How to prevent change in a listbox selected item when users click and move mouse before mouseup - livecode

Question

I am using the following code in a scrolling field. It works fine in both windows and android. The only problem is that the selected item changes as the mouse mouses up and down the list. I would like the original highlighted line to remain highlighted during the scroll and only change if the mouse have not moves move than 11 units(row height is 22) from initial vertical position. How do I modify this code to achieve that?
local lmousev,lvscroll,lscrolling
on mousedown
--If we don't use lscrolling the list will scroll when the mouse hovers over it
put true into lscrolling
--Set the initial vertical position of the cursor
put the mousev into lmousev
--Set the inital position of the vertical scroll
put the dgvscroll of me into lvscroll
end mousedown
on mousemove x,y
if lscrolling=true then --lscrolling is only true after mousedown so no scroll when mouse hovers over
--adjust the scroll position based on the vertical distance that the mouse has moved since mousedown
set the dgvscroll of me to lvscroll -(y - lmousev)
end if
end mousemove
on mouseUp
--stop scrolling when mouse hovers
put false into lscrolling
If abs( the mousev-lmousev)<11 then --If vertival position of mouse has not moved far from vertical position at mousedown
--selectlist command is in the group. It insert list selection into the textbox
selectlist
end if
end mouseUp
on mouserelease
--stop scrolling when mouse is release outside the listbox and there is no mouseup
put false into lscrolling
end mouserelease
The button,textbox and listbox that forms the combobox are grouped.The code to show/hide listbox and add selected to textbox is in the group script as follows:
Additional Info
local ldrop=false
on buttonclick --show/hide the listbox
--Get the name of the group,textbox & listbox.
--Naming convention required:- textboxname=txt & groupName,listboxname=lst & groupname
--Using quote as deliminater allows us to get the groupname from group "groupname"
set the itemdel to quote
put item 2 of the name of me into groupname
put "lst" & groupname into lstName
put "txt" & groupname into txtName
--status of ldrop let us know if the listbox is visible
if ldrop=false then
--show listbox
set the visible of field lstName to true
put true into ldrop
else
--hide listbox
set the visible of field lstName to false
put false into ldrop
end if
end buttonclick
on selectlist
--Get the name of the group,textbox & listbox.
--Naming convention required:- textboxname=txt & groupName,listboxname=lst & groupname
--Using quote as deliminater allows us to get the groupname from group "groupname"
set the itemdel to quote
put item 2 of the name of me into groupname
put "lst" & groupname into lstName
put "txt" & groupname into txtName
put the hilitedLine of field lstName into lhilitedLine
put line lhilitedLine of field lstName into field txtName
set the visible of field lstName to false
put false into ldrop
end selectlist

Answer 1

I think you have to make your own control that acts like a list so that you can control all the messages it sends and receives. You are otherwise stuck with some of those basic functions of LC's built-in controls. seems like you'd need an engine-level tweak to the control.