Commit 1225f637 authored by Kim F. Storm's avatar Kim F. Storm
Browse files

(Line Height): Total line-height is now specified

in line-height property of form (HEIGHT TOTAL).  Swap (FACE . RATIO)
in cons cells.  (nil . RATIO) is relative to actual line height.
Use line-height `t' instead of `0' to get minimum height.
parent 922e9c18
......@@ -1532,12 +1532,21 @@ 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 zero, the displayed height of the
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 zero, it is a height spec. A height
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
......@@ -1549,14 +1558,17 @@ 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{ratio} . @var{face})
@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. If @var{face} is @code{t}, it refers to the
current face.
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 nonzero property value specifies a height in pixels,
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,
......@@ -1595,18 +1607,6 @@ into a Lisp value as described above. However, in this case the
numeric height value specifies the line spacing, rather than the line
height.
There is one exception, however: if the @var{line-spacing} value is
a cons @code{(total . @var{spacing})}, then @var{spacing} itself is
treated as a heigh spec, and specifies the total displayed height of
the line, so the line spacing equals the specified amount minus the
line height. This differs from using the @code{line-height} property
because it adds space at the bottom of the line instead of the top.
If you specify both @code{line-spacing} using @code{total} and
@code{line-height}, they are not redundant. First @code{line-height}
goes to work, adding space above the line contents. Then
@code{line-spacing} goes to work, adding space below the contents.
@node Faces
@section Faces
@cindex faces
......
2004-12-30 Kim F. Storm <storm@cua.dk>
* xdisp.c (get_line_height_property): New function extracted from
original calc_line_height_property.
(calc_line_height_property): Rework. Handle t and (nil . ratio).
(x_produce_glyphs): Use them to handle line-height and
line-spacing according to new height spec.
(Qtotal): Remove.
(syms_of_xdisp): Remove defsubr and intern for Qtotal.
2004-12-30 Kenichi Handa <handa@m17n.org>
 
* fileio.c (Finsert_file_contents): Don't use
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment