[FEATURE] highlight selected item for dropdown widget about bokeh

[mattpap]

Dropdown provides access to actions via a menu (or a default action and a set of actions in the split dropdown case), but it doesn't store any state. For a stateful widget there's Select. I suppose we could add support for checked items and groups, which I have to do in other contexts anyway.

[bryevdv]

I just realized this wasn't about the Select widget. @m3lab-zzl I think a Select is what you want instead:

https://docs.bokeh.org/en/latest/docs/user_guide/interaction/widgets.html#select

I agree with @mattpap that dropdowns are stateless button/menu for initiating an immediate action, and note this is consistent with other sources e.g. bootstrap or w3schools

I think this issue can be closed with noaction

[bryevdv]

A visual indicator seems reasonable. Any thoughts @mattpap ?

[m3lab-zzl]

Many thanks. I did not check all the widgets and did not know there was a Select. Now I will use Select instead.