From: Richard M. Stallman Date: Wed, 31 May 2006 00:24:26 +0000 (+0000) Subject: (Line Height): Fix errors in description of X-Git-Tag: emacs-pretest-22.0.90~2170 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=6ac209a3f7d6a28ea4612c381ea4f63f49086f79;p=emacs.git (Line Height): Fix errors in description of default line height and line-height properyty. --- diff --git a/lispref/ChangeLog b/lispref/ChangeLog index 89f3f749696..03fc486ae5a 100644 --- a/lispref/ChangeLog +++ b/lispref/ChangeLog @@ -1,5 +1,8 @@ 2006-05-30 Richard Stallman + * display.texi (Line Height): Fix errors in description of + default line height and line-height properyty. + * nonascii.texi (Default Coding Systems): Further clarification. 2006-05-29 Luc Teirlinck diff --git a/lispref/display.texi b/lispref/display.texi index 3a8b8c1b7c0..1a34b0ff785 100644 --- a/lispref/display.texi +++ b/lispref/display.texi @@ -1582,41 +1582,41 @@ equal to or less than the display width of @var{ellipsis}. If @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. +contents of the line, plus optional additional vertical line spacing +above or below the display line. - 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. + The height of the line contents is the maximum height of any +character or image on that display line, including the final newline +if there is one. (A display line that is continued doesn't include a +final newline.) That is the default line height, if you do nothing to +specify a greater height. (In the most common case, this 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. + There are several ways to explicitly specify a larger line height, +either by specifying an absolute height for the display line, or by +specifying vertical space. However, no matter what you specify, the +actual line height can never be less than the default. @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 newline character has no +effect on the displayed height of the line---the visible contents +alone determine the height. This is useful for tiling small images +(or image slices) without adding blank areas between the images. - 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 a list of the form @code{(@var{height} +@var{total})}, that adds extra space @emph{below} the display line. +First Emacs uses @var{height} as a height spec to control extra space +@emph{above} the line; then it adds enough space @emph{below} the line +to bring the total line height up to @var{total}. In this case, the +other ways to specify the line spacing are ignored. - If the property value is not @code{t}, it is a height spec. A height -spec stands for a numeric height value; this height 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: + Any other kind of property value is a height spec, which translates +into a number---the specified line height. There are several ways to +write a height spec; here's how each of them translates into a number: @table @code @item @var{integer} @@ -1634,11 +1634,10 @@ 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. + Thus, any valid height spec determines the height in pixels, one way +or another. If the line contents' height is less than that, Emacs +adds extra vertical space above the line to achieve the specified +total height. If you don't specify the @code{line-height} property, the line's height consists of the contents' height plus the line spacing. @@ -1663,9 +1662,9 @@ 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. +property that overrides the default frame line spacing and the buffer +local @code{line-spacing} variable, for the display line ending in +that newline. 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