[Emacs-diffs] Changes to emacs/lispref/display.texi [emacs-unicode-2]

[Miles Bader]

Index: emacs/lispref/display.texi
diff -c emacs/lispref/display.texi:1.95.2.1 emacs/lispref/display.texi:1.95.2.2
*** emacs/lispref/display.texi:1.95.2.1 Mon Apr 19 07:01:41 2004
--- emacs/lispref/display.texi  Mon Jun 28 07:28:49 2004
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*** 2288,2297 ****
  @end defun
  
  @defun face-differs-from-default-p face &optional frame
! This returns @code{t} if the face @var{face} displays differently from
! the default face.  A face is considered to be ``the same'' as the
! default face if each attribute is either the same as that of the default
! face, or unspecified (meaning to inherit from the default).
  @end defun
  
  @node Auto Faces
--- 2288,2295 ----
  @end defun
  
  @defun face-differs-from-default-p face &optional frame
! This returns address@hidden if the face @var{face} displays
! differently from the default face.
  @end defun
  
  @node Auto Faces
***************
*** 2877,2884 ****
  @code{display} property, this feature is available starting in Emacs 21.
  
    Emacs can display a number of different image formats; some of them
! are supported only if particular support libraries are installed on your
! machine.  The supported image formats include XBM, XPM (needing the
  libraries @code{libXpm} version 3.4k and @code{libz}), GIF (needing
  @code{libungif} 4.1.0), Postscript, PBM, JPEG (needing the
  @code{libjpeg} library version v6a), TIFF (needing @code{libtiff} v3.4),
--- 2875,2887 ----
  @code{display} property, this feature is available starting in Emacs 21.
  
    Emacs can display a number of different image formats; some of them
! are supported only if particular support libraries are installed on
! your machine.  In some environments, Emacs allows loading image
! libraries on demand; if so, the variable @code{image-library-alist}
! can be used to modify the set of known names for these dynamic
! libraries (though it is not posible to add new image formats).
! 
!   The supported image formats include XBM, XPM (needing the
  libraries @code{libXpm} version 3.4k and @code{libz}), GIF (needing
  @code{libungif} 4.1.0), Postscript, PBM, JPEG (needing the
  @code{libjpeg} library version v6a), TIFF (needing @code{libtiff} v3.4),
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*** 2889,2898 ****
  @code{pbm}, @code{jpeg}, @code{tiff}, and @code{png}.
  
  @defvar image-types
  This variable contains a list of those image type symbols that are
! supported in the current configuration.
  @end defvar
  
  @menu
  * Image Descriptors::   How to specify an image for use in @code{:display}.
  * XBM Images::          Special features for XBM format.
--- 2892,2939 ----
  @code{pbm}, @code{jpeg}, @code{tiff}, and @code{png}.
  
  @defvar image-types
+ @vindex image-types
  This variable contains a list of those image type symbols that are
! potentially supported in the current configuration.
! @emph{Potentially} here means that Emacs knows about the image types,
! not necessarily that they can be loaded (they could depend on
! unavailable dynamic libraries, for example).
! 
! To know which image types are really available, use
! @code{image-type-available-p}.
! @end defvar
! 
! @defvar image-library-alist
! @vindex image-library-alist
! This in an alist of image types vs external libraries needed to
! display them.
! 
! Each element is a list @code{(@var{IMAGE-TYPE} @var{LIBRARY}...)},
! where the car is a supported image format from @code{image-types}, and
! the rest are strings giving alternate filenames for the corresponding
! external libraries to load.
! 
! They are tried in the order they appear on the list; if none of them
! can be loaded, the running session of Emacs won't support the image
! type.  No entries are needed for @code{pbm} and @code{xbm} images;
! they're always supported.
! 
! This variable is ignored if the image libraries are statically linked
! into Emacs.
  @end defvar
  
+ @defun  image-type-available-p type
+ @findex image-type-available-p
+ 
+ This function returns non-nil if image type TYPE is available, i.e.,
+ if images of this type can be loaded and displayed in Emacs.  TYPE
+ should be one of the types contained in @code{image-types}.
+ 
+ For image types whose support libraries are statically linked, this
+ function always returns @code{t}; for other image types, it returns
+ @code{t} if the dynamic library could be loaded, @code{nil} otherwise.
+ @end defun
+ 
  @menu
  * Image Descriptors::   How to specify an image for use in @code{:display}.
  * XBM Images::          Special features for XBM format.
***************
*** 3156,3162 ****
    For GIF images, specify image type @code{gif}.  Because of the patents
  in the US covering the LZW algorithm, the continued use of GIF format is
  a problem for the whole Internet; to end this problem, it is a good idea
! for everyone, even outside the US, to stop using GIFS right away
  (@uref{http://www.burnallgifs.org/}).  But if you still want to use
  them, Emacs can display them.
  
--- 3197,3203 ----
    For GIF images, specify image type @code{gif}.  Because of the patents
  in the US covering the LZW algorithm, the continued use of GIF format is
  a problem for the whole Internet; to end this problem, it is a good idea
! for everyone, even outside the US, to stop using GIFs right away
  (@uref{http://www.burnallgifs.org/}).  But if you still want to use
  them, Emacs can display them.
  
