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2216 lines
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2216 lines
88 KiB
Plaintext
@c -*-texinfo-*-
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@c This is part of the GNU Emacs Lisp Reference Manual.
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@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001,
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@c 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
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@c See the file elisp.texi for copying conditions.
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@setfilename ../info/frames
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@node Frames, Positions, Windows, Top
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@chapter Frames
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@cindex frame
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In Emacs editing, A @dfn{frame} is a screen object that contains one
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or more Emacs windows. It's the kind of object that is called a
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``window'' in the terminology of graphical environments; but we can't
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call it a ``window'' here, because Emacs uses that word in a different
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way.
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A frame initially contains a single main window and/or a minibuffer
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window; you can subdivide the main window vertically or horizontally
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into smaller windows. In Emacs Lisp, a @dfn{frame object} is a Lisp
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object that represents a frame on the screen.
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@cindex terminal frame
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When Emacs runs on a text-only terminal, it starts with one
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@dfn{terminal frame}. If you create additional ones, Emacs displays
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one and only one at any given time---on the terminal screen, of course.
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@cindex window frame
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When Emacs communicates directly with a supported window system, such
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as X, it does not have a terminal frame; instead, it starts with
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a single @dfn{window frame}, but you can create more, and Emacs can
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display several such frames at once as is usual for window systems.
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@defun framep object
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This predicate returns a non-@code{nil} value if @var{object} is a
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frame, and @code{nil} otherwise. For a frame, the value indicates which
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kind of display the frame uses:
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@table @code
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@item x
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The frame is displayed in an X window.
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@item t
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A terminal frame on a character display.
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@item mac
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The frame is displayed on a Macintosh.
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@item w32
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The frame is displayed on MS-Windows 9X/NT.
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@item pc
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The frame is displayed on an MS-DOS terminal.
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@end table
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@end defun
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@menu
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* Creating Frames:: Creating additional frames.
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* Multiple Displays:: Creating frames on other displays.
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* Frame Parameters:: Controlling frame size, position, font, etc.
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* Frame Titles:: Automatic updating of frame titles.
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* Deleting Frames:: Frames last until explicitly deleted.
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* Finding All Frames:: How to examine all existing frames.
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* Frames and Windows:: A frame contains windows;
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display of text always works through windows.
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* Minibuffers and Frames:: How a frame finds the minibuffer to use.
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* Input Focus:: Specifying the selected frame.
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* Visibility of Frames:: Frames may be visible or invisible, or icons.
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* Raising and Lowering:: Raising a frame makes it hide other windows;
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lowering it makes the others hide it.
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* Frame Configurations:: Saving the state of all frames.
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* Mouse Tracking:: Getting events that say when the mouse moves.
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* Mouse Position:: Asking where the mouse is, or moving it.
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* Pop-Up Menus:: Displaying a menu for the user to select from.
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* Dialog Boxes:: Displaying a box to ask yes or no.
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* Pointer Shape:: Specifying the shape of the mouse pointer.
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* Window System Selections:: Transferring text to and from other X clients.
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* Drag and Drop:: Internals of Drag-and-Drop implementation.
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* Color Names:: Getting the definitions of color names.
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* Text Terminal Colors:: Defining colors for text-only terminals.
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* Resources:: Getting resource values from the server.
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* Display Feature Testing:: Determining the features of a terminal.
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@end menu
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@xref{Display}, for information about the related topic of
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controlling Emacs redisplay.
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@node Creating Frames
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@section Creating Frames
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To create a new frame, call the function @code{make-frame}.
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@defun make-frame &optional alist
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This function creates and returns a new frame, displaying the current
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buffer. If you are using a supported window system, it makes a window
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frame; otherwise, it makes a terminal frame.
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The argument is an alist specifying frame parameters. Any parameters
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not mentioned in @var{alist} default according to the value of the
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variable @code{default-frame-alist}; parameters not specified even there
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default from the standard X resources or whatever is used instead on
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your system.
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The set of possible parameters depends in principle on what kind of
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window system Emacs uses to display its frames. @xref{Window Frame
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Parameters}, for documentation of individual parameters you can specify.
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This function itself does not make the new frame the selected frame.
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@xref{Input Focus}. The previously selected frame remains selected.
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However, the window system may select the new frame for its own reasons,
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for instance if the frame appears under the mouse pointer and your
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setup is for focus to follow the pointer.
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@end defun
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@defvar before-make-frame-hook
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A normal hook run by @code{make-frame} before it actually creates the
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frame.
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@end defvar
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@defvar after-make-frame-functions
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An abnormal hook run by @code{make-frame} after it creates the frame.
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Each function in @code{after-make-frame-functions} receives one argument, the
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frame just created.
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@end defvar
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@node Multiple Displays
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@section Multiple Displays
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@cindex multiple X displays
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@cindex displays, multiple
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A single Emacs can talk to more than one X display.
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Initially, Emacs uses just one display---the one chosen with the
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@code{DISPLAY} environment variable or with the @samp{--display} option
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(@pxref{Initial Options,,, emacs, The GNU Emacs Manual}). To connect to
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another display, use the command @code{make-frame-on-display} or specify
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the @code{display} frame parameter when you create the frame.
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Emacs treats each X server as a separate terminal, giving each one its
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own selected frame and its own minibuffer windows. However, only one of
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those frames is ``@emph{the} selected frame'' at any given moment, see
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@ref{Input Focus}.
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A few Lisp variables are @dfn{terminal-local}; that is, they have a
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separate binding for each terminal. The binding in effect at any time
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is the one for the terminal that the currently selected frame belongs
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to. These variables include @code{default-minibuffer-frame},
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@code{defining-kbd-macro}, @code{last-kbd-macro}, and
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@code{system-key-alist}. They are always terminal-local, and can never
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be buffer-local (@pxref{Buffer-Local Variables}).
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A single X server can handle more than one screen. A display name
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@samp{@var{host}:@var{server}.@var{screen}} has three parts; the last
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part specifies the screen number for a given server. When you use two
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screens belonging to one server, Emacs knows by the similarity in their
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names that they share a single keyboard, and it treats them as a single
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terminal.
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Note that some graphical terminals can output to more than a one
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monitor (or other output device) at the same time. On these
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``multi-monitor'' setups, a single @var{display} value controls the
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output to all the physical monitors. In this situation, there is
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currently no platform-independent way for Emacs to distinguish between
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the different physical monitors.
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@deffn Command make-frame-on-display display &optional parameters
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This creates and returns a new frame on display @var{display}, taking
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the other frame parameters from @var{parameters}. Aside from the
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@var{display} argument, it is like @code{make-frame} (@pxref{Creating
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Frames}).
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@end deffn
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@defun x-display-list
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This returns a list that indicates which X displays Emacs has a
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connection to. The elements of the list are strings, and each one is
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a display name.
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@end defun
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@defun x-open-connection display &optional xrm-string must-succeed
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This function opens a connection to the X display @var{display}. It
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does not create a frame on that display, but it permits you to check
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that communication can be established with that display.
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The optional argument @var{xrm-string}, if not @code{nil}, is a
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string of resource names and values, in the same format used in the
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@file{.Xresources} file. The values you specify override the resource
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values recorded in the X server itself; they apply to all Emacs frames
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created on this display. Here's an example of what this string might
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look like:
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@example
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"*BorderWidth: 3\n*InternalBorder: 2\n"
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@end example
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@xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}.
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If @var{must-succeed} is non-@code{nil}, failure to open the connection
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terminates Emacs. Otherwise, it is an ordinary Lisp error.
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@end defun
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@defun x-close-connection display
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This function closes the connection to display @var{display}. Before
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you can do this, you must first delete all the frames that were open on
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that display (@pxref{Deleting Frames}).
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@end defun
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@node Frame Parameters
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@section Frame Parameters
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@cindex frame parameters
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A frame has many parameters that control its appearance and behavior.
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Just what parameters a frame has depends on what display mechanism it
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uses.
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Frame parameters exist mostly for the sake of window systems. A
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terminal frame has a few parameters, mostly for compatibility's sake;
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only the @code{height}, @code{width}, @code{name}, @code{title},
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@code{menu-bar-lines}, @code{buffer-list} and @code{buffer-predicate}
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parameters do something special. If the terminal supports colors, the
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parameters @code{foreground-color}, @code{background-color},
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@code{background-mode} and @code{display-type} are also meaningful.
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@menu
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* Parameter Access:: How to change a frame's parameters.
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* Initial Parameters:: Specifying frame parameters when you make a frame.
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* Window Frame Parameters:: List of frame parameters for window systems.
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* Size and Position:: Changing the size and position of a frame.
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* Geometry:: Parsing geometry specifications.
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@end menu
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@node Parameter Access
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@subsection Access to Frame Parameters
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These functions let you read and change the parameter values of a
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frame.
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@defun frame-parameter frame parameter
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This function returns the value of the parameter @var{parameter} (a
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symbol) of @var{frame}. If @var{frame} is @code{nil}, it returns the
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selected frame's parameter. If @var{frame} has no setting for
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@var{parameter}, this function returns @code{nil}.
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@end defun
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@defun frame-parameters &optional frame
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The function @code{frame-parameters} returns an alist listing all the
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parameters of @var{frame} and their values. If @var{frame} is
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@code{nil} or omitted, this returns the selected frame's parameters
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@end defun
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@defun modify-frame-parameters frame alist
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This function alters the parameters of frame @var{frame} based on the
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elements of @var{alist}. Each element of @var{alist} has the form
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@code{(@var{parm} . @var{value})}, where @var{parm} is a symbol naming a
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parameter. If you don't mention a parameter in @var{alist}, its value
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doesn't change. If @var{frame} is @code{nil}, it defaults to the selected
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frame.
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@end defun
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@defun modify-all-frames-parameters alist
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This function alters the frame parameters of all existing frames
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according to @var{alist}, then modifies @code{default-frame-alist}
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(and, if necessary, @code{initial-frame-alist}) to apply the same
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parameter values to frames that will be created henceforth.
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@end defun
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@node Initial Parameters
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@subsection Initial Frame Parameters
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You can specify the parameters for the initial startup frame
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by setting @code{initial-frame-alist} in your init file (@pxref{Init File}).
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@defvar initial-frame-alist
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This variable's value is an alist of parameter values used when creating
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the initial window frame. You can set this variable to specify the
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appearance of the initial frame without altering subsequent frames.
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Each element has the form:
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@example
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(@var{parameter} . @var{value})
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@end example
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Emacs creates the initial frame before it reads your init
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file. After reading that file, Emacs checks @code{initial-frame-alist},
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and applies the parameter settings in the altered value to the already
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created initial frame.
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If these settings affect the frame geometry and appearance, you'll see
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the frame appear with the wrong ones and then change to the specified
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ones. If that bothers you, you can specify the same geometry and
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appearance with X resources; those do take effect before the frame is
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created. @xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}.
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X resource settings typically apply to all frames. If you want to
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specify some X resources solely for the sake of the initial frame, and
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you don't want them to apply to subsequent frames, here's how to achieve
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this. Specify parameters in @code{default-frame-alist} to override the
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X resources for subsequent frames; then, to prevent these from affecting
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the initial frame, specify the same parameters in
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@code{initial-frame-alist} with values that match the X resources.
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@end defvar
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If these parameters specify a separate minibuffer-only frame with
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@code{(minibuffer . nil)}, and you have not created one, Emacs creates
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one for you.
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@defvar minibuffer-frame-alist
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This variable's value is an alist of parameter values used when creating
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an initial minibuffer-only frame---if such a frame is needed, according
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to the parameters for the main initial frame.
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@end defvar
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@defvar default-frame-alist
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This is an alist specifying default values of frame parameters for all
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Emacs frames---the first frame, and subsequent frames. When using the X
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Window System, you can get the same results by means of X resources
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in many cases.
