Add un undo button into a PDF file

A pdf file has objects stored into an json format, in order to be drawn onto the page when displayed with the [login to view URL] librairy. Objects can be drawn onto the pdf pages with customs buttons on the tool bar, already programmed. I need a button which would allow to undo drawing objects until the page is not recorded. I also need a record button, which could transform the drawings into pdf (canvas2pdf librairy ?) before saving it into the existing pdf. The drawn object should be displayable into the pdf when opened by any pdf reader.