Improve elpy-shell-echo-output 'when-shell-not-visible for multiple frames

[dafxy]

Here is how to make it work with multiple frames.

(defmacro elpy-shell--with-maybe-echo-output (body)
  "Run BODY and grab shell output according to `elpy-shell-echo-output'.

This modifies the original function to check if shell is visible in other frames

"
  `(cl-letf (((symbol-function 'python-shell-send-file)
              (if elpy-shell-echo-output
                  (symbol-function 'elpy-shell-send-file)
                (symbol-function 'python-shell-send-file))))
     (let* ((process (elpy-shell--ensure-shell-running))
            (process-buf (process-buffer process))
            ;; Check if the buffer is visible in any window of any frame
            (shell-visible (or elpy-shell-display-buffer-after-send
                               (get-buffer-window-list process-buf nil t)))) ; Checks all frames
       (with-current-buffer process-buf
         (setq-local elpy-shell--capture-output
                     (and elpy-shell-echo-output
                          (or (not (eq elpy-shell-echo-output 'when-shell-not-visible))
                              (not (null shell-visible)))))) ; Properly check for visibility
       (progn ,body))))