Accessibility improvements: focus trapping, keyboard navigation, and controlling auto-close behavior

[stevelacey]

Hi, first of all thank you for the work on this package. The documentation mentions accessibility as an ongoing consideration, but I have found it fairly difficult to get some common accessibility patterns working in practice. I figured I would share the problems I have run into in case they help guide future improvements.

1. Focus trapping is hard to implement externally

I try to wrap all dropdown and popup components in a focus trap for accessibility. With this datepicker it has been quite tricky.

It is somewhat easier to manage when teleport: false, although there are still edge cases. Once teleport: true is used it becomes very difficult to attach a reliable focus trap around the menu. I can work around this a bit by querying for the dynamic .dp--menu-wrapper:not(:empty) element, but it is brittle.

It might be beyond the scope of the library to include a focus trap by default, but exposing a more stable hook, slot, or mount point would make it much easier.

2. Preventing auto-close is inconsistent

Even with the tab-out options disabled, I still see the picker closing itself in situations that seem hard or impossible to prevent:

• Shift+Tabing away from the picker always seems to trigger a close.
• I suspect this is being triggered by internal blur-handling or by focus returning to the input.
• For context: I am using the dp-input slot with all the recommended bindings. I have not tested without that slot.

This makes it difficult to use a focus trap or manage keyboard navigation inside the menu without fighting the auto-close logic.

3. Custom keyboard handling is difficult to implement

I would like to customise some of the keyboard interactions; for example:

• Using Space for date selection during keyboard navigation.
• Making Enter consistently behave as “select and close”.
• Preventing Enter from bubbling up and submitting the surrounding form.

Right now it is hard to bind these cleanly because:

• When teleport: false, it is difficult to access the internal elements that need preventDefault or stopPropagation.
• When teleport: true, some bindings work better but it is still very hard to avoid breaking built-in interactions such as the action buttons.
• There is no clear way to intercept keydown events at the correct level without interfering with internals.

I am not sure what the ideal solution is. More slots, more event hooks, or more granular disable-options might help. My goal here is mostly to highlight the friction points in case they are useful for planning.