window-purpose layer: fix for opening new eyebrowse workspace

Make sure spacemacs home buffers is the only window in the frame after
creating a new eyebrowse workspace.

contrib/!window-management/window-purpose/packages.el

@@ -104,4 +104,28 @@ PURPOSE defaults to the purpose of the current buffer."
 
 (defun window-purpose/post-init-window-purpose ()
   ;; *LV* buffer is used by corelv.el
-  (push "^\\*LV\\*$" purpose-action-function-ignore-buffer-names))
+  (push "^\\*LV\\*$" purpose-action-function-ignore-buffer-names)
+
+  (defvar window-purpose--eyebrowse-new-workspace eyebrowse-new-workspace)
+
+  (defun window-purpose/new-workspace ()
+    "Create a new eyebrowse workspace."
+    ;; partially copied from `eyebrowse-switch-to-window-config'
+    (cond
+     ((stringp window-purpose--eyebrowse-new-workspace)
+      (switch-to-buffer (get-buffer-create window-purpose--eyebrowse-new-workspace)))
+     ((functionp window-purpose--eyebrowse-new-workspace)
+      (funcall window-purpose--eyebrowse-new-workspace))
+     (t (switch-to-buffer "*scratch*")))
+
+    ;; in case opening the new buffer splitted the frame (e.g.
+    ;; `eyebrowse-switch-to-window-config' was called from a purpose-dedicated
+    ;; buffer)
+    (delete-other-windows))
+
+  (defun window-purpose/sync-eyebrowse ()
+    (if purpose-mode
+        (setq eyebrowse-new-workspace #'window-purpose/new-workspace)
+      (setq eyebrowse-new-workspace window-purpose--eyebrowse-new-workspace)))
+  (add-hook 'purpose-mode-hook #'window-purpose/sync-eyebrowse)
+  (window-purpose/sync-eyebrowse))