Function: frame-size-changed-p
frame-size-changed-p is a byte-compiled function defined in
frame.el.gz.
Signature
(frame-size-changed-p &optional FRAME)
Documentation
Return non-nil when the size of FRAME has changed.
More precisely, return non-nil when the inner width or height of
FRAME has changed since window-size-change-functions was run
for FRAME.
Probably introduced at or before Emacs version 26.1.
Source Code
;; Defined in /usr/src/emacs/lisp/frame.el.gz
(defun frame-size-changed-p (&optional frame)
"Return non-nil when the size of FRAME has changed.
More precisely, return non-nil when the inner width or height of
FRAME has changed since `window-size-change-functions' was run
for FRAME."
(let* ((frame (window-normalize-frame frame))
(root (frame-root-window frame))
(mini (minibuffer-window frame))
(mini-old-height 0)
(mini-height 0))
;; FRAME's minibuffer window counts iff it's on FRAME and FRAME is
;; not a minibuffer-only frame.
(when (and (eq (window-frame mini) frame) (not (eq mini root)))
(setq mini-old-height (window-old-pixel-height mini))
(setq mini-height (window-pixel-height mini)))
;; Return non-nil when either the width of the root or the sum of
;; the heights of root and minibuffer window changed.
(or (/= (window-old-pixel-width root) (window-pixel-width root))
(/= (+ (window-old-pixel-height root) mini-old-height)
(+ (window-pixel-height root) mini-height)))))