X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/572fd5aa8b4ab5f51e5f511b2c0ca17b5266b0d9..28f94a3454ace838b06d8bcdd86248d2b87ca57b:/lispref/display.texi

diff --git a/lispref/display.texi b/lispref/display.texi
index 70f5763253..17e4bc57ea 100644
--- a/lispref/display.texi
+++ b/lispref/display.texi
@@ -16,16 +16,21 @@ that Emacs presents to the user.
 * Truncation::          Folding or wrapping long text lines.
 * The Echo Area::       Where messages are displayed.
 * Warnings::            Displaying warning messages for the user.
+* Progress::            Informing user about progress of a long operation.
 * Invisible Text::      Hiding part of the buffer text.
 * Selective Display::   Hiding part of the buffer text (the old way).
 * Overlay Arrow::       Display of an arrow to indicate position.
 * Temporary Displays::  Displays that go away automatically.
 * Overlays::            Use overlays to highlight parts of the buffer.
 * Width::               How wide a character or string is on the screen.
+* Line Height::         Controlling the height of lines.
 * Faces::               A face defines a graphics style for text characters:
                           font, colors, etc.
 * Fringes::             Controlling window fringes.
+* Fringe Bitmaps::      Displaying bitmaps in the window fringes.
+* Customizing Bitmaps:: Specifying your own bitmaps to use in the fringes.
 * Scroll Bars::         Controlling vertical scroll bars.
+* Pointer Shape::       Controlling the mouse pointer shape.
 * Display Property::    Enabling special display features.
 * Images::              Displaying images in Emacs buffers.
 * Buttons::             Adding clickable buttons to Emacs buffers.
@@ -530,6 +535,104 @@ symbols.  If it matches the first few elements in a warning type, then
 that warning is not logged.
 @end defopt
 
+@node Progress
+@section Reporting Operation Progress
+@cindex progress reporting
+
+When an operation can take a while to finish, you should inform the
+user about the progress it makes.  This way the user can estimate
+remaining time and clearly see that Emacs is busy working, not hung.
+
+Functions listed in this section provide simple and efficient way of
+reporting operation progress.  Here is a working example that does
+nothing useful:
+
+@example
+(let ((progress-reporter
+       (make-progress-reporter "Collecting some mana for Emacs..."
+                               0  500)))
+  (dotimes (k 500)
+    (sit-for 0.01)
+    (progress-reporter-update progress-reporter k))
+  (progress-reporter-done progress-reporter))
+@end example
+
+@defun make-progress-reporter message min-value max-value &optional current-value min-change min-time
+This function creates a progress reporter---the object you will use as
+an argument for all other functions listed here.  The idea is to
+precompute as much data as possible to make progress reporting very
+fast.
+
+The @var{message} will be displayed in the echo area, followed by
+progress percentage.  @var{message} is treated as a simple string.  If
+you need it to depend on a filename, for instance, use @code{format}
+before calling this function.
+
+@var{min-value} and @var{max-value} arguments stand for starting and
+final states of your operation.  For instance, if you scan a buffer,
+they should be the results of @code{point-min} and @code{point-max}
+correspondingly.  It is required that @var{max-value} is greater than
+@var{min-value}.  If you create progress reporter when some part of
+the operation has already been completed, then specify
+@var{current-value} argument.  But normally you should omit it or set
+it to @code{nil}---it will default to @var{min-value} then.
+
+Remaining arguments control the rate of echo area updates.  Progress
+reporter will wait for at least @var{min-change} more percents of the
+operation to be completed before printing next message.
+@var{min-time} specifies the minimum time in seconds to pass between
+successive prints.  It can be fractional.  Depending on Emacs and
+system capabilities, progress reporter may or may not respect this
+last argument or do it with varying precision.  Default value for
+@var{min-change} is 1 (one percent), for @var{min-time}---0.2
+(seconds.)
+
+This function calls @code{progress-reporter-update}, so the first
+message is printed immediately.
+@end defun
+
+@defun progress-reporter-update reporter value
+This function does the main work of reporting progress of your
+operation.  It print the message of @var{reporter} followed by
+progress percentage determined by @var{value}.  If percentage is zero,
+then it is not printed at all.
+
+@var{reporter} must be the result of a call to
+@code{make-progress-reporter}.  @var{value} specifies the current
+state of your operation and must be between @var{min-value} and
+@var{max-value} (inclusive) as passed to
+@code{make-progress-reporter}.  For instance, if you scan a buffer,
+then @var{value} should be the result of a call to @code{point}.
+
+This function respects @var{min-change} and @var{min-time} as passed
+to @code{make-progress-reporter} and so does not output new messages
+on every invocation.  It is thus very fast and normally you should not
+try to reduce the number of calls to it: resulting overhead will most
+likely negate your effort.
+@end defun
+
+@defun progress-reporter-force-update reporter value &optional new-message
+This function is similar to @code{progress-reporter-update} except
+that it prints a message in the echo area unconditionally.
+
+The first two arguments have the same meaning as for
+@code{progress-reporter-update}.  Optional @var{new-message} allows
+you to change the message of the @var{reporter}.  Since this functions
+always updates the echo area, such a change will be immediately
+presented to the user.
+@end defun
+
+@defun progress-reporter-done reporter
+This function should be called when the operation is finished.  It
+prints the message of @var{reporter} followed by word ``done'' in the
+echo area.
+
+You should always call this function and not hope for
+@code{progress-reporter-update} to print ``100%.''  Firstly, it may
+never print it, there are many good reasons for this not to happen.
+Secondly, ``done'' is more explicit.
+@end defun
+
 @node Invisible Text
 @section Invisible Text
 
