/// <summary>
/// Updates all of the current buffer users.
/// </summary>
public void UpdateBufferUsers()
{
for (var i = 0; i < UserBuffer.Count; i++)
{
var bufferObject = UserBuffer.ElementAt(i);
// In the event that there aren't any available users left, we want to remove these unused
// contained drawable objects.
if (AvailableUsers.ElementAtOrDefault(PoolStartingIndex + i) == null)
{
RemoveContainedDrawable(bufferObject);
UserBufferObjectsUsed--;
continue;
}
bufferObject.Y = (PoolStartingIndex + i) * DrawableOnlineUser.HEIGHT;
bufferObject.UpdateUser(AvailableUsers[PoolStartingIndex + i]);
// Make sure the object is contained if it isn't already.
if (bufferObject.Parent != ContentContainer)
{
AddContainedDrawable(bufferObject);
}
}
}
/// <summary>
/// Handles shifting the pool whenever the container is scrolled.
/// Also initializing any new objects that need it.
/// </summary>
/// <param name="direction"></param>
private void HandlePoolShifting(Direction direction)
{
switch (direction)
{
case Direction.Forward:
// If there are no available users then there's no need to do anything.
if (AvailableUsers.ElementAtOrDefault(PoolStartingIndex) == null ||
AvailableUsers.ElementAtOrDefault(PoolStartingIndex + MAX_USERS_SHOWN) == null)
{
return;
}
var firstUser = UserBuffer.First();
// Check if the object is in the rect of the ScrollContainer.
// If it is, then there's no updating that needs to happen.
if (!Rectangle.Intersect(firstUser.ScreenRectangle, ScreenRectangle).IsEmpty)
{
return;
}
// Update the user's information and y position.
firstUser.Y = (PoolStartingIndex + MAX_USERS_SHOWN) * DrawableOnlineUser.HEIGHT;
lock (AvailableUsers)
firstUser.UpdateUser(AvailableUsers[PoolStartingIndex + MAX_USERS_SHOWN]);
// Circuluarly Shift the list forward one.
UserBuffer.RemoveFirst();
UserBuffer.AddLast(firstUser);
// Take this user, and place them at the bottom.
PoolStartingIndex++;
break;
case Direction.Backward:
// If there are no previous available user then there's no need to shift.
if (AvailableUsers.ElementAtOrDefault(PoolStartingIndex - 1) == null)
{
return;
}
var lastUser = UserBuffer.Last();
// Check if the object is in the rect of the ScrollContainer.
// If it is, then there's no updating that needs to happen.
if (!Rectangle.Intersect(lastUser.ScreenRectangle, ScreenRectangle).IsEmpty)
{
return;
}
lastUser.Y = (PoolStartingIndex - 1) * DrawableOnlineUser.HEIGHT;
lock (AvailableUsers)
lastUser.UpdateUser(AvailableUsers[PoolStartingIndex - 1]);
UserBuffer.RemoveLast();
UserBuffer.AddFirst(lastUser);
PoolStartingIndex--;
break;
default:
throw new ArgumentOutOfRangeException(nameof(direction), direction, null);
}
}