tinymce/tinymce — pull request #422 by Callidior (2014-08-29 09:20:19+00:00)
Title: Add CloseQuery event to FloatPanel

This event enables code, which creates a custom dialog, to prevent the user from closing the dialog window by calling `evt.preventDefault()`.
This can be useful to prohibit closing the dialog during critical sections of the process or to ask the user if they really want to close the window without submitting.