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| author | Chong Yidong <[email protected]> | 2008-11-18 07:05:36 +0000 |
|---|---|---|
| committer | Chong Yidong <[email protected]> | 2008-11-18 07:05:36 +0000 |
| commit | d9ce48d61886b921a2b4120fe4dec052151d5bf2 (patch) | |
| tree | 6f19516cb650cb50cb04c3f9f8a9b0d996a3e947 /doc/lispref/frames.texi | |
| parent | cc0910af5860705010559625f4b8827d3e3bbfe1 (diff) | |
(Color Parameters): Document alpha parameter.
Diffstat (limited to 'doc/lispref/frames.texi')
| -rw-r--r-- | doc/lispref/frames.texi | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi index 2f812ad2ff..bd7ef33878 100644 --- a/doc/lispref/frames.texi +++ b/doc/lispref/frames.texi @@ -230,6 +230,8 @@ only the @code{height}, @code{width}, @code{name}, @code{title}, parameters do something special. If the terminal supports colors, the parameters @code{foreground-color}, @code{background-color}, @code{background-mode} and @code{display-type} are also meaningful. +If the terminal supports frame transparency, the parameter +@code{alpha} is also meaningful. You can use frame parameters to define frame-local bindings for variables. @xref{Frame-Local Variables}. @@ -748,6 +750,27 @@ If your monitor displays colors too light, you should specify a @code{screen-gamma} value smaller than 2.2. This requests correction that makes colors darker. A screen gamma value of 1.5 may give good results for LCD color displays. + +@item alpha +@cindex opacity, frame +@cindex transparency, frame +@vindex frame-alpha-lower-limit +This parameter specifies the opacity of the frame, on graphical +displays that support variable opacity. It should be an integer +between 0 and 100, where 0 means completely transparent and 100 means +completely opaque. It can also have a @code{nil} value, which tells +Emacs not to set the frame opacity (leaving it to the window manager). + +To prevent the frame from disappearing completely from view, the +variable @var{frame-alpha-lower-limit} defines a lower opacity limit. +If the value of the frame parameter is less than the value of this +variable, Emacs uses the latter. By default, +@var{frame-alpha-lower-limit} is 20. + +The @code{alpha} frame parameter can also be a cons cell +@code{(@samp{active} . @samp{inactive})}, where @samp{active} is the +opacity of the frame when it is selected, and @samp{inactive} is the +opactity when it is not selected. @end table These frame parameters are semi-obsolete in that they are automatically |