@@ -562,7 +665,8 @@ the buffer looking for properties to change.
 
 @defvar buffer-invisibility-spec
 This variable specifies which kinds of @code{invisible} properties
-actually make a character invisible.
+actually make a character invisible.  Setting this variable makes it
+buffer-local.
 
 @table @asis
 @item @code{t}
@@ -1164,9 +1268,9 @@ sense---only on the screen.
 @item evaporate
 @kindex evaporate @r{(overlay property)}
 If this property is non-@code{nil}, the overlay is deleted automatically
-if it becomes empty (i.e., if its length becomes zero).  However,
-if the overlay is @emph{already} empty, @code{evaporate} does not
-delete it.
+if it becomes empty (i.e., if its length becomes zero).  If you give
+an empty overlay a non-@code{nil} @code{evaporate} property, that deletes
+it immediately.
 
 @item local-map
 @cindex keymap of character (and overlays)
@@ -1407,6 +1511,102 @@ the beginning of the result if one multi-column character in
 @end example
 @end defun
 
+@node Line Height
+@section Line Height
+@cindex line height
+
+  The total height of each display line consists of the height of the
+contents of the line, and additional vertical line spacing below the
+display row.
+
+  The height of the line contents is normally determined from the
+maximum height of any character or image on that display line,
+including the final newline if there is one.  (A line that is
+continued doesn't include a final newline.)  In the most common case,
+the line height equals the height of the default frame font.
+
+  There are several ways to explicitly control or change the line
+height, either by specifying an absolute height for the display line,
+or by adding additional vertical space below one or all lines.
+
+@kindex line-height @r{(text property)}
+  A newline can have a @code{line-height} text or overlay property
+that controls the total height of the display line ending in that
+newline.
+
+  If the property value is a list @code{(@var{height} @var{total})},
+then @var{height} is used as the actual property value for the
+@code{line-height}, and @var{total} specifies the total displayed
+height of the line, so the line spacing added below the line equals
+the @var{total} height minus the actual line height.  In this case,
+the other ways to specify the line spacing are ignored.
+
+  If the property value is @code{t}, the displayed height of the
+line is exactly what its contents demand; no line-spacing is added.
+This case is useful for tiling small images or image slices without
+adding blank areas between the images.
+
+  If the property value is not @code{t}, it is a height spec.  A height
+spec stands for a numeric height value; this heigh spec specifies the
+actual line height, @var{line-height}.  There are several ways to
+write a height spec; here's how each of them translates into a numeric
+height:
+
+@table @code
+@item @var{integer}
+If the height spec is a positive integer, the height value is that integer.
+@item @var{float}
+If the height spec is a float, @var{float}, the numeric height value
+is @var{float} times the frame's default line height.
+@item (@var{face} . @var{ratio})
+If the height spec is a cons of the format shown, the numeric height
+is @var{ratio} times the height of face @var{face}.  @var{ratio} can
+be any type of number, or @code{nil} which means a ratio of 1.
+If @var{face} is @code{t}, it refers to the current face.
+@item (@code{nil} . @var{ratio})
+If the height spec is a cons of the format shown, the numeric height
+is @var{ratio} times the height of the contents of the line.
+@end table
+
+  Thus, any valid non-@code{t} property value specifies a height in pixels,
+@var{line-height}, one way or another.  If the line contents' height
+is less than @var{line-height}, Emacs adds extra vertical space above
+the line to achieve the total height @var{line-height}.  Otherwise,
+@var{line-height} has no effect.
+
+  If you don't specify the @code{line-height} propery, the line's
+height consists of the contents' height plus the line spacing.
+There are several ways to specify the line spacing for different
+parts of Emacs text.
+
+@vindex default-line-spacing
+  You can specify the line spacing for all lines in a frame with the
+@code{line-spacing} frame parameter, @xref{Window Frame Parameters}.
+However, if the variable @code{default-line-spacing} is
+non-@code{nil}, it overrides the frame's @code{line-spacing}
+parameter.  An integer value specifies the number of pixels put below
+lines on window systems.  A floating point number specifies the
+spacing relative to the frame's default line height.
+
+@vindex line-spacing
+  You can specify the line spacing for all lines in a buffer via the
+buffer-local @code{line-spacing} variable.  An integer value specifies
+the number of pixels put below lines on window systems.  A floating
+point number specifies the spacing relative to the default frame line
+height.  This overrides line spacings specified for the frame.
+
+@kindex line-spacing @r{(text property)}
+  Finally, a newline can have a @code{line-spacing} text or overlay
+property that controls the height of the display line ending with that
+newline.  The property value overrides the default frame line spacing
+and the buffer local @code{line-spacing} variable.
+
+  One way or another, these mechanisms specify a Lisp value for the
+spacing of each line.  The value is a height spec, and it translates
+into a Lisp value as described above.  However, in this case the
+numeric height value specifies the line spacing, rather than the line
+height.
+
 @node Faces
 @section Faces
 @cindex faces
@@ -1436,7 +1636,7 @@ face name a special meaning in one frame if you wish.
 * Defining Faces::      How to define a face with @code{defface}.
 * Face Attributes::     What is in a face?
 * Attribute Functions::  Functions to examine and set face attributes.
-* Merging Faces::       How Emacs combines the faces specified for a character.
+* Displaying Faces::     How Emacs combines the faces specified for a character.
 * Font Selection::      Finding the best available font for a face.
 * Face Functions::      How to define and examine faces.
 * Auto Faces::          Hook for automatic face assignment.
@@ -1485,7 +1685,7 @@ font.  (This works only on certain systems.)
 
