Function: fit-frame-to-buffer-1
fit-frame-to-buffer-1 is a byte-compiled function defined in
window.el.gz.
Signature
(fit-frame-to-buffer-1 &optional FRAME MAX-HEIGHT MIN-HEIGHT MAX-WIDTH MIN-WIDTH ONLY FROM TO)
Documentation
Helper function for fit-frame-to-buffer(var)/fit-frame-to-buffer(fun).
FROM and TO are the buffer positions to determine the size to fit
to, see window-text-pixel-size. The remaining arguments are as
for fit-frame-to-buffer(var)/fit-frame-to-buffer(fun).
Source Code
;; Defined in /usr/src/emacs/lisp/window.el.gz
(defun fit-frame-to-buffer-1 (&optional frame max-height min-height max-width min-width only from to)
"Helper function for `fit-frame-to-buffer'.
FROM and TO are the buffer positions to determine the size to fit
to, see `window-text-pixel-size'. The remaining arguments are as
for `fit-frame-to-buffer'."
(unless (fboundp 'display-monitor-attributes-list)
(user-error "Cannot resize frame in non-graphic Emacs"))
(setq frame (window-normalize-frame frame))
(when (window-live-p (frame-root-window frame))
(let* ((char-width (frame-char-width frame))
(char-height (frame-char-height frame))
;; WINDOW is FRAME's root window.
(window (frame-root-window frame))
(line-height (window-default-line-height window))
(parent (frame-parent frame))
(monitor-attributes
(unless parent
(frame-monitor-attributes frame)))
;; FRAME'S parent or display sizes. Used in connection
;; with margins.
(geometry
(unless parent
(cdr (assq 'geometry monitor-attributes))))
(parent-or-display-width
(if parent
(frame-native-width parent)
(nth 2 geometry)))
(parent-or-display-height
(if parent
(frame-native-height parent)
(nth 3 geometry)))
;; FRAME's parent or workarea sizes. Used when no margins
;; are specified.
(parent-or-workarea
(if parent
`(0 0 ,parent-or-display-width ,parent-or-display-height)
(cdr (assq 'workarea monitor-attributes))))
;; The outer size of FRAME. Needed to calculate the
;; margins around the root window's body that have to
;; remain untouched by fitting.
(outer-edges (frame-edges frame 'outer-edges))
(outer-width (if outer-edges
(- (nth 2 outer-edges) (nth 0 outer-edges))
;; A poor guess.
(frame-pixel-width frame)))
(outer-height (if outer-edges
(- (nth 3 outer-edges) (nth 1 outer-edges))
;; Another poor guess.
(frame-pixel-height frame)))
;; The text size of FRAME. Needed to specify FRAME's
;; text size after the root window's body's new sizes have
;; been calculated.
(text-width (frame-text-width frame))
(text-height (frame-text-height frame))
;; WINDOW's body size.
(body-width (window-body-width window t))
(body-height (window-body-height window t))
;; The difference between FRAME's outer size and WINDOW's
;; body size.
(outer-minus-body-width (- outer-width body-width))
(outer-minus-body-height (- outer-height body-height))
;; The difference between FRAME's text size and WINDOW's
;; body size (these values "should" be positive).
(text-minus-body-width (- text-width body-width))
(text-minus-body-height (- text-height body-height))
;; The current position of FRAME.
(position (frame-position frame))
(left (car position))
(top (cdr position))
;; The margins specified for FRAME. These represent pixel
;; offsets from the left, top, right and bottom edge of the
;; display or FRAME's parent's native rectangle and have to
;; take care of the display's taskbar and other obstacles.
;; If they are unspecified, constrain the resulting frame
;; to its workarea or the parent frame's native rectangle.
(margins (or (frame-parameter frame 'fit-frame-to-buffer-margins)
fit-frame-to-buffer-margins))
;; Convert margins into pixel offsets from the left-top
;; corner of FRAME's display or parent.
