private bool SelectBy(int delta)
{
var list = GetSelectableItems();
var selection = GetSelectedItem();
if (selection != null)
{
var index = list.IndexOf(selection);
var direction = Math.Sign(delta);
delta = Math.Abs(delta);
var nextIndex = index;
var numVisibleElement = 0;
ISelectableItem nextElement = null;
while (numVisibleElement < delta)
{
nextIndex += direction;
if (nextIndex >= list.Count)
{
return(false);
}
if (nextIndex < 0)
{
return(false);
}
nextElement = list.ElementAt(nextIndex);
if (UIUtils.IsElementVisible(nextElement.element))
{
++numVisibleElement;
}
}
PageManager.instance.SetSelected(nextElement.package, nextElement.targetVersion);
foreach (var scrollView in UIUtils.GetParentsOfType <ScrollView>(nextElement.element))
{
ScrollIfNeeded(scrollView, nextElement.element);
}
}
return(true);
}
private void ScrollIfNeeded(ScrollView container = null, VisualElement target = null)
{
container = container ?? scrollView;
target = target ?? GetSelectedItem()?.element;
if (container == null || target == null)
{
return;
}
if (float.IsNaN(target.layout.height))
{
EditorApplication.delayCall += () => ScrollIfNeeded(container, target);
return;
}
var scrollViews = UIUtils.GetParentsOfType <ScrollView>(target);
foreach (var scrollview in scrollViews)
{
UIUtils.ScrollIfNeeded(scrollview, target);
}
}