;;; -*- lexical-binding: t -*-
;;
;; this file:
;;   https://dataswamp.org/~incal/emacs-init/erc/erc-element.el
;;
;; Tab through and cycle ERC interactive elements.
;;
;; An element is as for now either a button or the ERC input
;; prompt; eventually it should or could be any interactive
;; object visible in the ERC buffer.
;;
;; To use this with keys, bind for example backtab to
;; `erc-element-prev' and C-<tab> to `erc-element-next' in
;; `erc-mode-map'. But note then that these keys must also be
;; bound the same way in `erc-button-keymap' since that is in
;; effect when point is over a button.

(require 'erc)
(require 'erc-button)

(defun erc-at-prompt-p ()
  (let ((pos (marker-position erc-insert-marker)))
    (<= pos (point)) ))

(defun erc-element-next (&optional prev)
  (interactive "P")
  (when (erc-at-prompt-p)
    (goto-char (point-min)) )
  (condition-case nil
      (if prev
          (erc-button-previous 1)
        (erc-button-next 1) )
    (error (progn
             (goto-char (point-max))
             (when prev
               (erc-bol) )))))

(defun erc-element-prev ()
  (interactive)
  (let ((beg (point)))
    (erc-element-next t)
    (when (= (point) beg)
      (forward-line 0)
      (backward-char)
      (erc-element-next t) )))

(provide 'erc-element)