Viewer: Pin feature is currently not compatible with browser history navigation

[jabrah]

The "pin" feature of a given viewer window is supposed to let users prevent the window from being removed from view. It should also prevent the window from changing books/pages. However, the new history navigation enabled by persistent URLs do not respect a window's pin status.

(Note I use "window" and "panel" interchangeably)

Example:

• a user navigates to a page in the Domenichi
• navigates to a page in the Frontinus
• the user pins the Frontinus page
• the user uses the browser's Back button to go to a previous history state
• Current behavior
  • the viewer changes the window view to show the Domenichi
• Desired behavior
  • the viewer should not change the current window

Note pins should also be respected within multiple viewer panels.

[jabrah]

On review, I am not sure how the above situation should actually be handled. I would think that the Pin should not effect the behavior of the browser Back button as described above. Instead, the Pin should only effect normal browsing. At a minimum, the Pin status could be added to the history state, so it could be recreated as expected through browser navigation events.

However, we would need persistent URLs to work with multiple panels first, before we need to worry about this.