Callback on changed property.

Print the name of the property that has changed.

Here we can do something when the feature will be deleted

Set error and warning pop-up messages. Parameters ---------- message: (str) The string-based message to be displayed. err

Map the display mode with those defined in getDisplayModes. Map the display mode defined in `attach()` with those defined in getDispl

If a property of the handled feature has changed we have the chance to handle this here

Handle changes of a property.