Hide gloss table when all rows are hidden

[sciepsilon]

In multispeaker documents, users should be able to hide a speaker by hiding all the corresponding gloss rows. Currently, this doesn't work because the speaker label still takes up space on the page even when the corresponding gloss is empty.

[nickatomlin]

This seems difficult.

We could hide LabeledSentences which includes the sentence and associated speaker label, but the TimeBlock with timestamps would still exist. And some TimeBlocks might contain utterances from multiple speakers.

[sciepsilon]

Actually, do this with speaker checkboxes instead of tier checkboxes.

One possible scheme: Use React state, as follows. LabeledSentences have an attribute "data-speaker" or something. Speaker checkboxes use css to hide/show appropriate sentences. SOMEHOW, labeled sentences find out when they're shown/hidden and update state in their parents accordingly. Each timeblock has an array of the states (shown/hidden) of its children, and when all children are hidden, it hides. Or something.

This feature isn't worth a huge increase in loading time, so tread carefully.