@c -*-texinfo-*-
@c This is part of the XEmacs Lisp Reference Manual.
@c Copyright (C) 1995, 1996 Ben Wing.
@c See the file lispref.texi for copying conditions.
@setfilename ../../info/toolbar.info
@node Toolbar, Scrollbars, Dialog Boxes, top
@chapter Toolbar
@cindex toolbar

@menu
* Toolbar Intro::		An introduction.
* Toolbar Descriptor Format::	How to create a toolbar.
* Specifying the Toolbar::	Setting a toolbar's contents.
* Other Toolbar Variables::	Controlling the size of toolbars.
@end menu

@node Toolbar Intro
@section Toolbar Intro

A @dfn{toolbar} is a bar of icons displayed along one edge of a frame.
You can view a toolbar as a series of menu shortcuts -- the most
common menu options can be accessed with a single click rather than
a series of clicks and/or drags to select the option from a menu.
Consistent with this, a help string (called the @dfn{help-echo})
describing what an icon in the toolbar (called a @dfn{toolbar button})
does, is displayed in the minibuffer when the mouse is over the
button.

In XEmacs, a toolbar can be displayed along any of the four edges
of the frame, and two or more different edges can be displaying
toolbars simultaneously.  The contents, thickness, and visibility of
the toolbars can be controlled separately, and the values can
be per-buffer, per-frame, etc., using specifiers (@pxref{Specifiers}).

Normally, there is one toolbar displayed in a frame.  Usually, this is
the standard toolbar, but certain modes will override this and
substitute their own toolbar.  In some cases (e.g. the VM package), a
package will supply its own toolbar along a different edge from the
standard toolbar, so that both can be visible at once.  This standard
toolbar is usually positioned along the top of the frame, but this can
be changed using @code{set-default-toolbar-position}.

Note that, for each of the toolbar properties (contents, thickness,
and visibility), there is a separate specifier for each of the four
toolbar positions (top, bottom, left, and right), and an additional
specifier for the ``default'' toolbar, i.e. the toolbar whose
position is controlled by @code{set-default-toolbar-position}.  The
way this works is that @code{set-default-toolbar-position} arranges
things so that the appropriate position-specific specifiers for the
default position inherit from the corresponding default specifiers.
That way, if the position-specific specifier does not give a value
(which it usually doesn't), then the value from the default
specifier applies.  If you want to control the default toolbar, you
just change the default specifiers, and everything works.  A package
such as VM that wants to put its own toolbar in a different location
from the default just sets the position-specific specifiers, and if
the user sets the default toolbar to the same position, it will just
not be visible.

@node Toolbar Descriptor Format
@section Toolbar Descriptor Format

The contents of a toolbar are specified using a @dfn{toolbar descriptor}.
The format of a toolbar descriptor is a list of @dfn{toolbar button
descriptors}.  Each toolbar button descriptor is a vector in one of the
following formats:

@itemize @bullet
@item
@code{[@var{glyph-list} @var{function} @var{enabled-p} @var{help}]}
@item
@code{[:style @var{2d-or-3d}]}
@item
@code{[:style @var{2d-or-3d} :size @var{width-or-height}]}
@item
@code{[:size @var{width-or-height} :style @var{2d-or-3d}]}
@end itemize

Optionally, one of the toolbar button descriptors may be @code{nil}
instead of a vector; this signifies the division between the toolbar
buttons that are to be displayed flush-left, and the buttons to be
displayed flush-right.

The first vector format above specifies a normal toolbar button;
the others specify blank areas in the toolbar.

For the first vector format:

@itemize @bullet
@item
@var{glyph-list} should be a list of one to six glyphs (as created by
@code{make-glyph}) or a symbol whose value is such a list.  The first
glyph, which must be provided, is the glyph used to display the toolbar
button when it is in the ``up'' (not pressed) state.  The optional
second glyph is for displaying the button when it is in the ``down''
(pressed) state.  The optional third glyph is for when the button is
disabled.  The last three glyphs are for displaying the button in the
``up'', ``down'', and ``disabled'' states, respectively, but are used
when the user has called for captioned toolbar buttons (using
@code{toolbar-buttons-captioned-p}).  The function
@code{toolbar-make-button-list} is useful in creating these glyph lists.

@item
Even if you do not provide separate down-state and disabled-state
glyphs, the user will still get visual feedback to indicate which
state the button is in.  Buttons in the up-state are displayed
with a shadowed border that gives a raised appearance to the
button.  Buttons in the down-state are displayed with shadows that
give a recessed appearance.  Buttons in the disabled state are
displayed with no shadows, giving a 2-d effect.

