From db32a0e15ee7a3c506e96b7cff2b3c13941ed29a Mon Sep 17 00:00:00 2001
From: cqc <cqc@conrailqualitycontent.net>
Date: Thu, 9 May 2024 22:03:22 -0500
Subject: [PATCH] basic movement commands implemented

---
 ogui.ml | 103 ++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 71 insertions(+), 32 deletions(-)

diff --git a/ogui.ml b/ogui.ml
index da16114..4917149 100644
--- a/ogui.ml
+++ b/ogui.ml
@@ -97,10 +97,10 @@ module TextBuffer = struct
           | Some src ->
               let srcn = String.length src in
               assert (n < srcn);
-              let dst = Bytes.create srcn in
               let ucn =
                 Uchar.utf_decode_length (String.get_utf_8_uchar src n)
               in
+              let dst = Bytes.create (srcn - ucn) in
               Bytes.blit_string src 0 dst 0 n;
               Bytes.blit_string src (n + ucn) dst n (srcn - n - ucn);
               Some (Bytes.to_string dst)
@@ -980,36 +980,90 @@ module TextEdit = struct
                (fun () ->
                  TextBuffer.fold_string t.text (fun s ->
                      let sn = String.length s in
-                     let last_col = t.cursor.last_col in
                      let seol = Str.search_forward (Str.regexp "$") in
-                     let bol =
-                       Str.search_backward (Str.regexp "^") s
-                         t.cursor.index
+                     let next_bol =
+                       min sn (seol s t.cursor.index + 1)
                      in
-                     let eol = seol s t.cursor.index in
-                     let bol' = min sn eol + 1 in
-                     let eol' = seol s bol' in
-                     let next_line_len = eol' - bol' in
-                     F.epr
-                       "Down: index=%d last_col=%d eol=%d eol'=%d \
-                        bol=%d @."
-                       t.cursor.index last_col eol eol' bol;
+                     let next_line_len = seol s next_bol - next_bol in
+                     (* F.epr
+                        "Down: index=%d last_col=%d eol=%d eol'=%d \
+                         bol=%d @."
+                         t.cursor.index last_col  eol' bol; *)
                      t.cursor <-
                        {
                          t.cursor with
                          index =
-                           (bol'
+                           (next_bol
                            +
-                           if last_col > next_line_len then
+                           if t.cursor.last_col > next_line_len then
                              next_line_len
-                           else min next_line_len last_col);
+                           else min next_line_len t.cursor.last_col);
                        }));
            ]
       |> adds
            [
              [ Key (Press, P, [ Control ]) ]; [ Key (Press, Up, []) ];
            ]
-           [ Custom (fun () -> cursor_move t (-10)) ]
+           [
+             Custom
+               (fun () ->
+                 TextBuffer.fold_string t.text (fun s ->
+                     let sbol =
+                       Str.search_backward (Str.regexp "^") s
+                     in
+                     let bol = sbol t.cursor.index in
+                     if bol > 0 then (
+                       let prev_bol = sbol (max 0 (bol - 1)) in
+                       let prev_line_len = bol - 1 - prev_bol in
+                       F.epr
+                         "up: index=%d bol=%d prev_bol=%d \
+                          prev_line_len=%d @."
+                         t.cursor.index bol prev_bol prev_line_len;
+                       t.cursor <-
+                         {
+                           t.cursor with
+                           index =
+                             (prev_bol
+                             +
+                             if t.cursor.last_col > prev_line_len then
+                               prev_line_len
+                             else min prev_line_len t.cursor.last_col
+                             );
+                         })));
+           ]
+      |> adds (* EOL *)
+           [
+             [ Key (Press, E, [ Control ]) ]; [ Key (Press, End, []) ];
+           ]
+           [
+             Custom
+               (fun () ->
+                 TextBuffer.fold_string t.text (fun s ->
+                     let bol =
+                       Str.search_backward (Str.regexp "^") s
+                         t.cursor.index
+                     in
+                     let eol =
+                       Str.search_forward (Str.regexp "$") s
+                         t.cursor.index
+                     in
+                     t.cursor <-
+                       TextLayout.cursor ~last_col:(eol - bol) eol));
+           ]
+      |> adds (* BOL *)
+           [
+             [ Key (Press, A, [ Control ]) ];
+             [ Key (Press, Home, []) ];
+           ]
+           [
+             Custom
+               (fun () ->
+                 TextBuffer.fold_string t.text (fun s ->
+                     t.cursor <-
+                       TextLayout.cursor ~last_col:0
+                         (Str.search_backward (Str.regexp "^") s
+                            t.cursor.index)));
+           ]
       |> adds
            [ [ Key (Press, Backspace, []) ] ]
            [
@@ -1021,21 +1075,6 @@ module TextEdit = struct
                    t.text <- text;
                    cursor_move t (-1))
                  else Lwt.return_unit);
-           ]
-      |> adds (* EOL *)
-           [
-             [ Key (Press, E, [ Control ]) ]; [ Key (Press, End, []) ];
-           ]
-           [
-             Custom
-               (fun () ->
-                 TextBuffer.length t.text >>= fun _textlen ->
-                 TextBuffer.fold_string t.text (fun s ->
-                     Str.search_forward (Str.regexp "$") s
-                       t.cursor.index)
-                 >>= fun index ->
-                 t.cursor <- { t.cursor with index };
-                 Lwt.return_unit);
            ];
 
     (* WARN XXX TKTK TODO this is probably "breaking" the lwt context and being used in other calls to Lwt_main.run *)