[Emacs-diffs] Changes to emacs/lispref/display.texi

[Richard M. Stallman]

Index: emacs/lispref/display.texi
diff -c emacs/lispref/display.texi:1.99 emacs/lispref/display.texi:1.100
*** emacs/lispref/display.texi:1.99     Mon Sep  1 11:45:41 2003
--- emacs/lispref/display.texi  Thu Sep 11 20:59:55 2003
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*** 25,30 ****
--- 25,31 ----
  * Faces::             A face defines a graphics style for text characters:
                            font, colors, etc.
  * Fringes::             Controlling window fringes.
+ * Scroll Bars::         Controlling vertical scroll bars.
  * Display Property::    Enabling special display features.
  * Images::              Displaying images in Emacs buffers.
  * Blinking::            How Emacs shows the matching open parenthesis.
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*** 2477,2482 ****
--- 2478,2492 ----
  Chinese GB2312 characters has a wild card @samp{*} in the @var{family}
  field.
  
+ @defun char-displayable-p char
+ This function returns @code{t} if Emacs ought to be able to display
+ @var{char}.  More precisely, if the selected frame's fontset has a
+ font to display the character set that @var{char} belongs to.
+ 
+ Fontsets can specify a font on a per-character basis; when the fontset
+ does that, this function's value may not be accurate.
+ @end defun
+ 
  @node Fringes
  @section Fringes
  @cindex Fringes
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*** 2524,2529 ****
--- 2534,2587 ----
  @var{window}.  The value has the form @code{(@var{left-width}
  @var{right-width} @var{frames-outside-margins})}.
  @end defun
+ 
+ @node Scroll Bars
+ @section Scroll Bars
+ 
+ Normally the frame parameter @code{vertical-scroll-bars} controls
+ whether the windows in the frame have vertical scroll bars.  A
+ address@hidden parameter value means they do.  The frame parameter
+ @code{scroll-bar-width} specifies how wide they are (@code{nil}
+ meaning the default).  @xref{Window Frame Parameters}.
+ 
+ You can also control this for individual windows.  Call the function
+ @code{set-window-scroll-bars} to specify what to do for a specific window:
+ 
+ @defun set-window-scroll-bars window width &optional vertical-type 
horizontal-type
+ Set width and type of scroll bars of window @var{window}.  (If
+ @var{window} is @code{nil}, this applies to the selected window.)
+ @var{width} specifies the scroll bar width in pixels (@code{nil} means
+ use whatever is specified for width for the frame).
+ @var{vertical-type} specifies whether to have a vertical scroll bar
+ and, if so, where.  The possible values are @code{left}, @code{right}
+ and @code{nil}, just like the values of the
+ @code{vertical-scroll-bars} frame parameter.
+ 
+ The argument @var{horizontal-type} is meant to specify whether and
+ where to have horizontal scroll bars, but since they are not
+ implemented, it has no effect.
+ @end defun
+ 
+ @defun window-scroll-bars &optional window
+ Report the width and type of scroll bars specified for @var{window}.
+ If @var{window} is omitted or @code{nil}, it defaults to the currently
+ selected window.  The value is a list of the form @code{(@var{width}
+ @var{cols} @var{vertical-type} @var{horizontal-type})}.  The value
+ @var{width} is the value that was specified for the width (which may
+ be @code{nil}); @var{cols} is the number of columns that the scroll
+ bar actually occupies.
+ 
+ @var{horizontal-type} is not actually meaningful.
+ @end defun
+ 
+ If you don't specify these values for a window with
+ @code{set-window-scroll-bars}, the buffer-local variables
+ @code{scroll-bar-mode} and @code{scroll-bar-width} in the buffer being
+ displayed control the window's vertical scroll bars.  The function
+ @code{set-window-buffer} examines these variables.  If you change them
+ in a buffer that is already visible in a window, you can make the
+ window take note of the new values by calling @code{set-window-buffer}
+ specifying the same buffer that is already displayed.
  
  @node Display Property
  @section The @code{display} Property