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Setting this variable does not affect existing frames.
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@end defvar
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See also @code{special-display-frame-alist}. @xref{Definition of
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special-display-frame-alist}.
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If you use options that specify window appearance when you invoke Emacs,
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they take effect by adding elements to @code{default-frame-alist}. One
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exception is @samp{-geometry}, which adds the specified position to
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@code{initial-frame-alist} instead. @xref{Emacs Invocation,, Command
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Line Arguments for Emacs Invocation, emacs, The GNU Emacs Manual}.
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@node Window Frame Parameters
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@subsection Window Frame Parameters
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Just what parameters a frame has depends on what display mechanism
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it uses. This section describes the parameters that have special
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meanings on some or all kinds of terminals. Of these, @code{name},
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@code{title}, @code{height}, @code{width}, @code{buffer-list} and
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@code{buffer-predicate} provide meaningful information in terminal
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frames, and @code{tty-color-mode} is meaningful @emph{only} in
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terminal frames.
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@menu
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* Basic Parameters:: Parameters that are fundamental.
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* Position Parameters:: The position of the frame on the screen.
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* Size Parameters:: Frame's size.
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* Layout Parameters:: Size of parts of the frame, and
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enabling or disabling some parts.
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* Buffer Parameters:: Which buffers have been or should be shown.
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* Management Parameters:: Communicating with the window manager.
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* Cursor Parameters:: Controlling the cursor appearance.
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* Color Parameters:: Colors of various parts of the frame.
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@end menu
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@node Basic Parameters
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@subsubsection Basic Parameters
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These frame parameters give the most basic information about the
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frame. @code{title} and @code{name} are meaningful on all terminals.
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@table @code
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@item display
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The display on which to open this frame. It should be a string of the
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form @code{"@var{host}:@var{dpy}.@var{screen}"}, just like the
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@code{DISPLAY} environment variable.
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@item display-type
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This parameter describes the range of possible colors that can be used
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in this frame. Its value is @code{color}, @code{grayscale} or
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@code{mono}.
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@item title
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If a frame has a non-@code{nil} title, it appears in the window
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system's title bar at the top of the frame, and also in the mode line
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of windows in that frame if @code{mode-line-frame-identification} uses
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@samp{%F} (@pxref{%-Constructs}). This is normally the case when
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Emacs is not using a window system, and can only display one frame at
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a time. @xref{Frame Titles}.
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@item name
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The name of the frame. The frame name serves as a default for the frame
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title, if the @code{title} parameter is unspecified or @code{nil}. If
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you don't specify a name, Emacs sets the frame name automatically
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(@pxref{Frame Titles}).
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If you specify the frame name explicitly when you create the frame, the
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name is also used (instead of the name of the Emacs executable) when
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looking up X resources for the frame.
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@end table
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@node Position Parameters
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@subsubsection Position Parameters
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Position parameters' values are normally measured in pixels, but on
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text-only terminals they count characters or lines instead.
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@table @code
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@item left
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The screen position of the left edge, in pixels, with respect to the
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left edge of the screen. The value may be a positive number @var{pos},
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or a list of the form @code{(+ @var{pos})} which permits specifying a
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negative @var{pos} value.
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A negative number @minus{}@var{pos}, or a list of the form @code{(-
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@var{pos})}, actually specifies the position of the right edge of the
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window with respect to the right edge of the screen. A positive value
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of @var{pos} counts toward the left. @strong{Reminder:} if the
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parameter is a negative integer @minus{}@var{pos}, then @var{pos} is
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positive.
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Some window managers ignore program-specified positions. If you want to
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be sure the position you specify is not ignored, specify a
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non-@code{nil} value for the @code{user-position} parameter as well.
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@item top
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The screen position of the top edge, in pixels, with respect to the
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top edge of the screen. It works just like @code{left}, except vertically
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instead of horizontally.
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@item icon-left
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The screen position of the left edge @emph{of the frame's icon}, in
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pixels, counting from the left edge of the screen. This takes effect if
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and when the frame is iconified.
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If you specify a value for this parameter, then you must also specify
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a value for @code{icon-top} and vice versa. The window manager may
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ignore these two parameters.
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@item icon-top
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The screen position of the top edge @emph{of the frame's icon}, in
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pixels, counting from the top edge of the screen. This takes effect if
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and when the frame is iconified.
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@item user-position
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When you create a frame and specify its screen position with the
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@code{left} and @code{top} parameters, use this parameter to say whether
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the specified position was user-specified (explicitly requested in some
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way by a human user) or merely program-specified (chosen by a program).
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A non-@code{nil} value says the position was user-specified.
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Window managers generally heed user-specified positions, and some heed
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program-specified positions too. But many ignore program-specified
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positions, placing the window in a default fashion or letting the user
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place it with the mouse. Some window managers, including @code{twm},
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let the user specify whether to obey program-specified positions or
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ignore them.
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When you call @code{make-frame}, you should specify a non-@code{nil}
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value for this parameter if the values of the @code{left} and @code{top}
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parameters represent the user's stated preference; otherwise, use
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@code{nil}.
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@end table
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@node Size Parameters
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@subsubsection Size Parameters
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Size parameters' values are normally measured in pixels, but on
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text-only terminals they count characters or lines instead.
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@table @code
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@item height
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The height of the frame contents, in characters. (To get the height in
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pixels, call @code{frame-pixel-height}; see @ref{Size and Position}.)
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@item width
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The width of the frame contents, in characters. (To get the width in
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pixels, call @code{frame-pixel-width}; see @ref{Size and Position}.)
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@item user-size
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This does for the size parameters @code{height} and @code{width} what
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the @code{user-position} parameter (see above) does for the position
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parameters @code{top} and @code{left}.
|
|
|
|
@item fullscreen
|
|
Specify that width, height or both shall be set to the size of the screen.
|
|
The value @code{fullwidth} specifies that width shall be the size of the
|
|
screen. The value @code{fullheight} specifies that height shall be the
|
|
size of the screen. The value @code{fullboth} specifies that both the
|
|
width and the height shall be set to the size of the screen.
|
|
@end table
|
|
|
|
@node Layout Parameters
|
|
@subsubsection Layout Parameters
|
|
|
|
These frame parameters enable or disable various parts of the
|
|
frame, or control their sizes.
|
|
|
|
@table @code
|
|
@item border-width
|
|
The width in pixels of the frame's border.
|
|
|
|
@item internal-border-width
|
|
The distance in pixels between text (or fringe) and the frame's border.
|
|
|
|
@item vertical-scroll-bars
|
|
Whether the frame has scroll bars for vertical scrolling, and which side
|
|
of the frame they should be on. The possible values are @code{left},
|
|
@code{right}, and @code{nil} for no scroll bars.
|
|
|
|
@ignore
|
|
@item horizontal-scroll-bars
|
|
Whether the frame has scroll bars for horizontal scrolling
|
|
(non-@code{nil} means yes). Horizontal scroll bars are not currently
|
|
implemented.
|
|
@end ignore
|
|
|
|
@item scroll-bar-width
|
|
The width of vertical scroll bars, in pixels, or @code{nil} meaning to
|
|
use the default width.
|
|
|
|
@item left-fringe
|
|
@itemx right-fringe
|
|
The default width of the left and right fringes of windows in this
|
|
frame (@pxref{Fringes}). If either of these is zero, that effectively
|
|
removes the corresponding fringe. A value of @code{nil} stands for
|
|
the standard fringe width, which is the width needed to display the
|
|
fringe bitmaps.
|
|
|
|
The combined fringe widths must add up to an integral number of
|
|
columns, so the actual default fringe widths for the frame may be
|
|
larger than the specified values. The extra width needed to reach an
|
|
acceptable total is distributed evenly between the left and right
|
|
fringe. However, you can force one fringe or the other to a precise
|
|
width by specifying that width as a negative integer. If both widths are
|
|
negative, only the left fringe gets the specified width.
|
|
|
|
@item menu-bar-lines
|
|
The number of lines to allocate at the top of the frame for a menu
|
|
bar. The default is 1. A value of @code{nil} means don't display a
|
|
menu bar. @xref{Menu Bar}. (The X toolkit and GTK allow at most one
|
|
menu bar line; they treat larger values as 1.)
|
|
|
|
@item tool-bar-lines
|
|
The number of lines to use for the tool bar. A value of @code{nil}
|
|
means don't display a tool bar. (GTK allows at most one tool bar line;
|
|
it treats larger values as 1.)
|
|
|
|
@item line-spacing
|
|
Additional space to leave below each text line, in pixels (a positive
|
|
integer). @xref{Line Height}, for more information.
|
|
@end table
|
|
|
|
@node Buffer Parameters
|
|
@subsubsection Buffer Parameters
|
|
|
|
These frame parameters, meaningful on all kinds of terminals, deal
|
|
with which buffers have been, or should, be displayed in the frame.
|
|
|
|
@table @code
|
|
@item minibuffer
|
|
Whether this frame has its own minibuffer. The value @code{t} means
|
|
yes, @code{nil} means no, @code{only} means this frame is just a
|
|
minibuffer. If the value is a minibuffer window (in some other frame),
|
|
the new frame uses that minibuffer.
|
|
|
|
@item buffer-predicate
|
|
The buffer-predicate function for this frame. The function
|
|
@code{other-buffer} uses this predicate (from the selected frame) to
|
|
decide which buffers it should consider, if the predicate is not
|
|
@code{nil}. It calls the predicate with one argument, a buffer, once for
|
|
each buffer; if the predicate returns a non-@code{nil} value, it
|
|
considers that buffer.
|
|
|
|
@item buffer-list
|
|
A list of buffers that have been selected in this frame,
|
|
ordered most-recently-selected first.
|
|
|
|
@item unsplittable
|
|
If non-@code{nil}, this frame's window is never split automatically.
|
|
@end table
|
|
|
|
@node Management Parameters
|
|
@subsubsection Window Management Parameters
|
|
@cindex window manager, and frame parameters
|
|
|
|
These frame parameters, meaningful only on window system displays,
|
|
interact with the window manager.
|
|
|
|
@table @code
|
|
@item visibility
|
|
The state of visibility of the frame. There are three possibilities:
|
|
@code{nil} for invisible, @code{t} for visible, and @code{icon} for
|
|
iconified. @xref{Visibility of Frames}.
|
|
|
|
@item auto-raise
|
|
Whether selecting the frame raises it (non-@code{nil} means yes).
|
|
|
|
@item auto-lower
|
|
Whether deselecting the frame lowers it (non-@code{nil} means yes).
|
|
|
|
@item icon-type
|
|
The type of icon to use for this frame when it is iconified. If the
|
|
value is a string, that specifies a file containing a bitmap to use.
|
|
Any other non-@code{nil} value specifies the default bitmap icon (a
|
|
picture of a gnu); @code{nil} specifies a text icon.
|
|
|
|
@item icon-name
|
|
The name to use in the icon for this frame, when and if the icon
|
|
appears. If this is @code{nil}, the frame's title is used.
|
|
|
|
@item window-id
|
|
The number of the window-system window used by the frame
|
|
to contain the actual Emacs windows.
|
|
|
|
@item outer-window-id
|
|
The number of the outermost window-system window used for the whole frame.
|
|
|
|
@item wait-for-wm
|
|
If non-@code{nil}, tell Xt to wait for the window manager to confirm
|
|
geometry changes. Some window managers, including versions of Fvwm2
|
|
and KDE, fail to confirm, so Xt hangs. Set this to @code{nil} to
|
|
prevent hanging with those window managers.
|
|
|
|
@ignore
|
|
@item parent-id
|
|
@c ??? Not yet working.
|
|
The X window number of the window that should be the parent of this one.
|
|
Specifying this lets you create an Emacs window inside some other
|
|
application's window. (It is not certain this will be implemented; try
|
|
it and see if it works.)
