UIHANDLER OnCursorChanged

== Description ==
Called whenever the cursor in an edit box was moved. Note that the cursor is also moved when typing.
== Arguments ==
; arg1 : the new horizontal (x) position of the cursor in the edit box (the first column being 0, increasing to the right)
; arg2 : the new vertical (y) position of the cursor in the edit box (the first line being 0, DEcreasing downwards)
; arg3 : unknown
; arg4 : the height of one line
== Example ==
Say we have a plain textbox inside a scrollframe (inside UIPanelScrollFrameTemplate; as the only child-element, etc.), the following code will automatically move scrollframe viewport so that the cursor is inside it. (The 
ScrollingEdit_OnUpdate() function in UIPanelTemplates.lua does something akin to this also.)
 <OnCursorChanged>
 	local vs = self:GetParent():GetVerticalScroll();
 	local h = self:GetParent():GetHeight();
 
 	if vs+arg2 > 0 or 0 > vs+arg2-arg4+h then
 		self:GetParent():SetVerticalScroll(arg2*-1);
 	end
 </OnCursorChanged>