private ListItemBase CreateNewItem(ListItemBase prefab, int index, float dimension)
{
GameObject instance = (GameObject)Instantiate(prefab.gameObject, Vector3.zero, Quaternion.identity);
instance.transform.SetParent(_content.transform);
instance.transform.localScale = Vector3.one;
instance.SetActive(true);
float position = index * (dimension + _spacing) + dimension / 2;
RectTransform rectTransform = instance.GetComponent <RectTransform> ();
switch (_scrollOrientation)
{
case ScrollOrientation.HORIZONTAL:
rectTransform.anchorMin = new Vector2(0, 0);
rectTransform.anchorMax = new Vector2(0, 1);
rectTransform.anchoredPosition = new Vector2(position, 0);
rectTransform.offsetMin = new Vector2(rectTransform.offsetMin.x, 0);
rectTransform.offsetMax = new Vector2(rectTransform.offsetMax.x, 0);
break;
case ScrollOrientation.VERTICAL:
rectTransform.anchorMin = new Vector2(0, 1);
rectTransform.anchorMax = new Vector2(1, 1);
rectTransform.anchoredPosition = new Vector2(0, -position);
rectTransform.offsetMin = new Vector2(0, rectTransform.offsetMin.y);
rectTransform.offsetMax = new Vector2(0, rectTransform.offsetMax.y);
break;
}
return(instance.GetComponent <ListItemBase> ());
}
public void Create(int items, ListItemBase listItemPrefab)
{
_listItemHeight = listItemPrefab.Size.y;
_content.sizeDelta = new Vector2(_content.sizeDelta.x, _listItemHeight * items + _spacing * (items - 1));
_itemsTotal = items;
_itemsVisible = Mathf.FloorToInt(_viewport.rect.height / _listItemHeight) * 2;
_itemsToRecycleBottom = _itemsVisible / 2;
_currentIndex = _itemsVisible - 1;
_items = new List <ListItemBase> ();
for (int i = 0; i < _itemsVisible; i++)
{
ListItemBase item = CreateNewItem(listItemPrefab, i * (_listItemHeight + _spacing) + _listItemHeight / 2);
item.onSelected = HandleOnSelectedHandler;
item.Index = i;
_items.Add(item);
ItemLoaded(item);
}
_scrollRect.onValueChanged.AddListener((Vector2 position) =>
{
Recycle();
});
}
private void RecycleItem(Direction direction)
{
ListItemBase firstItem = _items [0];
ListItemBase lastItem = _items [_items.Count - 1];
float targetPositionY = (_listItemHeight + _spacing) * -1;
switch (direction)
{
case Direction.DOWN:
firstItem.Position = new Vector2(firstItem.Position.x, lastItem.Position.y + targetPositionY);
firstItem.Index = _currentIndex;
firstItem.transform.SetAsLastSibling();
_items.RemoveAt(0);
_items.Add(firstItem);
ItemLoaded(firstItem);
break;
case Direction.UP:
lastItem.Position = new Vector2(lastItem.Position.x, firstItem.Position.y - targetPositionY);
lastItem.Index = _currentIndex - _itemsVisible;
lastItem.transform.SetAsFirstSibling();
_items.RemoveAt(_items.Count - 1);
_items.Insert(0, lastItem);
ItemLoaded(lastItem);
break;
}
}
private void RecycleItem(ScrollDirection direction)
{
ListItemBase firstItem = _itemsList [0];
ListItemBase lastItem = _itemsList [_itemsList.Count - 1];
float targetPosition = (_itemSize + _spacing);
switch (direction)
{
case ScrollDirection.NEXT:
switch (_scrollOrientation)
{
case ScrollOrientation.HORIZONTAL:
firstItem.Position = new Vector2(lastItem.Position.x + targetPosition, firstItem.Position.y);
break;
case ScrollOrientation.VERTICAL:
firstItem.Position = new Vector2(firstItem.Position.x, lastItem.Position.y - targetPosition);
break;
}
firstItem.Index = _lastItemIndex;