 @item fringe
 @kindex fringe @r{(face name)}
-This face controls the colors of window fringes, the thin areas on
+This face controls the default colors of window fringes, the thin areas on
 either side that are used to display continuation and truncation glyphs.
 
 @item minibuffer-prompt
@@ -1690,7 +1890,7 @@ as if they had a light background.
 attributes}.  This table lists all the face attributes, and what they
 mean.  Note that in general, more than one face can be specified for a
 given piece of text; when that happens, the attributes of all the faces
-are merged to specify how to display the text.  @xref{Merging Faces}.
+are merged to specify how to display the text.  @xref{Displaying Faces}.
 
   In Emacs 21, any attribute in a face can have the value
 @code{unspecified}.  This means the face doesn't specify that attribute.
@@ -1741,10 +1941,14 @@ On a text-only terminal, slanted text is displayed as half-bright, if
 the terminal supports the feature.
 
 @item :foreground
-Foreground color, a string.
+Foreground color, a string.  The value can be a system-defined color
+name, or a hexadecimal color specification of the form
+@samp{#@var{rr}@var{gg}@var{bb}}.  (@samp{#000000} is black,
+@samp{#ff0000} is red, @samp{#00ff00} is green, @samp{#0000ff} is
+blue, and @samp{#ffffff} is white.)
 
 @item :background
-Background color, a string.
+Background color, a string, like the foreground color.
 
 @item :inverse-video
 Whether or not characters should be displayed in inverse video.  The
@@ -2065,8 +2269,8 @@ This function returns the @code{:underline} attribute of face @var{face}.
 This function returns the @code{:inverse-video} attribute of face @var{face}.
 @end defun
 
-@node Merging Faces
-@subsection Merging Faces for Display
+@node Displaying Faces
+@subsection Displaying Faces
 
   Here are the ways to specify which faces to use for display of text:
 
@@ -2559,7 +2763,7 @@ non-@code{nil} value.
 
