iOS Question ScrollChanged event: Scrollview inside a Scrollview

[Marcus Araujo]

Inside one main scrollview (parent) I have several panels placed vertically, each panel contains other scrollviews (children). The children contain page indicators (UIPageControl).

It's as in the picture.

The problem I am facing is that I need to get the children's event _ScrollChanged fired, because I need to indicate in UIPageControl the current page, but it's not getting fired. I suspect that there is an interception of _ScrollChanged between the children and the parent scrollview.

Any ideas?

 

[Erel]

This is a problematic interface. Are you able to scroll the child scroll views?

 

[Marcus Araujo]

Yes, both are scrolling fine. In B4a, the event is fired, though.

The main difference besides the operating system/architecture, is that in B4a, I am using AHViewPager and in B4i, iMashPager, as a child.

The only thing I want to achieve is to know when user switched pages, that's all that matters.

 

[Yvon Steinthal]

One way i would go about doing that is catch the _Touch event on the scrollview's panel and follow steps in order to figure out what the user is doing.

Step 1: catch if its an horizontal scroll (Action_Move if new X > old_x by 100dip (example))
Step 2: catch the relative scrollview by going through a loop:

For each v as view in sv.panel.Getallviewsrecursive
if(v is scrollview)then
dim tempscroll as scrollview = v
if(tempscroll.top > y and (tempscroll.top+tempscroll.height)<y)then
'This is the scrollview targeted
'Act accordingly in relation to the Action Move direction
end if
end if

I do things like this and it works very well. It does depend on the number of views you have in the main scrollview. if there are a lot of views you will slow down the app for sure because of the loop.

I am unsure if thats what you are looking for. I am just trying to help

Y.

 

[Erel]

The ScrollChanged event should be raised. I guess that there is a mistake in your code somewhere. I'm not familiar with iMashPager however try this example: https://www.b4x.com/android/forum/threads/paging-indicator-for-scrollview.66094/#post-418575

 

[Marcus Araujo]

Thanks for the tips, colleagues! I have deeply analyzed the differences and found one clue: actually only the last child works (they're all added dynamically).

 

[narek adonts]

you can add GestureRecognizer and add Pan event and it will work