Function: frameset-move-onscreen

frameset-move-onscreen is a byte-compiled function defined in frameset.el.gz.

Signature

(frameset-move-onscreen FRAME FORCE-ONSCREEN)

Documentation

If FRAME is offscreen, move it back onscreen and, if necessary, resize it.

For the description of FORCE-ONSCREEN, see frameset-restore. When forced onscreen, frames wider than the monitor's workarea are converted to fullwidth, and frames taller than the workarea are converted to fullheight. NOTE: This only works for non-iconified frames.

Source Code

;; Defined in /usr/src/emacs/lisp/frameset.el.gz
(defun frameset-move-onscreen (frame force-onscreen)
  "If FRAME is offscreen, move it back onscreen and, if necessary, resize it.
For the description of FORCE-ONSCREEN, see `frameset-restore'.
When forced onscreen, frames wider than the monitor's workarea are converted
to fullwidth, and frames taller than the workarea are converted to fullheight.
NOTE: This only works for non-iconified frames."
  (pcase-let* ((`(,left ,top ,width ,height) (cdadr (frame-monitor-attributes frame)))
	       (right (+ left width -1))
	       (bottom (+ top height -1))
	       (fr-left (frameset-compute-pos (frame-parameter frame 'left) left right))
	       (fr-top (frameset-compute-pos (frame-parameter frame 'top) top bottom))
	       (ch-width (frame-char-width frame))
	       (ch-height (frame-char-height frame))
	       (fr-width (max (frame-pixel-width frame) (* ch-width (frame-width frame))))
	       (fr-height (max (frame-pixel-height frame) (* ch-height (frame-height frame))))
	       (fr-right (+ fr-left fr-width -1))
	       (fr-bottom (+ fr-top fr-height -1)))
    (when (pcase force-onscreen
	    ;; A predicate.
	    ((pred functionp)
	     (funcall force-onscreen
		      frame
		      (list fr-left fr-top fr-width fr-height)
		      (list left top width height)))
	    ;; Any corner is outside the screen.
	    (:all (or (< fr-bottom top)  (> fr-bottom bottom)
		      (< fr-left   left) (> fr-left   right)
		      (< fr-right  left) (> fr-right  right)
		      (< fr-top    top)  (> fr-top    bottom)))
	    ;; Displaced to the left, right, above or below the screen.
	    ('t   (or (> fr-left   right)
		      (< fr-right  left)
		      (> fr-top    bottom)
		      (< fr-bottom top)))
	    ;; Fully inside, no need to do anything.
	    (_ nil))
      (let ((fullwidth (> fr-width width))
	    (fullheight (> fr-height height))
	    (params nil))
	;; Position frame horizontally.
	(cond (fullwidth
	       (push `(left . ,left) params))
	      ((> fr-right right)
	       (push `(left . ,(+ left (- width fr-width))) params))
	      ((< fr-left left)
	       (push `(left . ,left) params)))
	;; Position frame vertically.
	(cond (fullheight
	       (push `(top . ,top) params))
	      ((> fr-bottom bottom)
	       (push `(top . ,(+ top (- height fr-height))) params))
	      ((< fr-top top)
	       (push `(top . ,top) params)))
	;; Compute fullscreen state, if required.
	(when (or fullwidth fullheight)
	  (push (cons 'fullscreen
		      (cond ((not fullwidth) 'fullheight)
			    ((not fullheight) 'fullwidth)
			    (t 'maximized)))
		params))
	;; Finally, move the frame back onscreen.
	(when params
	  (modify-frame-parameters frame params))))))