Move focus tracking into the Screen object

kitty/fast_data_types.pyi

@@ -1063,6 +1063,12 @@ class Screen:
     def erase_in_display(self, how: int = 0, private: bool = False) -> None:
         pass
 
+    def focus_changed(self, focused: bool) -> bool:
+        pass
+
+    def has_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

@@ -2525,6 +2525,24 @@ paste_bytes(Screen *self, PyObject *bytes) {
     Py_RETURN_NONE;
 }
 
+static PyObject*
+focus_changed(Screen *self, PyObject *has_focus_) {
+    bool previous = self->has_focus;
+    bool has_focus = PyObject_IsTrue(has_focus_) ? true : false;
+    if (has_focus != previous) {
+        self->has_focus = has_focus;
+        if (self->modes.mFOCUS_TRACKING) write_escape_code_to_child(self, CSI, has_focus ? "I" : "O");
+        Py_RETURN_TRUE;
+    }
+    Py_RETURN_FALSE;
+}
+
+static PyObject*
+has_focus(Screen *self, PyObject *args UNUSED) {
+    if (self->has_focus) Py_RETURN_TRUE;
+    Py_RETURN_FALSE;
+}
+
 
 WRAP2(cursor_position, 1, 1)
 
@@ -2608,6 +2626,8 @@ static PyMethodDef methods[] = {
     MND(reset_callbacks, METH_NOARGS)
     MND(paste, METH_O)
     MND(paste_bytes, METH_O)
+    MND(focus_changed, METH_O)
+    MND(has_focus, METH_NOARGS)
     MND(copy_colors_from, METH_O)
     MND(set_marker, METH_VARARGS)
     MND(marked_cells, METH_NOARGS)

kitty/screen.h

@@ -121,6 +121,7 @@ typedef struct {
     } pending_mode;
     DisableLigature disable_ligatures;
     PyObject *marker;
+    bool has_focus;
 } Screen;
 
 

kitty/window.py

@@ -20,7 +20,7 @@ from .config import build_ansi_color_table
 from .constants import ScreenGeometry, WindowGeometry, appname, wakeup
 from .fast_data_types import (
     BGIMAGE_PROGRAM, BLIT_PROGRAM, CELL_BG_PROGRAM, CELL_FG_PROGRAM,
-    CELL_PROGRAM, CELL_SPECIAL_PROGRAM, CSI, DCS, DECORATION, DIM,
+    CELL_PROGRAM, CELL_SPECIAL_PROGRAM, DCS, DECORATION, DIM,
     GRAPHICS_ALPHA_MASK_PROGRAM, GRAPHICS_PREMULT_PROGRAM, GRAPHICS_PROGRAM,
     MARK, MARK_MASK, OSC, REVERSE, SCROLL_FULL, SCROLL_LINE, SCROLL_PAGE,
     STRIKETHROUGH, TINT_PROGRAM, Screen, add_timer, add_window,
@@ -493,18 +493,14 @@ class Window:
         if self.destroyed:
             return
         call_watchers(weakref.ref(self), 'on_focus_change', {'focused': focused})
+        self.screen.focus_changed(focused)
         if focused:
             changed = self.needs_attention
             self.needs_attention = False
-            if self.screen.focus_tracking_enabled:
-                self.screen.send_escape_code_to_child(CSI, 'I')
             if changed:
                 tab = self.tabref()
                 if tab is not None:
                     tab.relayout_borders()
-        else:
-            if self.screen.focus_tracking_enabled:
-                self.screen.send_escape_code_to_child(CSI, 'O')
 
     def title_changed(self, new_title: Optional[str]) -> None:
         self.child_title = sanitize_title(new_title or self.default_title)