 @defvar fringes-outside-margins
 If the value is non-@code{nil}, the frames appear outside
-the display margins. 
+the display margins.
 @end defvar
 
 @defvar left-fringe-width
@@ -2595,6 +2799,125 @@ window is used.  The value has the form @code{(@var{left-width}
 @var{right-width} @var{frames-outside-margins})}.
 @end defun
 
+@defvar overflow-newline-into-fringe
+If this is non-@code{nil}, lines exactly as wide as the window (not
+counting the final newline character) are not continued.  Instead,
+when point is at the end of the line, the cursor appears in the right
+fringe.
+@end defvar
+
+@node Fringe Bitmaps
+@section Fringe Bitmaps
+@cindex fringe bitmaps
+@cindex bitmaps, fringe
+
+  The @dfn{fringe bitmaps} are tiny icons Emacs displays in the window
+fringe (on a graphic display) to indicate truncated or continued
+lines, buffer boundaries, overlay arrow, etc.  The fringe bitmaps are
+shared by all frames and windows.  You can redefine the built-in
+fringe bitmaps, and you can define new fringe bitmaps.
+
+  The way to display a bitmap in the left or right fringes for a given
+line in a window is by specifying the @code{display} property for one
+of the characters that appears in it.  Use a display specification of
+the form @code{(left-fringe @var{bitmap} [@var{face}])} or
+@code{(right-fringe @var{bitmap} [@var{face}])} (@pxref{Display
+Property}).  Here, @var{bitmap} is a symbol identifying the bitmap
+you want, and @var{face} (which is optional) is the name of the face
+whose colors should be used for displaying the bitmap.
+
+  These are the symbols identify the standard fringe bitmaps.
+Evaluate @code{(require 'fringe)} to define them.  Fringe bitmap
+symbols have their own name space.
+
+@table @asis
+@item Truncation and continuation line bitmaps:
+@code{left-truncation}, @code{right-truncation},
+@code{continued-line}, @code{continuation-line}.
+
+@item Buffer indication bitmaps:
+@code{up-arrow}, @code{down-arrow},
+@code{top-left-angle}, @code{top-right-angle},
+@code{bottom-left-angle}, @code{bottom-right-angle},
+@code{left-bracket}, @code{right-bracket}.
+
+@item Empty line indication bitmap:
+@code{empty-line}.
+
+@item Overlay arrow bitmap:
+@code{overlay-arrow}.
+
+@item Bitmaps for displaying the cursor in right fringe:
+@code{filled-box-cursor}, @code{hollow-box-cursor}, @code{hollow-square},
+@code{bar-cursor}, @code{hbar-cursor}.
+@end table
+
+@defun fringe-bitmaps-at-pos &optional pos window
+This function returns the fringe bitmaps of the display line
+containing position @var{pos} in window @var{window}.  The return
+value has the form @code{(@var{left} @var{right} @var{ov})}, where @var{left}
+is the symbol for the fringe bitmap in the left fringe (or @code{nil}
+if no bitmap), @var{right} is similar for the right fringe, and @var{ov}
+is non-@code{nil} if there is an overlay arrow in the left fringe.
+
+The value is @code{nil} if @var{pos} is not visible in @var{window}.
+If @var{window} is @code{nil}, that stands for the selected window.
+If @var{pos} is @code{nil}, that stands for the value of point in
+@var{window}.
+@end defun
+
+@node Customizing Bitmaps
+@section Customizing Fringe Bitmaps
+
+@defun define-fringe-bitmap bitmap bits &optional height width align
+This function defines the symbol @var{bitmap} as a new fringe bitmap,
+or replaces an existing bitmap with that name.
+
+The argument @var{bits} specifies the image to use.  It should be
+either a string or a vector of integers, where each element (an
+integer) corresponds to one row of the bitmap.  Each bit of an integer
+corresponds to one pixel of the bitmap, where the low bit corresponds
+to the rightmost pixel of the bitmap.
+
+The height is normally the length of @var{bits}.  However, you
+can specify a different height with non-@code{nil} @var{height}.  The width
+is normally 8, but you can specify a different width with non-@code{nil}
+@var{width}.  The width must be an integer between 1 and 16.
+
+The argument @var{align} specifies the positioning of the bitmap
+relative to the range of rows where it is used; the default is to
+center the bitmap.  The allowed values are @code{top}, @code{center},
+or @code{bottom}.
+
+The @var{align} argument may also be a list @code{(@var{align}
+@var{periodic})} where @var{align} is interpreted as described above.
+If @var{periodic} is non-@code{nil}, it specifies that the rows in
+@code{bits} should be repeated enough times to reach the specified
+height.
+
+The return value on success is an integer identifying the new bitmap.
+You should save that integer in a variable so it can be used to select
+this bitmap.
+
+This function signals an error if there are no more free bitmap slots.
+@end defun
+
+@defun destroy-fringe-bitmap bitmap
+This function destroy the fringe bitmap identified by @var{bitmap}.
+If @var{bitmap} identifies a standard fringe bitmap, it actually
+restores the standard definition of that bitmap, instead of
+eliminating it entirely.
+@end defun
+
+@defun set-fringe-bitmap-face bitmap &optional face
+This sets the face for the fringe bitmap @var{bitmap} to @var{face}.
+If @var{face} is @code{nil}, it selects the @code{fringe} face.  The
+bitmap's face controls the color to draw it in.
+
+The face you use here should be derived from @code{fringe}, and should
+specify only the foreground color.
+@end defun
+
 @node Scroll Bars
 @section Scroll Bars
 
