Navigator: pause is broken on Android

[JayPanoz]

Since pause is not implemented properly here, we cancel as others do, but it breaks navigation in significant ways (pause state no triggering, playback losing track of index). I will have to come back at it later.

[renevanderark]

I noticed it did not emit the paused event here:

https://github.com/readium/speech/blob/main/src/WebSpeech/webSpeechEngine.ts#L423

[JayPanoz]

Yeah I am not sure how to best handle this w/o debugging first.

As far as I can tell, there seems to be no easy way around this patch, and I don't have enough details to come up with possible resolutions yet.

It is weird in the first place that it cancels on pause and I am not sure what's expected, playback-wise, as it effectively will not resume but restart the utterance. So it's more like a stop, etc.

But any idea is welcome and appreciated of course.

[renevanderark]

Well if I get the opportunity to get more immersed in the subject matter I would feel more confident coming up with any suggestions, but at the moment I do not even have a proper set of test-devices. All I can say is that the edge emulator on windows 11 tests true to the isAndroid patch test (I guess because it's a flavour of webkit?) and that it (specifically this one) does indeed handle pause/resume correctly... I don't know in what way that could possibly be helpful in a structural way, but I sure hope it is!

[renevanderark]

Ok, so the workaround I have right now is simply stop the navigator and then re-invoke navigator.loadContent() and spacing out the first half. This way I preserve the character positions of the text nodes.

• ["This is utterance 0.", "I want to pause utterance 1 here, before I resume.", "Utterance 2."]
• ["This is utterance 0.", " here, before I resume.", "Utterance 2."]

[JayPanoz]

This is good to know, thanks. 👍

I should come back at this either tomorrow or Thursday BTW so I will try keeping you in the loop as much as possible.

[JayPanoz]

Alright so the fun part is that I have to handle this in a self-contained way in the engine itself, navigator supposed to be an engine-agnostic component in the architecture.

I'm starting with resuming at the current index, which already has some challenges because this is an extra state to track, with its glorious side effects of well, handling errors propagation.

Then I'll see what I can do with boundaries, as this effectively requires internal reloading of the utterances, that is temporary on top of it, and with some voices not supporting the boundary event. This will be fun. 😬

[renevanderark]

Given that a lot of these voices do not yet seem to emit boundary events seems like a tough sell. So my assignment kind of has the extra agenda of showing how things could be if all the browsers and voices were up to spec. Because of this I may not be able to contribute much that would be durable.

However, I will try using as much of readium speech as possible.