There are several ways to supply the image for a toolbar button, including direct specification of an image object. The simplest approach is to use a symbol which is registered as an image identifier, including the pre-registered standard images, as in the preceding examples. For details of this and the other way to supply images, see toolbar-button.
You can, if desired, supply an alternative image which is displayed while the button is selected in a :multiple-selection
component (see 9.7 Advanced toolbar features), using the initarg selected-image.
In a toolbar-component it is possible to specify images for the buttons by supplying an image-set as the default-image-set, along with integers in the images initarg specifying the index for the image of each button:
(display (make-instance 'interface :toolbar-items (list (make-instance 'toolbar-component :items '(1 2) :names '(1 2) :texts '("One" "Two") :images '(0 1) :default-image-set (make-general-image-set :image-count 5 :id (gp:read-external-image (example-file "capi/elements/images/toolbar-radio-images.bmp") :transparent-color-index 7))))))
CAPI User Guide and Reference Manual (Unix version) - 01 Dec 2021 19:32:36