@@ -2604,22 +2927,30 @@ non-@code{nil} 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
+@vindex vertical-scroll-bar
+  You can enable or disable scroll bars for a particular buffer,
+by setting the variable @code{vertical-scroll-bar}.  This variable
+automatically becomes buffer-local when set.  The possible values are
+@code{left}, @code{right}, @code{t}, which means to use the
+frame's default, and @code{nil} for no scroll bar.
+
+  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}, the selected window is used.
+This function sets the width and type of scroll bars for window
+@var{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.
+use the width specified 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.
+implemented, it has no effect.  If @var{window} is @code{nil}, the
+selected window is used.
 @end defun
 
 @defun window-scroll-bars &optional window
@@ -2643,6 +2974,39 @@ 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.
 
+@defvar scroll-bar-mode
+This variable, always local in all buffers, controls whether and where
+to put scroll bars in windows displaying the buffer.  The possible values
+are @code{nil} for no scroll bar, @code{left} to put a scroll bar on
+the left, and @code{right} to put a scroll bar on the right.
+@end defvar
+
+@defvar scroll-bar-width
+This variable, always local in all buffers, specifies the width of the
+buffer's scroll bars, measured in pixels.  A value of @code{nil} means
+to use the value specified by the frame.
+@end defvar
+
+@node Pointer Shape
+@section Pointer Shape
+
+  Normally, the mouse pointer has the @code{text} shape over text and
+the @code{arrow} shape over window areas which do not correspond to
+any buffer text.  You can specify the mouse pointer shape over text or
+images via the @code{pointer} text property, and for images with the
+@code{:pointer} and @code{:map} image properties.
+
+  The available pointer shapes are: @code{text} (or @code{nil}),
+@code{arrow}, @code{hand}, @code{vdrag}, @code{hdrag},
+@code{modeline}, and @code{hourglass}.
+
+@defvar void-text-area-pointer
+@tindex void-text-area-pointer
+This variable specifies the mouse pointer shape in void text areas,
+i.e. the areas after the end of a line or below the last line in the
+buffer.  The default is to use the @code{arrow} (non-text) pointer.
+@end defvar
+
 @node Display Property
 @section The @code{display} Property
 @cindex display specification
@@ -2658,6 +3022,7 @@ they mean.
 
 @menu
 * Specified Space::      Displaying one space with a specified width.
+* Pixel Specification::  Specifying space width or height in pixels.
 * Other Display Specs::  Displaying an image; magnifying text; moving it
                           up or down on the page; adjusting the width
                           of spaces within text.
@@ -2682,9 +3047,10 @@ can use in @var{props} to specify the weight of the space:
 
 @table @code
 @item :width @var{width}
-Specifies that the space width should be @var{width} times the normal
-character width.  @var{width} can be an integer or floating point
-number.
+If @var{width} is an integer or floating point number, it specifies
+that the space width should be @var{width} times the normal character
+width.  @var{width} can also be a @dfn{pixel width} specification
+(@pxref{Pixel Specification}).
 
 @item :relative-width @var{factor}
 Specifies that the width of the stretch should be computed from the
@@ -2693,41 +3059,131 @@ same @code{display} property.  The space width is the width of that
 character, multiplied by @var{factor}.
 
 @item :align-to @var{hpos}
-Specifies that the space should be wide enough to reach @var{hpos}.  The
-value @var{hpos} is measured in units of the normal character width.  It
-may be an integer or a floating point number.
+Specifies that the space should be wide enough to reach @var{hpos}.
+If @var{hpos} is a number, it is measured in units of the normal
+character width.  @var{hpos} can also be a @dfn{pixel width}
+specification (@pxref{Pixel Specification}).
 @end table
 
   You should use one and only one of the above properties.  You can
-also specify the height of the space, with other properties:
+also specify the height of the space, with these properties:
 
 @table @code
 @item :height @var{height}
-Specifies the height of the space, as @var{height},
-measured in terms of the normal line height.
+Specifies the height of the space.
+If @var{height} is an integer or floating point number, it specifies
+that the space height should be @var{height} times the normal character
+height.  The @var{height} may also be a @dfn{pixel height} specification
+(@pxref{Pixel Specification}).
 
