Vertical scrollbar and touchscreen devices


This is a very annoying thing I am not able to fix. I Have a canvas and inside the canvas a tab panel. I have also a vertical scrollbar for scrolling data inside the tab panel. In a normal computer everything is fine. But on my 2 touchscreen computers, when I change tab using finger, vertical scrollbar does not run normally and instead of scrolling data, it is unresponsive for 5-6 secs. If I wait 5-6 secs not touching the screen, vertical scrollbar is ok again. However, if I use mouse, vertical scrollbar runs always smooth and ok. What happens??

Low cost touchscreen device and OS ?

Emile, no. Windows 10 both Lenovo devices IdeaPad. Do you really think Xojo is for expensive devices? A developer has to do programs for customers regardless its devices, I think. Silly answer IMHO…


Did you try your program on another touchscreen device (Lenovo or other) with latest Windows 10 (up to date) ?

Did you checked the control panel in case there’s a special case (a property set that explain the difference)?

Last week, @ Offenburg (Germany), I saw a touchscreen tablet that cost less than 50€ (35 € ?).

Just a wild guess, add some debugging to the scrollbar to make sure that its only firing when you move your finger and not all the time your finger is on there as it might be flooding the event queue with position changes that might need a little while to clear down.

Also, are you able to replicate it on a new simple project that you can upload for us to take a look at?

Yes Julian, I’m not at home but I Will try to replicate the issue in a simple project. Actually, the problem is weird because If I wait for a few seconds, vertical scrollbar is ok again! On the other hand, if I use only mouse, no error at all.

On a touchscreen, scrolling is achieved with two fingers gesture. Chances are someone who is familiar with the touchscreen interface will use that before the scrollbar. Have you tried that ?

there is a simple project replicating my problem. If you use only mouse, everything is fine. But on a touchscreen Windows 10 device, since you change tab, vertical scrollbar is useless unless you wait for 5 secs (??) doing nothing. That thing is driving me crazy because I don’t find any logical on it. I think is an incompatibility between Xojo controls and Windows 10 touchscreen stuff.

Vscrollbar Problem

I can’t test this right now as MS Windows Simulator just refuses to start. Maybe someone with access to a touch screen can test this?

I just tested on my Asus Transformer book under Windows 10, and confirm the issue.

That said, the scrollbar is definitely not touch friendly. This is the kind of control Windows has done away in its latest UWP apps design guidelines.

But the weirdest thing is the fact that if you wait for 5 secs or so after changing tab, scrollbar is running fine again…

I would try to replace the native scrollbar by a custom one. It may not be affected by the same issue. You could even make it much bigger to be more friendly with touch.

I use the WFS TabletPC function to know if I have touch only.

That way you know when to replace the native scrollbar by the touch friendly one.

Yes. I did same. I put some kind of “custom scroll bar” on my app but… I’m not a professional programmer si… My scrollbar is not very good and it scrolls a bit odd hehehe. And also I had to figure out the height of the palet, distance of the pallet inside the rectangle…too much… Michel, could you do this reporting issue to Xojo’s creators? Sorry for my English… This #xxxx thing…

Enrique, just refer to this discussion, and attach the test project to the feedback case, and you will be fine.

I hope I did well the feedback case…