Well, i thought i would answer myself... I certainly cannot find a
built in way to automatically scroll to a display object inside a
VBox.
So, here's my hack at it:
private function scrollObjectIntoView
(vBox:VBox,scrollToObject:DisplayObject):void
{
var startViewPosition:int = vBox.verticalScrollPosition;
var endViewPosition:int = vBox.verticalScrollPosition +
vBox.height;
var scrollToObjectPosition:int = 0;
// determine intended scroll position of the input DisplayObject
// just sum up the virtual Y position of the child display object
for each (var displayObj:DisplayObject in vBox.getChildren())
{
if (displayObj == scrollToObject) break;
scrollToObjectPosition += displayObj.height;
}
// is already in view if the scroll to position is
// between the start and end current view position
if (scrollToObjectPosition > startViewPosition &&
scrollToObjectPosition < endViewPosition) return;
// don't let the scroll to postion be greater than
// the max scroll to position, could also use a Math.max here.
if (scrollToObjectPosition > vBox.maxVerticalScrollPosition)
scrollToObjectPosition = vBox.maxVerticalScrollPosition;
// set the scroll to positin.
vBox.verticalScrollPosition = scrollToObjectPosition;
}
--- In [email protected], "scott_flex" <[EMAIL PROTECTED]> wrote:
>
>
>
> Is there no automatic way to scroll to a particualar child object
> inside a VBox?
>
> I'm writing a tool that allows the user to select a child control
in
> a vbox, (it get highlighted just like a row in a datagrid) and then
> give them an up and down arrow to move the object up or down.
>
> However, when you move a question up (using the vbox's
setChildIndex
> method) it's moved up or below the window i want to programatically
> scroll the selected child into view but only if it needs to.
>
> Right now i've just writing my own code, basically reading the
scroll
> postion of the vertical scroll bar and all the heights of the child
> object in the vbox.... it's a hack though.
>
> I think i've see a "scrollIntoView" method somewhere but it's not
> listed on the VBox ui object.
>
> Thanks for anyones help.... i could be missing something really
easy.
>
