser#set_current_name name;
+  ignore (chooser#set_current_folder folder);
+  let rec get_result chooser =
+    let code = chooser#run () in
+    let choice = chooser#filename in
+    if code <> `filechooser then
+      None
+    else
+      if Option.is_none choice ||
+        overwrite_check ~filename:(Option.get choice)
+      then
+        choice
+      else
+        get_result chooser in
+  let result = get_result chooser in
+  chooser#destroy ();
+  result
+
+let save_file ?(folder = "") ?(name = "") () =
+  save_export_file ~title:"Save Sequence - Number Wall Viewer" ~folder ~name ()
+
+let export_file ?(folder = "") ?(name = "") () =
+  save_export_file ~title:"Export Image - Number Wall Viewer" ~folder ~name ()
+
+
+
+let colors ~fore ~back =
+  let colormap = Gdk.Color.get_system_colormap () in
+  let fore_color = Gdk.Color.alloc ~colormap (`RGB fore) in
+  let back_color = Gdk.Color.alloc ~colormap (`RGB back) in
+  let kaleidoscope =
+    GWindow.dialog
+      ~title:"Change Colors - Number Wall Viewer" () in
+  let dialog_box =
+    GPack.vbox
+      ~border_width:10
+      ~packing:kaleidoscope#vbox#add () in
+  let frame =
+    GBin.frame
+      ~label:"Colors"
+      ~packing:dialog_box#add () in
+  let frame_box =
+    GPack.vbox
+      ~border_width:5
+      ~packing:frame#add () in
+  let fg_box =
+    GPack.hbox
+      ~packing:frame_box#add () in
+  let _ =
+    GMisc.label
+      ~text:"Foreground : "
+      ~packing:fg_box#add () in
+  let fg_button =
+    GButton.color_button
+      ~color:fore_color
+      ~title:"Change Foreground Color"
+      ~packing:fg_box#add () in
+  let bg_box =
+    GPack.hbox
+      ~packing:frame_box#add () in
+  let _ =
+    GMisc.label
+      ~text:"Background : "
+      ~packing:bg_box#add () in
+  let bg_button =
+    GButton.color_button
+      ~color:back_color
+      ~title:"Change Background Color"
+      ~packing:bg_box#add () in
+  kaleidoscope#add_button_stock `CANCEL `CANCEL;
+  kaleidoscope#add_button_stock `APPLY `APPLY;
+  let code = kaleidoscope#run () in
+  let (new_fg, new_bg) = (fg_button#color, bg_button#color) in
+  kaleidoscope#destroy ();
+  let fg_r = Gdk.Color.red new_fg in
+  let fg_g = Gdk.Color.green new_fg in
+  let fg_b = Gdk.Color.blue new_fg in
+  let bg_r = Gdk.Color.red new_bg in
+  let bg_g = Gdk.Color.green new_bg in
+  let bg_b = Gdk.Color.blue new_bg in
+  if code = `APPLY then Some ((fg_r, fg_g, fg_b), (bg_r, bg_g, bg_b)) else None
+
+
+
+let modulus ~current =
+  let changer =
+    GWindow.dialog
+      ~title:"Set Modulus - Number Wall Viewer" () in
+  let dialog_box =
+    GPack.vbox
+      ~border_width:10
+      ~packing:changer#vbox#add () in
+  let frame =
+    GBin.frame
+      ~label:"Modulus"
+      ~packing:dialog_box#add () in
+  let frame_box =
+    GPack.vbox
+      ~border_width:5
+      ~packing:frame#add () in
+  let adj =
+    GData.adjustment
+      ~value:(float_of_int current)
+      ~lower:2.0
+      ~upper:10001.0
+      ~step_incr:1.0
+      ~page_incr:100.0
+      ~page_size:0.0 () in
+  let _ =
+    GEdit.spin_button
+      ~adjustment:adj
+      ~rate:0.0
+      ~digits:0
+      ~wrap:false
+      ~packing:frame_box#add () in
+  changer#add_button_stock `CANCEL `CANCEL;
+  changer#add_button_stock `APPLY `APPLY;
+  let code = changer#run () in
+  let maybe_result = adj#value in
+  changer#destroy ();
+  if code = `APPLY then Some (int_of_float maybe_result) else None
+
+
+
+let about () =
+  let about_window =
+    GWindow.about_dialog
+      ~authors:["Jedidiah Barber"]
+      ~comments:"A simple program to generate and visualise number walls."
+      ~license:license_text
+      ~title:"About - Number Wall Viewer"
+      ~modal:true () in
+  let destroy_me button = about_window#destroy () in
+  ignore (about_window#connect#response ~callback:destroy_me);
+  about_window#show ()
+
+
diff --git a/src/dialog.mli b/src/dialog.mli
new file mode 100644
index 0000000..29bcf12
--- /dev/null
+++ b/src/dialog.mli
@@ -0,0 +1,26 @@
+
+
+(* Programmed by Jedidiah Barber *)
+(* Licensed under the Sunset License v1.0 *)
+
+
+val license_text : string
+
+
+
+val new_wall : unit -> (int * int * string) option
+
+val open_file : ?folder:string -> unit -> string option
+
+val save_file : ?folder:string -> ?name:string -> unit -> string option
+
+val export_file : ?folder:string -> ?name:string -> unit -> string option
+
+val colors : fore:(int * int * int) -> back:(int * int * int) ->
+  ((int * int * int) * (int * int * int)) option
+
+val modulus : current:int -> int option
+
+val about : unit -> unit
+
+
diff --git a/src/visualwall.ml b/src/visualwall.ml
index 3c07363..773f226 100644
--- a/src/visualwall.ml
+++ b/src/visualwall.ml
@@ -4,29 +4,56 @@
 (* Licensed under the Sunset License v1.0 *)
 
