helm-projectile-elscreen-find-file.el

(defun my/helm-elscreen-find-file-or-marked (candidate)
  "Open file CANDIDATE or open helm marked files with elscreen.
Called with a prefix arg open files in background without selecting them."
  (let ((marked (helm-marked-candidates :with-wildcard t))
        (url-p (and ffap-url-regexp ; we should have only one candidate.
                    (string-match ffap-url-regexp candidate)))
        (ffap-newfile-prompt helm-ff-newfile-prompt-p)
        (find-file-wildcards nil)
        (make-dir-fn
         (lambda (dir &optional helm-ff)
           (when (or (not confirm-nonexistent-file-or-buffer)
                     (y-or-n-p (format "Create directory `%s'? " dir)))
             (let ((dirfname (directory-file-name dir)))
               (if (file-exists-p dirfname)
                   (error
                    "Mkdir: Unable to create directory `%s': file exists."
                    (helm-basename dirfname))
                 (make-directory dir 'parent)))
             (when helm-ff
               ;; Allow having this new dir in history
               ;; to be able to retrieve it immediately
               ;; if we want to e.g copy a file from somewhere in it.
               (setq helm-ff-default-directory
                     (file-name-as-directory dir))
               (push helm-ff-default-directory helm-ff-history))
             (or (and helm-ff (helm-find-files-1 dir)) t))))
        (helm--reading-passwd-or-string t))
    (if (cdr marked)
        (if helm-current-prefix-arg
            (dired-simultaneous-find-file marked nil)
          (mapc 'elscreen-find-file (cdr marked))
          (elscreen-find-file (car marked)))
      (if (and (not (file-exists-p candidate))
               (not url-p)
               (string-match "/$" candidate))
          ;; A a non--existing filename ending with /
          ;; Create a directory and jump to it.
          (funcall make-dir-fn candidate 'helm-ff)
        ;; A non--existing filename NOT ending with / or
        ;; an existing filename, create or jump to it.
        ;; If the basedir of candidate doesn't exists,
        ;; ask for creating it.
        (let ((dir (and (not url-p) (helm-basedir candidate))))
          (elscreen-find-file
           (cond ((and dir (file-directory-p dir))
                  (substitute-in-file-name candidate))
                 (url-p candidate)
                 ((funcall make-dir-fn dir) candidate))))))))

(defvar my/helm-source-projectile-elscreen-files-list
  (helm-build-in-buffer-source "Projectile files"
    :data (lambda ()
            (condition-case nil
                (projectile-current-project-files)
              (error nil)))
    :fuzzy-match helm-projectile-fuzzy-match
    :coerce 'helm-projectile-coerce-file
    :keymap helm-projectile-find-file-map
    :help-message 'helm-ff-help-message
    :mode-line helm-read-file-name-mode-line-string
    :action (cons my/helm-elscreen-find-file-or-marked 
                  helm-projectile-file-actions))
  "Helm source definition for Projectile files.")

(helm-projectile-command "elscreen-find-file" 'my/helm-source-projectile-elscreen-files-list "Find file in projects (elscreen): " t)