can-save-file? in editor:basic-mixin

Called just before the editor is saved to a file. If the return value is #f, the file is not saved. See also on-save-file and after-save-file.

• (send an-editor:basic-mixin can-save-file? filename format) -> boolean
     filename : string
     format : symbol

  The filename argument is the name the file will be saved to. See load-file for information about format.

  Checks to see if the file on the disk has been modified out side of this editor, using save-file-out-of-date?. If it has, this method prompts the user to be sure they want to save.