 
+module My_Algebra =
+  struct
+    type t = Z.t
+    let zero = Z.zero
+    let one = Z.one
+    let add = Z.add
+    let sub = Z.sub
+    let mul = Z.mul
+    let div = Z.div
+    let to_string = Z.to_string
+  end
+
+module My_Wall = Wall.Make (My_Algebra)
+
+
+
 let main () =
   ignore (GtkMain.Main.init ());
 
-  let window = GWindow.window
-    ~title:"Number Wall Viewer"
-    ~width:250 () in
+  let window =
+    GWindow.window
+      ~title:"Number Wall Viewer"
+      ~width:250 () in
   ignore (window#connect#destroy ~callback:GMain.quit);
 
-  let main_vbox = GPack.vbox
-    ~packing:window#add () in
+  let main_vbox =
+    GPack.vbox
+      ~packing:window#add () in
+
+  let menubar =
+    GMenu.menu_bar
+      ~packing:(main_vbox#pack ~expand:false) () in
 
-  let menubar = GMenu.menu_bar
-    ~packing:(main_vbox#pack ~expand:false) () in
-  let wall_view = GBin.scrolled_window
-    ~hpolicy:`AUTOMATIC
-    ~vpolicy:`AUTOMATIC
-    ~packing:(main_vbox#pack ~expand:true) () in
-  let statusbar = GMisc.statusbar
-    ~packing:(main_vbox#pack ~expand:false) () in
+  let wall_view =
+    GBin.scrolled_window
+      ~hpolicy:`AUTOMATIC
+      ~vpolicy:`AUTOMATIC
+      ~packing:(main_vbox#pack ~expand:true) () in
 
+  let statusbar =
+    GMisc.statusbar
+      ~packing:(main_vbox#pack ~expand:false) () in
+
+  let context =
+    statusbar#new_context ~name:"Program status" in
+
+  let system_colormap =
+    Gdk.Color.get_system_colormap () in
 
 
-  let context = statusbar#new_context ~name:"Program status" in
 
   let set_status ~msg =
     context#pop ();
@@ -34,130 +61,261 @@ let main () =
 
 
 
