previously visible in the window that was split.
@deffn Command split-window &optional window size horizontal
-This function splits @var{window} into two windows. The original
-window @var{window} remains the selected window, but occupies only
-part of its former screen area. The rest is occupied by a newly created
-window which is returned as the value of this function.
+This function splits a new window out of @var{window}'s screen area.
+It returns the new window.
If @var{horizontal} is non-@code{nil}, then @var{window} splits into
two side by side windows. The original window @var{window} keeps the
left-hand or upper of the two, and the new window is the right-hand or
lower.
-If @var{window} is omitted or @code{nil}, then the selected window is
-split. If @var{size} is omitted or @code{nil}, then @var{window} is
-divided evenly into two parts. (If there is an odd line, it is
-allocated to the new window.) When @code{split-window} is called
-interactively, all its arguments are @code{nil}.
+If @var{window} is omitted or @code{nil}, that stands for the selected
+window. When you split the selected window, it remains selected.
+
+If @var{size} is omitted or @code{nil}, then @var{window} is divided
+evenly into two parts. (If there is an odd line, it is allocated to
+the new window.) When @code{split-window} is called interactively,
+all its arguments are @code{nil}.
If splitting would result in making a window that is smaller than
@code{window-min-height} or @code{window-min-width}, the function
@var{position} defaults to the current position of point in
@var{window}; @var{window}, to the selected window.
+If @var{position} is @code{t}, that means to check the last visible
+position in @var{window}.
+
The @code{pos-visible-in-window-p} function considers only vertical
scrolling. If @var{position} is out of view only because @var{window}
has been scrolled horizontally, @code{pos-visible-in-window-p} returns
If @var{position} is visible, @code{pos-visible-in-window-p} returns
@code{t} if @var{partially} is @code{nil}; if @var{partially} is
-non-@code{nil}, it returns a list of the form @code{(@var{x} @var{y}
-@var{partial})}, where @var{x} and @var{y} are the pixel coordinates
-relative to the top left corner of the window, and @var{partial} is
-@code{nil} if the character after @var{position} is fully visible;
-otherwise it is a cons @code{(@var{rtop} . @var{rbot})} where the
-@var{rtop} and @var{rbot} specify the number of invisible pixels at
-the top and bottom of the row at @var{position}.
+non-@code{nil}, and the character after @var{position} is fully
+visible, it returns a list of the form @code{(@var{x} @var{y})}, where
+@var{x} and @var{y} are the pixel coordinates relative to the top left
+corner of the window; otherwise it returns an extended list of the
+form @code{(@var{x} @var{y} @var{rtop} @var{rbot} @var{rowh}
+@var{vpos})}, where the @var{rtop} and @var{rbot} specify the number
+of off-window pixels at the top and bottom of the row at
+@var{position}, @var{rowh} specifies the visible height of that row,
+and @var{vpos} specifies the vertical position (zero-based row number)
+of that row.
Here is an example:
@end example
@end defun
+@defun window-line-height &optional line window
+This function returns information about text line @var{line} in @var{window}.
+If @var{line} is one of @code{header-line} or @code{mode-line},
+@code{window-line-height} returns information about the corresponding
+line of the window. Otherwise, @var{line} is a text line number
+starting from 0. A negative number counts from the end of the window.
+The argument @var{line} defaults to the current line in @var{window};
+@var{window}, to the selected window.
+
+If the display is not up to date, @code{window-line-height} returns
+@code{nil}. In that case, @code{pos-visible-in-window-p} may be used
+to obtain related information.
+
+If there is no line corresponding to the specified @var{line},
+@code{window-line-height} returns @code{nil}. Otherwise, it returns
+a list @code{(@var{height} @var{vpos} @var{ypos} @var{offbot})},
+where @var{height} is the height in pixels of the visible part of the
+line, @var{vpos} and @var{ypos} are the vertical position in lines and
+pixels of the line relative to the top of the first text line, and
+@var{offbot} is the number of off-window pixels at the bottom of the
+text line. If there are off-window pixels at the top of the (first)
+text line, @var{ypos} is negative.
+@end defun
+
@node Textual Scrolling
@section Textual Scrolling
@cindex textual scrolling
window. @xref{Current Buffer}.
If the window contains a row which is taller than the height of the
-window (for example in the presense of a large image), the scroll
+window (for example in the presence of a large image), the scroll
functions will adjust the window vscroll to scroll the partially
visible row. To disable this feature, Lisp code may bind the variable
`auto-window-vscroll' to @code{nil} (@pxref{Vertical Scrolling}).
@code{scroll-other-window} attempts to scroll the minibuffer. If the
minibuffer contains just one line, it has nowhere to scroll to, so the
line reappears after the echo area momentarily displays the message
-``Beginning of buffer''.
+@samp{Beginning of buffer}.
@end deffn
@c Emacs 19 feature
@end defopt
@defopt scroll-down-aggressively
-@tindex scroll-down-aggressively
The value of this variable should be either @code{nil} or a fraction
@var{f} between 0 and 1. If it is a fraction, that specifies where on
the screen to put point when scrolling down. More precisely, when a
@end defopt
@defopt scroll-up-aggressively
-@tindex scroll-up-aggressively
Likewise, for scrolling up. The value, @var{f}, specifies how far
point should be placed from the bottom of the window; thus, as with
@code{scroll-up-aggressively}, a larger value scrolls more aggressively.
If this variable is non-@code{nil}, the line-move, scroll-up, and
scroll-down functions will automatically modify the window vscroll to
scroll through display rows that are taller that the height of the
-window, for example in the presense of large images.
+window, for example in the presence of large images.
@end defvar
@node Horizontal Scrolling
disappear off to the left depends on their width, and could vary from
line to line.
- Because we read from side to side in the ``inner loop'', and from top
-to bottom in the ``outer loop'', the effect of horizontal scrolling is
+ Because we read from side to side in the ``inner loop,'' and from top
+to bottom in the ``outer loop,'' the effect of horizontal scrolling is
not like that of textual or vertical scrolling. Textual scrolling
involves selection of a portion of text to display, and vertical
scrolling moves the window contents contiguously; but horizontal
@end example
@end defun
-@tindex window-body-height
@defun window-body-height &optional window
Like @code{window-height} but the value does not include the
mode line (if any) or the header line (if any).
and @code{nil} otherwise.
@end deffn
-@tindex window-size-fixed
@defvar window-size-fixed
If this variable is non-@code{nil}, in any given buffer,
then the size of any window displaying the buffer remains fixed
If the root window is not split, @var{root} is the root window itself.
Otherwise, @var{root} is a list @code{(@var{dir} @var{edges} @var{w1}
-@var{w2} ...)} where @var{dir} is @code{nil} for a horisontal split,
+@var{w2} ...)} where @var{dir} is @code{nil} for a horizontal split,
and @code{t} for a vertical split, @var{edges} gives the combined size and
position of the subwindows in the split, and the rest of the elements
are the subwindows in the split. Each of the subwindows may again be
These functions must be careful in using @code{window-end}
(@pxref{Window Start}); if you need an up-to-date value, you must use
the @var{update} argument to ensure you get it.
+
+@strong{Warning:} don't use this feature to alter the way the window
+is scrolled. It's not designed for that, and such use probably won't
+work.
@end defvar
@defvar window-size-change-functions