firstItem.transform.SetAsLastSibling();
_itemsList.RemoveAt(0);
_itemsList.Add(firstItem);
ItemLoaded(firstItem);
break;
case ScrollDirection.PREVIOUS:
switch (_scrollOrientation)
{
case ScrollOrientation.HORIZONTAL:
lastItem.Position = new Vector2(firstItem.Position.x - targetPosition, lastItem.Position.y);
break;
case ScrollOrientation.VERTICAL:
lastItem.Position = new Vector2(lastItem.Position.x, firstItem.Position.y + targetPosition);
break;
}
lastItem.Index = _lastItemIndex - _itemsList.Count;
lastItem.transform.SetAsFirstSibling();
_itemsList.RemoveAt(_itemsList.Count - 1);
_itemsList.Insert(0, lastItem);
ItemLoaded(lastItem);
break;
}
Canvas.ForceUpdateCanvases();
}
public void ItemSelected(ListItemBase item, bool clear = false)
{
if (onItemSelected != null)
{
onItemSelected(item);
if (clear)
{
onItemSelected = null;
}
}
}
private ListItemBase CreateNewItem(ListItemBase prefab, float positionY)
{
GameObject instance = (GameObject)Instantiate(prefab.gameObject, Vector3.zero, Quaternion.identity);
instance.transform.SetParent(_content.transform);
instance.transform.localScale = Vector3.one;
instance.SetActive(true);
RectTransform rectTransform = instance.GetComponent <RectTransform> ();
rectTransform.anchoredPosition = new Vector2(0, -positionY);
rectTransform.offsetMin = new Vector2(0, rectTransform.offsetMin.y);
rectTransform.offsetMax = new Vector2(0, rectTransform.offsetMax.y);
return(instance.GetComponent <ListItemBase> ());
}
void HandleOnSelectedHandler(ListItemBase item)
{
ItemSelected(item);
}
public void Create(int items, ListItemBase listItemPrefab)
{
switch (_scrollOrientation)
{
case ScrollOrientation.HORIZONTAL:
_scrollRect.vertical = false;
_scrollRect.horizontal = true;
_content.anchorMin = new Vector2(0, 0);
_content.anchorMax = new Vector2(0, 1);
if (_fitItemToViewport)
{
listItemPrefab.Size = new Vector2(_viewport.rect.width, listItemPrefab.Size.y);
}
_itemSize = listItemPrefab.Size.x;
_content.sizeDelta = new Vector2(_itemSize * items + _spacing * (items - 1), 0);
break;
case ScrollOrientation.VERTICAL:
_scrollRect.vertical = true;
_scrollRect.horizontal = false;
_content.anchorMin = new Vector2(0, 1);
_content.anchorMax = new Vector2(1, 1);
if (_fitItemToViewport)
{
listItemPrefab.Size = new Vector2(listItemPrefab.Size.x, _viewport.rect.height);
}
_itemSize = listItemPrefab.Size.y;
_content.sizeDelta = new Vector2(0, _itemSize * items + _spacing * (items - 1));
break;
}
if (_centerOnItem)
{
_scrollRect.inertia = false;
}
//_itemsVisible = Mathf.CeilToInt (GetViewportSize () / _itemSize);
_itemsVisible = 1; //TODO: hard coded fix, need to be changed to work
int itemsToInstantiate = _itemsVisible;
if (_itemsVisible == 1)
{
itemsToInstantiate = 5;
}
else if (itemsToInstantiate < items)
{
itemsToInstantiate *= 2;
}
if (itemsToInstantiate > items)
{
itemsToInstantiate = items;
}
_itemsList = new List <ListItemBase> ();
for (int i = 0; i < itemsToInstantiate; i++)
{
ListItemBase item = CreateNewItem(listItemPrefab, i, _itemSize);
item.onSelected = HandleOnSelectedHandler;
item.Index = i;
_itemsList.Add(item);
ItemLoaded(item);
}
_itemsTotal = items;
_lastItemIndex = _itemsList.Count - 1;
_itemsToRecycleAfter = _itemsList.Count - _itemsVisible;
_scrollRect.onValueChanged.AddListener((Vector2 position) =>
{
if (!_centerOnItem)
{
Recycle();
}
});
}