-  let choose_open_file ~title ?(folder = "") () =
-    let chooser = GWindow.file_chooser_dialog
-      ~action:`OPEN
-      ~title:title () in
-    chooser#add_button_stock `CANCEL `dialog;
-    chooser#add_select_button_stock `OPEN `filechooser;
-    ignore (chooser#set_current_folder folder);
-    let code = chooser#run () in
-    let maybe_result = chooser#filename in
-    chooser#destroy ();
-    match maybe_result with
-      | None -> ""
-      | Some result -> if code = `filechooser then result else "" in
-
-  let choose_save_file ~title ?(folder = "") ?(name = "") () =
-    let chooser = GWindow.file_chooser_dialog
-      ~action:`SAVE
-      ~title:title () in
-    chooser#add_button_stock `CANCEL `dialog;
-    chooser#add_select_button_stock `SAVE `filechooser;
-    chooser#set_current_name name;
-    ignore (chooser#set_current_folder folder);
-    let code = chooser#run () in
-    let maybe_result = chooser#filename in
-    chooser#destroy ();
-    match maybe_result with
-      | None -> ""
-      | Some result -> if code = `filechooser then result else "" in
+  let number_wall = ref My_Wall.empty in
+  let modulus = ref 2 in
+
+  let magnify = ref 2 in
+
+  (* Default to orange foreground, blue background. *)
+  let foreground_color = ref (65535, 40447, 0) in
+  let background_color = ref (11519, 21247, 65535) in
+
+  let x_dim = ref 1 in
+  let y_dim = ref 1 in
+  let x_offset = ref 0 in
+
+  let wall_loaded = ref false in
+
+
+
+  let expose (drawitem:GMisc.drawing_area) (backing:GDraw.pixmap ref) event =
+    let area = GdkEvent.Expose.area event in
+    let x = Gdk.Rectangle.x area in
+    let y = Gdk.Rectangle.y area in
+    let width = Gdk.Rectangle.width area in
+    let height = Gdk.Rectangle.height area in
+    let drawing =
+      drawitem#misc#realize ();
+      new GDraw.drawable (drawitem#misc#window) in
+    drawing#put_pixmap ~x ~y ~xsrc:x ~ysrc:y ~width ~height !backing#pixmap;
+    false in
+
+  let draw_area =
+    GMisc.drawing_area
+      ~packing:wall_view#add_with_viewport () in
+
+  let pixmap_area = ref
+   (GDraw.pixmap
+      ~width:!x_dim
+      ~height:!y_dim
+      ~window:wall_view
+      ~colormap:system_colormap ()) in
+
+  ignore (draw_area#event#connect#expose ~callback:(expose draw_area pixmap_area));
+  draw_area#event#add [`EXPOSURE];
+
+  let redraw_pixmap () =
+    for j = 0 to !y_dim - 1 do
+      for i = !x_offset to !x_dim + !x_offset - 1 do
+        if My_Wall.has_value !number_wall ~x:i ~y:j &&
+          Z.rem (My_Wall.get !number_wall ~x:i ~y:j) (Z.of_int !modulus) <> My_Algebra.zero
+        then
+          !pixmap_area#set_foreground (`RGB !background_color)
+        else
+          !pixmap_area#set_foreground (`RGB !foreground_color);
+        !pixmap_area#rectangle
+          ~x:((i - !x_offset) * !magnify)
+          ~y:(j * !magnify)
+          ~width:!magnify
+          ~height:!magnify
+          ~filled:true ()
+      done
+    done;
+    let update_rectangle =
+      Gdk.Rectangle.create
+        ~x:0 ~y:0
+        ~width:(!x_dim * !magnify)
+        ~height:(!y_dim * !magnify) in
+    draw_area#misc#draw (Some update_rectangle) in
+
+  let new_pixmap () =
+    pixmap_area :=
+      GDraw.pixmap
+        ~width:(!x_dim * !magnify)
+        ~height:(!y_dim * !magnify)
+        ~window:wall_view
+        ~colormap:system_colormap ();
+    draw_area#misc#set_size_request
+      ~width:(!x_dim * !magnify)
+      ~height:(!y_dim * !magnify) () in
 
