Plot::items::highlight set highlight in plot and in legend plot

[haricot]

While working on a proposal for feature additions for the Plot widget, I realized that the Plot: items were not reacting with the parameter highlight function.
I take this opportunity to propose BoolState which will make it a little clearer than the double boolean necessary for its operation, it seems to me. Also the same case repeats itself if we want to add this functionality with allow_hover , which I would like to propose soon among others.

[haricot]

otherwise I propose a branch with double booleans:
If the first boolean is true, it highlights
and the second boolean is its changing state.

[emilk]

Can you expand a bit on the problem? I would expect .highlight(true) to highlight the given item this frame. What is the difference between init and state?

[haricot]

In fact, the highlight function doesn't seem to work without the two booleans.
in Plot::Items:

    pub fn highlight(mut self, highlight: bool) -> Self {
        self.highlight = highlight;
        self
    }

And personally, I don't see any point in disabling it (since PR #2558 allow_hover) , so another possibility is to remove those chunks if you don't want to give the option to enable or disable highlighting in setting.

[haricot]

What is the difference between init and state?

if init is false and highlight becomes true (state = true) then it will not be highlighted.
if init is true and highlight becomes true (state = true) then it will be highlighted.

[haricot]

I understood my mistake in what I expected from the highlight function.
what I was proposing here is to be able to authorize or not highlight in the plot and when hovering over the legend of the plot.
For example if a plot item has allow_hover = false we could expect it to also be in the plot legend.

[haricot]

I close this PR because it seems more necessary to me and should be named Default_highlight if necessary because it allows elements not to be highlighted when hovering in the legend of the plot.