The @code{display} text property (or overlay property) is used to
insert images into text, and to control other aspects of how text
-displays. The value of the @code{display} property should be a
-display specification, or a list or vector containing several display
-specifications. Display specifications in the same @code{display}
+displays. Display specifications in the same @code{display}
property value generally apply in parallel to the text they cover.
If several sources (overlays and/or a text property) specify values
following the rules of @code{get-char-property}. @xref{Examining
Properties}.
+ The value of the @code{display} property should be a display
+specification, or a list or vector containing several display
+specifications.
+
+@defun get-display-property position prop &optional object properties
+This convenience function can be used to get a specific display
+property, no matter whether the @code{display} property is a vector, a
+list or a simple property. This is like @code{get-text-property}
+(@pxref{Examining Properties}), but works on the @code{display}
+property only.
+
+@var{position} is the position in the buffer or string to examine, and
+@var{prop} is the @code{display} property to return. The optional
+@var{object} argument should be either a string or a buffer, and
+defaults to the current buffer. If the optional @var{properties}
+argument is non-@code{nil}, it should be a @code{display} property,
+and in that case, @var{position} and @var{object} are ignored. (This
+can be useful if you've already gotten the @code{display} property
+with @code{get-char-property}, for instance (@pxref{Examining
+Properties}).
+@end defun
+
@cindex display property, unsafe evaluation
@cindex security, and display specifications
Some of the display specifications allow inclusion of Lisp forms,
be an integer or float. Characters other than spaces are not affected
at all; in particular, this has no effect on tab characters.
+@item (min-width (@var{width}))
+This display specification adds padding to the end of the text if the
+text is shorter than @var{width}. The text is partitioned using the
+identity of the parameter, which is why the parameter is a list with
+one element. For instance:
+
+@lisp
+(insert (propertize "foo" '(display (min-width (6.0)))))
+@end lisp
+
+This will add padding after @samp{foo} bringing the total width up to
+the width of six normal characters. Note that the ``range'' is
+identified by the @code{(6.0)} list, compared with @code{eq}. The
+width can be either a character width or a pixel specification
+(@pxref{Pixel Specification}).
+
@item (height @var{height})
This display specification makes the text taller or shorter.
Here are the possibilities for @var{height}:
/* Functions to mark elements as needing redisplay. */
enum { REDISPLAY_SOME = 2}; /* Arbitrary choice. */
+static bool calc_pixel_width_or_height (double *, struct it *, Lisp_Object,
+ struct font *, bool, int *);
+
void
redisplay_other_windows (void)
{
it->ellipsis_p = true;
}
+\f
+static Lisp_Object
+find_display_property (Lisp_Object disp, Lisp_Object prop)
+{
+ if (NILP (disp))
+ return Qnil;
+ /* We have a vector of display specs. */
+ if (VECTORP (disp))
+ {
+ for (ptrdiff_t i = 0; i < ASIZE (disp); i++)
+ {
+ Lisp_Object elem = AREF (disp, i);
+ if (CONSP (elem)
+ && CONSP (XCDR (elem))
+ && EQ (XCAR (elem), prop))
+ return XCAR (XCDR (elem));
+ }
+ return Qnil;
+ }
+ /* We have a list of display specs. */
+ else if (CONSP (disp)
+ && CONSP (XCAR (disp)))
+ {
+ while (!NILP (disp))
+ {
+ Lisp_Object elem = XCAR (disp);
+ if (CONSP (elem)
+ && CONSP (XCDR (elem))
+ && EQ (XCAR (elem), prop))
+ return XCAR (XCDR (elem));
+
+ /* Check that we have a proper list before going to the next
+ element. */
+ if (CONSP (XCDR (disp)))
+ disp = XCDR (disp);
+ else
+ disp = Qnil;
+ }
+ return Qnil;
+ }
+ /* A simple display spec. */
+ else if (CONSP (disp)
+ && CONSP (XCDR (disp))
+ && EQ (XCAR (disp), prop))
+ return XCAR (XCDR (disp));
+ else
+ return Qnil;
+}
+
+static Lisp_Object get_display_property (ptrdiff_t bufpos, Lisp_Object prop,
+ Lisp_Object object)
+{
+ return find_display_property (Fget_text_property (make_fixnum (bufpos),
