[ANGULAR] iPad's Gantt View: Jumpiness and Quick Horizontal Scroll creating problems with the drag and drop.

[accounts@projul.com]

Hello, Bryntum community,

I'm reaching out because I've encountered an issue while using the Gantt view on iPad devices, specifically related to horizontal scrolling and dragging inconsistencies.

When attempting to horizontally scroll within the Gantt view on an iPad, I've noticed that the behavior is inconsistent and sometimes unresponsive and jumps the scroll too far for no reason. The scroll action doesn't always respond as expected, leading to difficulties in navigating the Gantt chart horizontally.
i.e. When you simply scroll the Gantt horizontally left or right you see it jump/jerk the view and goes to irrelevant dates.

Additionally, there seem to be inconsistencies with dragging tasks or elements within the Gantt view on iPad devices. The dragging functionality doesn't consistently register touch inputs or behaves unpredictably, making it challenging to manage tasks effectively on the chart.
i.e. When you drag the task and when you go left or right till the screen ends it quickly scrolls so fast that I miss the date where I have to drop and it goes 1-2 years after, That's really annoying.

I've thoroughly tested this behavior across different iPads, On the web it's kinda better.

Has anyone else in the community encountered similar issues with Gantt view on iPads? If so, I would greatly appreciate any insights, workarounds, or potential solutions you may have discovered

I have attached the demo video from your site. Please resolve this problem as soon as possible Thanks.

iPad's Gantt View Scrolling Problem and Incosisent Dragging.MP4

(4.56 MiB) Downloaded 21 times

[mats]

Thanks for your extensive feedback. Are you only seeing problems with iPad + infiniteScroll? Or do you see issues in all demos?

[accounts@projul.com]

Thank you for your prompt reply. This issue seems to be specific to the iPad; however, it functions more effectively on other devices. While it's not optimal, it does perform better elsewhere.

[mats]

I meant, do you only see the issue when using infiniteScroll?

[accounts@projul.com]

Certainly! Using an infinite scroll is inconsistent and jumpy and that frustrates the user.

[Animal]

Infinite scroll is done by scrolling a large scroll width and detecting when you are reaching the end of the range.

If you are within 0.2 (bufferThreshold) of the scroll width of the end, it bumps the rendered time range forwards by a block of time, and quickly scrolls backwards to keep the visual appearance the same.

You can see the scrollbar thumb zipping backwards on desktop browsers.

It appears that on Safari (As opposed to on a Blink based browser), momentum scrolling can't survive this operation. It seems that on non-Safari browsers, wheel events continue to be fired into the UI even after the scrollLeft has been chunked back leftwards, so that the momentum continues to appear from the new, central scroll position. Safari abruptly gives up. There's not anything we can do about this browser behaviour.

Dragging events seems to be difficult on iPad. The touch scrolling seems to interfere in the operation. We will try to fix that.

[Animal]

Here's the ticket: https://github.com/bryntum/support/issues/8619

[accounts@projul.com]

I'd really appreciate it if you could fix this problem soon. It's nice to hear positive feedback from you. Thanks a lot, and I'll be waiting for the fix.