void ScrollUpdate()
{
var oldTopHiddenItems = topHiddenItems;
topHiddenItems = GetFirstVisibleIndex();
bottomHiddenItems = Mathf.Max(0, DataSource.Count - visibleItems - topHiddenItems);
if (oldTopHiddenItems == topHiddenItems)
{
//do nothing
}
// optimization on +-1 item scroll
else if (oldTopHiddenItems == (topHiddenItems + 1))
{
var bottomComponent = ComponentTopToBottom();
bottomComponent.Index = topHiddenItems;
bottomComponent.Text.text = DataSource[topHiddenItems];
Coloring(bottomComponent);
}
else if (oldTopHiddenItems == (topHiddenItems - 1))
{
var topComponent = ComponentBottomToTop();
var new_index = topHiddenItems + visibleItems - 1;
topComponent.Index = new_index;
topComponent.Text.text = DataSource[new_index];
Coloring(topComponent);
}
// all other cases
else
{
//!
var new_indicies = Enumerable.Range(topHiddenItems, visibleItems).ToArray();
components.ForEach((x, i) => {
x.Index = new_indicies[i];
x.Text.text = DataSource[new_indicies[i]];
Coloring(x);
});
}
if (LayoutBridge != null)
{
LayoutBridge.SetFiller(CalculateTopFillerSize(), CalculateBottomFillerSize());
LayoutBridge.UpdateLayout();
}
}
/// <summary>
/// On ScrollUpdate.
/// </summary>
protected virtual void ScrollUpdate()
{
var oldTopHiddenItems = topHiddenItems;
topHiddenItems = GetFirstVisibleIndex();
bottomHiddenItems = Mathf.Max(0, DataSource.Count - visibleItems - topHiddenItems);
if (oldTopHiddenItems == topHiddenItems)
{
//do nothing
}
// optimization on +-1 item scroll
else if (oldTopHiddenItems == (topHiddenItems + 1))
{
var bottomComponent = components[components.Count - 1];
components.RemoveAt(components.Count - 1);
components.Insert(0, bottomComponent);
bottomComponent.transform.SetAsFirstSibling();
bottomComponent.Index = topHiddenItems;
SetData(bottomComponent, DataSource[topHiddenItems]);
Coloring(bottomComponent as ListViewItem);
}
else if (oldTopHiddenItems == (topHiddenItems - 1))
{
var topComponent = components[0];
components.RemoveAt(0);
components.Add(topComponent);
topComponent.transform.SetAsLastSibling();
topComponent.Index = topHiddenItems + visibleItems - 1;
SetData(topComponent, DataSource[topHiddenItems + visibleItems - 1]);
Coloring(topComponent as ListViewItem);
}
// all other cases
else
{
var current_visible_range = components.Convert <TComponent, int>(GetComponentIndex);
var new_visible_range = Enumerable.Range(topHiddenItems, visibleItems).ToArray();
var new_indicies_to_change = new_visible_range.Except(current_visible_range).ToList();
var components_to_change = new Stack <TComponent>(components.Where(x => !new_visible_range.Contains(x.Index)));
new_indicies_to_change.ForEach(index => {
var component = components_to_change.Pop();
component.Index = index;
SetData(component, DataSource[index]);
Coloring(component as ListViewItem);
});
components.Sort(ComponentsComparer);
components.ForEach(SetComponentAsLastSibling);
}
if (LayoutBridge != null)
{
LayoutBridge.SetFiller(CalculateTopFillerSize(), CalculateBottomFillerSize());
LayoutBridge.UpdateLayout();
}
}