Since Emacs predates the widespread adoption of the modern GUI andmouse, its vernacular can be somewhat hard to follow. What you would call a window in a modern GUI is called a frame in Emacs. A window is a panel of a frame in Emacs.
Most window managers have some facility to arrange the visible windows. With Emacs, you cna programmatically manipulate a frame’s size and position from Lisp.
There are a few ways I like to arrange my Emacs frames. I generally use one or two – more are harder to manage – and dedicate them to specific purposes. One always has code buffers in it, and the other can have compilation buffers, IRC, w3m, unit test output, or any other variety of programming-related tools.
When I work with a single frame, I like it to be centered on my screen. When I have two, I like them to be next to each other, in the center. Since it’s hard to align by hand, I wrote some code do to it for me.
(defun screen-usable-height (&optional display)
"Return the usable height of the display.
Some window-systems have portions of the screen which Emacs
cannot address. This function should return the height of the
screen, minus anything which is not usable."
(- (display-pixel-height display)
(cond ((eq window-system 'ns) 22)
(t 0))))
(defun screen-usable-width (&optional display)
"Return the usable width of the display.
This works like `screen-usable-height', but for the width of the display."
(display-pixel-width display))
(defun frame-sort-ltr (frames)
"Sort frames by their visual order, left to right.
This method takes a list of frames, and returns that list, sorted
by the visual display order. This is determined by comparing the
left position of the frames; the leftmost frames are returned
first."
(sort frames (lambda (framea frameb)
(< (frame-parameter framea 'left)
(frame-parameter frameb 'left)))))
(defun frame-box-get-center (w h cw ch)
"Center a box inside another box.
Returns a list of `(TOP LEFT)' representing the centered position
of the box `(w h)' inside the box `(cw ch)'."
(list (/ (- cw w) 2) (/ (- ch h) 2)))
(defun frame-get-center (frame)
"Return the center position of FRAME on its display."
(frame-box-get-center (frame-pixel-width frame) (frame-pixel-height frame)
(screen-usable-width) (screen-usable-height)))
(defun frame-center (&optional frame)
"Center a frame on the screen."
(interactive)
(apply 'set-frame-position
`(,(or frame (selected-frame)) ,@(frame-get-center frame))))
(defun frame-tile-horizonal ()
"Tile visible frames horizontally.
This function tiles visible frames, distributing them evenly
across the display, and centering them vertically.
It doesn't know about multi-head displays, and will probably fail
dramatically if used in such an environment."
(interactive)
(let ((pos)
(offset 0)
(vwidth (/ (screen-usable-width) (length (visible-frame-list)))))
(dolist (frame (frame-sort-ltr (visible-frame-list)))
(setq pos (frame-box-get-center (frame-pixel-width frame)
(frame-pixel-height frame)
vwidth (screen-usable-height)))
(set-frame-position frame (+ offset (car pos)) (cadr pos))
(incf offset vwidth))))
(defun frame-tile-center-horizonal ()
"Tile visible frames horizontally, center-weighted.
Rather than tiling frames evenly across the available width of
the display, this function tiles them into the center of the
display, adding a 2% margin in between frames.
It doesn't know about multi-head displays, and will probably fail
dramatically if used in such an environment."
(interactive)
(let* ((framewidth (apply '+ (mapcar 'frame-pixel-width (visible-frame-list))))
(margin (/ (screen-usable-width) 50)) ;; = (/ s-u-w *.02) = 2%
(totalwidth (+ framewidth (* margin
(- (length (visible-frame-list)) 1))))
(offset (car (frame-box-get-center totalwidth 0 (screen-usable-width)
(screen-usable-height)))))
(dolist (frame (frame-sort-ltr (visible-frame-list)))
(set-frame-position frame offset (cadr (frame-get-center frame)))
(incf offset (+ margin (frame-pixel-width frame))))))
(defun frame-restore-defaults (frame)
(modify-frame-parameters frame default-frame-alist))
(defun frame-default ()
(interactive)
(mapcar 'frame-restore-defaults (frame-list))
(if (> (length (frame-list)) 1)
(frame-tile-center-horizonal)
(frame-center)))
(provide 'ime-frame)
You can also call M-x frame-tile-center-horizonal or M-x frame-center by hand, if you like.