Cleanup clear to prompt implementation and allow moving cleared lies into scrollback

docs/changelog.rst

@@ -72,6 +72,9 @@ Detailed list of changes
 
 - icat kitten: Add a command line argument to override terminal window size detection (:iss:`7165`)
 
+- When :ac:`clearing terminal <clear_terminal>` add a new type ``to_cursor_scroll`` which can be
+  used to clear to prompt while moving cleared lines into the scrollback
+
 
 0.32.2 [2024-02-12]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

kitty/boss.py

@@ -1170,8 +1170,11 @@ class Boss:
             map f1 clear_terminal scrollback active
             # Scroll the contents of the screen into the scrollback
             map f1 clear_terminal scroll active
-            # Clear everything up to the line with the cursor
+            # Clear everything up to the line with the cursor or if the cursor is at a prompt, the first line of the prompt.
+            # Useful for clearing the screen up to the shell prompt and moving the shell prompt to the top of the screen.
             map f1 clear_terminal to_cursor active
+            # Clear everything up to the line with the cursor or prompt, saving the cleared lines in the scrollback
+            map f1 clear_terminal to_cursor_scroll active
         ''')
     def clear_terminal(self, action: str, only_active: bool) -> None:
         if only_active:
@@ -1196,6 +1199,11 @@ class Boss:
         elif action == 'to_cursor':
             for w in windows:
                 w.scroll_prompt_to_top(clear_scrollback=True)
+        elif action == 'to_cursor_scroll':
+            for w in windows:
+                w.scroll_prompt_to_top(clear_scrollback=False)
+        else:
+            self.show_error(_('Unknown clear type'), _('The clear type: {} is unknown').format(action))
 
     def increase_font_size(self) -> None:  # legacy
         cfs = global_font_size()

kitty/fast_data_types.pyi

@@ -1171,7 +1171,7 @@ class Screen:
     def cmd_output(self, which: int, callback: Callable[[str], None], as_ansi: bool, insert_wrap_markers: bool) -> bool:
         pass
 
-    def scroll_until_cursor_prompt(self) -> None:
+    def scroll_until_cursor_prompt(self, add_to_scrollback: bool = True) -> None:
         pass
 
     def reset(self) -> None:

kitty/options/utils.py

@@ -93,6 +93,11 @@ def parse_send_text_bytes(text: str) -> bytes:
     return defines.expand_ansi_c_escapes(text).encode('utf-8')
 
 
+@func_with_args('scroll_prompt_to_top')
+def scroll_prompt_to_top(func: str, rest: str) -> FuncArgsType:
+    return func, [to_bool(rest) if rest else False]
+
+
 @func_with_args('send_text')
 def send_text_parse(func: str, rest: str) -> FuncArgsType:
     args = rest.split(maxsplit=1)
@@ -211,7 +216,7 @@ def clear_terminal(func: str, rest: str) -> FuncArgsType:
         args = ['reset', True]
     else:
         action = vals[0].lower()
-        if action not in ('reset', 'scroll', 'scrollback', 'clear', 'to_cursor',):
+        if action not in ('reset', 'scroll', 'scrollback', 'clear', 'to_cursor', 'to_cursor_scroll'):
             log_error(f'{action} is unknown for clear_terminal, using reset')
             action = 'reset'
         args = [action, vals[1].lower() == 'active']

kitty/screen.c

@@ -1503,10 +1503,10 @@ screen_cursor_to_column(Screen *self, unsigned int column) {
     }
 }
 
-#define INDEX_UP \
+#define INDEX_UP(add_to_history) \
     linebuf_index(self->linebuf, top, bottom); \
     INDEX_GRAPHICS(-1) \
-    if (self->linebuf == self->main_linebuf && self->margin_top == 0) { \
+    if (add_to_history) { \
         /* Only add to history when no top margin has been set */ \
         linebuf_init_line(self->linebuf, bottom); \
         historybuf_add_line(self->historybuf, self->linebuf->line, &self->as_ansi_buf); \
@@ -1525,17 +1525,29 @@ screen_index(Screen *self) {
     // Move cursor down one line, scrolling screen if needed
     unsigned int top = self->margin_top, bottom = self->margin_bottom;
     if (self->cursor->y == bottom) {
-        INDEX_UP;
+        const bool add_to_history = self->linebuf == self->main_linebuf && self->margin_top == 0;
+        INDEX_UP(add_to_history);
     } else screen_cursor_down(self, 1);
 }
 
