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Testing and Issues

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

Install .ipa files via AltStore

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


by rating


Good speed overall, bonus goal implemented.
iPhone 6 Plus, iOS 12.1
Jolly Croc May 7, 2019 at 08:46
Since the contest is over, I think it is fair to let the world know my real name. I am Pavel Gurov, a 27y.o. developer from Moscow, Russia.
Very laggy date selection (tremendous input lag for vertical line drawing)
iPhone 6+, iOS 11.2
Jolly Croc Apr 23, 2019 at 07:40
Could be improved upon, totally agree. Strange that you have this on a not so old device, even my old iPhone 4s looks better in this regard. That is probably because of the pixel amount to CPU processing power ratio.

Are you sure that you do not have the battery saving mode on? It cuts the processing power of the CPU significantly.
Jolly Croc Apr 17, 2019 at 20:20
I actually think it looks cute. And totally appropriate, given the circumstances we find ourselves in.
You can still scroll the 4th chart in zoomed in stage if u were holding the trimmer handle while transitioning. 

Once u release the finger the graph ends up in a scaled state, where u can no longer scale it until u go back to main chart.

More of a hidden easter egg though, since it doesnt crash :D

Just like in Classy Ram's app
iphone 6 12.1.4
Jolly Croc Apr 23, 2019 at 06:28
Nice one, mate! While I just do not see this a a real life scenario, I still agree, that it should be fixed, which by the way is not hard as you might guess.
Critical issue? Watch the video with landscape orientation on iOS 8.
Jolly Croc Apr 23, 2019 at 06:47
Wow, that looks bad indeed. Unfortunately was unable to reproduce on my iPhone 4S with iOS 8. Looks like a whole system glitch, btw, not like something to do exactly with my code.

I would like to point out, that fully supporting landscape was not really a goal here, I just left the default project settings on. Supporting iOS 8 was also not a requirement, and most of the contestants did not (I'm glad that you did, great job!). It really gave them an advantage, since it left out a bunch of old devices, where many problems might arise. I took that requirement from the TG official app minimum iOS version.

But anyhow, this has to be checked and fixed, thanks. Just a little over a week was not enough time (at least for me), to make sure that everything works perfect on iOS 8.
Deleted Account Apr 19, 2019 at 07:38
Multi-touch not supported in range control selector.

Can't grab and move another side of the selector while first one under the finger.

Yeah, it wasn't any requirements about it, but iPhone was built with multitouch support from the ground and this issue looks not user friendly and wierd. 
iPhone X / 12.2
Jolly Croc Apr 23, 2019 at 06:26
That would be a nice touch, totally agree.
5th chart's y axis doesn't match the required design
Jolly Croc Apr 23, 2019 at 06:50
True, the design has lines that are in 25 intervals, while I have them at 20s. This is because I did not want to introduce more ifs-elses, and just used the same grid for all charts. I agree, not by design, but in the short time that we had, that was the best I came up with, to pay attention to other, far more important details (from my point of view).
Sergey Dikovitsky Apr 17, 2019 at 22:49
Pie chart animation are done in easy way. It's standard morph animation. This is the only difficulty in this type of chart - correct animation.
iPhone 5s / iOS 12.2
Deleted Account Apr 24, 2019 at 20:31
Wrong chart position
iPhone Xs, iOS 12.2
Jolly Croc Apr 25, 2019 at 04:27
Yes, there is definately a problem here on my part. Writing 34k on the line, that is actually a rounded representation of something else is wrong. The best fix for this would be to move the line where 34k actually is, instead of writing values like 33,9k i think. Good find!
Deleted Account Apr 24, 2019 at 20:34
Wrong end date
iPhone Xs, iOS 12.2
Fair Quokka Apr 27, 2019 at 17:46
— The pie chart blinks when filtering Apples (the attached video). 
— Not possible to tap the latest date for the third graph (maximum scale).
iPhone 6s, iOS 12.0.2
Jolly Croc Apr 27, 2019 at 19:00
Thank you for the feedback!

#1 The pie chart blinking.
Yes, unfortunately did not have enough time to implement a beautiful animation there. At one point was considering to remove any kind of animation, but then left the animation that you see, which at times may look pretty bad. Definitely some room for improvement there.