(left-margin (if (nth 0 margins)
(window--sanitize-margin
(nth 0 margins) 0 parent-or-display-width)
(nth 0 parent-or-workarea)))
(top-margin (if (nth 1 margins)
(window--sanitize-margin
(nth 1 margins) 0 parent-or-display-height)
(nth 1 parent-or-workarea)))
(right-margin (if (nth 2 margins)
(- parent-or-display-width
(window--sanitize-margin
(nth 2 margins) left-margin
parent-or-display-width))
(+ (nth 0 parent-or-workarea)
(nth 2 parent-or-workarea))))
(bottom-margin (if (nth 3 margins)
(- parent-or-display-height
(window--sanitize-margin
(nth 3 margins) top-margin
parent-or-display-height))
(+ (nth 1 parent-or-workarea)
(nth 3 parent-or-workarea))))
;; Minimum and maximum sizes specified for FRAME.
(sizes (or (frame-parameter frame 'fit-frame-to-buffer-sizes)
fit-frame-to-buffer-sizes))
;; Calculate the minimum and maximum pixel sizes of FRAME
;; from the values provided by the MAX-HEIGHT, MIN-HEIGHT,
;; MAX-WIDTH and MIN-WIDTH arguments or, if these are nil,
;; from those provided by `fit-frame-to-buffer-sizes'.
(max-height
(min
(cond
((numberp max-height) (* max-height line-height))
((numberp (nth 0 sizes)) (* (nth 0 sizes) line-height))
(t parent-or-display-height))
;; The following is the maximum height that fits into the
;; top and bottom margins.
(max (- bottom-margin top-margin outer-minus-body-height))))
(min-height
(cond
((numberp min-height) (* min-height line-height))
((numberp (nth 1 sizes)) (* (nth 1 sizes) line-height))
(t (window-min-size window nil nil t))))
(max-width
(min
(cond
((numberp max-width) (* max-width char-width))
((numberp (nth 2 sizes)) (* (nth 2 sizes) char-width))
(t parent-or-display-width))
;; The following is the maximum width that fits into the
;; left and right margins.
(max (- right-margin left-margin outer-minus-body-width))))
(min-width
(cond
((numberp min-width) (* min-width char-width))
((numberp (nth 3 sizes)) (nth 3 sizes))
(t (window-min-size window t nil t))))
;; Note: Currently, for a new frame the sizes of the header
;; and mode line may be estimated incorrectly
(size
(window-text-pixel-size window from to max-width max-height))
(width (max (car size) min-width))
(height (max (cdr size) min-height)))
;; Don't change height or width when the window's size is fixed
;; in either direction or ONLY forbids it.
(cond
((or (eq window-size-fixed 'width) (eq only 'vertically))
(setq width nil))
((or (eq window-size-fixed 'height) (eq only 'horizontally))
(setq height nil)))
;; Fit width to constraints.
(when width
(unless frame-resize-pixelwise
;; Round to character sizes.
(setq width (* (/ (+ width char-width -1) char-width)
char-width)))
;; The new outer width (in pixels).
(setq outer-width (+ width outer-minus-body-width))
;; Maybe move FRAME to preserve margins.
(let ((right (+ left outer-width)))
(cond
((> right right-margin)
;; Move frame to left.
(setq left (max left-margin (- left (- right right-margin)))))
((< left left-margin)
;; Move frame to right.
(setq left left-margin)))))
;; Fit height to constraints.
(when height
(unless frame-resize-pixelwise
(setq height (* (/ (+ height char-height -1) char-height)
char-height)))
;; The new outer height.
(setq outer-height (+ height outer-minus-body-height))
;; Preserve margins.
(let ((bottom (+ top outer-height)))
(cond
((> bottom bottom-margin)
;; Move frame up.
(setq top (max top-margin (- top (- bottom bottom-margin)))))
((< top top-margin)
;; Move frame down.
(setq top top-margin)))))
;; Apply our changes.
(setq text-width
(if width
(+ width text-minus-body-width)
(frame-text-width frame)))
(setq text-height
(if height
(+ height text-minus-body-height)
(frame-text-height frame)))
(modify-frame-parameters
frame `((left . ,left) (top . ,top)
(width . (text-pixels . ,text-width))
(height . (text-pixels . ,text-height)))))))