on-change

Called whenever any change is made to the editor that affects the way the editor is drawn or the values reported for the location/size of any snip in the editor. The on-change method is called just before the editor calls its administrator's needs-update method to refresh the editor's display.

The editor is locked for writing and reflowing during the call to on-change.

• (send an-editor:backup-autosave-mixin on-change) -> void

  Sets a flag indicating that this editor<%> needs to be autosaved.