@item
If some of the toolbar glyphs are not provided, they inherit as follows:

@example
     UP:                up
     DOWN:              down -> up
     DISABLED:          disabled -> up
     CAP-UP:            cap-up -> up
     CAP-DOWN:          cap-down -> cap-up -> down -> up
     CAP-DISABLED:      cap-disabled -> cap-up -> disabled -> up
@end example

@item
The second element @var{function} is a function to be called when the
toolbar button is activated (i.e. when the mouse is released over the
toolbar button, if the press occurred in the toolbar).  It can be any
form accepted by @code{call-interactively}, since this is how it is
invoked.

@item
The third element @var{enabled-p} specifies whether the toolbar button
is enabled (disabled buttons do nothing when they are activated, and are
displayed differently; see above).  It should be either a boolean or a
form that evaluates to a boolean.

@item
The fourth element @var{help}, if non-@code{nil}, should be a string.
This string is displayed in the echo area when the mouse passes over the
toolbar button.
@end itemize

For the other vector formats (specifying blank areas of the toolbar):

@itemize @bullet
@item
@var{2d-or-3d} should be one of the symbols @code{2d} or @code{3d},
indicating whether the area is displayed with shadows (giving it a
raised, 3-d appearance) or without shadows (giving it a flat
appearance).

@item
@var{width-or-height} specifies the length, in pixels, of the blank
area.  If omitted, it defaults to a device-specific value (8 pixels for
X devices).
@end itemize

@defun toolbar-make-button-list up &optional down disabled cap-up cap-down cap-disabled
This function calls @code{make-glyph} on each arg and returns a list of
the results.  This is useful for setting the first argument of a toolbar
button descriptor (typically, the result of this function is assigned
to a symbol, which is specified as the first argument of the toolbar
button descriptor).
@end defun

@defun check-toolbar-button-syntax button &optional noerror
Verify the syntax of entry @var{button} in a toolbar description list.
If you want to verify the syntax of a toolbar description list as a
whole, use @code{check-valid-instantiator} with a specifier type of
@code{toolbar}.
@end defun

@node Specifying the Toolbar
@section Specifying the Toolbar

In order to specify the contents of a toolbar, set one of the specifier
variables @code{default-toolbar}, @code{top-toolbar},
@code{bottom-toolbar}, @code{left-toolbar}, or @code{right-toolbar}.
These are specifiers, which means you set them with @code{set-specifier}
and query them with @code{specifier-specs} or @code{specifier-instance}.
You will get an error if you try to set them using @code{setq}.  The
valid instantiators for these specifiers are toolbar descriptors, as
described above.  @xref{Specifiers}, for more information.

Most of the time, you will set @code{default-toolbar}, which allows
the user to choose where the toolbar should go.

@defvr Specifier default-toolbar
The position of this toolbar is specified in the function
@code{default-toolbar-position}.  If the corresponding 
position-specific toolbar (e.g. @code{top-toolbar} if
@code{default-toolbar-position} is @code{top}) does not specify a
toolbar in a particular domain, then the value of @code{default-toolbar}
in that domain, of any, will be used instead.
@end defvr

Note that the toolbar at any particular position will not be displayed
unless its thickness (width or height, depending on orientation) is
non-zero and its visibility status is true.  The thickness is controlled
by the specifiers @code{top-toolbar-height},
@code{bottom-toolbar-height}, @code{left-toolbar-width}, and
@code{right-toolbar-width}, and the visibility status is controlled by
the specifiers @code{top-toolbar-visible-p},
@code{bottom-toolbar-visible-p}, @code{left-toolbar-visible-p}, and
@code{right-toolbar-visible-p} (@pxref{Other Toolbar Variables}).

@defun set-default-toolbar-position position
This function sets the position that the @code{default-toolbar} will be
displayed at.  Valid positions are the symbols @code{top},
@code{bottom}, @code{left} and @code{right}.  What this actually does is
set the fallback specifier for the position-specific specifier
corresponding to the given position to @code{default-toolbar}, and set
the fallbacks for the other position-specific specifiers to @code{nil}.
It also does the same thing for the position-specific thickness and
visibility specifiers, which inherit from one of
@code{default-toolbar-height} or @code{default-toolbar-width}, and from
@code{default-toolbar-visible-p}, respectively (@pxref{Other Toolbar
Variables}).
@end defun

@defun default-toolbar-position
This function returns the position that the @code{default-toolbar} will
be displayed at.
@end defun

You can also explicitly set a toolbar at a particular position.  When
redisplay determines what to display at a particular position in a
particular domain (i.e. window), it first consults the position-specific
toolbar.  If that does not yield a toolbar descriptor, the
@code{default-toolbar} is consulted if @code{default-toolbar-position}
indicates this position.