|
|
@end ignore
|
|
@end table
|
|
|
|
@node Cursor Parameters
|
|
@subsubsection Cursor Parameters
|
|
|
|
This frame parameter controls the way the cursor looks.
|
|
|
|
@table @code
|
|
@item cursor-type
|
|
How to display the cursor. Legitimate values are:
|
|
|
|
@table @code
|
|
@item box
|
|
Display a filled box. (This is the default.)
|
|
@item hollow
|
|
Display a hollow box.
|
|
@item nil
|
|
Don't display a cursor.
|
|
@item bar
|
|
Display a vertical bar between characters.
|
|
@item (bar . @var{width})
|
|
Display a vertical bar @var{width} pixels wide between characters.
|
|
@item hbar
|
|
Display a horizontal bar.
|
|
@item (hbar . @var{height})
|
|
Display a horizontal bar @var{height} pixels high.
|
|
@end table
|
|
@end table
|
|
|
|
@vindex cursor-type
|
|
The buffer-local variable @code{cursor-type} overrides the value of
|
|
the @code{cursor-type} frame parameter, but if it is @code{t}, that
|
|
means to use the cursor specified for the frame.
|
|
|
|
@defvar blink-cursor-alist
|
|
This variable specifies how to blink the cursor. Each element has the
|
|
form @code{(@var{on-state} . @var{off-state})}. Whenever the cursor
|
|
type equals @var{on-state} (comparing using @code{equal}), the
|
|
corresponding @var{off-state} specifies what the cursor looks like
|
|
when it blinks ``off.'' Both @var{on-state} and @var{off-state}
|
|
should be suitable values for the @code{cursor-type} frame parameter.
|
|
|
|
There are various defaults for how to blink each type of cursor, if
|
|
the type is not mentioned as an @var{on-state} here. Changes in this
|
|
variable do not take effect immediately, only when you specify the
|
|
@code{cursor-type} frame parameter.
|
|
@end defvar
|
|
|
|
@defvar cursor-in-non-selected-windows
|
|
This variable controls how the cursor looks in a window that is not
|
|
selected. It supports the same values as the @code{cursor-type} frame
|
|
parameter; also, @code{nil} means don't display a cursor in
|
|
nonselected windows, and @code{t} (the default) means use a standard
|
|
modificatoin of the usual cursor type (solid box becomes hollow box,
|
|
and bar becomes a narrower bar).
|
|
@end defvar
|
|
|
|
@node Color Parameters
|
|
@subsubsection Color Parameters
|
|
|
|
These frame parameters control the use of colors.
|
|
|
|
@table @code
|
|
@item background-mode
|
|
This parameter is either @code{dark} or @code{light}, according
|
|
to whether the background color is a light one or a dark one.
|
|
|
|
@item tty-color-mode
|
|
@cindex standard colors for character terminals
|
|
This parameter overrides the terminal's color support as given by the
|
|
system's terminal capabilities database in that this parameter's value
|
|
specifies the color mode to use in terminal frames. The value can be
|
|
either a symbol or a number. A number specifies the number of colors
|
|
to use (and, indirectly, what commands to issue to produce each
|
|
color). For example, @code{(tty-color-mode . 8)} specifies use of the
|
|
ANSI escape sequences for 8 standard text colors. A value of -1 turns
|
|
off color support.
|
|
|
|
If the parameter's value is a symbol, it specifies a number through
|
|
the value of @code{tty-color-mode-alist}, and the associated number is
|
|
used instead.
|
|
|
|
@item screen-gamma
|
|
@cindex gamma correction
|
|
If this is a number, Emacs performs ``gamma correction'' which adjusts
|
|
the brightness of all colors. The value should be the screen gamma of
|
|
your display, a floating point number.
|
|
|
|
Usual PC monitors have a screen gamma of 2.2, so color values in
|
|
Emacs, and in X windows generally, are calibrated to display properly
|
|
on a monitor with that gamma value. If you specify 2.2 for
|
|
@code{screen-gamma}, that means no correction is needed. Other values
|
|
request correction, designed to make the corrected colors appear on
|
|
your screen the way they would have appeared without correction on an
|
|
ordinary monitor with a gamma value of 2.2.
|
|
|
|
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.
|
|
@end table
|
|
|
|
These frame parameters are semi-obsolete in that they are automatically
|
|
equivalent to particular face attributes of particular faces.
|
|
@xref{Standard Faces,,, emacs, The Emacs Manual}.
|
|
|
|
@table @code
|
|
@item font
|
|
The name of the font for displaying text in the frame. This is a
|
|
string, either a valid font name for your system or the name of an Emacs
|
|
fontset (@pxref{Fontsets}). It is equivalent to the @code{font}
|
|
attribute of the @code{default} face.
|
|
|
|
@item foreground-color
|
|
The color to use for the image of a character. It is equivalent to
|
|
the @code{:foreground} attribute of the @code{default} face.
|
|
|
|
@item background-color
|
|
The color to use for the background of characters. It is equivalent to
|
|
the @code{:background} attribute of the @code{default} face.
|
|
|
|
@item mouse-color
|
|
The color for the mouse pointer. It is equivalent to the @code{:background}
|
|
attribute of the @code{mouse} face.
|
|
|
|
@item cursor-color
|
|
The color for the cursor that shows point. It is equivalent to the
|
|
@code{:background} attribute of the @code{cursor} face.
|
|
|
|
@item border-color
|
|
The color for the border of the frame. It is equivalent to the
|
|
@code{:background} attribute of the @code{border} face.
|
|
|
|
@item scroll-bar-foreground
|
|
If non-@code{nil}, the color for the foreground of scroll bars. It is
|
|
equivalent to the @code{:foreground} attribute of the
|
|
@code{scroll-bar} face.
|
|
|
|
@item scroll-bar-background
|
|
If non-@code{nil}, the color for the background of scroll bars. It is
|
|
equivalent to the @code{:background} attribute of the
|
|
@code{scroll-bar} face.
|
|
@end table
|
|
|
|
@node Size and Position
|
|
@subsection Frame Size And Position
|
|
@cindex size of frame
|
|
@cindex screen size
|
|
@cindex frame size
|
|
@cindex resize frame
|
|
|
|
You can read or change the size and position of a frame using the
|
|
frame parameters @code{left}, @code{top}, @code{height}, and
|
|
@code{width}. Whatever geometry parameters you don't specify are chosen
|
|
by the window manager in its usual fashion.
|
|
|
|
Here are some special features for working with sizes and positions.
|
|
(For the precise meaning of ``selected frame'' used by these functions,
|
|
see @ref{Input Focus}.)
|
|
|
|
@defun set-frame-position frame left top
|
|
This function sets the position of the top left corner of @var{frame} to
|
|
@var{left} and @var{top}. These arguments are measured in pixels, and
|
|
normally count from the top left corner of the screen.
|
|
|
|
Negative parameter values position the bottom edge of the window up from
|
|
the bottom edge of the screen, or the right window edge to the left of
|
|
the right edge of the screen. It would probably be better if the values
|
|
were always counted from the left and top, so that negative arguments
|
|
would position the frame partly off the top or left edge of the screen,
|
|
but it seems inadvisable to change that now.
|
|
@end defun
|
|
|
|
@defun frame-height &optional frame
|
|
@defunx frame-width &optional frame
|
|
These functions return the height and width of @var{frame}, measured in
|
|
lines and columns. If you don't supply @var{frame}, they use the
|
|
selected frame.
|
|
@end defun
|
|
|
|
@defun screen-height
|
|
@defunx screen-width
|
|
These functions are old aliases for @code{frame-height} and
|
|
@code{frame-width}. When you are using a non-window terminal, the size
|
|
of the frame is normally the same as the size of the terminal screen.
|
|
@end defun
|
|
|
|
@defun frame-pixel-height &optional frame
|
|
@defunx frame-pixel-width &optional frame
|
|
These functions return the height and width of the main display area
|
|
of @var{frame}, measured in pixels. If you don't supply @var{frame},
|
|
they use the selected frame.
|
|
|
|
These values include the internal borders, and windows' scroll bars
|
|
and fringes (which belong to individual windows, not to the frame
|
|
itself), but do not include menu bars or tool bars (except when using
|
|
X without an X toolkit).
|
|
@end defun
|
|
|
|
@defun frame-char-height &optional frame
|
|
@defunx frame-char-width &optional frame
|
|
These functions return the height and width of a character in
|
|
@var{frame}, measured in pixels. The values depend on the choice of
|
|
font. If you don't supply @var{frame}, these functions use the selected
|
|
frame.
|
|
@end defun
|
|
|
|
@defun set-frame-size frame cols rows
|
|
This function sets the size of @var{frame}, measured in characters;
|
|
@var{cols} and @var{rows} specify the new width and height.
|
|
|
|
To set the size based on values measured in pixels, use
|
|
@code{frame-char-height} and @code{frame-char-width} to convert
|
|
them to units of characters.
|
|
@end defun
|
|
|
|
@defun set-frame-height frame lines &optional pretend
|
|
This function resizes @var{frame} to a height of @var{lines} lines. The
|
|
sizes of existing windows in @var{frame} are altered proportionally to
|
|
fit.
|
|
|
|
If @var{pretend} is non-@code{nil}, then Emacs displays @var{lines}
|
|
lines of output in @var{frame}, but does not change its value for the
|
|
actual height of the frame. This is only useful for a terminal frame.
|
|
Using a smaller height than the terminal actually implements may be
|
|
useful to reproduce behavior observed on a smaller screen, or if the
|
|
terminal malfunctions when using its whole screen. Setting the frame
|
|
height ``for real'' does not always work, because knowing the correct
|
|
actual size may be necessary for correct cursor positioning on a
|
|
terminal frame.
|
|
@end defun
|
|
|
|
@defun set-frame-width frame width &optional pretend
|
|
This function sets the width of @var{frame}, measured in characters.
|
|
The argument @var{pretend} has the same meaning as in
|
|
@code{set-frame-height}.
|
|
@end defun
|
|
|
|
@findex set-screen-height
|
|
@findex set-screen-width
|
|
The older functions @code{set-screen-height} and
|
|
@code{set-screen-width} were used to specify the height and width of the
|
|
screen, in Emacs versions that did not support multiple frames. They
|
|
are semi-obsolete, but still work; they apply to the selected frame.
|
|
|
|
@node Geometry
|
|
@subsection Geometry
|
|
|
|
Here's how to examine the data in an X-style window geometry
|
|
specification:
|
|
|
|
@defun x-parse-geometry geom
|
|
@cindex geometry specification
|
|
The function @code{x-parse-geometry} converts a standard X window
|
|
geometry string to an alist that you can use as part of the argument to
|
|
@code{make-frame}.
|
|
|
|
The alist describes which parameters were specified in @var{geom}, and
|
|
gives the values specified for them. Each element looks like
|
|
@code{(@var{parameter} . @var{value})}. The possible @var{parameter}
|
|
values are @code{left}, @code{top}, @code{width}, and @code{height}.
|
|
|
|
For the size parameters, the value must be an integer. The position
|
|
parameter names @code{left} and @code{top} are not totally accurate,
|
|
because some values indicate the position of the right or bottom edges
|
|
instead. These are the @var{value} possibilities for the position
|
|
parameters:
|
|
|
|
@table @asis
|
|
@item an integer
|
|
A positive integer relates the left edge or top edge of the window to
|
|
the left or top edge of the screen. A negative integer relates the
|
|
right or bottom edge of the window to the right or bottom edge of the
|
|
screen.
|
|
|
|
@item @code{(+ @var{position})}
|
|
This specifies the position of the left or top edge of the window
|
|
relative to the left or top edge of the screen. The integer
|
|
@var{position} may be positive or negative; a negative value specifies a
|
|
position outside the screen.
