Add a setting tab_activity_symbol

Fixes #2515

docs/changelog.rst

@@ -27,6 +27,10 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Allow specifying watchers in session files and via a command line argument
   (:iss:`2933`)
 
+- Add a setting :opt:`tab_activity_symbol` to show a symbol in the tab title
+  if one of the windows has some activity after it was last focused
+  (:iss:`2515`)
+
 - macOS: Switch to using the User Notifications framework for notifications.
   The current notifications framework has been deprecated in Big Sur. The new
   framework only allows notifications from signed and notarized applications,

kitty/config_data.py

@@ -883,6 +883,17 @@ o('tab_separator', '"{}"'.format(default_tab_separator), option_type=tab_separat
 The separator between tabs in the tab bar when using :code:`separator` as the :opt:`tab_bar_style`.'''))
 
 
+def tab_activity_symbol(x: str) -> Optional[str]:
+    if x == 'none':
+        return None
+    return x or None
+
+
+o('tab_activity_symbol', 'none', option_type=tab_activity_symbol, long_text=_('''
+Some text or a unicode symbol to show on the tab if a window in the tab that does
+not have focus has some activity.'''))
+
+
 def tab_title_template(x: str) -> str:
     if x:
         for q in '\'"':

kitty/fast_data_types.pyi

@@ -1069,6 +1069,9 @@ class Screen:
     def has_focus(self) -> bool:
         pass
 
+    def has_activity_since_last_focus(self) -> bool:
+        pass
+
 
 def set_tab_bar_render_data(
     os_window_id: int, xstart: float, ystart: float, dx: float, dy: float,

kitty/screen.c

@@ -444,6 +444,9 @@ draw_combining_char(Screen *self, char_type ch) {
 void
 screen_draw(Screen *self, uint32_t och) {
     if (is_ignored_char(och)) return;
+    if (!self->has_activity_since_last_focus && !self->has_focus) {
+        self->has_activity_since_last_focus = true;
+    }
     uint32_t ch = och < 256 ? self->g_charset[och] : och;
     bool is_cc = is_combining_char(ch);
     if (UNLIKELY(is_cc)) {
@@ -2531,6 +2534,7 @@ focus_changed(Screen *self, PyObject *has_focus_) {
     bool has_focus = PyObject_IsTrue(has_focus_) ? true : false;
     if (has_focus != previous) {
         self->has_focus = has_focus;
+        if (has_focus) self->has_activity_since_last_focus = false;
         if (self->modes.mFOCUS_TRACKING) write_escape_code_to_child(self, CSI, has_focus ? "I" : "O");
         Py_RETURN_TRUE;
     }
@@ -2543,6 +2547,11 @@ has_focus(Screen *self, PyObject *args UNUSED) {
     Py_RETURN_FALSE;
 }
 
+static PyObject*
+has_activity_since_last_focus(Screen *self, PyObject *args UNUSED) {
+    if (self->has_activity_since_last_focus) Py_RETURN_TRUE;
+    Py_RETURN_FALSE;
+}
 
 WRAP2(cursor_position, 1, 1)
 
@@ -2628,6 +2637,7 @@ static PyMethodDef methods[] = {
     MND(paste_bytes, METH_O)
     MND(focus_changed, METH_O)
     MND(has_focus, METH_NOARGS)
+    MND(has_activity_since_last_focus, METH_NOARGS)
     MND(copy_colors_from, METH_O)
     MND(set_marker, METH_VARARGS)
     MND(marked_cells, METH_NOARGS)

kitty/screen.h

@@ -122,6 +122,7 @@ typedef struct {
     DisableLigature disable_ligatures;
     PyObject *marker;
     bool has_focus;
+    bool has_activity_since_last_focus;
 } Screen;
 
 

kitty/tab_bar.py

@@ -24,6 +24,7 @@ class TabBarData(NamedTuple):
     needs_attention: bool
     num_windows: int
     layout_name: str
+    has_activity_since_last_focus: bool
 
 
 class DrawData(NamedTuple):
@@ -40,6 +41,7 @@ class DrawData(NamedTuple):
     default_bg: Color
     title_template: str
     active_title_template: Optional[str]
+    tab_activity_symbol: Optional[str]
 
 
 def as_rgb(x: int) -> int:
@@ -65,6 +67,12 @@ def draw_title(draw_data: DrawData, screen: Screen, tab: TabBarData, index: int)
         screen.cursor.fg = draw_data.bell_fg
         screen.draw('🔔 ')
         screen.cursor.fg = fg
+    if tab.has_activity_since_last_focus and draw_data.tab_activity_symbol:
+        fg = screen.cursor.fg
+        screen.cursor.fg = draw_data.bell_fg
+        screen.draw(draw_data.tab_activity_symbol)
+        screen.cursor.fg = fg
+
     template = draw_data.title_template
     if tab.is_active and draw_data.active_title_template is not None:
         template = draw_data.active_title_template
@@ -226,7 +234,8 @@ class TabBar:
             self.opts.tab_fade, self.opts.active_tab_foreground, self.opts.active_tab_background,
             self.opts.inactive_tab_foreground, self.opts.inactive_tab_background,
             self.opts.tab_bar_background or self.opts.background, self.opts.tab_title_template,
-            self.opts.active_tab_title_template
+            self.opts.active_tab_title_template,
+            self.opts.tab_activity_symbol
         )
         if self.opts.tab_bar_style == 'separator':
             self.draw_func = draw_tab_with_separator

kitty/tabs.py

@@ -736,13 +736,16 @@ class TabManager:  # {{{
         for t in self.tabs:
             title = (t.name or t.title or appname).strip()
             needs_attention = False
+            has_activity_since_last_focus = False
             for w in t:
                 if w.needs_attention:
                     needs_attention = True
-                    break
+                if w.has_activity_since_last_focus:
+                    has_activity_since_last_focus = True
             ans.append(TabBarData(
                 title, t is at, needs_attention,
-                len(t), t.current_layout.name or ''
+                len(t), t.current_layout.name or '',
+                has_activity_since_last_focus
             ))
         return ans
 

kitty/window.py

@@ -514,6 +514,10 @@ class Window:
     def is_active(self) -> bool:
         return get_boss().active_window is self
 
+    @property
+    def has_activity_since_last_focus(self) -> bool:
+        return self.screen.has_activity_since_last_focus()
+
     def on_bell(self) -> None:
         if self.opts.command_on_bell and self.opts.command_on_bell != ['none']:
             import subprocess