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Testing and Issues

You can test this app and submit issues during the testing period of the Android Chart contest.

Entries with serious issues will not be able to win the contest, but even minor issues might be important for overall results.


by rating


Fair Quokka Apr 28, 2019 at 09:53
— Good speed overall.
— The third and fifth graphs are slow when filtering.
— Sloppy on zooming in and out.
— Bonus goal completed (+).
LG Nexus 5X, Android 8.1.0
Doesn't start on Android 5. Otherwise good app.
Samsung A7, Android 5.0.2
UNUSABLE PERFORMANCE (up to ANR) for every zoom in/out transition. It's a really strange, but on mi A1, it hangs for several seconds and every transition frame is dropped. Zoom out hangs even more (it's easy to catch ANR on stacked bar if trying to interact with app during transition). Checked on two different Xiaomi A1, but results are the same. (Maybe it's a data reading or large bitmap generation each frame? - device screen is 1080x1920)
To confirm that device isn't broken and there is no throttling I'm also recorded video (the last one) when I've switched to stage 1 winner's app, to confirm it's OK (~ 60fps on the last chart).
Xiaomi A1 / Android 9
Sturdy Pony Apr 24, 2019 at 19:55
Wow, it's really UNUSABLE on your device.

I checked that issue on my Xiaomi Redmi Note 4 running Android 6 and Samsung Galaxy S5 running Android 6.0.1, and there are no such issues. Including the fact that there are no data reading or generating any bitmaps on the main thread, I have no idea why it's like that on your device.

I also checked it on my Android 9 device (SGS8) and app works even better there.
Can't reproduce the performance issue on Nexus 5 I've described before for Mi A1, but on Nexus 5 overall performance is poor, even on simple line chart.
Nexus 5 / Android 6
Sturdy Pony Apr 24, 2019 at 19:58
I can't reproduce this issue on my devices too. Maybe video recording kills all the performance, because even in my attached videos to the previous issue gpu profiler shows significantly worse values while I was recording videos. Without recording — values are much better.
chart 3 in zoomed state should be shown as bars, not lines
Sturdy Pony Apr 24, 2019 at 02:33
Yes, it's true.

I did that mistake due to inattention: there is no such transition in the mockup images or videos, so I was completely sure that there should be yet another line chart just like in other cases. Of course, it's not as useful to visualize such dataset in line chart form as in stacked bar chart form, so it's violation of usability, but not so big because you still can see this data.

In case telegram team won't believe me, I prepared a very small instruction to make it look stacked bar instead of line here (video with those changes attached). And it will work without any issues, so this problem was caused only due to inattention without any particular intentions.
kotlin was not allowed
Sturdy Pony Apr 24, 2019 at 02:35
There were no problems with usage of Kotlin from telegram team at the first stage.

In addition, I can't see any reasons to make such a restriction, because Kotlin is an official "first-class" language for Android development which is fully Java-interopable.

And in the same time, it's not easier to make apps with good performance on Kotlin instead of Java, because in that case you have to know Java and Kotlin together + a lot of information how and where to use useful kotlin's stuff without degradation of app's performance. So it's harder, but also faster if you know how to cook it.
Chart 2 not scaled to minimum point at some times
Sturdy Pony Apr 24, 2019 at 02:36
App is looking for peaks a bit out of the visible screen bounds. It's a compromise between smooth scrolling and similar situations as in your screenshot.
Hello. I tested your app on 2 real devices. I found some 
1. App crashed on Innos d6000. (screenshot 1 and video 1).
2. On the Fruits chart time on items lable looks wrong (screenshot 2)
3. There is only one date on the view chart (right top date label). (screenshot 3)
4. the animation of items label looks strange if I check/unceck checkboxes quickly (video 2)
5. a) Check on a chart and see on the items label. If after it channge position of the selector. The items table will be invisiable, but opasity of chart will be less than 100% (video 2)
Innos d6000 (API 22 - android 5.1.1), OUKITEL C5 (Api 24 - android 7.0).
Sturdy Pony Apr 24, 2019 at 02:44
In every chart, there are dots on the lowest y guideline that connect x values with their labels, so it's all correct with labels in 2.png
The chart is not scaled to the full height sometimes.
Nexus 5 / Android 6.0.1
Sturdy Pony Apr 24, 2019 at 02:36
App is looking for peaks a bit out of the visible screen bounds. It's a compromise between smooth scrolling and similar situations as in your screenshot.
Hard to click on change theme button.
Nexus 5X Android 8.0.0
Sturdy Pony Apr 24, 2019 at 02:46
Oh, margin! It's not cool, of course.
App crashes on Sony Xperia / Android 5.1.1
It's possible to select small range in discrete range selector
Xiaomi A1 / Android 9
No tooltip when selecting pie sector
Xiaomi A1 / Andrid 9
Red bars are too big
Sturdy Pony Apr 24, 2019 at 19:15
There is a minimum height for items as shown in the mockups
>Maybe video recording kills all the performance
no, it reproducible without recording. Also I reviewed with this device more than ~40 apps, and seeing this first time (when animation stuck for several seconds). But I've tried everything like charging/reboot to understand what happening, and again I tried on two different mi a1 with the same result. 
But it's a really strange behavior.

Fortunately, you've submit debuggable apk, so I can profile it and bring some more details. Looks like you didn't do anything in main thread for this time, but RenderThread which executes your commands doing a lot of work(really a lot), and main thread just waits for it (mSyncAndDrawFrame).
Xiaomi A1 / Android 9
Sturdy Pony Apr 24, 2019 at 22:51
I made this video recording assumption about Nexus' issue, not about the perf bug on Xiaomi. I completely believe you about that bug, it's not cool, but I can't reproduce it on my devices so I have nothing left to add.
Nobody added any issues yet...