#2 Not possible to tap on a date.
I have exactly the same iPhone model with iOS 12, and was unable to reproduce the issue. Attaching a video below, where I do exactly the stated impossible thing - tapping on the latest date on the maxed out scale of the 3rd chart. I also double checked, that all other charts can do the same, in all possible states of range selector and zoom in/out. Maybe I'm not understanding something correctly, a video would help a ton.
iPhone 6S / iOS 12
No preview charts animations...
No Y labels animations - only change value
Jolly Croc Apr 17, 2019 at 20:17
Yes, indeed. I implemented that animation in stage 1, just because that was a challenge, but I stopped liking it eventually. To me it looks like too much, and does not necessarily bring that much value. Without it the charts just look cleaner when scrolling, IMHO.
Major issue: No y-axis animation. Not only the UX is suffering, but also it gives this contestant a major advantage in performance over other participants.
Jolly Croc Apr 23, 2019 at 06:33
Indeed, that has been reported before, in fact it's the first issue that has been reported here. Go check out that answer.
On full interval has only 3 dates
IPhone 6s, iOS 12.2
Sergey Dikovitsky Apr 17, 2019 at 22:50
According to design, view with values should be shown on top of selected date (centerX) whenever it's possible.
iPhone 5s / iOS 12.2
Jolly Croc Apr 18, 2019 at 05:57
True, if you look at design screenshots. However, in real life that leads to the "view with values" jiggling back and forth from center of line to the side, and it just is not very pleasing in my opinion. The route that I took (when it is always on the side) is more consistent and eye friendly.
maxY on chart has to be on the same position as y-coordinate of the highest y-value by design
Visual artefacts during filter toggle.
iPhone 6+, iOS 11.2
Jolly Croc Apr 23, 2019 at 06:25
I see what you mean, yes, animations of the overlaying mask could be improved upon, thanks for pointing that out. Wonder why you did not put a "Major issue" label on this one?)
Major issue: Dates appear/disappear not by design. One group of labels appears, another disappears. Not only the UX is suffering, but also it gives this contestant a major advantage in performance over other participants.
Jolly Croc Apr 23, 2019 at 06:22
The only thing that you might be referring to is the appearance/disappearance of the rightmost label in the beginning. Well that label appears/disappears not according to the main logic, but because my viewport is 20pt inset from both sides and when the label is leaving viewport it just has to disappear with animation, so that it looks nice. Do not see, where the advantage is, really)
Major issue: filter toggle animation of hiding/showing line is almost not scaled at all on the large chart and it is completely not scaled at all on small one. Not only the UX is suffering, but also it gives this contestant a major advantage in performance over other participants.
Jolly Croc Apr 23, 2019 at 06:13
I wonder how you determine the majority of your issues) "Almost not scaled", does not work here. The large chart is scaled accordingly with animation any time the min/max change in real time, with animation, simultanious with slides (pretty hard to make). Exactly as the animation video suggested in the 1-st round.

Now, going down to the preview chart. This contest is all about attention to detail, and there is one detail here, that you obviously missed. If you look at the design videos from stage 1 you can clearly see, that the animation of chart appearance/disappearance is different in the main chart and in the preview chart. In the main chart the disappearing/appearing graph is faded AND scaled at the same time with all the other graphs. But in the preview chart, the disappearing chart is NOT scaled, it is only faded, while all others are just scaled to the new min max. Glad I payed atention to that detail.

Here is the video I'm talikng about, give it another good look.
Can't select another date by sliding your finger horizontally
Jolly Croc Apr 23, 2019 at 06:03
That is true, however, you can long press and then slide your finger (which might not be obvious, I agree). In ideal world, the chart should respond to any touches, but the touches intended to scroll the table. Unfortunately did not have time to also make it respond to just slides. Thank you for pointing that out.
Major issue: The app UI flickers on the start.
iPhone 5, iOS 10.3
Jolly Croc Apr 23, 2019 at 07:01
Interesting find, thanks! Even my iOS 8 iPhone 4S does not show anything close to that, has to be something specific about that iOS version, will check it out. I also think you need to get your major-meter checked)
iPhone 4S / iOS 8
Deleted Account Apr 24, 2019 at 20:30
Points must be exactly on selected date
iPhone Xs, iOS 12.2
Jolly Croc Apr 25, 2019 at 04:24
I totally agree, after watching other works around here. It would be nicer to have the points stick to the dates instead of sliding on the line. It is actually way easier to do, since you do not have to calculate a mid position between points. Thanks for pointing that out.
Deleted Account Apr 24, 2019 at 20:31
Max line must be higher than last y-axis line
iPhone Xs, iOS 12.2
Jolly Croc Apr 25, 2019 at 04:22
I do not know where that "must" comes from, it just so happens, that in design Y-s are calculated in such fashion that in those particular circumstances the line is higher than the last Y line. There are cases in my app where this also happens (see screenshot), but I do not see a point in guaranteeing it for every possible case.
iPhone SE / iOS 12
Deleted Account Apr 24, 2019 at 20:32
Just two labels on x-axis
iPhone Xs, iOS 12.2
Jolly Croc Apr 25, 2019 at 04:28
Yes, this is a moment just before the new set of x dates is going to appear.
Deleted Account Apr 24, 2019 at 20:33
Buttons have dark border on selection
Jolly Croc Apr 25, 2019 at 04:29
Yes, that is called highlighted state. In iOS it happens when you tap a button. You could customise it, but there are no specs on that, so I stuck with default button highlighting here.
Deleted Account Apr 24, 2019 at 20:35
Buttons blinks on zoom animation
iPhone Xs, iOS 12.2
Jolly Croc Apr 25, 2019 at 04:32
You are very attentive, thank you! This happens because the cell gets reset with the data, and should be optimised to only happen when the data is updated. Have that in my to-do list, priority was too low to actually get to do it. Could definitely be improved upon.
Deleted Account Apr 24, 2019 at 20:35
Day/night switching has no animation
Jolly Croc Apr 25, 2019 at 04:34
Thats just a fact, thank you for pointing that out. Am not sure that animating the change will bring that much value here. By value I mean helping the user really understand what is going on, whats coming from where and so on. So it could be done, pretty easily, in fact if you check out Telegram iOS client, it animates the change yes.
Nobody added any issues yet...