|
|
|
|
@item @code{(- @var{position})}
|
|
This specifies the position of the right or bottom edge of the window
|
|
relative to the right or bottom edge of the screen. The integer
|
|
@var{position} may be positive or negative; a negative value specifies a
|
|
position outside the screen.
|
|
@end table
|
|
|
|
Here is an example:
|
|
|
|
@example
|
|
(x-parse-geometry "35x70+0-0")
|
|
@result{} ((height . 70) (width . 35)
|
|
(top - 0) (left . 0))
|
|
@end example
|
|
@end defun
|
|
|
|
@node Frame Titles
|
|
@section Frame Titles
|
|
@cindex frame title
|
|
|
|
Every frame has a @code{name} parameter; this serves as the default
|
|
for the frame title which window systems typically display at the top of
|
|
the frame. You can specify a name explicitly by setting the @code{name}
|
|
frame property.
|
|
|
|
Normally you don't specify the name explicitly, and Emacs computes the
|
|
frame name automatically based on a template stored in the variable
|
|
@code{frame-title-format}. Emacs recomputes the name each time the
|
|
frame is redisplayed.
|
|
|
|
@defvar frame-title-format
|
|
This variable specifies how to compute a name for a frame when you have
|
|
not explicitly specified one. The variable's value is actually a mode
|
|
line construct, just like @code{mode-line-format}, except that the
|
|
@samp{%c} and @samp{%l} constructs are ignored. @xref{Mode Line
|
|
Data}.
|
|
@end defvar
|
|
|
|
@defvar icon-title-format
|
|
This variable specifies how to compute the name for an iconified frame,
|
|
when you have not explicitly specified the frame title. This title
|
|
appears in the icon itself.
|
|
@end defvar
|
|
|
|
@defvar multiple-frames
|
|
This variable is set automatically by Emacs. Its value is @code{t} when
|
|
there are two or more frames (not counting minibuffer-only frames or
|
|
invisible frames). The default value of @code{frame-title-format} uses
|
|
@code{multiple-frames} so as to put the buffer name in the frame title
|
|
only when there is more than one frame.
|
|
|
|
The value of this variable is not guaranteed to be accurate except
|
|
while processing @code{frame-title-format} or
|
|
@code{icon-title-format}.
|
|
@end defvar
|
|
|
|
@node Deleting Frames
|
|
@section Deleting Frames
|
|
@cindex deleting frames
|
|
|
|
Frames remain potentially visible until you explicitly @dfn{delete}
|
|
them. A deleted frame cannot appear on the screen, but continues to
|
|
exist as a Lisp object until there are no references to it.
|
|
|
|
@deffn Command delete-frame &optional frame force
|
|
@vindex delete-frame-functions
|
|
This function deletes the frame @var{frame}. Unless @var{frame} is a
|
|
tooltip, it first runs the hook @code{delete-frame-functions} (each
|
|
function gets one argument, @var{frame}). By default, @var{frame} is
|
|
the selected frame.
|
|
|
|
A frame cannot be deleted if its minibuffer is used by other frames.
|
|
Normally, you cannot delete a frame if all other frames are invisible,
|
|
but if the @var{force} is non-@code{nil}, then you are allowed to do so.
|
|
@end deffn
|
|
|
|
@defun frame-live-p frame
|
|
The function @code{frame-live-p} returns non-@code{nil} if the frame
|
|
@var{frame} has not been deleted. The possible non-@code{nil} return
|
|
values are like those of @code{framep}. @xref{Frames}.
|
|
@end defun
|
|
|
|
Some window managers provide a command to delete a window. These work
|
|
by sending a special message to the program that operates the window.
|
|
When Emacs gets one of these commands, it generates a
|
|
@code{delete-frame} event, whose normal definition is a command that
|
|
calls the function @code{delete-frame}. @xref{Misc Events}.
|
|
|
|
@node Finding All Frames
|
|
@section Finding All Frames
|
|
@cindex frames, scanning all
|
|
|
|
@defun frame-list
|
|
The function @code{frame-list} returns a list of all the frames that
|
|
have not been deleted. It is analogous to @code{buffer-list} for
|
|
buffers, and includes frames on all terminals. The list that you get is
|
|
newly created, so modifying the list doesn't have any effect on the
|
|
internals of Emacs.
|
|
@end defun
|
|
|
|
@defun visible-frame-list
|
|
This function returns a list of just the currently visible frames.
|
|
@xref{Visibility of Frames}. (Terminal frames always count as
|
|
``visible,'' even though only the selected one is actually displayed.)
|
|
@end defun
|
|
|
|
@defun next-frame &optional frame minibuf
|
|
The function @code{next-frame} lets you cycle conveniently through all
|
|
the frames on the current display from an arbitrary starting point. It
|
|
returns the ``next'' frame after @var{frame} in the cycle. If
|
|
@var{frame} is omitted or @code{nil}, it defaults to the selected frame
|
|
(@pxref{Input Focus}).
|
|
|
|
The second argument, @var{minibuf}, says which frames to consider:
|
|
|
|
@table @asis
|
|
@item @code{nil}
|
|
Exclude minibuffer-only frames.
|
|
@item @code{visible}
|
|
Consider all visible frames.
|
|
@item 0
|
|
Consider all visible or iconified frames.
|
|
@item a window
|
|
Consider only the frames using that particular window as their
|
|
minibuffer.
|
|
@item anything else
|
|
Consider all frames.
|
|
@end table
|
|
@end defun
|
|
|
|
@defun previous-frame &optional frame minibuf
|
|
Like @code{next-frame}, but cycles through all frames in the opposite
|
|
direction.
|
|
@end defun
|
|
|
|
See also @code{next-window} and @code{previous-window}, in @ref{Cyclic
|
|
Window Ordering}.
|
|
|
|
@node Frames and Windows
|
|
@section Frames and Windows
|
|
|
|
Each window is part of one and only one frame; you can get the frame
|
|
with @code{window-frame}.
|
|
|
|
@defun window-frame window
|
|
This function returns the frame that @var{window} is on.
|
|
@end defun
|
|
|
|
All the non-minibuffer windows in a frame are arranged in a cyclic
|
|
order. The order runs from the frame's top window, which is at the
|
|
upper left corner, down and to the right, until it reaches the window at
|
|
the lower right corner (always the minibuffer window, if the frame has
|
|
one), and then it moves back to the top. @xref{Cyclic Window Ordering}.
|
|
|
|
@defun frame-first-window &optional frame
|
|
This returns the topmost, leftmost window of frame @var{frame}.
|
|
If omitted or @code{nil}, @var{frame} defaults to the selected frame.
|
|
@end defun
|
|
|
|
At any time, exactly one window on any frame is @dfn{selected within the
|
|
frame}. The significance of this designation is that selecting the
|
|
frame also selects this window. You can get the frame's current
|
|
selected window with @code{frame-selected-window}.
|
|
|
|
@defun frame-selected-window &optional frame
|
|
This function returns the window on @var{frame} that is selected
|
|
within @var{frame}. If omitted or @code{nil}, @var{frame} defaults to
|
|
the selected frame.
|
|
@end defun
|
|
|
|
@defun set-frame-selected-window frame window
|
|
This sets the selected window of frame @var{frame} to @var{window}.
|
|
If @var{frame} is @code{nil}, it operates on the selected frame. If
|
|
@var{frame} is the selected frame, this makes @var{window} the
|
|
selected window. This function returns @var{window}.
|
|
@end defun
|
|
|
|
Conversely, selecting a window for Emacs with @code{select-window} also
|
|
makes that window selected within its frame. @xref{Selecting Windows}.
|
|
|
|
Another function that (usually) returns one of the windows in a given
|
|
frame is @code{minibuffer-window}. @xref{Definition of minibuffer-window}.
|
|
|
|
@node Minibuffers and Frames
|
|
@section Minibuffers and Frames
|
|
|
|
Normally, each frame has its own minibuffer window at the bottom, which
|
|
is used whenever that frame is selected. If the frame has a minibuffer,
|
|
you can get it with @code{minibuffer-window} (@pxref{Definition of
|
|
minibuffer-window}).
|
|
|
|
However, you can also create a frame with no minibuffer. Such a frame
|
|
must use the minibuffer window of some other frame. When you create the
|
|
frame, you can specify explicitly the minibuffer window to use (in some
|
|
other frame). If you don't, then the minibuffer is found in the frame
|
|
which is the value of the variable @code{default-minibuffer-frame}. Its
|
|
value should be a frame that does have a minibuffer.
|
|
|
|
If you use a minibuffer-only frame, you might want that frame to raise
|
|
when you enter the minibuffer. If so, set the variable
|
|
@code{minibuffer-auto-raise} to @code{t}. @xref{Raising and Lowering}.
|
|
|
|
@defvar default-minibuffer-frame
|
|
This variable specifies the frame to use for the minibuffer window, by
|
|
default. It does not affect existing frames. It is always local to
|
|
the current terminal and cannot be buffer-local. @xref{Multiple
|
|
Displays}.
|
|
@end defvar
|
|
|
|
@node Input Focus
|
|
@section Input Focus
|
|
@cindex input focus
|
|
@c @cindex selected frame Duplicates selected-frame
|
|
|
|
At any time, one frame in Emacs is the @dfn{selected frame}. The selected
|
|
window always resides on the selected frame.
|
|
|
|
When Emacs displays its frames on several terminals (@pxref{Multiple
|
|
Displays}), each terminal has its own selected frame. But only one of
|
|
these is ``@emph{the} selected frame'': it's the frame that belongs to
|
|
the terminal from which the most recent input came. That is, when Emacs
|
|
runs a command that came from a certain terminal, the selected frame is
|
|
the one of that terminal. Since Emacs runs only a single command at any
|
|
given time, it needs to consider only one selected frame at a time; this
|
|
frame is what we call @dfn{the selected frame} in this manual. The
|
|
display on which the selected frame is displayed is the @dfn{selected
|
|
frame's display}.
|
|
|
|
@defun selected-frame
|
|
This function returns the selected frame.
|
|
@end defun
|
|
|
|
Some window systems and window managers direct keyboard input to the
|
|
window object that the mouse is in; others require explicit clicks or
|
|
commands to @dfn{shift the focus} to various window objects. Either
|
|
way, Emacs automatically keeps track of which frame has the focus. To
|
|
switch to a different frame from a Lisp function, call
|
|
@code{select-frame-set-input-focus}.
|
|
|
|
Lisp programs can also switch frames ``temporarily'' by calling the
|
|
function @code{select-frame}. This does not alter the window system's
|
|
concept of focus; rather, it escapes from the window manager's control
|
|
until that control is somehow reasserted.
|
|
|
|
When using a text-only terminal, only one frame can be displayed at a
|
|
time on the terminal, so after a call to @code{select-frame}, the next
|
|
redisplay actually displays the newly selected frame. This frame
|
|
remains selected until a subsequent call to @code{select-frame} or
|
|
@code{select-frame-set-input-focus}. Each terminal frame has a number
|
|
which appears in the mode line before the buffer name (@pxref{Mode
|
|
Line Variables}).
|
|
|
|
@defun select-frame-set-input-focus frame
|
|
This function makes @var{frame} the selected frame, raises it (should
|
|
it happen to be obscured by other frames) and tries to give it the X
|
|
server's focus. On a text-only terminal, the next redisplay displays
|
|
the new frame on the entire terminal screen. The return value of this
|
|
function is not significant.
|
|
@end defun
|
|
|
|
@c ??? This is not yet implemented properly.
