@menu
* Window Choice:: How @code{display-buffer} works.
+* Temporary Displays:: Displaying non-editable buffers.
@end menu
@node Window Choice
@code{graphic-only} means to do this only on graphical displays.
@item
-Otherwise, try to create a new window by splitting the selected
-window, and display the buffer in that new window.
+Otherwise, try to create a new window by splitting a window on the
+selected frame, and display the buffer in that new window.
@vindex split-height-threshold
@vindex split-width-threshold
The split can be either vertical or horizontal, depending on the
variables @code{split-height-threshold} and
@code{split-width-threshold}. These variables should have integer
-values. If @code{split-height-threshold} is smaller than the selected
+values. If @code{split-height-threshold} is smaller than the chosen
window's height, the split puts the new window below. Otherwise, if
@code{split-width-threshold} is smaller than the window's width, the
split puts the new window on the right. If neither condition holds,
Emacs tries to split so that the new window is below---but only if the
window was not split before (to avoid excessive splitting).
+@item
+Otherwise, display the buffer in a window previously showing it.
+Normally, only windows on the selected frame are considered, but if
+@code{pop-up-frames} is non-@code{nil} the window may be also on another
+frame.
+
@item
Otherwise, display the buffer in an existing window on the selected
frame.
and display the buffer there.
@end itemize
+A more advanced and flexible way to customize the behavior of
+@code{display-buffer} is by using the option @code{display-buffer-alist}
+mentioned in the next section.
+
+
+@node Temporary Displays
+@subsection Displaying non-editable buffers.
+
+Some buffers are shown in windows for perusal rather than for editing.
+Help commands (@pxref{Help}) typically use a buffer called @file{*Help*}
+for that purpose, minibuffer completion (@pxref{Completion}) uses a
+buffer called @file{*Completions*} instead. Such buffers are usually
+displayed only for a short period of time.
+
+ Normally, Emacs chooses the window for such temporary displays via
+@code{display-buffer} as described above. The @file{*Completions*}
+buffer, on the other hand, is preferably displayed in a window at the
+bottom of the selected frame, regardless of the number of windows
+already shown on that frame.
+
+ If you prefer Emacs to display a temporary buffer in a different
+fashion, the recommended approach is to customize the variable
+@code{display-buffer-alist} (@pxref{Choosing Window,,Choosing a Window
+for Display, elisp, The Emacs Lisp Reference Manual}). For example, to
+display @file{*Completions*} by splitting a window as described in the
+previous section, use the following form in your initialization file
+(@pxref{Init File}):
+
+@example
+@group
+(customize-set-variable
+ 'display-buffer-alist
+ '(("\\*Completions\\*" display-buffer-pop-up-window)))
+@end group
+@end example
+
+ The @file{*Completions*} buffer is also special in the sense that
+Emacs usually tries to make its window just as large as to display all
+of its contents. To resize windows showing other temporary displays
+like, for example, the @file{*Help*} buffer accordingly, you have to
+explicitly invoke the minor mode (@pxref{Minor Modes})
+@code{temp-buffer-resize-mode} (@pxref{Temporary Displays,,Temporary
+Displays, elisp, The Emacs Lisp Reference Manual}).
+
+ The maximum size of windows resized by @code{temp-buffer-resize-mode}
+can be controlled by customizing the options
+@code{temp-buffer-max-height} and @code{temp-buffer-max-width}
+(@pxref{Temporary Displays,,Temporary Displays, elisp, The Emacs Lisp
+Reference Manual}) and cannot exceed the size of the containing frame.
+
+
@node Window Convenience
@section Convenience Features for Window Handling