using an indirection through @code{tool-bar-map}.
@defvar tool-bar-map
-@tindex tool-bar-map
By default, the global map binds @code{[tool-bar]} as follows:
@example
(global-set-key [tool-bar]
follows.
@defun tool-bar-add-item icon def key &rest props
-@tindex tool-bar-add-item
This function adds an item to the tool bar by modifying
@code{tool-bar-map}. The image to use is defined by @var{icon}, which
is the base name of an XPM, XBM or PBM image file to be located by
@end defun
@defun tool-bar-add-item-from-menu command icon &optional map &rest props
-@tindex tool-bar-add-item-from-menu
This function is a convenience for defining tool bar items which are
consistent with existing menu bar bindings. The binding of
@var{command} is looked up in the menu bar in @var{map} (default
@code{tool-bar-add-item-from-menu}.
@end defun
-@tindex auto-resize-tool-bar
@defvar auto-resize-tool-bar
If this variable is non-@code{nil}, the tool bar automatically resizes to
show all defined tool bar items---but not larger than a quarter of the
frame's height.
@end defvar
-@tindex auto-raise-tool-bar-buttons
@defvar auto-raise-tool-bar-buttons
If this variable is non-@code{nil}, tool bar items display
in raised form when the mouse moves over them.
@end defvar
-@tindex tool-bar-button-margin
@defvar tool-bar-button-margin
This variable specifies an extra margin to add around tool bar items.
The value is an integer, a number of pixels. The default is 4.
@end defvar
-@tindex tool-bar-button-relief
@defvar tool-bar-button-relief
This variable specifies the shadow width for tool bar items.
The value is an integer, a number of pixels. The default is 1.
@end defvar
-@tindex tool-bar-border
@defvar tool-bar-border
This variable specifies the height of the border drawn below the tool
bar area. An integer value specifies height as a number of pixels.