|
|
@defun select-frame frame
|
|
This function selects frame @var{frame}, temporarily disregarding the
|
|
focus of the X server if any. The selection of @var{frame} lasts until
|
|
the next time the user does something to select a different frame, or
|
|
until the next time this function is called. (If you are using a
|
|
window system, the previously selected frame may be restored as the
|
|
selected frame after return to the command loop, because it still may
|
|
have the window system's input focus.) The specified @var{frame}
|
|
becomes the selected frame, as explained above, and the terminal that
|
|
@var{frame} is on becomes the selected terminal. This function
|
|
returns @var{frame}, or @code{nil} if @var{frame} has been deleted.
|
|
|
|
In general, you should never use @code{select-frame} in a way that could
|
|
switch to a different terminal without switching back when you're done.
|
|
@end defun
|
|
|
|
Emacs cooperates with the window system by arranging to select frames as
|
|
the server and window manager request. It does so by generating a
|
|
special kind of input event, called a @dfn{focus} event, when
|
|
appropriate. The command loop handles a focus event by calling
|
|
@code{handle-switch-frame}. @xref{Focus Events}.
|
|
|
|
@deffn Command handle-switch-frame frame
|
|
This function handles a focus event by selecting frame @var{frame}.
|
|
|
|
Focus events normally do their job by invoking this command.
|
|
Don't call it for any other reason.
|
|
@end deffn
|
|
|
|
@defun redirect-frame-focus frame &optional focus-frame
|
|
This function redirects focus from @var{frame} to @var{focus-frame}.
|
|
This means that @var{focus-frame} will receive subsequent keystrokes and
|
|
events intended for @var{frame}. After such an event, the value of
|
|
@code{last-event-frame} will be @var{focus-frame}. Also, switch-frame
|
|
events specifying @var{frame} will instead select @var{focus-frame}.
|
|
|
|
If @var{focus-frame} is omitted or @code{nil}, that cancels any existing
|
|
redirection for @var{frame}, which therefore once again receives its own
|
|
events.
|
|
|
|
One use of focus redirection is for frames that don't have minibuffers.
|
|
These frames use minibuffers on other frames. Activating a minibuffer
|
|
on another frame redirects focus to that frame. This puts the focus on
|
|
the minibuffer's frame, where it belongs, even though the mouse remains
|
|
in the frame that activated the minibuffer.
|
|
|
|
Selecting a frame can also change focus redirections. Selecting frame
|
|
@code{bar}, when @code{foo} had been selected, changes any redirections
|
|
pointing to @code{foo} so that they point to @code{bar} instead. This
|
|
allows focus redirection to work properly when the user switches from
|
|
one frame to another using @code{select-window}.
|
|
|
|
This means that a frame whose focus is redirected to itself is treated
|
|
differently from a frame whose focus is not redirected.
|
|
@code{select-frame} affects the former but not the latter.
|
|
|
|
The redirection lasts until @code{redirect-frame-focus} is called to
|
|
change it.
|
|
@end defun
|
|
|
|
@defopt focus-follows-mouse
|
|
This option is how you inform Emacs whether the window manager transfers
|
|
focus when the user moves the mouse. Non-@code{nil} says that it does.
|
|
When this is so, the command @code{other-frame} moves the mouse to a
|
|
position consistent with the new selected frame. (This option has no
|
|
effect on MS-Windows, where the mouse pointer is always automatically
|
|
moved by the OS to the selected frame.)
|
|
@end defopt
|
|
|
|
@node Visibility of Frames
|
|
@section Visibility of Frames
|
|
@cindex visible frame
|
|
@cindex invisible frame
|
|
@cindex iconified frame
|
|
@cindex frame visibility
|
|
|
|
A window frame may be @dfn{visible}, @dfn{invisible}, or
|
|
@dfn{iconified}. If it is visible, you can see its contents, unless
|
|
other windows cover it. If it is iconified, the frame's contents do
|
|
not appear on the screen, but an icon does. If the frame is
|
|
invisible, it doesn't show on the screen, not even as an icon.
|
|
|
|
Visibility is meaningless for terminal frames, since only the selected
|
|
one is actually displayed in any case.
|
|
|
|
@deffn Command make-frame-visible &optional frame
|
|
This function makes frame @var{frame} visible. If you omit
|
|
@var{frame}, it makes the selected frame visible. This does not raise
|
|
the frame, but you can do that with @code{raise-frame} if you wish
|
|
(@pxref{Raising and Lowering}).
|
|
@end deffn
|
|
|
|
@deffn Command make-frame-invisible &optional frame force
|
|
This function makes frame @var{frame} invisible. If you omit
|
|
@var{frame}, it makes the selected frame invisible.
|
|
|
|
Unless @var{force} is non-@code{nil}, this function refuses to make
|
|
@var{frame} invisible if all other frames are invisible..
|
|
@end deffn
|
|
|
|
@deffn Command iconify-frame &optional frame
|
|
This function iconifies frame @var{frame}. If you omit @var{frame}, it
|
|
iconifies the selected frame.
|
|
@end deffn
|
|
|
|
@defun frame-visible-p frame
|
|
This returns the visibility status of frame @var{frame}. The value is
|
|
@code{t} if @var{frame} is visible, @code{nil} if it is invisible, and
|
|
@code{icon} if it is iconified.
|
|
|
|
On a text-only terminal, all frames are considered visible, whether
|
|
they are currently being displayed or not, and this function returns
|
|
@code{t} for all frames.
|
|
@end defun
|
|
|
|
The visibility status of a frame is also available as a frame
|
|
parameter. You can read or change it as such. @xref{Management
|
|
Parameters}.
|
|
|
|
The user can iconify and deiconify frames with the window manager.
|
|
This happens below the level at which Emacs can exert any control, but
|
|
Emacs does provide events that you can use to keep track of such
|
|
changes. @xref{Misc Events}.
|
|
|
|
@node Raising and Lowering
|
|
@section Raising and Lowering Frames
|
|
|
|
Most window systems use a desktop metaphor. Part of this metaphor is
|
|
the idea that windows are stacked in a notional third dimension
|
|
perpendicular to the screen surface, and thus ordered from ``highest''
|
|
to ``lowest.'' Where two windows overlap, the one higher up covers
|
|
the one underneath. Even a window at the bottom of the stack can be
|
|
seen if no other window overlaps it.
|
|
|
|
@c @cindex raising a frame redundant with raise-frame
|
|
@cindex lowering a frame
|
|
A window's place in this ordering is not fixed; in fact, users tend
|
|
to change the order frequently. @dfn{Raising} a window means moving
|
|
it ``up,'' to the top of the stack. @dfn{Lowering} a window means
|
|
moving it to the bottom of the stack. This motion is in the notional
|
|
third dimension only, and does not change the position of the window
|
|
on the screen.
|
|
|
|
You can raise and lower Emacs frame Windows with these functions:
|
|
|
|
@deffn Command raise-frame &optional frame
|
|
This function raises frame @var{frame} (default, the selected frame).
|
|
If @var{frame} is invisible or iconified, this makes it visible.
|
|
@end deffn
|
|
|
|
@deffn Command lower-frame &optional frame
|
|
This function lowers frame @var{frame} (default, the selected frame).
|
|
@end deffn
|
|
|
|
@defopt minibuffer-auto-raise
|
|
If this is non-@code{nil}, activation of the minibuffer raises the frame
|
|
that the minibuffer window is in.
|
|
@end defopt
|
|
|
|
You can also enable auto-raise (raising automatically when a frame is
|
|
selected) or auto-lower (lowering automatically when it is deselected)
|
|
for any frame using frame parameters. @xref{Management Parameters}.
|
|
|
|
@node Frame Configurations
|
|
@section Frame Configurations
|
|
@cindex frame configuration
|
|
|
|
A @dfn{frame configuration} records the current arrangement of frames,
|
|
all their properties, and the window configuration of each one.
|
|
(@xref{Window Configurations}.)
|
|
|
|
@defun current-frame-configuration
|
|
This function returns a frame configuration list that describes
|
|
the current arrangement of frames and their contents.
|
|
@end defun
|
|
|
|
@defun set-frame-configuration configuration &optional nodelete
|
|
This function restores the state of frames described in
|
|
@var{configuration}. However, this function does not restore deleted
|
|
frames.
|
|
|
|
Ordinarily, this function deletes all existing frames not listed in
|
|
@var{configuration}. But if @var{nodelete} is non-@code{nil}, the
|
|
unwanted frames are iconified instead.
|
|
@end defun
|
|
|
|
@node Mouse Tracking
|
|
@section Mouse Tracking
|
|
@cindex mouse tracking
|
|
@c @cindex tracking the mouse Duplicates track-mouse
|
|
|
|
Sometimes it is useful to @dfn{track} the mouse, which means to display
|
|
something to indicate where the mouse is and move the indicator as the
|
|
mouse moves. For efficient mouse tracking, you need a way to wait until
|
|
the mouse actually moves.
|
|
|
|
The convenient way to track the mouse is to ask for events to represent
|
|
mouse motion. Then you can wait for motion by waiting for an event. In
|
|
addition, you can easily handle any other sorts of events that may
|
|
occur. That is useful, because normally you don't want to track the
|
|
mouse forever---only until some other event, such as the release of a
|
|
button.
|
|
|
|
@defspec track-mouse body@dots{}
|
|
This special form executes @var{body}, with generation of mouse motion
|
|
events enabled. Typically @var{body} would use @code{read-event} to
|
|
read the motion events and modify the display accordingly. @xref{Motion
|
|
Events}, for the format of mouse motion events.
|
|
|
|
The value of @code{track-mouse} is that of the last form in @var{body}.
|
|
You should design @var{body} to return when it sees the up-event that
|
|
indicates the release of the button, or whatever kind of event means
|
|
it is time to stop tracking.
|
|
@end defspec
|
|
|
|
The usual purpose of tracking mouse motion is to indicate on the screen
|
|
the consequences of pushing or releasing a button at the current
|
|
position.
|
|
|
|
In many cases, you can avoid the need to track the mouse by using
|
|
the @code{mouse-face} text property (@pxref{Special Properties}).
|
|
That works at a much lower level and runs more smoothly than
|
|
Lisp-level mouse tracking.
|
|
|
|
@ignore
|
|
@c These are not implemented yet.
|
|
|
|
These functions change the screen appearance instantaneously. The
|
|
effect is transient, only until the next ordinary Emacs redisplay. That
|
|
is OK for mouse tracking, since it doesn't make sense for mouse tracking
|
|
to change the text, and the body of @code{track-mouse} normally reads
|
|
the events itself and does not do redisplay.
|
|
|
|
@defun x-contour-region window beg end
|
|
This function draws lines to make a box around the text from @var{beg}
|
|
to @var{end}, in window @var{window}.
|
|
@end defun
|
|
|
|
@defun x-uncontour-region window beg end
|
|
This function erases the lines that would make a box around the text
|
|
from @var{beg} to @var{end}, in window @var{window}. Use it to remove
|
|
a contour that you previously made by calling @code{x-contour-region}.
|
|
@end defun
|
|
|
|
@defun x-draw-rectangle frame left top right bottom
|
|
This function draws a hollow rectangle on frame @var{frame} with the
|
|
specified edge coordinates, all measured in pixels from the inside top
|
|
left corner. It uses the cursor color, the one used for indicating the
|
|
location of point.
|
|
@end defun
|
|
|
|
@defun x-erase-rectangle frame left top right bottom
|
|
This function erases a hollow rectangle on frame @var{frame} with the
|
|
specified edge coordinates, all measured in pixels from the inside top
|
|
left corner. Erasure means redrawing the text and background that
|
|
normally belong in the specified rectangle.
|
|
@end defun
|
|
@end ignore
|
|
|
|
@node Mouse Position
|
|
@section Mouse Position
|
|
@cindex mouse position
|
|
@cindex position of mouse
|
|
|
|
The functions @code{mouse-position} and @code{set-mouse-position}
|
|
give access to the current position of the mouse.
