Unless I'm misunderstanding the documentation. It seems that the ENABLED-P slot in the button descriptor only gets evaluated when the specifier is evaluated. I am in the midst of writing all the test cases for XEmacs/GTK and first off was making sure dynamically-enabled toolbar buttons worked. Guess what, they don't work in XEmacs 21.1.10 either. :( With this test function: ------------------------------------------------------------------------------- (defvar gtk-torture-test-toolbar-open-active-p t) (defvar gtk-torture-test-toolbar '([toolbar-file-icon (lambda () (setq gtk-torture-test-toolbar-open-active-p (not gtk-torture-test-toolbar-open-active-p))) gtk-torture-test-toolbar-open-active-p "Open a file"] [toolbar-folder-icon toolbar-dired t "Edit a directory"] [toolbar-disk-icon toolbar-save t "Save buffer"] [toolbar-printer-icon toolbar-print t "Print buffer"] [toolbar-cut-icon toolbar-cut t "Kill region"] [toolbar-copy-icon toolbar-copy t "Copy region"] [toolbar-paste-icon toolbar-paste t "Paste from clipboard"] [toolbar-undo-icon toolbar-undo t "Undo edit"] [toolbar-spell-icon toolbar-ispell t "Check spelling"] [toolbar-replace-icon toolbar-replace t "Search & Replace"] [toolbar-mail-icon toolbar-mail t "Read mail"] [toolbar-info-icon toolbar-info t "Info documentation"] [toolbar-compile-icon toolbar-compile t "Start a compilation"] [toolbar-debug-icon toolbar-debug t "Start a debugger"] [toolbar-news-icon toolbar-news t "Read news"] )) (defun gtk-torture-test-toolbar () (interactive) (switch-to-buffer (get-buffer-create "Toolbar testing")) (set-specifier default-toolbar gtk-torture-test-toolbar (current-buffer)) (set-specifier default-toolbar-visible-p t (current-buffer))) ------------------------------------------------------------------------------- If you do M-x gtk-torture-test-toolbar, you will get a buffer with a toolbar that looks normal, but if you click the 'open' button, I would have expected the toolbar button to be immediately marked as disabled. But it is not until you switch buffers to another buffer and then back to the 'Toolbar testing' buffer. If this is the way things are meant to be, then the documentation in default-toolbar needs to be updated to reflect this. It makes it sound like this slot will get evaluated quite a bit. Perhaps if there was a (set-toolbar-dirty-flag position) function... but that is kind of ugly. -Bill P.