Convenience method to get the mouse position for a window

Fix #7652

kitty/fast_data_types.pyi

@@ -1685,3 +1685,10 @@ def monotonic() -> float: ...
 def timed_debug_print(x: str) -> None: ...
 def opengl_version_string() -> str: ...
 def systemd_move_pid_into_new_scope(pid: int, scope_name: str, description: str) -> str: ...
+
+class MousePosition(TypedDict):
+    cell_x: int
+    cell_y: int
+    in_left_half_of_cell: bool
+
+def get_mouse_data_for_window(os_window_id: int, tab_id: int, window_id: int) -> Optional[MousePosition]: ...

kitty/state.c

@@ -1376,11 +1376,22 @@ os_window_focus_counters(PyObject *self UNUSED, PyObject *args UNUSED) {
     return ans;
 }
 
+static PyObject*
+get_mouse_data_for_window(PyObject *self UNUSED, PyObject *args) {
+    id_type os_window_id, tab_id, window_id;
+    PA("KKK", &os_window_id, &tab_id, &window_id);
+    WITH_WINDOW(os_window_id, tab_id, window_id)
+        return Py_BuildValue("{sI sI sO}", "cell_x", window->mouse_pos.cell_x, "cell_y", window->mouse_pos.cell_y, "in_left_half_of_cell", window->mouse_pos.in_left_half_of_cell);
+    END_WITH_WINDOW
+    Py_RETURN_NONE;
+}
+
 #define M(name, arg_type) {#name, (PyCFunction)name, arg_type, NULL}
 #define MW(name, arg_type) {#name, (PyCFunction)py##name, arg_type, NULL}
 
 static PyMethodDef module_methods[] = {
     M(os_window_focus_counters, METH_NOARGS),
+    M(get_mouse_data_for_window, METH_VARARGS),
     MW(update_pointer_shape, METH_VARARGS),
     MW(current_os_window, METH_NOARGS),
     MW(next_window_id, METH_NOARGS),

kitty/window.py

@@ -68,6 +68,7 @@ from .fast_data_types import (
     encode_key_for_tty,
     get_boss,
     get_click_interval,
+    get_mouse_data_for_window,
     get_options,
     is_css_pointer_name_valid,
     last_focused_os_window_id,
@@ -125,6 +126,7 @@ MatchPatternType = Union[Pattern[str], Tuple[Pattern[str], Optional[Pattern[str]
 if TYPE_CHECKING:
     from kittens.tui.handler import OpenUrlHandler
 
+    from .fast_data_types import MousePosition
     from .file_transmission import FileTransmission
 
 
@@ -1710,6 +1712,10 @@ class Window:
         else:
             self.screen.erase_in_display(3 if scrollback else 2, False)
 
+    def current_mouse_position(self) -> Optional['MousePosition']:
+        ' Return the last position at which a mouse event was received by this window '
+        return get_mouse_data_for_window(self.os_window_id, self.tab_id, self.id)
+
     # actions {{{
 
     @ac('cp', 'Show scrollback in a pager like less')