 @item :relative-height @var{factor}
 Specifies the height of the space, multiplying the ordinary height
 of the text having this display specification by @var{factor}.
 
 @item :ascent @var{ascent}
-Specifies that @var{ascent} percent of the height of the space should be
-considered as the ascent of the space---that is, the part above the
-baseline.  The value of @var{ascent} must be a non-negative number no
-greater than 100.
+If the value of @var{ascent} is a non-negative number no greater than
+100, it specifies that @var{ascent} percent of the height of the space
+should be considered as the ascent of the space---that is, the part
+above the baseline.  The ascent may also be specified in pixel units
+with a @dfn{pixel ascent} specification (@pxref{Pixel Specification}).
+
 @end table
 
   Don't use both @code{:height} and @code{:relative-height} together.
 
+  The @code{:height} and @code{:align-to} properties are supported on
+non-graphic terminals, but the other space properties in this section
+are not.
+
+@node Pixel Specification
+@subsection Pixel Specification for Spaces
+@cindex spaces, pixel specification
+
+  The value of the @code{:width}, @code{:align-to}, @code{:height},
+and @code{:ascent} properties can be a special kind of expression that
+is evaluated during redisplay.  The result of the evaluation is used
+as an absolute number of pixels.
+
+  The following expressions are supported:
+
+@example
+@group
+  @var{expr} ::= @var{num} | (@var{num}) | @var{unit} | @var{elem} | @var{pos} | @var{image} | @var{form}
+  @var{num}  ::= @var{integer} | @var{float} | @var{symbol}
+  @var{unit} ::= in | mm | cm | width | height
+  @var{elem} ::= left-fringe | right-fringe | left-margin | right-margin
+        |  scroll-bar | text
+  @var{pos}  ::= left | center | right
+  @var{form} ::= (@var{num} . @var{expr}) | (@var{op} @var{expr} ...)
+  @var{op}   ::= + | -
+@end group
+@end example
+
+  The form @var{num} specifies a fraction of the default frame font
+height or width.  The form @code{(@var{num})} specifies an absolute
+number of pixels.  If @var{num} is a symbol, @var{symbol}, its
+buffer-local variable binding is used.
+
+  The @code{in}, @code{mm}, and @code{cm} units specify the number of
+pixels per inch, millimeter, and centimeter, respectively.  The
+@code{width} and @code{height} units correspond to the default width
+and height of the current face.  An image specification @code{image}
+corresponds to the width or height of the image.
+
+  The @code{left-fringe}, @code{right-fringe}, @code{left-margin},
+@code{right-margin}, @code{scroll-bar}, and @code{text} elements
+specify to the width of the corresponding area of the window.
+
+  The @code{left}, @code{center}, and @code{right} positions can be
+used with @code{:align-to} to specify a position relative to the left
+edge, center, or right edge of the text area.
+
+  Any of the above window elements (except @code{text}) can also be
+used with @code{:align-to} to specify that the position is relative to
+the left edge of the given area.  Once the base offset for a relative
+position has been set (by the first occurrence of one of these
+symbols), further occurrences of these symbols are interpreted as the
+width of the specified area.  For example, to align to the center of
+the left-margin, use
+
+@example
+:align-to (+ left-margin (0.5 . left-margin))
+@end example
+
+  If no specific base offset is set for alignment, it is always relative
+to the left edge of the text area.  For example, @samp{:align-to 0} in a
+header-line aligns with the first text column in the text area.
+
+  A value of the form @code{(@var{num} . @var{expr})} stands
+multiplying the values of @var{num} and @var{expr}.  For example,
+@code{(2 . in)} specifies a width of 2 inches, while @code{(0.5 .
+@var{image})} specifies half the width (or height) of the specified image.
+
+  The form @code{(+ @var{expr} ...)} adds up the value of the
+expressions.  The form @code{(- @var{expr} ...)} negates or subtracts
+the value of the expressions.
+
 @node Other Display Specs
 @subsection Other Display Specifications
 
+  Here are the other sorts of display specifications that you can use
+in the @code{display} text property.
+
 @table @code
 @item (image . @var{image-props})
 This is in fact an image descriptor (@pxref{Images}).  When used as a
 display specification, it means to display the image instead of the text
 that has the display specification.
 
