client: Remember last candle duration

[ukane-philemon]

This adds the ability to remember a user's last candle duration selection and fixes an issue where the candle selection is not known when navigating away from and back to the market's view. Closes #2198

UI changes(#2284 (comment)): fbadbf8 hopefully the colors stand out.

[norwnd]

Seems to be working!

[buck54321]

I think this causes an issue with our 24-hour high/low values. See description from issue #2198, but we are expecting to have the 5-minute candles loaded. See also setHighLow.

[ukane-philemon]

I think this causes an issue with our 24-hour high/low values

@buck54321, we've been using the fiveMinBin in setHighLow as default but now we can just use the spot.high24 and spot.low24 if the current candle dur is 24h, right?

Also, for the 1h dur, do we intend to do what Cache.Delta(...) does? Or leave the existing behaviour? It seems all this data would eventually come from the backend in the future.

[buck54321]

I think this causes an issue with our 24-hour high/low values

@buck54321, we've been using the fiveMinBin in setHighLow as default but now we can just use the spot.high24 and spot.low24 if the current candle dur is 24h, right?

The most recent release, v0.5.9, does not include the high24 and low24 fields.

Also, for the 1h dur, do we intend to do what Cache.Delta(...) does? Or leave the existing behaviour? It seems all this data would eventually come from the backend in the future.

It wouldn't be accurate enough to calculate the 24-hour change/high/low from the 1-hour bin. This is why I was forcing loading of the 5-min bins first.

[ukane-philemon]

@buck54321, I'm forcing a request of the fiveMinBin if we don't have cache in 1a82aaf, hope that resolves the potential issue with the 24high/low rates?

[chappjc]

On account of the redefined candles in 0.6, if no candle bin size was selected, I believe the default should now be 1hr instead of 5min. I think this change is needed now that 0.6 is faithfully producing candles from match data only, not just mid-book for epochs. For the 5 min candles to be useful, matches need to be far more frequent.

[ukane-philemon]

@chappjc what do you think?

@buck54321- we've been using the fiveMinBin in setHighLow as default but now we can just use the spot.high24 and spot.low24 if the current candle dur is 24h, right?

[chappjc]

Oh yeah, page.durBttnBox needs to be populated in order for loadCandles to apply the selected class. Seems fine but have not re-tested.

[chappjc]

Thanks for your guidance through this PR @buck54321. It seems to be working as expected now. Everything look alright to you?

After this one, I'll put up a backport PR for all the milestone items in https://github.com/decred/dcrdex/milestone/30

[buck54321]

I feel like loadMarket should still be called in setMarket, just moved to right after this.setCandleDurBttns(). Not a big deal though.