 
 
   let generate_unused ~basename ~extension =
     let rec checker num =
       let testname = basename ^ "-" ^ (string_of_int num) ^ "." ^ extension in
-      if not (Sys.file_exists testname) then testname else checker (num + 1) in
+      if not (Sys.file_exists testname) then
+        testname
+      else
+        checker (num + 1) in
     checker 1 in
 
 
 
-  let overwrite_check ~filename =
-    if not (Sys.file_exists filename) then true else
-     (let asker = GWindow.dialog
-        ~title:"Confirm Overwrite"
-        ~resizable:false
-        ~width:380 ~height:130 () in
-      let box = GPack.hbox
-        ~packing:asker#vbox#add () in
-      let _ = GMisc.image
-        ~stock:`DIALOG_ERROR
-        ~packing:box#add () in
-      let message = GMisc.label
-        ~text:("Error: " ^ filename ^ " already exists.")
-        ~packing:box#add () in
-      message#set_line_wrap true;
-      asker#add_button "Cancel" `dialog;
-      asker#add_button "Overwrite" `filechooser;
-      let code = asker#run () in
-      asker#destroy ();
-      code = `filechooser) in
+  let menus = ref ([] : (string * GMenu.menu) list) in
+
+  let disable_menu_items menu placelist =
+    let disable nth = (List.nth menu#children nth)#misc#set_sensitive false in
+    List.iter disable placelist in
+
+  let enable_menu_items menu placelist =
+    let enable nth = (List.nth menu#children nth)#misc#set_sensitive true in
+    List.iter enable placelist in
 
 
 
   let new_cb () =
-    print_endline "New..." in
+    let maybe_new = Dialog.new_wall () in
+    if Option.is_some maybe_new then
+     (let (x,y,s) = Option.get maybe_new in
+      x_dim := x;
+      y_dim := y;
+      x_offset := y;
+      let real_x_dim = x + 2 * y in
+      let real_y_dim = y + x / 2 + 1 in
+      if s = "Pagoda" then
+        number_wall :=
+          My_Wall.create
+            ~dimx:real_x_dim
+            ~dimy:real_y_dim
+            ~init:(Sequence.pagoda ~len:real_x_dim)
+      else
+        number_wall :=
+          My_Wall.create
+            ~dimx:real_x_dim
+            ~dimy:real_y_dim
+            ~init:(Sequence.random ~len:real_x_dim);
+      new_pixmap ();
+      redraw_pixmap ();
+      wall_loaded := true;
+      enable_menu_items (List.assoc "file" !menus) [3;4;6];
+      set_status ~msg:"New wall created")
+    else
+     (set_status ~msg:"Canceled new wall")in
 
 
 
   let open_cb () =
-    let filename = choose_open_file
-      ~title:"Open Sequence - Number Wall Viewer"
-      ~folder:(Sys.getcwd ()) () in
-    if filename != "" then
-     (set_status ~msg:("Opened " ^ filename);
-      print_endline filename)
+    let maybe_filename =
+      Dialog.open_file
+        ~folder:(Sys.getcwd ()) () in
+    if Option.is_some maybe_filename then
+     (let filename = Option.get maybe_filename in
+      try
+        let input_seq = Util.read_sequence_file filename in
+        let real_x_dim = Array.length input_seq in
+        x_dim := real_x_dim / 3;
+        y_dim := !x_dim;
+        let real_y_dim = !y_dim + !x_dim / 2 + 1 in
+        x_offset := !y_dim;
+        number_wall :=
+          My_Wall.create
+            ~dimx:real_x_dim
+            ~dimy:real_y_dim
+            ~init:input_seq;
+        new_pixmap ();
+        redraw_pixmap ();
+        wall_loaded := true;
+        enable_menu_items (List.assoc "file" !menus) [3;4;6];
+        set_status ~msg:("Opened " ^ filename)
+      with
+        Util.Not_an_integer s ->
+          set_status ~msg:("Error: " ^ s ^ " is not an integer"))
     else
      (set_status ~msg:"Canceled open") in
 
