Revert "fix adjust_topline fix #222"

This reverts commit 855976e2283551db53617d4abb4c1399579a560d.

3 files changed, 20 insertions, 29 deletions

diff --git a/elisp.c b/elisp.c
index 9541728..1a6021a 100644
--- a/elisp.c
+++ b/elisp.c
@@ -55,7 +55,8 @@ void insert(emacs_env *env, emacs_value string) {
   env->funcall(env, Finsert, 1, (emacs_value[]){string});
 }
 
-void goto_char(emacs_env *env, emacs_value point) {
+void goto_char(emacs_env *env, int pos) {
+  emacs_value point = env->make_integer(env, pos);
   env->funcall(env, Fgoto_char, 1, (emacs_value[]){point});
 }
 
@@ -85,12 +86,6 @@ emacs_value point(emacs_env *env) { return env->funcall(env, Fpoint, 0, NULL); }
 void set_window_point(emacs_env *env, emacs_value win, emacs_value point) {
   env->funcall(env, Fset_window_point, 2, (emacs_value[]){win, point});
 }
-void set_window_start(emacs_env *env, emacs_value win, emacs_value point) {
-  env->funcall(env, Fset_window_start, 2, (emacs_value[]){win, point});
-}
-emacs_value window_body_height(emacs_env *env, emacs_value win) {
-  return env->funcall(env, Fwindow_body_height, 1, (emacs_value[]){win});
-}
 
 bool eq(emacs_env *env, emacs_value e1, emacs_value e2) {
   emacs_value Qeq = env->funcall(env, Feq, 2, (emacs_value[]){e1, e2});
diff --git a/elisp.h b/elisp.h
index 0a67090..efee3d3 100644
--- a/elisp.h
+++ b/elisp.h
@@ -37,8 +37,6 @@ emacs_value Fgoto_line;
 emacs_value Fdelete_lines;
 emacs_value Frecenter;
 emacs_value Fset_window_point;
-emacs_value Fset_window_start;
-emacs_value Fwindow_body_height;
 emacs_value Fpoint;
 
 emacs_value Fput_text_property;
@@ -65,15 +63,13 @@ void put_text_property(emacs_env *env, emacs_value string, emacs_value property,
                        emacs_value value);
 void erase_buffer(emacs_env *env);
 void insert(emacs_env *env, emacs_value string);
-void goto_char(emacs_env *env, emacs_value point);
+void goto_char(emacs_env *env, int pos);
 void forward_line(emacs_env *env, int n);
 void goto_line(emacs_env *env, int n);
 void set_cursor_type(emacs_env *env, emacs_value cursor_type);
 void delete_lines(emacs_env *env, int linenum, int count, bool del_whole_line);
 void recenter(emacs_env *env, emacs_value pos);
 void set_window_point(emacs_env *env, emacs_value win, emacs_value point);
-void set_window_start(emacs_env *env, emacs_value win, emacs_value point);
-emacs_value window_body_height(emacs_env *env, emacs_value win);
 emacs_value point(emacs_env *env);
 bool eq(emacs_env *env, emacs_value e1, emacs_value e2);
 void forward_char(emacs_env *env, emacs_value n);
diff --git a/vterm-module.c b/vterm-module.c
index 439df20..367761e 100644
--- a/vterm-module.c
+++ b/vterm-module.c
@@ -427,24 +427,29 @@ static void adjust_topline(Term *term, emacs_env *env) {
   size_t offset = get_col_offset(term, pos.row, pos.col);
   forward_char(env, env->make_integer(env, pos.col - offset));
 
-  emacs_value cursor_point = point(env);
+  bool following =
+      term->height == 1 + pos.row + term->linenum_added; // cursor at end?
+
   emacs_value windows = get_buffer_window_list(env);
+  emacs_value swindow = selected_window(env);
   int winnum = env->extract_integer(env, length(env, windows));
   for (int i = 0; i < winnum; i++) {
     emacs_value window = nth(env, i, windows);
-    if (env->is_not_nil(env, window)) {
-      int win_height =
-          env->extract_integer(env, window_body_height(env, window));
-      /*
-        -win_height is negative,so we backward win_height lines from end of
-        buffer
-       */
-      goto_line(env, -win_height);
-      set_window_start(env, window, point(env));
-      set_window_point(env, window, cursor_point);
+    if (eq(env, window, swindow)) {
+      if (following) {
+        // "Follow" the terminal output
+        recenter(env,
+                 env->make_integer(
+                     env, -1)); /* make current line at the screen bottom */
+      } else {
+        recenter(env, env->make_integer(env, pos.row));
+      }
+    } else {
+      if (env->is_not_nil(env, window)) {
+        set_window_point(env, window, point(env));
+      }
     }
   }
-  goto_char(env, cursor_point);
 }
 
 static void invalidate_terminal(Term *term, int start_row, int end_row) {
@@ -1094,11 +1099,6 @@ int emacs_module_init(struct emacs_runtime *ert) {
   Frecenter = env->make_global_ref(env, env->intern(env, "recenter"));
   Fset_window_point =
       env->make_global_ref(env, env->intern(env, "set-window-point"));
-  Fset_window_start =
-      env->make_global_ref(env, env->intern(env, "set-window-start"));
-  Fwindow_body_height =
-      env->make_global_ref(env, env->intern(env, "window-body-height"));
-
   Fpoint = env->make_global_ref(env, env->intern(env, "point"));
   Fforward_char = env->make_global_ref(env, env->intern(env, "forward-char"));
   Fget_buffer_window_list =