+@item (slice @var{x} @var{y} @var{width} @var{height})
+This specification together with @code{image} specifies a @dfn{slice}
+(a partial area) of the image to display.  The elements @var{y} and
+@var{x} specify the top left corner of the slice, within the image;
+@var{width} and @var{height} specify the width and height of the
+slice.  Integer values are numbers of pixels.  A floating point number
+in the range 0.0--1.0 stands for that fraction of the width or height
+of the entire image.
+
 @item ((margin nil) @var{string})
 @itemx @var{string}
 A display specification of this form means to display @var{string}
@@ -2875,8 +3331,13 @@ property of text that is displayed (@pxref{Display Property}).  Like the
 @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
+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 possible 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),
@@ -2888,9 +3349,46 @@ type symbols are @code{xbm}, @code{xpm}, @code{gif}, @code{postscript},
 
 @defvar image-types
 This variable contains a list of those image type symbols that are
-supported in the current configuration.
+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
+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.
+
+Emacs tries to load the libraries in the order they appear on the
+list; if none is loaded, the running session of Emacs won't support
+the image type.  @code{pbm} and @code{xbm} don't need to be listed;
+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-@code{nil} if image type @var{type} is
+available, i.e., if images of this type can be loaded and displayed in
+Emacs.  @var{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.
@@ -3062,6 +3560,43 @@ specifying the color to assume for the background of the image.
 If @var{mask} is @code{nil}, remove a mask from the image, if it has
 one.  Images in some formats include a mask which can be removed by
 specifying @code{:mask nil}.
+
+@item :pointer @var{shape}
+This specifies the pointer shape when the mouse pointer is over this
+image.  @xref{Pointer Shape}, for available pointer shapes.
+
+@item :map @var{map}
+This associates an image map of @dfn{hot spots} with this image.
+
+An image map is an alist where each element has the format
+@code{(@var{area} @var{id} @var{plist})}.  An @var{area} is specified
+as either a rectangle, a circle, or a polygon.
+
+A rectangle is a cons
+@code{(rect . ((@var{x0} . @var{y0}) . (@var{x1} . @var{y1})))}
+which specifies the pixel coordinates of the upper left and bottom right
+corners of the rectangle area.
+
+A circle is a cons
+@code{(circle . ((@var{x0} . @var{y0}) . @var{r}))}
+which specifies the center and the radius of the circle; @var{r} may
+be a float or integer.
+
+A polygon is a cons
+@code{(poly . [@var{x0} @var{y0} @var{x1} @var{y1} ...])}
+where each pair in the vector describes one corner in the polygon.
+
+When the mouse pointer is above a hot-spot area of an image, the
+@var{plist} of that hot-spot is consulted; if it contains a @code{help-echo}
+property it defines a tool-tip for the hot-spot, and if it contains
+a @code{pointer} property, it defines the shape of the mouse cursor when
+it is over the hot-spot.
+@xref{Pointer Shape}, for available pointer shapes.
+
+When you click the mouse when the mouse pointer is over a hot-spot, an
+event is composed by combining the @var{id} of the hot-spot with the
+mouse event; for instance, @code{[area4 mouse-1]} if the hot-spot's
+@var{id} is @code{area4}.
 @end table
 
 @defun image-mask-p spec &optional frame
@@ -3329,7 +3864,7 @@ The image is looked for first on @code{load-path} and then in
 property yourself, but it is easier to use the functions in this
 section.
 
-@defun insert-image image &optional string area
+@defun insert-image image &optional string area slice
 This function inserts @var{image} in the current buffer at point.  The
 value @var{image} should be an image descriptor; it could be a value
 returned by @code{create-image}, or the value of a symbol defined with
@@ -3342,11 +3877,26 @@ If it is @code{left-margin}, the image appears in the left margin;
 @code{nil} or omitted, the image is displayed at point within the
 buffer's text.
 
+The argument @var{slice} specifies a slice of the image to insert.  If
+@var{slice} is @code{nil} or omitted the whole image is inserted.
+Otherwise, @var{slice} is a list @code{(@var{x} @var{y} @var{width}
+@var{height})} which specifies the @var{x} and @var{y} positions and
+@var{width} and @var{height} of the image area to insert.  Integer
+values are in units of pixels.  A floating point number in the range
+0.0--1.0 stands for that fraction of the width or height of the entire
+image.
+
 Internally, this function inserts @var{string} in the buffer, and gives
 it a @code{display} property which specifies @var{image}.  @xref{Display
 Property}.
 @end defun
 
+@defun insert-sliced-image image &optional string area rows cols
+This function inserts @var{image} in the current buffer at point, like
+@code{insert-image}, but splits the image into @var{rows}x@var{cols}
+equally sized slices.
+@end defun
+
 @defun put-image image pos &optional string area
 This function puts image @var{image} in front of @var{pos} in the
 current buffer.  The argument @var{pos} should be an integer or a
@@ -3455,7 +4005,7 @@ entries).
 * 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:: 
+* Manipulating Button Types::
 @end menu
 
