Discussion: Selector control

[ghost]

The item selector is a common scenario, used by many controls such as NavigationView, Pivot, ListView, ComboBox and so on.
Currently, the selector is implemented individually for each control, and a lot of times there are differences in behavior.

My idea was to have a new selector control, which would be used instead by all of those, and could also be used in custom controls.
It would also be useful to allow having a selector style in TabView (as described in #5223). Multiple selection styles for a single control are also discussed in #2310.

Some animations that could be supported:

• moving between two elements (NavigationView)
• fading in/out (ListView)
• animation when being pressed (ListView)
• changing between two colors: two elements have different colored selectors (NavigationView used to have this), changing state.

The Windows 11 tasbkar supports multiple states: normal, selected, progress bar etc. There can also be multiple selectors visible at the same time.

Pivot currently has the selector span the width of the item, while the other selectors have it as a fixed size. This could be a property of the selector.