+static void
+screen_index_without_adding_to_history(Screen *self) {
+    // Move cursor down one line, scrolling screen if needed
+    unsigned int top = self->margin_top, bottom = self->margin_bottom;
+    if (self->cursor->y == bottom) {
+        INDEX_UP(false);
+    } else screen_cursor_down(self, 1);
+}
+
+
 void
 screen_scroll(Screen *self, unsigned int count) {
     // Scroll the screen up by count lines, not moving the cursor
     unsigned int top = self->margin_top, bottom = self->margin_bottom;
+    const bool add_to_history = self->linebuf == self->main_linebuf && self->margin_top == 0;
     while (count > 0) {
         count--;
-        INDEX_UP;
+        INDEX_UP(add_to_history);
     }
 }
 
@@ -1868,9 +1880,10 @@ screen_move_into_scrollback(Screen *self) {
     }
     if (num_of_lines_to_move) {
         unsigned int top, bottom;
+        const bool add_to_history = self->linebuf == self->main_linebuf && self->margin_top == 0;
         for (; num_of_lines_to_move; num_of_lines_to_move--) {
             top = 0, bottom = num_of_lines_to_move - 1;
-            INDEX_UP
+            INDEX_UP(add_to_history);
         }
     }
 }
@@ -1945,14 +1958,15 @@ screen_insert_lines(Screen *self, unsigned int count) {
 }
 
 static void
-screen_scroll_until_cursor_prompt(Screen *self) {
+screen_scroll_until_cursor_prompt(Screen *self, bool add_to_scrollback) {
     bool in_margins = cursor_within_margins(self);
     int q = screen_cursor_at_a_shell_prompt(self);
     unsigned int y = q > -1 ? (unsigned int)q : self->cursor->y;
     unsigned int num_lines_to_scroll = MIN(self->margin_bottom, y);
     unsigned int final_y = num_lines_to_scroll <= self->cursor->y ? self->cursor->y - num_lines_to_scroll : 0;
     self->cursor->y = self->margin_bottom;
-    while (num_lines_to_scroll--) screen_index(self);
+    if (add_to_scrollback) while (num_lines_to_scroll--) screen_index(self);
+    else while (num_lines_to_scroll--) screen_index_without_adding_to_history(self);
     self->cursor->y = final_y;
     screen_ensure_bounds(self, false, in_margins);
 }
@@ -3751,7 +3765,8 @@ is_using_alternate_linebuf(Screen *self, PyObject *a UNUSED) {
 WRAP1E(cursor_back, 1, -1)
 WRAP1B(erase_in_line, 0)
 WRAP1B(erase_in_display, 0)
-WRAP0(scroll_until_cursor_prompt)
+static PyObject* scroll_until_cursor_prompt(Screen *self, PyObject *args) { int b=false; if(!PyArg_ParseTuple(args, "|p", &b)) return NULL; screen_scroll_until_cursor_prompt(self, b); Py_RETURN_NONE; }
+
 WRAP0(clear_scrollback)
 
 #define MODE_GETSET(name, uname) \
@@ -4699,7 +4714,7 @@ static PyMethodDef methods[] = {
     MND(erase_in_line, METH_VARARGS)
     MND(erase_in_display, METH_VARARGS)
     MND(clear_scrollback, METH_NOARGS)
-    MND(scroll_until_cursor_prompt, METH_NOARGS)
+    MND(scroll_until_cursor_prompt, METH_VARARGS)
     MND(hyperlinks_as_list, METH_NOARGS)
     MND(garbage_collect_hyperlink_pool, METH_NOARGS)
     MND(hyperlink_for_id, METH_O)

kitty/window.py

@@ -1821,14 +1821,13 @@ class Window:
             return None
         return True
 
-    @ac('sc', 'Scroll prompt to the top of the screen, filling screen with empty lines, when in main screen')
+    @ac('sc', 'Scroll prompt to the top of the screen, filling screen with empty lines, when in main screen.'
+        ' To avoid putting the lines above the prompt into the scrollback use scroll_prompt_to_top y')
     def scroll_prompt_to_top(self, clear_scrollback: bool = False) -> Optional[bool]:
         if self.screen.is_main_linebuf():
-            self.screen.scroll_until_cursor_prompt()
+            self.screen.scroll_until_cursor_prompt(not clear_scrollback)
-            if clear_scrollback:
+            if self.screen.scrolled_by > 0:
-                self.screen.clear_scrollback()
+                self.scroll_end()
-            elif self.screen.scrolled_by > 0:
-                self.screen.scroll(SCROLL_FULL, False)
             return None
         return True