window-resizable

window-resizable is a compiled Lisp function in `window.el'.

(window-resizable WINDOW DELTA &optional HORIZONTAL IGNORE PIXELWISE)

Return DELTA if WINDOW can be resized vertically by DELTA lines.
WINDOW must be a valid window and defaults to the selected one.
Optional argument HORIZONTAL non-nil means return DELTA if WINDOW
can be resized horizontally by DELTA columns. A return value of
zero means that WINDOW is not resizable.

DELTA positive means WINDOW shall be enlarged by DELTA lines or
columns. If WINDOW cannot be enlarged by DELTA lines or columns
return the maximum value in the range 0..DELTA by which WINDOW
can be enlarged.

DELTA negative means WINDOW shall be shrunk by -DELTA lines or
columns. If WINDOW cannot be shrunk by -DELTA lines or columns,
return the minimum value in the range DELTA..0 that can be used
for shrinking WINDOW.

Optional argument IGNORE, if non-nil, means to ignore restraints
induced by fixed size windows or the values of the variables
`window-min-height' and `window-min-width'. The following values
have special meanings: `safe' means that in addition live windows
are allowed to get as small as `window-safe-min-height' lines and
`window-safe-min-width' columns. `preserved' means to ignore
only restrictions induced by `window-preserve-size'. If IGNORE
is a window, then ignore restrictions for that window only.

Optional argument PIXELWISE non-nil means interpret DELTA as
pixels.