|
|
|
|
@defun mouse-position
|
|
This function returns a description of the position of the mouse. The
|
|
value looks like @code{(@var{frame} @var{x} . @var{y})}, where @var{x}
|
|
and @var{y} are integers giving the position in characters relative to
|
|
the top left corner of the inside of @var{frame}.
|
|
@end defun
|
|
|
|
@defvar mouse-position-function
|
|
If non-@code{nil}, the value of this variable is a function for
|
|
@code{mouse-position} to call. @code{mouse-position} calls this
|
|
function just before returning, with its normal return value as the
|
|
sole argument, and it returns whatever this function returns to it.
|
|
|
|
This abnormal hook exists for the benefit of packages like
|
|
@file{xt-mouse.el} that need to do mouse handling at the Lisp level.
|
|
@end defvar
|
|
|
|
@defun set-mouse-position frame x y
|
|
This function @dfn{warps the mouse} to position @var{x}, @var{y} in
|
|
frame @var{frame}. The arguments @var{x} and @var{y} are integers,
|
|
giving the position in characters relative to the top left corner of the
|
|
inside of @var{frame}. If @var{frame} is not visible, this function
|
|
does nothing. The return value is not significant.
|
|
@end defun
|
|
|
|
@defun mouse-pixel-position
|
|
This function is like @code{mouse-position} except that it returns
|
|
coordinates in units of pixels rather than units of characters.
|
|
@end defun
|
|
|
|
@defun set-mouse-pixel-position frame x y
|
|
This function warps the mouse like @code{set-mouse-position} except that
|
|
@var{x} and @var{y} are in units of pixels rather than units of
|
|
characters. These coordinates are not required to be within the frame.
|
|
|
|
If @var{frame} is not visible, this function does nothing. The return
|
|
value is not significant.
|
|
@end defun
|
|
|
|
@need 3000
|
|
|
|
@node Pop-Up Menus
|
|
@section Pop-Up Menus
|
|
|
|
When using a window system, a Lisp program can pop up a menu so that
|
|
the user can choose an alternative with the mouse.
|
|
|
|
@defun x-popup-menu position menu
|
|
This function displays a pop-up menu and returns an indication of
|
|
what selection the user makes.
|
|
|
|
The argument @var{position} specifies where on the screen to put the
|
|
top left corner of the menu. It can be either a mouse button event
|
|
(which says to put the menu where the user actuated the button) or a
|
|
list of this form:
|
|
|
|
@example
|
|
((@var{xoffset} @var{yoffset}) @var{window})
|
|
@end example
|
|
|
|
@noindent
|
|
where @var{xoffset} and @var{yoffset} are coordinates, measured in
|
|
pixels, counting from the top left corner of @var{window}. @var{window}
|
|
may be a window or a frame.
|
|
|
|
If @var{position} is @code{t}, it means to use the current mouse
|
|
position. If @var{position} is @code{nil}, it means to precompute the
|
|
key binding equivalents for the keymaps specified in @var{menu},
|
|
without actually displaying or popping up the menu.
|
|
|
|
The argument @var{menu} says what to display in the menu. It can be a
|
|
keymap or a list of keymaps (@pxref{Menu Keymaps}). In this case, the
|
|
return value is the list of events corresponding to the user's choice.
|
|
(This list has more than one element if the choice occurred in a
|
|
submenu.) Note that @code{x-popup-menu} does not actually execute the
|
|
command bound to that sequence of events.
|
|
|
|
Alternatively, @var{menu} can have the following form:
|
|
|
|
@example
|
|
(@var{title} @var{pane1} @var{pane2}...)
|
|
@end example
|
|
|
|
@noindent
|
|
where each pane is a list of form
|
|
|
|
@example
|
|
(@var{title} @var{item1} @var{item2}...)
|
|
@end example
|
|
|
|
Each item should normally be a cons cell @code{(@var{line} . @var{value})},
|
|
where @var{line} is a string, and @var{value} is the value to return if
|
|
that @var{line} is chosen. An item can also be a string; this makes a
|
|
non-selectable line in the menu.
|
|
|
|
If the user gets rid of the menu without making a valid choice, for
|
|
instance by clicking the mouse away from a valid choice or by typing
|
|
keyboard input, then this normally results in a quit and
|
|
@code{x-popup-menu} does not return. But if @var{position} is a mouse
|
|
button event (indicating that the user invoked the menu with the
|
|
mouse) then no quit occurs and @code{x-popup-menu} returns @code{nil}.
|
|
@end defun
|
|
|
|
@strong{Usage note:} Don't use @code{x-popup-menu} to display a menu
|
|
if you could do the job with a prefix key defined with a menu keymap.
|
|
If you use a menu keymap to implement a menu, @kbd{C-h c} and @kbd{C-h
|
|
a} can see the individual items in that menu and provide help for them.
|
|
If instead you implement the menu by defining a command that calls
|
|
@code{x-popup-menu}, the help facilities cannot know what happens inside
|
|
that command, so they cannot give any help for the menu's items.
|
|
|
|
The menu bar mechanism, which lets you switch between submenus by
|
|
moving the mouse, cannot look within the definition of a command to see
|
|
that it calls @code{x-popup-menu}. Therefore, if you try to implement a
|
|
submenu using @code{x-popup-menu}, it cannot work with the menu bar in
|
|
an integrated fashion. This is why all menu bar submenus are
|
|
implemented with menu keymaps within the parent menu, and never with
|
|
@code{x-popup-menu}. @xref{Menu Bar}.
|
|
|
|
If you want a menu bar submenu to have contents that vary, you should
|
|
still use a menu keymap to implement it. To make the contents vary, add
|
|
a hook function to @code{menu-bar-update-hook} to update the contents of
|
|
the menu keymap as necessary.
|
|
|
|
@node Dialog Boxes
|
|
@section Dialog Boxes
|
|
@cindex dialog boxes
|
|
|
|
A dialog box is a variant of a pop-up menu---it looks a little
|
|
different, it always appears in the center of a frame, and it has just
|
|
one level and one or more buttons. The main use of dialog boxes is
|
|
for asking questions that the user can answer with ``yes,'' ``no,''
|
|
and a few other alternatives. With a single button, they can also
|
|
force the user to acknowledge important information. The functions
|
|
@code{y-or-n-p} and @code{yes-or-no-p} use dialog boxes instead of the
|
|
keyboard, when called from commands invoked by mouse clicks.
|
|
|
|
@defun x-popup-dialog position contents &optional header
|
|
This function displays a pop-up dialog box and returns an indication of
|
|
what selection the user makes. The argument @var{contents} specifies
|
|
the alternatives to offer; it has this format:
|
|
|
|
@example
|
|
(@var{title} (@var{string} . @var{value})@dots{})
|
|
@end example
|
|
|
|
@noindent
|
|
which looks like the list that specifies a single pane for
|
|
@code{x-popup-menu}.
|
|
|
|
The return value is @var{value} from the chosen alternative.
|
|
|
|
As for @code{x-popup-menu}, an element of the list may be just a
|
|
string instead of a cons cell @code{(@var{string} . @var{value})}.
|
|
That makes a box that cannot be selected.
|
|
|
|
If @code{nil} appears in the list, it separates the left-hand items from
|
|
the right-hand items; items that precede the @code{nil} appear on the
|
|
left, and items that follow the @code{nil} appear on the right. If you
|
|
don't include a @code{nil} in the list, then approximately half the
|
|
items appear on each side.
|
|
|
|
Dialog boxes always appear in the center of a frame; the argument
|
|
@var{position} specifies which frame. The possible values are as in
|
|
@code{x-popup-menu}, but the precise coordinates or the individual
|
|
window don't matter; only the frame matters.
|
|
|
|
If @var{header} is non-@code{nil}, the frame title for the box is
|
|
@samp{Information}, otherwise it is @samp{Question}. The former is used
|
|
for @code{message-box} (@pxref{message-box}).
|
|
|
|
In some configurations, Emacs cannot display a real dialog box; so
|
|
instead it displays the same items in a pop-up menu in the center of the
|
|
frame.
|
|
|
|
If the user gets rid of the dialog box without making a valid choice,
|
|
for instance using the window manager, then this produces a quit and
|
|
@code{x-popup-dialog} does not return.
|
|
@end defun
|
|
|
|
@node Pointer Shape
|
|
@section Pointer Shape
|
|
@cindex pointer shape
|
|
@cindex mouse pointer shape
|
|
|
|
You can specify the mouse pointer style for particular text or
|
|
images using the @code{pointer} text property, and for images with the
|
|
@code{:pointer} and @code{:map} image properties. The values you can
|
|
use in these properties are @code{text} (or @code{nil}), @code{arrow},
|
|
@code{hand}, @code{vdrag}, @code{hdrag}, @code{modeline}, and
|
|
@code{hourglass}. @code{text} stands for the usual mouse pointer
|
|
style used over text.
|
|
|
|
Over void parts of the window (parts that do not correspond to any
|
|
of the buffer contents), the mouse pointer usually uses the
|
|
@code{arrow} style, but you can specify a different style (one of
|
|
those above) by setting @code{void-text-area-pointer}.
|
|
|
|
@defvar void-text-area-pointer
|
|
This variable specifies the mouse pointer style for void text areas.
|
|
These include 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 style.
|
|
@end defvar
|
|
|
|
You can specify what the @code{text} pointer style really looks like
|
|
by setting the variable @code{x-pointer-shape}.
|
|
|
|
@defvar x-pointer-shape
|
|
This variable specifies the pointer shape to use ordinarily in the
|
|
Emacs frame, for the @code{text} pointer style.
|
|
@end defvar
|
|
|
|
@defvar x-sensitive-text-pointer-shape
|
|
This variable specifies the pointer shape to use when the mouse
|
|
is over mouse-sensitive text.
|
|
@end defvar
|
|
|
|
These variables affect newly created frames. They do not normally
|
|
affect existing frames; however, if you set the mouse color of a
|
|
frame, that also installs the current value of those two variables.
|
|
@xref{Color Parameters}.
|
|
|
|
The values you can use, to specify either of these pointer shapes, are
|
|
defined in the file @file{lisp/term/x-win.el}. Use @kbd{M-x apropos
|
|
@key{RET} x-pointer @key{RET}} to see a list of them.
|
|
|
|
@node Window System Selections
|
|
@section Window System Selections
|
|
@cindex selection (for window systems)
|
|
|
|
The X server records a set of @dfn{selections} which permit transfer of
|
|
data between application programs. The various selections are
|
|
distinguished by @dfn{selection types}, represented in Emacs by
|
|
symbols. X clients including Emacs can read or set the selection for
|
|
any given type.
|
|
|
|
@deffn Command x-set-selection type data
|
|
This function sets a ``selection'' in the X server. It takes two
|
|
arguments: a selection type @var{type}, and the value to assign to it,
|
|
@var{data}. If @var{data} is @code{nil}, it means to clear out the
|
|
selection. Otherwise, @var{data} may be a string, a symbol, an integer
|
|
(or a cons of two integers or list of two integers), an overlay, or a
|
|
cons of two markers pointing to the same buffer. An overlay or a pair
|
|
of markers stands for text in the overlay or between the markers.
|
|
|
|
The argument @var{data} may also be a vector of valid non-vector
|
|
selection values.
|
|
|
|
Each possible @var{type} has its own selection value, which changes
|
|
independently. The usual values of @var{type} are @code{PRIMARY},
|
|
@code{SECONDARY} and @code{CLIPBOARD}; these are symbols with upper-case
|
|
names, in accord with X Window System conventions. If @var{type} is
|
|
@code{nil}, that stands for @code{PRIMARY}.
|
|
|
|
This function returns @var{data}.
|
|
@end deffn
|
|
|
|
@defun x-get-selection &optional type data-type
|
|
This function accesses selections set up by Emacs or by other X
|
|
clients. It takes two optional arguments, @var{type} and
|
|
@var{data-type}. The default for @var{type}, the selection type, is
|
|
@code{PRIMARY}.
