Changing the SVG diagram doesnt make the "Apply changes" enabled, and doesnt save image

[LucienMP]

There used to be a draw-io save button, which would fire a "save" event.
However I have now disabled the draw-io buttons and want the "Apply Changes" button to do the same.

So I turned on "autosave" event for drawio, this will send the updated XML every time something changes.
you will need to work out how to keep the XML/PNG data until the Apply button is hit. AND also need to make the APPLY button change to blue when you get the autosave event. You can see an example of changing the Apply button inside the UI update functions.

Alternatively you might need to send a "export" message to get the PNG/XML file back when you close the window.