Reviewer's Guide by Sourcery

This PR implements keyboard navigation for word lookup in the bottom sheet using the left and right arrow keys. It also updates the help text to reflect this change. The original access key functionality is preserved.

Sequence diagram for bottom sheet keyboard navigation

sequenceDiagram
    actor User
    participant BS as Bottom Sheet
    participant KH as Keyboard Handler
    participant Nav as Navigation Logic

    User->>BS: Press Arrow Key
    BS->>KH: _handleKeydown(event)
    alt Arrow Left
        KH->>Nav: _handleArrowLeftKeydown()
        Nav->>Nav: _previous()
    else Arrow Right
        KH->>Nav: _handleArrowRightKeydown()
        Nav->>Nav: _next()
    end
    Nav-->>BS: Update current word
    BS-->>User: Display new word

Class diagram for SCBottomSheet changes

classDiagram
    class SCBottomSheet {
        -Object _keydownHandlers
        +connectedCallback()
        +disconnectedCallback()
        -_handleKeydown(event)
        -_handleArrowLeftKeydown()
        -_handleArrowRightKeydown()
        -_previous()
        -_next()
    }
    note for SCBottomSheet "Added keyboard navigation
handlers for arrow keys"

File-Level Changes

Interesting. Without your PR, alt n does nothing for me on FF and alt b triggers the browser's bookmark interface. So for sure that needs to be fixed.

Generally we seem to avoid having two ways of doing things, so I doubt Bhante @sujato will want to do arrow keys and alt b/n.

There has also been talk of using the arrow keys for navigating to the previous and next suttas. In fact the browser extension does just that.

Thank you for working on this! Bhante @sujato is traveling atm so it may take a little bit for him to respond.

Just as an FYI, here are all the existing hotkeys:

Thanks for the hot key reference, these are indeed the same as defined in sc-top-sheet-view.js.

I notice now that actually the backward access key (Alt+b) does work in Firefox, only the forward (Alt+n) does not. The Ctrl+n (in my case the modifier is Ctrl+⌥ Opt) I think conflicts in Firefox with other behaviour. In Chrome it actually does work for me.

Since I don't see access keys used anywhere else in the SuttaCentral applications, they are quite hard to discover and can conflict with other browser behaviour, maybe best to not use access keys and introduce new regular hot keys for navigating the word lookup? But what keys to use if the arrow keys and n (toggle notes view) are already taken? Perhaps just like in vi the h and l keys for going left and right one word, though this is not so discoverable. Or maybe overload the arrows keys that when the sc-bottom-sheet-view.js is open they are used for navigating the word lookup instead of the suttas? (Though I don't think the latter is technically feasible if the capturing of arrow keys comes from an extension, but if the hotkeys are all defined in the main application it should be possible to arrange it like that.)

Hey @thesunshade, you commented on this. Do you think it is still relevant or can I close it?

No idea! Would be good if it could get resolved