Very sensitive swiping in portrait mode

[eNBeWe]

When using the app in portrait orientation the swiping gesture to move to the next/previous room is very slow. This leads to usually swiping too fast and switching all the way to the first/last room.

System:
Nexus 5X
LineageOS 14.1, Android 7.1.2

Version:
1.33.0

[Noxmiles]

Yes, this is a Problem. If you don't know it, it seems Like there are only 2 rooms.

[johnjohndoe]

Thank you for reporting the issue. At the moment I cannot reproduce it - the problem does not occur on the device (Nexus 5, Android 6.0.1) I am using. I would love to try adjusting the SWIPE_MIN_DISTANCE and SWIPE_THRESHOLD_VELOCITY - but I cannot do that without the device. If you can compile the app yourself and try different values I would be interested in the values you come up with. The relevant constants can be found in HorizontalSnapScrollView.java.
Other then that I can offer that we met at 34C3 and try it out together.

[eNBeWe]

I didn't find direct contact Info for you @johnjohndoe You can reach me at DECT 2311, so we can have a look together.

[johnjohndoe]

Can we meet around 17:30 at c-base assembly? I will try to call you.

[eNBeWe]

A follow-up after our recent analysis: What do you think about splitting the function of the two constants:
Velocity: Select between fling or touch logic
Distance: Number of swiped columns if flinging
?

I would see if I can get a toolchain running and try that out if you like the idea.

[johnjohndoe]

Sounds reasonable to investigate. I would certainly clean up the code before (variable names, formatting).

[johnjohndoe]

@eNBeWe I did a basic cleanup of the code in HorizontalSnapScrollView here - it would be nice if you could review it. Feel free to comment - the code changes are not final. Please have a look at the commits one by one since it makes it much more easy to consume them.

[johnjohndoe]

@eNBeWe Can you please specify above the Android version you are running on your Nexus 5X?
I tried multiple devices but could not reproduce the swiping behavior except for with your Nexus 5x and a Pixel 2 and @Noxmiles' Moto Z Play.

Swipes one column

• Samsung S8, SM-G950F, Android 7.0: 1440 x 2960 pixels, 18.5:9 ratio (~570 ppi density)
• Samsung S7, SM-G930F, Android 7.0: 1440 x 2560 pixels, 16:9 ratio (~577 ppi density)
• Nexus 6, Android 5.1.1: 1440 x 2560 pixels, 16:9 ratio (~493 ppi density)
• Nexus 5, Android 6.0.1: 1080 x 1920 pixels, 16:9 ratio (~445 ppi density)

Swipes multiple columns

• Pixel 2, Android 8.1.0: 1080 x 1920 pixels, 16:9 ratio (~441 ppi density)
• Nexus 5x, Android 7.1.2: 1080 x 1920 pixels, 16:9 ratio (~423 ppi density)
• Moto Z Play, Android 7.1.1: 1080 x 1920 pixels, 16:9 ratio (~403 ppi density)

It might not just depend on the resolution/density of the display but also on the Android version..

[eNBeWe]

I am using LineageOS 14.1, resulting in Android 7.1.2

[johnjohndoe]

@Noxmiles Can you please post the specs of your device?

[johnjohndoe]

... I did a basic cleanup of the code in HorizontalSnapScrollView ...

The cleanup branch has been merged here: 6753a52

[Noxmiles]

@johnjohndoe Moto Z Play. Android 7.1.1. 1920 x 1080 @ 5,5" 16:9 (~400ppi). I could make a video of the problem if you want.

[johnjohndoe]

@Noxmiles Thank you. The video is not needed since I can in general reproduce the behavior. I just have no access to the relevant devices myself. I update the list above to include your device.

[johnjohndoe]

Maybe of interest: What's New in ConstraintLayout mentions that with MotionLayout it is possible to track "your velocity of your finger and matches the velocity of the object you tag to it".

[isiko]

screen-20220423-004047.2.mp4

Here's a GIF of the Behavior I mentioned in #479. You can see that I'm flinging to the left, but after watching the GIF a few times, I think it is actually overshooting and then moving back.

A possible solution to this would be to switch from calculating the target column when starting the fling, to just snapping to the next column when the velocity is lower than a certain value, although I wouldn't know how to integrate that with the Android API.

[johnjohndoe]

@isiko It is very hard to see when the overshot happens because the GIF replays all the time. Could you instead upload a video (which stops automatically or can be stopped)?

[isiko]

@isiko It is very hard to see when the overshot happens because the GIF replays all the time. Could you instead upload a video (which stops automatically or can be stopped)?

Updated the Video 👍

[johnjohndoe]

Thank you. - I downloaded the video to playback frame by frame. What I see is:

1. Scrolls fast rightwards to room "Stage" which is the ~32. column
2. Scrolls leftwards to room "Eliza" which is the 5. column (4 columns have been scrolled in effect)