ambevar-dotfiles/.emacs.d/lisp/patch-helm.el

(defvar helm-buffer-switcher-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map helm-map)
    (define-key map (kbd "C-c o") 'helm-buffer-switch-other-window)
    (define-key map (kbd "C-c C-o") 'helm-buffer-switch-other-frame)
    (define-key map (kbd "M-D") 'helm-buffer-run-kill-buffers)
    map)
  "Keymap for buffer switcher source in Helm.")

(defun helm-buffer-transformer (buffers)
  (mapcar #'buffer-name buffers))

(defmacro helm-deflister (name predicate new-fn &optional extra-sources)
  (let ((buffer-source-name (format "%s buffers" name)))
    (add-to-list 'helm-source-names-using-follow buffer-source-name)
    `(defun ,(intern (format "helm-%s-buffers" (downcase name))) ()
       (interactive)
       (helm :sources
             (list (helm-build-sync-source ,buffer-source-name
                     :candidates (seq-filter ,predicate (buffer-list))
                     :candidate-transformer #'helm-buffer-transformer
                     :action '(("Switch to buffer(s)" . helm-buffer-switch-buffers)
                               (,(substitute-command-keys "Switch to buffer(s) in other window \\<helm-buffer-switcher-map>`\\[helm-buffer-switch-other-window]'")
                                . helm-buffer-switch-buffers-other-window)
                               (,(substitute-command-keys "Switch to buffer in other frame \\<helm-buffer-switcher-map>`\\[helm-buffer-switch-other-frame]'")
                                . switch-to-buffer-other-frame)
                               (,(substitute-command-keys "Kill buffer(s) \\<helm-buffer-switcher-map>`\\[helm-buffer-run-kill-buffers]'")
                                . helm-kill-marked-buffers))
                     :keymap helm-buffer-switcher-map
                     :persistent-action 'helm-buffers-list-persistent-action)
                   ,@extra-sources
                   (helm-build-dummy-source ,(format "Open new %s" name)
                     :action (helm-make-actions ,(format "Open new %s" name) ',new-fn)))
             :buffer ,(format "*helm-%s-buffers*" name)))))

(defmacro helm-defswitcher (name predicate new-fn &optional extra-sources)
  "Create an interactive Eshell buffer.
Switch to last Eshell session if any.
Otherwise create a new one and switch to it.
See `eshell' for the numeric prefix ARG."
  (let ((mode (intern (format "%s-mode" (downcase name)))))
    `(progn
       (helm-deflister ,name ,predicate ,new-fn ,extra-sources)
       (defun ,(intern (format "helm-%s-switch" (downcase name))) (&rest arg)
         (interactive "P")
         (if (or arg (derived-mode-p ',mode))
             ;; TODO: Funcall the return value of helm-deflister.
             (funcall ',(intern (format  "helm-%s-buffers" (downcase name))))
           (let ((last (cl-loop for buffer in (buffer-list)
                                when (funcall ,predicate buffer)
                                return buffer)))
             (if last
                 (switch-to-buffer last)
               (funcall ,new-fn))))))))

(provide 'patch-helm)