iOS - picking from a scrolling list

[Thomas McGrath III]

Howard,

I am running out right now so I won't be able to look deeper into this just yet. But remember that with that code there are two scrolls going on. One for use in the IDE and the other for use on the device. The IDE code is:    set the vScroll of group "InputScrollerGroup" to pOffsetY  and the mobile code is:   iphoneControlSet sScrollerId, "vscroll", 0

If it is not going back to the top when coming back from another card then try adding both of them in an open card handler like this:

on openCard
  iphoneControlSet sScrollerId, "vscroll", 0
   set the vScroll of group "InputScrollerGroup" to 0
end openCard

to tested but should work if the controls exist at that point.

I'll look at it later.

HTHs

-- Tom McGrath III
http://lazyriver.on-rev.com
3mcgrath at comcast.net

On Jul 29, 2012, at 5:34 PM, Howard Bornstein wrote:

> Hi Tom,
> 
> Thank you for this code. It has been very helpful in getting me going on
> using an IOS scroller. It works fine except for the following situation,
> which is baffling me at this point.
> 
> If I implement a scroller with your code, everything works they way I would
> expect it to. However, if I scroll the list (say half-way down) and then
> leave the card, when I return back, the top of the scrollable field is not
> at the top of the scroller group (which I would expect because of this line
> of code:  set the top of field "Counter" to the top of group
> "InputScrollerGroup") but is, in fact, half-way down the scroller group.
> Then, if I try to scroll the field up, it never gets to the bottom of the
> field, but instead "bounces" somewhere near the middle of the content. In
> other words, it looks like the entire field is offset down by some amount
> (probably a function of how much I had it scrolled before I left the card).
> 
> I can't figure out why this would happen since the CloseCard handler
> deletes the IOS scroll group and OpenCard should create it fresh each time
> I go to the card. Somehow, the field position is getting stuck after I
> scroll it and then leave the card.
> 
> Do you understand why this is happening?
> 
> -- 
> Regards,
> 
> Howard Bornstein
> -----------------------
> www.designeq.com
> 
> On Thu, Apr 5, 2012 at 6:44 AM, Thomas McGrath III <mcgrath3 at mac.com> wrote:
> 
>> Graham,
>> 
>> I don't use mobgui but instead I use tmControl for layout of iOS elements.
>> There are two types of scrolling lists possible in LC. The first is using
>> mobilePick by itself or use an option button (that uses the iOS
>> mobilePicker). The second is using either an LC field object or other
>> objects like the list field in tmControl but either of these needs to be in
>> a group and the group can now have an iOS scroller applied to it.
>> 
>> If you create a field that is very long and group it then select the group
>> and make it shorter than that field it will scroll. I can't remember if the
>> group needs locked or not. There are a couple of glitches to watch out for.
>> 
>> Here is parts of a script that controls a grouped field and an iOS
>> scroller. A mouseUp in the field can return the desired line etc.
>> 
>> local sScrollerId
>> on scrollerDidScroll pOffsetX, pOffsetY
>>    lock screen
>>    set the hScroll of group "InputScrollerGroup" to pOffsetX
>>    set the vScroll of group "InputScrollerGroup" to pOffsetY
>>    unlock screen
>> end scrollerDidScroll
>> 
>> on openCard
>>    set the layerMode of group "InputScrollerGroup" of this card to
>> "scrolling"
>> 
>>    set the unboundedHScroll of group "InputScrollerGroup" to true
>>    set the unboundedVScroll of group "InputScrollerGroup" to true
>> 
>>     -- add items to a field "Counter" and have it grow to fit the contents
>>    set the height of field "Counter" of this card to the formattedHeight
>> of field "Counter"
>>    set the top of field "Counter" to the top of group "InputScrollerGroup"
>> 
>>    set the threeDHilite of field "Lap Counter" to false
>>    iphoneControlCreate "scroller", "InputScroller"
>>    put the result into sScrollerId
>>    put the rect of group "InputScrollerGroup" into tRect
>>    iphoneControlSet sScrollerId, "rect", tRect
>>    put the formattedHeight of field "Counter" into tHeight
>>    iphoneControlSet sScrollerId, "contentRect", (0, 0, 0, tHeight)
>>    iphoneControlSet sScrollerId, "indicatorInsets", (0,0,6,0)
>>    iphoneControlSet sScrollerId, "visible", "true"
>>    iphoneControlSet sScrollerId, "canBounce", true
>> 
>>    iphoneControlSet sScrollerId, "declerationRate", fast
>>    iphoneControlSet sScrollerId, "scrollingEnabled", true
>>    iphoneControlSet sScrollerId, "canScrollToTop", true
>>    iphoneControlSet sScrollerId, "delayTouches", true
>> 
>>    iphoneControlSet sScrollerId, "vscroll", 0
>>    set the vScroll of group "InputScrollerGroup" to 0
>>    set the vScroll of field "Counter" to 0
>> 
>>    focus on nothing
>>    iphoneControlDo sScrollerId, "flashScrollIndicators"
>> end openCard
>> 
>> on closeCard
>>    iphoneControlDelete "InputScrollerGroup"
>> end closeCard
>> 
>> -- Tom McGrath III
>> http://lazyriver.on-rev.com
>> 3mcgrath at comcast.net
>> 
>> 
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