How to make interactive drop-down menu?

Hello Everyone

When i’m creating a drop-down menu for my panel like in example in Blender Code Snippets (link), is there an option to run a setswatches function automatically when i pick an object from my drop-down list?

Also is there an option to show in panel that Enum List a current picked index (like “Red”) instead of its name “Swatches” ?

i’ve thought of layout.operator_menu_enum() but it still dont know how to connect it with my_swatch property and swatches.set operator…

Anyone could help?