Preserve toggled annotations when navigating multipage

[syg]

When navigating both between single page/multipage mode and between different multipage pages, toggled user-code annotations should be preserved.

Probably the toggle should append a query string snippet that gets preserved. Also makes the annotations linkable.

[bakkot]

Probably the toggle should append a query string snippet that gets preserved

Alternative is to put it in localStorage, so it's also preserved when you come back to it. That means it's not linkable, though.

[syg]

Alternative is to put it in localStorage, so it's also preserved when you come back to it. That means it's not linkable, though.

Maybe both?

[bakkot]

Sure, that works. Makes the state machine a little complicated, though, because you don't want navigating to such a URL to set the persistent bit.

What I'm thinking is:

• state of "annotation is displayed" is always in agreement with "url indicates annotations are displayed"
• when hitting u:
  • if annotations are not displayed, they are turned on (and therefore also URL is updated) & bit in localStorage is set to on (regardless of its previous state)
  • if annotations are displayed, they are turned off (and therefore also URL is updated) & bit in localStorage is set to off (regardless of its previous state)
• when loading a page:
  • if localStorage bit is set, annotations are turned on (and therefore also URL is updated)

(I guess that's not actually particularly complicated.)

[gibson042]

I was just about to open an issue regarding the loss of search results when I saw this one. Should they be considered together?

[bakkot]

@gibson042 That's a slightly different thing - search results would probably go in sessionStorage, like we do for the references pane. So go ahead and open a different issue I think.