|
|
|
|
The @var{data-type} argument specifies the form of data conversion to
|
|
use, to convert the raw data obtained from another X client into Lisp
|
|
data. Meaningful values include @code{TEXT}, @code{STRING},
|
|
@code{UTF8_STRING}, @code{TARGETS}, @code{LENGTH}, @code{DELETE},
|
|
@code{FILE_NAME}, @code{CHARACTER_POSITION}, @code{NAME},
|
|
@code{LINE_NUMBER}, @code{COLUMN_NUMBER}, @code{OWNER_OS},
|
|
@code{HOST_NAME}, @code{USER}, @code{CLASS}, @code{ATOM}, and
|
|
@code{INTEGER}. (These are symbols with upper-case names in accord
|
|
with X conventions.) The default for @var{data-type} is
|
|
@code{STRING}.
|
|
@end defun
|
|
|
|
@cindex cut buffer
|
|
The X server also has a set of eight numbered @dfn{cut buffers} which can
|
|
store text or other data being moved between applications. Cut buffers
|
|
are considered obsolete, but Emacs supports them for the sake of X
|
|
clients that still use them. Cut buffers are numbered from 0 to 7.
|
|
|
|
@defun x-get-cut-buffer &optional n
|
|
This function returns the contents of cut buffer number @var{n}.
|
|
If omitted @var{n} defaults to 0.
|
|
@end defun
|
|
|
|
@defun x-set-cut-buffer string &optional push
|
|
@anchor{Definition of x-set-cut-buffer}
|
|
This function stores @var{string} into the first cut buffer (cut buffer
|
|
0). If @var{push} is @code{nil}, only the first cut buffer is changed.
|
|
If @var{push} is non-@code{nil}, that says to move the values down
|
|
through the series of cut buffers, much like the way successive kills in
|
|
Emacs move down the kill ring. In other words, the previous value of
|
|
the first cut buffer moves into the second cut buffer, and the second to
|
|
the third, and so on through all eight cut buffers.
|
|
@end defun
|
|
|
|
@defvar selection-coding-system
|
|
This variable specifies the coding system to use when reading and
|
|
writing selections or the clipboard. @xref{Coding
|
|
Systems}. The default is @code{compound-text-with-extensions}, which
|
|
converts to the text representation that X11 normally uses.
|
|
@end defvar
|
|
|
|
@cindex clipboard support (for MS-Windows)
|
|
When Emacs runs on MS-Windows, it does not implement X selections in
|
|
general, but it does support the clipboard. @code{x-get-selection}
|
|
and @code{x-set-selection} on MS-Windows support the text data type
|
|
only; if the clipboard holds other types of data, Emacs treats the
|
|
clipboard as empty.
|
|
|
|
@cindex scrap support (for Mac OS)
|
|
On Mac OS, selection-like data transfer between applications is
|
|
performed through a mechanism called @dfn{scraps}. The clipboard is a
|
|
particular scrap named @code{com.apple.scrap.clipboard}. Types of scrap
|
|
data are called @dfn{scrap flavor types}, which are identified by
|
|
four-char codes such as @code{TEXT}. Emacs associates a selection with
|
|
a scrap, and a selection type with a scrap flavor type via
|
|
@code{mac-scrap-name} and @code{mac-ostype} properties, respectively.
|
|
|
|
@example
|
|
(get 'CLIPBOARD 'mac-scrap-name)
|
|
@result{} "com.apple.scrap.clipboard"
|
|
(get 'com.apple.traditional-mac-plain-text 'mac-ostype)
|
|
@result{} "TEXT"
|
|
@end example
|
|
|
|
Conventionally, selection types for scrap flavor types on Mac OS have
|
|
the form of @acronym{UTI, Uniform Type Identifier} such as
|
|
@code{com.apple.traditional-mac-plain-text},
|
|
@code{public.utf16-plain-text}, and @code{public.file-url}.
|
|
|
|
@defopt x-select-enable-clipboard
|
|
If this is non-@code{nil}, the Emacs yank functions consult the
|
|
clipboard before the primary selection, and the kill functions store in
|
|
the clipboard as well as the primary selection. Otherwise they do not
|
|
access the clipboard at all. The default is @code{nil} on most systems,
|
|
but @code{t} on MS-Windows and Mac.
|
|
@end defopt
|
|
|
|
@node Drag and Drop
|
|
@section Drag and Drop
|
|
|
|
@vindex x-dnd-test-function
|
|
@vindex x-dnd-known-types
|
|
When a user drags something from another application over Emacs, that other
|
|
application expects Emacs to tell it if Emacs can handle the data that is
|
|
dragged. The variable @code{x-dnd-test-function} is used by Emacs to determine
|
|
what to reply. The default value is @code{x-dnd-default-test-function}
|
|
which accepts drops if the type of the data to be dropped is present in
|
|
@code{x-dnd-known-types}. You can customize @code{x-dnd-test-function} and/or
|
|
@code{x-dnd-known-types} if you want Emacs to accept or reject drops based
|
|
on some other criteria.
|
|
|
|
@vindex x-dnd-types-alist
|
|
If you want to change the way Emacs handles drop of different types
|
|
or add a new type, customize @code{x-dnd-types-alist}. This requires
|
|
detailed knowledge of what types other applications use for drag and
|
|
drop.
|
|
|
|
@vindex dnd-protocol-alist
|
|
When an URL is dropped on Emacs it may be a file, but it may also be
|
|
another URL type (ftp, http, etc.). Emacs first checks
|
|
@code{dnd-protocol-alist} to determine what to do with the URL. If
|
|
there is no match there and if @code{browse-url-browser-function} is
|
|
an alist, Emacs looks for a match there. If no match is found the
|
|
text for the URL is inserted. If you want to alter Emacs behavior,
|
|
you can customize these variables.
|
|
|
|
@node Color Names
|
|
@section Color Names
|
|
|
|
@cindex color names
|
|
@cindex specify color
|
|
@cindex numerical RGB color specification
|
|
A color name is text (usually in a string) that specifies a color.
|
|
Symbolic names such as @samp{black}, @samp{white}, @samp{red}, etc.,
|
|
are allowed; use @kbd{M-x list-colors-display} to see a list of
|
|
defined names. You can also specify colors numerically in forms such
|
|
as @samp{#@var{rgb}} and @samp{RGB:@var{r}/@var{g}/@var{b}}, where
|
|
@var{r} specifies the red level, @var{g} specifies the green level,
|
|
and @var{b} specifies the blue level. You can use either one, two,
|
|
three, or four hex digits for @var{r}; then you must use the same
|
|
number of hex digits for all @var{g} and @var{b} as well, making
|
|
either 3, 6, 9 or 12 hex digits in all. (See the documentation of the
|
|
X Window System for more details about numerical RGB specification of
|
|
colors.)
|
|
|
|
These functions provide a way to determine which color names are
|
|
valid, and what they look like. In some cases, the value depends on the
|
|
@dfn{selected frame}, as described below; see @ref{Input Focus}, for the
|
|
meaning of the term ``selected frame.''
|
|
|
|
@defun color-defined-p color &optional frame
|
|
This function reports whether a color name is meaningful. It returns
|
|
@code{t} if so; otherwise, @code{nil}. The argument @var{frame} says
|
|
which frame's display to ask about; if @var{frame} is omitted or
|
|
@code{nil}, the selected frame is used.
|
|
|
|
Note that this does not tell you whether the display you are using
|
|
really supports that color. When using X, you can ask for any defined
|
|
color on any kind of display, and you will get some result---typically,
|
|
the closest it can do. To determine whether a frame can really display
|
|
a certain color, use @code{color-supported-p} (see below).
|
|
|
|
@findex x-color-defined-p
|
|
This function used to be called @code{x-color-defined-p},
|
|
and that name is still supported as an alias.
|
|
@end defun
|
|
|
|
@defun defined-colors &optional frame
|
|
This function returns a list of the color names that are defined
|
|
and supported on frame @var{frame} (default, the selected frame).
|
|
If @var{frame} does not support colors, the value is @code{nil}.
|
|
|
|
@findex x-defined-colors
|
|
This function used to be called @code{x-defined-colors},
|
|
and that name is still supported as an alias.
|
|
@end defun
|
|
|
|
@defun color-supported-p color &optional frame background-p
|
|
This returns @code{t} if @var{frame} can really display the color
|
|
@var{color} (or at least something close to it). If @var{frame} is
|
|
omitted or @code{nil}, the question applies to the selected frame.
|
|
|
|
Some terminals support a different set of colors for foreground and
|
|
background. If @var{background-p} is non-@code{nil}, that means you are
|
|
asking whether @var{color} can be used as a background; otherwise you
|
|
are asking whether it can be used as a foreground.
|
|
|
|
The argument @var{color} must be a valid color name.
|
|
@end defun
|
|
|
|
@defun color-gray-p color &optional frame
|
|
This returns @code{t} if @var{color} is a shade of gray, as defined on
|
|
@var{frame}'s display. If @var{frame} is omitted or @code{nil}, the
|
|
question applies to the selected frame. If @var{color} is not a valid
|
|
color name, this function returns @code{nil}.
|
|
@end defun
|
|
|
|
@defun color-values color &optional frame
|
|
@cindex rgb value
|
|
This function returns a value that describes what @var{color} should
|
|
ideally look like on @var{frame}. If @var{color} is defined, the
|
|
value is a list of three integers, which give the amount of red, the
|
|
amount of green, and the amount of blue. Each integer ranges in
|
|
principle from 0 to 65535, but some displays may not use the full
|
|
range. This three-element list is called the @dfn{rgb values} of the
|
|
color.
|
|
|
|
If @var{color} is not defined, the value is @code{nil}.
|
|
|
|
@example
|
|
(color-values "black")
|
|
@result{} (0 0 0)
|
|
(color-values "white")
|
|
@result{} (65280 65280 65280)
|
|
(color-values "red")
|
|
@result{} (65280 0 0)
|
|
(color-values "pink")
|
|
@result{} (65280 49152 51968)
|
|
(color-values "hungry")
|
|
@result{} nil
|
|
@end example
|
|
|
|
The color values are returned for @var{frame}'s display. If
|
|
@var{frame} is omitted or @code{nil}, the information is returned for
|
|
the selected frame's display. If the frame cannot display colors, the
|
|
value is @code{nil}.
|
|
|
|
@findex x-color-values
|
|
This function used to be called @code{x-color-values},
|
|
and that name is still supported as an alias.
|
|
@end defun
|
|
|
|
@node Text Terminal Colors
|
|
@section Text Terminal Colors
|
|
@cindex colors on text-only terminals
|
|
|
|
Text-only terminals usually support only a small number of colors,
|
|
and the computer uses small integers to select colors on the terminal.
|
|
This means that the computer cannot reliably tell what the selected
|
|
color looks like; instead, you have to inform your application which
|
|
small integers correspond to which colors. However, Emacs does know
|
|
the standard set of colors and will try to use them automatically.
|
|
|
|
The functions described in this section control how terminal colors
|
|
are used by Emacs.
|
|
|
|
Several of these functions use or return @dfn{rgb values}, described
|
|
in @ref{Color Names}.
|
|
|
|
These functions accept a display (either a frame or the name of a
|
|
terminal) as an optional argument. We hope in the future to make Emacs
|
|
support more than one text-only terminal at one time; then this argument
|
|
will specify which terminal to operate on (the default being the
|
|
selected frame's terminal; @pxref{Input Focus}). At present, though,
|
|
the @var{frame} argument has no effect.
|
|
|
|
@defun tty-color-define name number &optional rgb frame
|
|
This function associates the color name @var{name} with
|
|
color number @var{number} on the terminal.