+
+ Qdisplay, object),
+ prop);
+}
+
+static void
+display_min_width (struct it *it, ptrdiff_t bufpos,
+ Lisp_Object object, Lisp_Object width_spec)
+{
+ /* We're being called at the end of the `min-width' sequence,
+ probably. */
+ if (!NILP (it->min_width_property)
+ && !EQ (width_spec, it->min_width_property))
+ {
+ if (!it->glyph_row)
+ return;
+
+ /* Check that we're really right after the sequence of
+ characters covered by this `min-width'. */
+ if (bufpos > BEGV
+ && EQ (it->min_width_property,
+ get_display_property (bufpos - 1, Qmin_width, object)))
+ {
+ Lisp_Object w = Qnil;
+ double width;
+#ifdef HAVE_WINDOW_SYSTEM
+ if (FRAME_WINDOW_P (it->f))
+ {
+ struct font *font = NULL;
+ struct face *face = FACE_FROM_ID (it->f, it->face_id);
+ font = face->font ? face->font : FRAME_FONT (it->f);
+ calc_pixel_width_or_height (&width, it,
+ XCAR (it->min_width_property),
+ font, true, NULL);
+ width -= it->current_x - it->min_width_start;
+ w = list1 (make_int (width));
+ }
+ else
+#endif
+ {
+ calc_pixel_width_or_height (&width, it,
+ XCAR (it->min_width_property),
+ NULL, true, NULL);
+ width -= (it->current_x - it->min_width_start) /
+ FRAME_COLUMN_WIDTH (it->f);
+ w = make_int (width);
+ }
+
+ /* Insert the stretch glyph. */
+ it->object = list3 (Qspace, QCwidth, w);
+ produce_stretch_glyph (it);
+ it->min_width_property = Qnil;
+ }
+ }
+
+ /* We're at the start of a `min-width' sequence -- record the
+ position and the property, so that we can later see if we're at
+ the end. */
+ if (CONSP (width_spec))
+ {
+ if (bufpos == BEGV
+ || (bufpos > BEGV
+ && !EQ (width_spec,
+ get_display_property (bufpos - 1, Qmin_width, object))))
+ {
+ it->min_width_property = width_spec;
+ it->min_width_start = it->current_x;
+ }
+ }
+}
+
+DEFUN ("get-display-property", Fget_display_property,
+ Sget_display_property, 2, 4, 0,
+ doc: /* Get the `display' property PROP at POSITION.
+If OBJECT, this should be a buffer or string where the property is
+fetched from. This defaults to the current buffer.
+
+If PROPERTIES, use those properties instead of the properties at
+POSITION. */)
+ (Lisp_Object position, Lisp_Object prop, Lisp_Object object,
+ Lisp_Object properties)
+{
+ if (NILP (properties))
+ properties = Fget_text_property (position, Qdisplay, object);
+ else
+ CHECK_LIST (properties);
+
+ return find_display_property (properties, prop);
+}
+
\f
/***********************************************************************
if (!it->string_from_display_prop_p)
it->area = TEXT_AREA;
+ if (!STRINGP (it->string))
+ object = it->w->contents;
+
propval = get_char_property_and_overlay (make_fixnum (position->charpos),
Qdisplay, object, &overlay);
+
+ /* Handle min-width ends. */
+ if (! NILP (it->min_width_property)
+ && NILP (find_display_property (propval, Qmin_width)))
+ display_min_width (it, bufpos, object, Qnil);
+
if (NILP (propval))
return HANDLED_NORMALLY;
/* Now OVERLAY is the overlay that gave us this property, or nil
if it was a text property. */
- if (!STRINGP (it->string))
- object = it->w->contents;
-
display_replaced = handle_display_spec (it, propval, object, overlay,
position, bufpos,
FRAME_WINDOW_P (it->f));
&& !(CONSP (XCAR (spec)) && EQ (XCAR (XCAR (spec)), Qmargin))
&& !EQ (XCAR (spec), Qleft_fringe)
&& !EQ (XCAR (spec), Qright_fringe)
+ && !EQ (XCAR (spec), Qmin_width)
&& !NILP (XCAR (spec)))
{
for (; CONSP (spec); spec = XCDR (spec))
return 0;
}
+ /* Handle `(min-width (WIDTH))'. */
+ if (CONSP (spec)
+ && EQ (XCAR (spec), Qmin_width)
+ && CONSP (XCDR (spec))
+ && CONSP (XCAR (XCDR (spec))))
+ {
+ if (it)
+ display_min_width (it, bufpos, object, XCAR (XCDR (spec)));
+ return 0;
+ }
+
/* Handle `(slice X Y WIDTH HEIGHT)'. */
if (CONSP (spec)
&& EQ (XCAR (spec), Qslice))
}
/* This make the information stored in it->cmp_it invalidate. */
it->cmp_it.id = -1;
+ it->min_width_property = Qnil;
}
defsubr (&Smove_point_visually);
defsubr (&Sbidi_find_overridden_directionality);
defsubr (&Sdisplay__line_is_continued_p);
+ defsubr (&Sget_display_property);
DEFSYM (Qmenu_bar_update_hook, "menu-bar-update-hook");
DEFSYM (Qoverriding_terminal_local_map, "overriding-terminal-local-map");
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