Setting mobile scroller hScroll fails

[J. Landman Gay]

Thanks Monte, I did over-summarize. I'm not sure why it's going wrong, 
but it sounds like it's something I'm doing. I have a standard 
"createScroller" handler that I've been using for years, but I've never 
had to set the hScroll before. It's always been zero.

In this case, I set the hScroll of the group to the formattedWidth of 
the group, which may be wrong. The engine seems to compensate though and 
sets the scroll as far as it should go. Then I call "createScroller" and 
pass the name of the group. The handler:

command createScroller pName
   -- pName = the long ID of a grp
   put the rect of control pName into tRect
   put the hScrollBar of control pName into tHScroller
   put the vScrollBar of control pName into tVScroller
   put the hScroll of control pName into tHScroll
   put the vScroll of control pName into tVScroll
   set the hScrollBar of control pName to false -- remove fld scrollbars 
on mobile
   set the vScrollBar of control pName to false
   mobileControlCreate "scroller", pName
   mobileControlSet pName, "rect", tRect
   put  ("0,0," & (the formattedwidth of control pName) & "," & the 
formattedheight of control pName) into tContentRect
   mobileControlSet pName, "contentRect", tContentRect
   mobileControlSet pName, "hScroll", 0
   mobileControlSet pName, "vScroll", 0
   mobileControlSet pName, "hIndicator", tHScroller
   mobileControlSet pName, "vIndicator", tVScroller
   mobileControlSet pName, "hScroll", tHScroll
   mobileControlSet pName, "vScroll", tVScroll
   mobileControlSet pName, "visible", true
end createScroller

I initialize both the group and the scroller to 0 before doing anything 
else, because when I wrote it I couldn't get them to align correctly 
otherwise. I should also probably mention that I'm using fullscreenMode 
"showAll" and the group is expanded beyond the borders of the card to 
fill the screen; i.e., it probably has a negative left margin and a 
wider right margin. When the scroller finally does scroll (after 
resetting itself) it scrolls too far at the left side by the number of 
pixels between the screen left and the card left, and cuts off the same 
amount on the right side.

Can you see what I should change?


On 5/28/19 6:33 PM, Monte Goulding via use-livecode wrote:
> Hi Jacque
> 
> I’m thinking you are over summarising what you are doing here. For example, I expect you mean to set the hScroll of the group to the formattedWidth - the width of the group. Are you setting the contentRect appropriately before setting the hScroll of the scroller?
> 
> Cheers
> 
> Monte
> 
>> On 27 May 2019, at 8:03 am, J. Landman Gay via use-livecode <use-livecode at lists.runrev.com> wrote:
>>
>> I want to verify this is a bug and not just me.
>>
>> I'm creating a mobile scroller over a group. I want the group to initially display with its hScroll all the way to the right. I'm doing this:
>>
>> zoom the group out to fill the screen
>> create a mobile scroller with the same rect
>> set the hScroll of the group to its formattedWidth
>> set the hScroll of the scroller to the scroll of the group
>>
>> If I insert an answer command to show the scroller's hScroll it reports the correct number. But the scroller always acts like its scroll is 0, and it won't scroll to the left at all. But scrolling it to the right zaps both it and the group to zero and after that it scrolls normally.
>>
>> I've also tried not setting the group's scroll and just setting the scroller alone, thinking it might trigger the scrollerDidScroll handler, but it doesn't.
>>
>> If I don't set any hScroll at all on either the group or the scroller, all is well.
>>
>> Has anyone else seen this?
>>
>> -- 
>> Jacqueline Landman Gay         |     jacque at hyperactivesw.com
>> HyperActive Software           |     http://www.hyperactivesw.com
>>
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-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com