|
|
|
|
The optional argument @var{rgb}, if specified, is an rgb value, a list
|
|
of three numbers that specify what the color actually looks like.
|
|
If you do not specify @var{rgb}, then this color cannot be used by
|
|
@code{tty-color-approximate} to approximate other colors, because
|
|
Emacs will not know what it looks like.
|
|
@end defun
|
|
|
|
@defun tty-color-clear &optional frame
|
|
This function clears the table of defined colors for a text-only terminal.
|
|
@end defun
|
|
|
|
@defun tty-color-alist &optional frame
|
|
This function returns an alist recording the known colors supported by a
|
|
text-only terminal.
|
|
|
|
Each element has the form @code{(@var{name} @var{number} . @var{rgb})}
|
|
or @code{(@var{name} @var{number})}. Here, @var{name} is the color
|
|
name, @var{number} is the number used to specify it to the terminal.
|
|
If present, @var{rgb} is a list of three color values (for red, green,
|
|
and blue) that says what the color actually looks like.
|
|
@end defun
|
|
|
|
@defun tty-color-approximate rgb &optional frame
|
|
This function finds the closest color, among the known colors
|
|
supported for @var{display}, to that described by the rgb value
|
|
@var{rgb} (a list of color values). The return value is an element of
|
|
@code{tty-color-alist}.
|
|
@end defun
|
|
|
|
@defun tty-color-translate color &optional frame
|
|
This function finds the closest color to @var{color} among the known
|
|
colors supported for @var{display} and returns its index (an integer).
|
|
If the name @var{color} is not defined, the value is @code{nil}.
|
|
@end defun
|
|
|
|
@node Resources
|
|
@section X Resources
|
|
|
|
@defun x-get-resource attribute class &optional component subclass
|
|
The function @code{x-get-resource} retrieves a resource value from the X
|
|
Window defaults database.
|
|
|
|
Resources are indexed by a combination of a @dfn{key} and a @dfn{class}.
|
|
This function searches using a key of the form
|
|
@samp{@var{instance}.@var{attribute}} (where @var{instance} is the name
|
|
under which Emacs was invoked), and using @samp{Emacs.@var{class}} as
|
|
the class.
|
|
|
|
The optional arguments @var{component} and @var{subclass} add to the key
|
|
and the class, respectively. You must specify both of them or neither.
|
|
If you specify them, the key is
|
|
@samp{@var{instance}.@var{component}.@var{attribute}}, and the class is
|
|
@samp{Emacs.@var{class}.@var{subclass}}.
|
|
@end defun
|
|
|
|
@defvar x-resource-class
|
|
This variable specifies the application name that @code{x-get-resource}
|
|
should look up. The default value is @code{"Emacs"}. You can examine X
|
|
resources for application names other than ``Emacs'' by binding this
|
|
variable to some other string, around a call to @code{x-get-resource}.
|
|
@end defvar
|
|
|
|
@defvar x-resource-name
|
|
This variable specifies the instance name that @code{x-get-resource}
|
|
should look up. The default value is the name Emacs was invoked with,
|
|
or the value specified with the @samp{-name} or @samp{-rn} switches.
|
|
@end defvar
|
|
|
|
To illustrate some of the above, suppose that you have the line:
|
|
|
|
@example
|
|
xterm.vt100.background: yellow
|
|
@end example
|
|
|
|
@noindent
|
|
in your X resources file (whose name is usually @file{~/.Xdefaults}
|
|
or @file{~/.Xresources}). Then:
|
|
|
|
@example
|
|
@group
|
|
(let ((x-resource-class "XTerm") (x-resource-name "xterm"))
|
|
(x-get-resource "vt100.background" "VT100.Background"))
|
|
@result{} "yellow"
|
|
@end group
|
|
@group
|
|
(let ((x-resource-class "XTerm") (x-resource-name "xterm"))
|
|
(x-get-resource "background" "VT100" "vt100" "Background"))
|
|
@result{} "yellow"
|
|
@end group
|
|
@end example
|
|
|
|
@xref{X Resources,, X Resources, emacs, The GNU Emacs Manual}.
|
|
|
|
@node Display Feature Testing
|
|
@section Display Feature Testing
|
|
@cindex display feature testing
|
|
|
|
The functions in this section describe the basic capabilities of a
|
|
particular display. Lisp programs can use them to adapt their behavior
|
|
to what the display can do. For example, a program that ordinarily uses
|
|
a popup menu could use the minibuffer if popup menus are not supported.
|
|
|
|
The optional argument @var{display} in these functions specifies which
|
|
display to ask the question about. It can be a display name, a frame
|
|
(which designates the display that frame is on), or @code{nil} (which
|
|
refers to the selected frame's display, @pxref{Input Focus}).
|
|
|
|
@xref{Color Names}, @ref{Text Terminal Colors}, for other functions to
|
|
obtain information about displays.
|
|
|
|
@defun display-popup-menus-p &optional display
|
|
This function returns @code{t} if popup menus are supported on
|
|
@var{display}, @code{nil} if not. Support for popup menus requires that
|
|
the mouse be available, since the user cannot choose menu items without
|
|
a mouse.
|
|
@end defun
|
|
|
|
@defun display-graphic-p &optional display
|
|
This function returns @code{t} if @var{display} is a graphic display
|
|
capable of displaying several frames and several different fonts at
|
|
once. This is true for displays that use a window system such as X, and
|
|
false for text-only terminals.
|
|
@end defun
|
|
|
|
@defun display-mouse-p &optional display
|
|
@cindex mouse, availability
|
|
This function returns @code{t} if @var{display} has a mouse available,
|
|
@code{nil} if not.
|
|
@end defun
|
|
|
|
@defun display-color-p &optional display
|
|
@findex x-display-color-p
|
|
This function returns @code{t} if the screen is a color screen.
|
|
It used to be called @code{x-display-color-p}, and that name
|
|
is still supported as an alias.
|
|
@end defun
|
|
|
|
@defun display-grayscale-p &optional display
|
|
This function returns @code{t} if the screen can display shades of gray.
|
|
(All color displays can do this.)
|
|
@end defun
|
|
|
|
@defun display-supports-face-attributes-p attributes &optional display
|
|
@anchor{Display Face Attribute Testing}
|
|
This function returns non-@code{nil} if all the face attributes in
|
|
@var{attributes} are supported (@pxref{Face Attributes}).
|
|
|
|
The definition of `supported' is somewhat heuristic, but basically
|
|
means that a face containing all the attributes in @var{attributes},
|
|
when merged with the default face for display, can be represented in a
|
|
way that's
|
|
|
|
@enumerate
|
|
@item
|
|
different in appearance than the default face, and
|
|
|
|
@item
|
|
`close in spirit' to what the attributes specify, if not exact.
|
|
@end enumerate
|
|
|
|
Point (2) implies that a @code{:weight black} attribute will be
|
|
satisfied by any display that can display bold, as will
|
|
@code{:foreground "yellow"} as long as some yellowish color can be
|
|
displayed, but @code{:slant italic} will @emph{not} be satisfied by
|
|
the tty display code's automatic substitution of a `dim' face for
|
|
italic.
|
|
@end defun
|
|
|
|
@defun display-selections-p &optional display
|
|
This function returns @code{t} if @var{display} supports selections.
|
|
Windowed displays normally support selections, but they may also be
|
|
supported in some other cases.
|
|
@end defun
|
|
|
|
@defun display-images-p &optional display
|
|
This function returns @code{t} if @var{display} can display images.
|
|
Windowed displays ought in principle to handle images, but some
|
|
systems lack the support for that. On a display that does not support
|
|
images, Emacs cannot display a tool bar.
|
|
@end defun
|
|
|
|
@defun display-screens &optional display
|
|
This function returns the number of screens associated with the display.
|
|
@end defun
|
|
|
|
@defun display-pixel-height &optional display
|
|
This function returns the height of the screen in pixels.
|
|
On a character terminal, it gives the height in characters.
|
|
|
|
For graphical terminals, note that on ``multi-monitor'' setups this
|
|
refers to the pixel width for all physical monitors associated with
|
|
@var{display}. @xref{Multiple Displays}.
|
|
@end defun
|
|
|
|
@defun display-pixel-width &optional display
|
|
This function returns the width of the screen in pixels.
|
|
On a character terminal, it gives the width in characters.
|
|
|
|
For graphical terminals, note that on ``multi-monitor'' setups this
|
|
refers to the pixel width for all physical monitors associated with
|
|
@var{display}. @xref{Multiple Displays}.
|
|
@end defun
|
|
|
|
@defun display-mm-height &optional display
|
|
This function returns the height of the screen in millimeters,
|
|
or @code{nil} if Emacs cannot get that information.
|
|
@end defun
|
|
|
|
@defun display-mm-width &optional display
|
|
This function returns the width of the screen in millimeters,
|
|
or @code{nil} if Emacs cannot get that information.
|
|
@end defun
|
|
|
|
@defvar display-mm-dimensions-alist
|
|
This variable allows the user to specify the dimensions of graphical
|
|
displays returned by @code{display-mm-height} and
|
|
@code{display-mm-width} in case the system provides incorrect values.
|
|
@end defvar
|
|
|
|
@defun display-backing-store &optional display
|
|
This function returns the backing store capability of the display.
|
|
Backing store means recording the pixels of windows (and parts of
|
|
windows) that are not exposed, so that when exposed they can be
|
|
displayed very quickly.
|
|
|
|
Values can be the symbols @code{always}, @code{when-mapped}, or
|
|
@code{not-useful}. The function can also return @code{nil}
|
|
when the question is inapplicable to a certain kind of display.
|
|
@end defun
|
|
|
|
@defun display-save-under &optional display
|
|
This function returns non-@code{nil} if the display supports the
|
|
SaveUnder feature. That feature is used by pop-up windows
|
|
to save the pixels they obscure, so that they can pop down
|
|
quickly.
|
|
@end defun
|
|
|
|
@defun display-planes &optional display
|
|
This function returns the number of planes the display supports.
|
|
This is typically the number of bits per pixel.
|
|
For a tty display, it is log to base two of the number of colors supported.
|
|
@end defun
|
|
|
|
@defun display-visual-class &optional display
|
|
This function returns the visual class for the screen. The value is one
|
|
of the symbols @code{static-gray}, @code{gray-scale},
|
|
@code{static-color}, @code{pseudo-color}, @code{true-color}, and
|
|
@code{direct-color}.
|
|
@end defun
|
|
|
|
@defun display-color-cells &optional display
|
|
This function returns the number of color cells the screen supports.
|
|
@end defun
|
|
|
|
These functions obtain additional information specifically
|
|
about X displays.
|
|
|
|
@defun x-server-version &optional display
|
|
This function returns the list of version numbers of the X server
|
|
running the display. The value is a list of three integers: the major
|
|
and minor version numbers of the X protocol, and the
|
|
distributor-specific release number of the X server software itself.
|
|
@end defun
|
|
|
|
@defun x-server-vendor &optional display
|
|
This function returns the ``vendor'' that provided the X server
|
|
software (as a string). Really this means whoever distributes the X
|
|
server.
|
|
|
|
When the developers of X labelled software distributors as
|
|
``vendors,'' they showed their false assumption that no system could
|
|
ever be developed and distributed noncommercially.
|
|
@end defun
|
|
|
|
@ignore
|
|
@defvar x-no-window-manager
|
|
This variable's value is @code{t} if no X window manager is in use.
|
|
@end defvar
|
|
@end ignore
|
|
|
|
@ignore
|
|
@item
|
|
The functions @code{x-pixel-width} and @code{x-pixel-height} return the
|
|
width and height of an X Window frame, measured in pixels.
|
|
@end ignore
|
|
|
|
@ignore
|
|
arch-tag: 94977df6-3dca-4730-b57b-c6329e9282ba
|
|
@end ignore
|