diff options
Diffstat (limited to 'lisp/help-fns.el')
| -rw-r--r-- | lisp/help-fns.el | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/lisp/help-fns.el b/lisp/help-fns.el index b9536470631..5a99103f6af 100644 --- a/lisp/help-fns.el +++ b/lisp/help-fns.el @@ -1769,6 +1769,50 @@ documentation for the major and minor modes of that buffer." ;; For the sake of IELM and maybe others nil) +;; Widgets. + +(defvar describe-widget-functions + '(button-describe widget-describe) + "A list of functions for `describe-widget' to call. +Each function should take one argument, a buffer position, and return +non-nil if it described a widget at that position.") + +;;;###autoload +(defun describe-widget (&optional pos) + "Display a buffer with information about a widget. +You can use this command to describe buttons (e.g., the links in a *Help* +buffer), editable fields of the customization buffers, etc. + +Interactively, click on a widget to describe it, or hit RET to describe the +widget at point. + +When called from Lisp, POS may be a buffer position or a mouse position list. + +Calls each function of the list `describe-widget-functions' in turn, until +one of them returns non-nil." + (interactive + (list + (let ((key + (read-key + "Click on a widget, or hit RET to describe the widget at point"))) + (cond ((eq key ?\C-m) (point)) + ((and (mouse-event-p key) + (eq (event-basic-type key) 'mouse-1) + (equal (event-modifiers key) '(click))) + (event-end key)) + ((eq key ?\C-g) (signal 'quit nil)) + (t (user-error "You didn't specify a widget")))))) + (let (buf) + ;; Allow describing a widget in a different window. + (when (posnp pos) + (setq buf (window-buffer (posn-window pos)) + pos (posn-point pos))) + (with-current-buffer (or buf (current-buffer)) + (unless (cl-some (lambda (fun) (when (fboundp fun) (funcall fun pos))) + describe-widget-functions) + (message "No widget found at that position"))))) + + ;;; Replacements for old lib-src/ programs. Don't seem especially useful. ;; Replaces lib-src/digest-doc.c. |