   let save_as_cb () =
-    let filename = choose_save_file
-      ~title:"Save Sequence - Number Wall Viewer"
-      ~folder:(Sys.getcwd ())
-      ~name:(generate_unused ~basename:"sequence" ~extension:"txt") () in
-    if filename != "" && overwrite_check ~filename then
-     (set_status ~msg:("Saved sequence to " ^ filename);
-      print_endline filename)
+    let maybe_filename =
+      Dialog.save_file
+        ~folder:(Sys.getcwd ())
+        ~name:(generate_unused ~basename:"sequence" ~extension:"txt") () in
+    if Option.is_some maybe_filename then
+     (let filename = Option.get maybe_filename in
+      let write channel =
+        for i = 0 to My_Wall.x_length !number_wall - 2 do
+          output_string channel (Z.to_string (My_Wall.get !number_wall ~x:i ~y:1) ^ ",");
+        done;
+        output_string channel (Z.to_string
+          (My_Wall.get !number_wall ~x:(My_Wall.x_length !number_wall - 1) ~y:1) ^ "\n") in
+      Util.call_with_open_output_file ~filename ~func:write;
+      set_status ~msg:("Saved sequence to " ^ filename))
     else
      (set_status ~msg:"Canceled save") in
 
   let export_cb () =
-    let filename = choose_save_file
-      ~title:"Export Image - Number Wall Viewer"
-      ~folder:(Sys.getcwd ())
-      ~name:(generate_unused ~basename:"image" ~extension:"png") () in
-    if filename != "" && overwrite_check ~filename then
-     (set_status ~msg:("Exported image to " ^ filename);
-      print_endline filename)
+    let maybe_filename =
+      Dialog.export_file
+        ~folder:(Sys.getcwd ())
+        ~name:(generate_unused ~basename:"image" ~extension:"png") () in
+    if Option.is_some maybe_filename then
+     (let filename = Option.get maybe_filename in
+      let buffer = GdkPixbuf.create
+        ~width:(!x_dim * !magnify)
+        ~height:(!y_dim * !magnify)
+        ~has_alpha:false () in
+      !pixmap_area#get_pixbuf
+        ~dest_x:0 ~dest_y:0
+        ~width:(!x_dim * !magnify)
+        ~height:(!y_dim * !magnify)
+        ~src_x:0 ~src_y:0
+        buffer;
+      GdkPixbuf.save
+        ~filename
+        ~typ:"png"
+        buffer;
+      set_status ~msg:("Exported image to " ^ filename))
     else
      (set_status ~msg:"Canceled export") in
 
 
 
   let discard_cb () =
-    print_endline "Discard" in
+    number_wall := My_Wall.empty;
+    x_dim := 1;
+    y_dim := 1;
+    new_pixmap ();
+    redraw_pixmap ();
+    wall_loaded := false;
+    disable_menu_items (List.assoc "file" !menus) [3;4;6];
+    set_status ~msg:"Discarded sequence" in
 
 
 
   let color_cb () =
-    print_endline "Color..." in
+    let maybe_colors =
+      Dialog.colors ~fore:!foreground_color ~back:!background_color in
+    if Option.is_some maybe_colors then
+     (foreground_color := fst (Option.get maybe_colors);
+      background_color := snd (Option.get maybe_colors);
+      if !wall_loaded then redraw_pixmap ();
+      set_status ~msg:"Color change applied")
+    else
+     (set_status ~msg:"Canceled color change") in
 
   let modulus_cb () =
-    print_endline "Modulus..." in
+    let maybe_modulus =
+      Dialog.modulus ~current:!modulus in
+    if Option.is_some maybe_modulus then
+     (modulus := Option.get maybe_modulus;
+      if !wall_loaded then redraw_pixmap ();
+      set_status ~msg:("Changed modulus to " ^ string_of_int !modulus))
+    else
+     (set_status ~msg:"Canceled modulus change") in
+
+
+
+  let zoom_cb n active =
+    if active then
+     (magnify := n;
+      if !wall_loaded then
+       (new_pixmap ();
+        redraw_pixmap ());
+      set_status ~msg:("Zoom set to " ^ string_of_int n ^ "x")) in
 
