Run window change functions during redisplay

* doc/lispref/windows.texi (Window Sizes): Move (and rename)
descriptions of 'window-pixel-height-before-size-change' and
'window-pixel-width-before-size-change' to Window Hooks
section.
(Window Configurations): Remove warning against use of
'save-window-excursion' in 'window-size-change-functions'.
(Window Hooks): Rewrite section according to redesign of
window change functions.
* lisp/erc/erc-track.el (erc-window-configuration-change)
(erc-modified-channels-update): Call latter directly from
'window-configuration-change-hook' instead via
'post-command-hook'.
* lisp/frame.el (frame-size-changed-p): Change nomenclature
in let bindings.
* lisp/net/rcirc.el (rcirc-window-configuration-change)
(rcirc-window-configuration-change-1): Call latter directly
from 'window-configuration-change-hook' instead via
'post-command-hook'.
* lisp/window.el (window-pixel-width-before-size-change)
(window-pixel-height-before-size-change): Defalias.
(window--resize-mini-window, window-resize)
(adjust-window-trailing-edge, delete-window)
(delete-other-windows, balance-windows): Don't run
'window-configuration-change-hook' any more from here.
(split-window): Don't run 'window-configuration-change-hook'
from here.  'run-window-scroll-functions' from here.
(window--adjust-process-windows): Run from
'window-configuration-change-hook' only.
* src/frame.c (old_selected_frame): New Lisp variable.
(make_frame): Initialize frame's change_stamp slot.
(Fold_selected_frame): New function.
* src/frame.h (struct frame): New slots old_selected_window,
window_change, change_stamp and number_of_windows.
(fset_old_selected_window): New inlined function.
(FRAME_WINDOW_CHANGE, FRAME_OLD_SELECTED_WINDOW): New macros.
* src/window.c (old_selected_window): New Lisp variable.
(wset_old_buffer): New inlined function.
(Fframe_old_selected_window, Fold_selected_window)
(Fwindow_old_buffer): New functions.
(Fwindow_old_pixel_width, Fwindow_old_pixel_height): Rename
from Fwindow_pixel_width_before_size_change and
Fwindow_pixel_height_before_size_change.  Update doc-strings.
(Fwindow_old_body_pixel_width, Fwindow_old_body_pixel_height):
New functions.
(Fdelete_other_windows_internal): Set frame's window_change
slot instead of running 'window-configuration-change-hook'.
(Frun_window_configuration_change_hook): In doc-string tell
that this function is no more needed.
(Frun_window_scroll_functions): Amend doc-string.  Run with
window's buffer current.
(window_sub_list, window_change_record_windows)
(window_change_record_frame, window_change_record)
(run_window_change_functions_1, run_window_change_functions):
New functions.
(set_window_buffer): Set frame's window_change slot instead of
running 'window-configuration-change-hook'.
(make_window): Don't initialize pixel_width_before_size_change
and pixel_height_before_size_change slots.
(window_resize_apply, Fdelete_window_internal): Set frame's
window_change slot.
(Fsplit_window_internal): Set frame's window_change slot.
Don't run 'window-scroll-functions' from here.
* src/window.h (struct window): New slots old_buffer,
change_stamp, old_pixel_width (renamed from
pixel_width_before_size_change), old_pixel_height (renamed
from pixel_height_before_size_change), old_body_pixel_width
and old_body_pixel_height.
* src/xdisp.c (init_iterator): Set frame's window_change slot
when the body height or width changes.
(prepare_menu_bars): Don't run_window_size_change_functions.
(redisplay_internal): Don't run_window_size_change_functions,
run_window_change_functions instead.

1 files changed, 21 insertions, 4 deletions

diff --git a/src/frame.c b/src/frame.c
index ca6704a44c0..6d93abd09bf 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -55,9 +55,11 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #endif
 
 /* The currently selected frame.  */
-
 Lisp_Object selected_frame;
 
+/* The selected frame the last time window change functions were run.  */
+Lisp_Object old_selected_frame;
+
 /* A frame which is not just a mini-buffer, or NULL if there are no such
    frames.  This is usually the most recent such frame that was selected.  */
 
@@ -855,7 +857,8 @@ make_frame (bool mini_p)
   f->ns_transparent_titlebar = false;
 #endif
 #endif
-
+  /* This one should never be zero.  */
+  f->change_stamp = 1;
   root_window = make_window ();
   rw = XWINDOW (root_window);
   if (mini_p)
@@ -1451,7 +1454,8 @@ This function returns FRAME, or nil if FRAME has been deleted.  */)
   return do_switch_frame (frame, 1, 0, norecord);
 }
 
-DEFUN ("handle-switch-frame", Fhandle_switch_frame, Shandle_switch_frame, 1, 1, "^e",
+DEFUN ("handle-switch-frame", Fhandle_switch_frame,
+       Shandle_switch_frame, 1, 1, "^e",
        doc: /* Handle a switch-frame event EVENT.
 Switch-frame events are usually bound to this function.
 A switch-frame event is an event Emacs sends itself to
@@ -1471,6 +1475,18 @@ DEFUN ("selected-frame", Fselected_frame, Sselected_frame, 0, 0, 0,
 {
   return selected_frame;
 }
+
+DEFUN ("old-selected-frame", Fold_selected_frame,
+       Sold_selected_frame, 0, 0, 0,
+       doc: /* Return the old selected FRAME.
+FRAME must be a live frame and defaults to the selected one.
+
+The return value is the frame selected the last time window change
+functions were run.  */)
+  (void)
+{
+  return old_selected_frame;
+}
 
 DEFUN ("frame-list", Fframe_list, Sframe_list,
        0, 0, 0,
@@ -6098,9 +6114,10 @@ iconify the top level frame instead.  */);
   defsubr (&Swindow_system);
   defsubr (&Sframe_windows_min_size);
   defsubr (&Smake_terminal_frame);
-  defsubr (&Shandle_switch_frame);
   defsubr (&Sselect_frame);
+  defsubr (&Shandle_switch_frame);
   defsubr (&Sselected_frame);
+  defsubr (&Sold_selected_frame);
   defsubr (&Sframe_list);
   defsubr (&Sframe_parent);
   defsubr (&Sframe_ancestor_p);