@defvr Specifier top-toolbar
Specifier for the toolbar at the top of the frame.
@end defvr

@defvr Specifier bottom-toolbar
Specifier for the toolbar at the bottom of the frame.
@end defvr

@defvr Specifier left-toolbar
Specifier for the toolbar at the left edge of the frame.
@end defvr

@defvr Specifier right-toolbar
Specifier for the toolbar at the right edge of the frame.
@end defvr

@defun toolbar-specifier-p object
This function returns non-nil if @var{object} is a toolbar specifier.
Toolbar specifiers are the actual objects contained in the toolbar
variables described above, and their valid instantiators are
toolbar descriptors (@pxref{Toolbar Descriptor Format}).
@end defun

@node Other Toolbar Variables
@section Other Toolbar Variables

The variables to control the toolbar thickness, visibility status, and
captioned status are all specifiers.  @xref{Specifiers}.

@defvr Specifier default-toolbar-height
This specifies the height of the default toolbar, if it's oriented
horizontally.  The position of the default toolbar is specified by the
function @code{set-default-toolbar-position}.  If the corresponding
position-specific toolbar thickness specifier
(e.g. @code{top-toolbar-height} if @code{default-toolbar-position} is
@code{top}) does not specify a thickness in a particular domain (a
window or a frame), then the value of @code{default-toolbar-height} or
@code{default-toolbar-width} (depending on the toolbar orientation) in
that domain, if any, will be used instead.
@end defvr

@defvr Specifier default-toolbar-width
This specifies the width of the default toolbar, if it's oriented
vertically.  This behaves like @code{default-toolbar-height}.
@end defvr

Note that @code{default-toolbar-height} is only used when
@code{default-toolbar-position} is @code{top} or @code{bottom}, and
@code{default-toolbar-width} is only used when
@code{default-toolbar-position} is @code{left} or @code{right}.

@defvr Specifier top-toolbar-height
This specifies the height of the top toolbar.
@end defvr

@defvr Specifier bottom-toolbar-height
This specifies the height of the bottom toolbar.
@end defvr

@defvr Specifier left-toolbar-width
This specifies the width of the left toolbar.
@end defvr

@defvr Specifier right-toolbar-width
This specifies the width of the right toolbar.
@end defvr

Note that all of the position-specific toolbar thickness specifiers
have a fallback value of zero when they do not correspond to the
default toolbar.  Therefore, you will have to set a non-zero thickness
value if you want a position-specific toolbar to be displayed.

@defvr Specifier default-toolbar-visible-p
This specifies whether the default toolbar is visible.  The position of
the default toolbar is specified by the function
@code{set-default-toolbar-position}.  If the corresponding position-specific
toolbar visibility specifier (e.g. @code{top-toolbar-visible-p} if
@code{default-toolbar-position} is @code{top}) does not specify a
visible-p value in a particular domain (a window or a frame), then the
value of @code{default-toolbar-visible-p} in that domain, if any, will
be used instead.
@end defvr

@defvr Specifier top-toolbar-visible-p
This specifies whether the top toolbar is visible.
@end defvr

@defvr Specifier bottom-toolbar-visible-p
This specifies whether the bottom toolbar is visible.
@end defvr

@defvr Specifier left-toolbar-visible-p
This specifies whether the left toolbar is visible.
@end defvr

@defvr Specifier right-toolbar-visible-p
This specifies whether the right toolbar is visible.
@end defvr

@code{default-toolbar-visible-p} and all of the position-specific
toolbar visibility specifiers have a fallback value of true.

Internally, toolbar thickness and visibility specifiers are instantiated
in both window and frame domains, for different purposes.  The value in
the domain of a frame's selected window specifies the actual toolbar
thickness or visibility that you will see in that frame.  The value in
the domain of a frame itself specifies the toolbar thickness or
visibility that is used in frame geometry calculations.

Thus, for example, if you set the frame width to 80 characters and the
left toolbar width for that frame to 68 pixels, then the frame will be
sized to fit 80 characters plus a 68-pixel left toolbar.  If you then
set the left toolbar width to 0 for a particular buffer (or if that
buffer does not specify a left toolbar or has a nil value specified for
@code{left-toolbar-visible-p}), you will find that, when that buffer is
displayed in the selected window, the window will have a width of 86 or
87 characters -- the frame is sized for a 68-pixel left toolbar but the
selected window specifies that the left toolbar is not visible, so it is
expanded to take up the slack.

@defvr Specifier toolbar-buttons-captioned-p
Whether toolbar buttons are captioned.  This affects which glyphs from a
toolbar button descriptor are chosen.  @xref{Toolbar Descriptor Format}.
@end defvr

You can also reset the toolbar to what it was when XEmacs started up.

@defvr Constant initial-toolbar-spec
The toolbar descriptor used to initialize @code{default-toolbar} at
startup.
@end defvr
