Add macos_hide_from_tasks option

kitty/cocoa_window.m

@@ -228,6 +228,12 @@ macos_change_titlebar_color(PyObject *self UNUSED, PyObject *val) {
     Py_RETURN_NONE;
 }
 
+static PyObject*
+macos_set_hide_from_tasks(PyObject *self UNUSED, PyObject *val UNUSED) {
+    [NSApp setActivationPolicy:NSApplicationActivationPolicyAccessory];
+    Py_RETURN_NONE;
+}
+
 void
 cocoa_set_titlebar_color(void *w)
 {
@@ -260,6 +266,7 @@ static PyMethodDef module_methods[] = {
     {"cocoa_get_lang", (PyCFunction)cocoa_get_lang, METH_NOARGS, ""},
     {"cwd_of_process", (PyCFunction)cwd_of_process, METH_O, ""},
     {"macos_change_titlebar_color", (PyCFunction)macos_change_titlebar_color, METH_O, ""},
+    {"macos_set_hide_from_tasks", (PyCFunction)macos_set_hide_from_tasks, METH_NOARGS, ""},
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
 

kitty/config.py

@@ -318,6 +318,7 @@ type_map = {
     'initial_window_width': positive_int,
     'initial_window_height': positive_int,
     'macos_hide_titlebar': to_bool,
+    'macos_hide_from_tasks': to_bool,
     'macos_option_as_alt': to_bool,
     'macos_titlebar_color': macos_titlebar_color,
     'box_drawing_scale': box_drawing_scale,

kitty/kitty.conf

@@ -499,4 +499,7 @@ macos_hide_titlebar no
 # break any Alt+key keyboard shortcuts in your terminal programs, but you
 # can use the macOS unicode input technique.
 macos_option_as_alt yes
+
+# Hide the kitty window from running tasks (alt-tab) on macOS.
+macos_hide_from_tasks yes
 # }}}

kitty/main.py

@@ -45,6 +45,10 @@ def run_app(opts, args):
     with cached_values_for('main') as cached_values:
         w, h = initial_window_size(opts, cached_values)
         window_id = create_os_window(w, h, appname, args.name or args.cls or appname, args.cls or appname, load_all_shaders)
+        if is_macos and opts.macos_hide_from_tasks:
+            from .fast_data_types import macos_set_hide_from_tasks
+            # This needs to be done after creating the OS window as glfw sets the activation policy as well.
+            macos_set_hide_from_tasks()
         startup_ctx = init_startup_notification(window_id)
         show_window(window_id)
         if not is_wayland and not is_macos:  # no window icons on wayland