 @node Button Properties
@@ -3499,8 +4049,9 @@ the usual Emacs @code{highlight} face.
 @kindex keymap @r{(button property)}
 The button's keymap, defining bindings active within the button
 region.  By default this is the usual button region keymap, stored
-in the variable @code{button-map}, which defines @key{RET} and
-@key{mouse-2} to invoke the button.
+in the variable @code{button-map}, which defines @key{RET},
+@key{mouse-1} (if @var{mouse-1-click-follows-link} is set),
+and @key{mouse-2} to invoke the button.
 
 @item type
 @kindex type @r{(button property)}
@@ -3513,6 +4064,10 @@ usually specified using the @code{:type} keyword argument.
 A string displayed by the Emacs tool-tip help system; by default,
 @code{"mouse-2, RET: Push this button"}.
 
+@item follow-link
+@kindex follow-link @r{(button property)}
+The follow-link property, defining how a @key{mouse-1} click behaves
+on this button, @xref{Enabling Mouse-1 to Follow Links}.
 @item button
 @kindex button @r{(button property)}
 All buttons have a non-@code{nil} @code{button} property, which may be useful
@@ -3684,7 +4239,8 @@ 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}
+a button, and is bound by default in the button itself to @key{RET},
+to @key{mouse-1} (if @var{mouse-1-click-follows-link} is set),
 and to @key{mouse-2} using a region-specific keymap.  Commands
 that are useful outside the buttons itself, such as
 @code{forward-button} and @code{backward-button} are additionally
@@ -3920,6 +4476,14 @@ The value of this variable is the default value for @code{ctl-arrow} in
 buffers that do not override it.  @xref{Default Value}.
 @end defvar
 
+@defopt tab-width
+The value of this variable is the spacing between tab stops used for
+displaying tab characters in Emacs buffers.  The value is in units of
+columns, and the default is 8.  Note that this feature is completely
+independent of the user-settable tab stops used by the command
+@code{tab-to-tab-stop}.  @xref{Indent Tabs}.
+@end defopt
+
 @defopt indicate-empty-lines
 @tindex indicate-empty-lines
 @cindex fringes, and empty line indication
@@ -3928,13 +4492,42 @@ fringe of each empty line at the end of the buffer, on terminals that
 support it (window systems).  @xref{Fringes}.
 @end defopt
 
-@defopt tab-width
-The value of this variable is the spacing between tab stops used for
-displaying tab characters in Emacs buffers.  The value is in units of
-columns, and the default is 8.  Note that this feature is completely
-independent of the user-settable tab stops used by the command
-@code{tab-to-tab-stop}.  @xref{Indent Tabs}.
-@end defopt
+@defvar indicate-buffer-boundaries
+This buffer-local variable controls how the buffer boundaries and
+window scrolling are indicated in the window fringes.
+
+Emacs can indicate the buffer boundaries---that is, the first and last
+line in the buffer---with angle icons when they appear on the screen.
+In addition, Emacs can display an up-arrow in the fringe to show
+that there is text above the screen, and a down-arrow to show
+there is text below the screen.
+
+There are four kinds of basic values:
+
+@table @asis
+@item @code{nil}
+Don't display the icons.
+@item @code{left}
+Display them in the left fringe.
+@item @code{right}
+Display them in the right fringe.
+@item @var{anything-else}
+Display the icon at the top of the window top in the left fringe, and other
+in the right fringe.
+@end table
+
+If value is a cons @code{(@var{angles} . @var{arrows})}, @var{angles}
+controls the angle icons, and @var{arrows} controls the arrows.  Both
+@var{angles} and @var{arrows} work according to the table above.
+Thus, @code{(t .  right)} places the top angle icon in the left
+fringe, the bottom angle icon in the right fringe, and both arrows in
+the right fringe.
+@end defvar
+
+@defvar default-indicate-buffer-boundaries
+The value of this variable is the default value for
+@code{indicate-buffer-boundaries} in buffers that do not override it.
+@end defvar
 
 @node Display Tables
 @section Display Tables
@@ -3994,7 +4587,7 @@ in these situations.
 @item 1
 The glyph for the end of a continued line (the default is @samp{\}).
 Newer Emacs versions, on some platforms, display curved arrows to
-indicate truncation---the display table has no effect in these
+indicate continuation---the display table has no effect in these
 situations.
 @item 2
 The glyph for indicating a character displayed as an octal character