 
 
   let about_cb () =
-    let about_window = GWindow.about_dialog
-      ~authors:["Jedidiah Barber"]
-      ~comments:"A simple program to generate and visualise number walls."
-      ~license:"Sunset License v1.0"
-      ~title:"About - Number Wall Viewer"
-      ~modal:true () in
-    let destroy_me button = about_window#destroy () in
-    ignore (about_window#connect#response ~callback:destroy_me);
-    about_window#show () in
+    Dialog.about () in
 
 
 
@@ -177,6 +335,13 @@ let main () =
     `I ("Modulus...", modulus_cb)
   ] in
 
+  let zoom_menu_entries = [
+    `R [ ("1x", false, (zoom_cb 1))
+       ; ("2x", true,  (zoom_cb 2))
+       ; ("3x", false, (zoom_cb 3))
+       ; ("4x", false, (zoom_cb 4))]
+  ] in
+
   let help_menu_entries = [
     `I ("About", about_cb)
   ] in
@@ -184,13 +349,24 @@ let main () =
 
 
   let create_menu ~label ~bar ~entries =
-    let item = GMenu.menu_item ~label ~packing:bar#append () in
-    let menu = GMenu.menu ~packing:item#set_submenu () in
-    GToolbox.build_menu menu ~entries in
-
-  ignore (create_menu ~label:"File" ~bar:menubar ~entries:file_menu_entries);
-  ignore (create_menu ~label:"Options" ~bar:menubar ~entries:option_menu_entries);
-  ignore (create_menu ~label:"Help" ~bar:menubar ~entries:help_menu_entries);
+    let item =
+      GMenu.menu_item
+        ~label
+        ~packing:bar#append () in
+    let menu =
+      GMenu.menu
+        ~packing:item#set_submenu () in
+    GToolbox.build_menu menu ~entries;
+    menu in
+
+  let file_menu   = create_menu ~label:"File"    ~bar:menubar ~entries:file_menu_entries   in
+  let option_menu = create_menu ~label:"Options" ~bar:menubar ~entries:option_menu_entries in
+  let zoom_menu   = create_menu ~label:"Zoom"    ~bar:menubar ~entries:zoom_menu_entries   in
+  let help_menu   = create_menu ~label:"Help"    ~bar:menubar ~entries:help_menu_entries   in
+
+  menus := [("file",file_menu); ("option",option_menu); ("zoom",zoom_menu); ("help",help_menu)];
+
+  disable_menu_items (List.assoc "file" !menus) [3;4;6];
 
   set_status ~msg:"No wall loaded";
   window#show ();
diff --git a/src/wall.ml b/src/wall.ml
index 94043dc..6c11939 100644
--- a/src/wall.ml
+++ b/src/wall.ml
@@ -22,6 +22,7 @@ module type S =
   sig
     type element
     type wall
+    val empty : wall
     val create : dimx:int -> dimy:int -> init:element array -> wall
     val x_length : wall -> int
     val y_length : wall -> int
@@ -281,6 +282,11 @@ module Make (A : Algebra) =
       with Exit ->
         result
 
+    (* The empty wall isn't truly empty because every wall has *)
+    (* a row of ones at the very top, regardless of the input sequence. *)
+    let empty =
+      Array.make_matrix 1 1 (Some A.one)
+
 
 
     let get wall ~x ~y =
diff --git a/src/wall.mli b/src/wall.mli
index 59d8edb..dc96218 100644
--- a/src/wall.mli
+++ b/src/wall.mli
@@ -26,6 +26,8 @@ module type S =
     type element
     type wall
 
+    val empty : wall
+
     val create : dimx:int -> dimy:int -> init:element array -> wall
 
     val x_length : wall -> int