***************
*** 3433,3439 ****
  etc.  Emacs uses buttons for the hyper-links in help text and the like.
  
  A button is essentially a set of properties attached (via text
! properties or overlays) to a region of text in an emacs buffer, which
  are called its button properties.  @xref{Button Properties}.
  
  One of the these properties (@code{action}) is a function, which will
--- 3474,3480 ----
  etc.  Emacs uses buttons for the hyper-links in help text and the like.
  
  A button is essentially a set of properties attached (via text
! properties or overlays) to a region of text in an Emacs buffer, which
  are called its button properties.  @xref{Button Properties}.
  
  One of the these properties (@code{action}) is a function, which will
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*** 3441,3447 ****
  The invoked function may then examine the button and use its other
  properties as desired.
  
! In some ways the emacs button package duplicates functionality offered
  by the widget package (@pxref{Top, , Introduction, widget, The Emacs
  Widget Library}), but the button package has the advantage that it is
  much faster, much smaller, and much simpler to use (for elisp
--- 3482,3488 ----
  The invoked function may then examine the button and use its other
  properties as desired.
  
! In some ways the Emacs button package duplicates functionality offered
  by the widget package (@pxref{Top, , Introduction, widget, The Emacs
  Widget Library}), but the button package has the advantage that it is
  much faster, much smaller, and much simpler to use (for elisp
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*** 3454,3460 ****
  @menu
  * Button Properties::      Button properties with special meanings.
  * Button Types::           Defining common properties for classes of buttons.
! * Making Buttons::         Adding buttons to emacs buffers.
  * Manipulating Buttons::   Getting and setting properties of buttons.
  * Button Buffer Commands:: Buffer-wide commands and bindings for buttons.
  * Manipulating Button Types:: 
--- 3495,3501 ----
  @menu
  * Button Properties::      Button properties with special meanings.
  * Button Types::           Defining common properties for classes of buttons.
! * Making Buttons::         Adding buttons to Emacs buffers.
  * Manipulating Buttons::   Getting and setting properties of buttons.
  * Button Buffer Commands:: Buffer-wide commands and bindings for buttons.
  * Manipulating Button Types:: 
***************
*** 3488,3501 ****
  
  @item face
  @kindex face @r{(button property)}
! This is an emacs face controlling how buttons of this type are
  displayed; by default this is the @code{button} face.
  
  @item mouse-face
  @kindex mouse-face @r{(button property)}
  This is an additional face which controls appearance during
  mouse-overs (merged with the usual button face); by default this is
! the usual emacs @code{highlight} face.
  
  @item keymap
  @kindex keymap @r{(button property)}
--- 3529,3542 ----
  
  @item face
  @kindex face @r{(button property)}
! This is an Emacs face controlling how buttons of this type are
  displayed; by default this is the @code{button} face.
  
  @item mouse-face
  @kindex mouse-face @r{(button property)}
  This is an additional face which controls appearance during
  mouse-overs (merged with the usual button face); by default this is
! the usual Emacs @code{highlight} face.
  
  @item keymap
  @kindex keymap @r{(button property)}
***************
*** 3512,3518 ****
  
  @item help-echo
  @kindex help-index @r{(button property)}
! A string displayed by the emacs tool-tip help system; by default,
  @code{"mouse-2, RET: Push this button"}.
  
  @item button
--- 3553,3559 ----
  
  @item help-echo
  @kindex help-index @r{(button property)}
! A string displayed by the Emacs tool-tip help system; by default,
  @code{"mouse-2, RET: Push this button"}.
  
  @item button
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*** 3562,3568 ****
    Buttons are associated with a region of text, using an overlay or
  text-properties to hold button-specific information, all of which are
  initialized from the button's type (which defaults to the built-in
! button type @code{button}).  Like all emacs text, the appearance of
  the button is governed by the @code{face} property; by default (via
  the @code{face} property inherited from the @code{button} button-type)
  this is a simple underline, like a typical web-page link.
--- 3603,3609 ----
    Buttons are associated with a region of text, using an overlay or
  text-properties to hold button-specific information, all of which are
  initialized from the button's type (which defaults to the built-in
! button type @code{button}).  Like all Emacs text, the appearance of
  the button is governed by the @code{face} property; by default (via
  the @code{face} property inherited from the @code{button} button-type)
  this is a simple underline, like a typical web-page link.
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*** 3594,3600 ****
  Insert a button with the label @var{label}.
  @end defun
  
! The following functions are similar, but use emacs text-properties
  (@pxref{Text Properties}) to hold the button properties, making the
  button actually part of the text instead of being a property of the
  buffer (using text-properties is usually faster than using overlays,
--- 3635,3641 ----
  Insert a button with the label @var{label}.
  @end defun
  
! The following functions are similar, but use Emacs text-properties
  (@pxref{Text Properties}) to hold the button properties, making the
  button actually part of the text instead of being a property of the
  buffer (using text-properties is usually faster than using overlays,
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*** 3683,3689 ****
  @cindex button buffer commands
  
  These are commands and functions for locating and operating on
! buttons in an emacs buffer.
  
  @code{push-button} is the command that a user uses to actually `push'
  a button, and is bound by default in the button itself to @key{RET}
--- 3724,3730 ----
  @cindex button buffer commands
  
  These are commands and functions for locating and operating on
! buttons in an Emacs buffer.
  
  @code{push-button} is the command that a user uses to actually `push'
  a button, and is bound by default in the button itself to @key{RET}