/// <summary>
/// Adds a listener to this Signal.
/// </summary>
/// <param name="listener">The Delegate to call when this Signal is dispatched.</param>
/// <param name="priority">The priority of this Slot. Slots are called lowest-to-highest priority.</param>
/// <param name="isOnce">Determines if this listener is called only once or indefinitely on Dispatch().</param>
/// <returns></returns>
protected SlotBase Add(Delegate listener, int priority, bool isOnce)
{
if (listener == null)
{
return(null);
}
SlotBase slot = Get(listener);
if (!slot)
{
if (slotsPooled.Count > 0)
{
slot = slotsPooled.Pop();
}
else
{
slot = CreateSlot();
}
}
slot.Listener = listener;
slot.Priority = priority;
slot.IsOnce = isOnce;
slot.Signal = this;
PriorityChanged(slot, slot.Priority, 0);
isDisposed = false;
return(slot);
}
/// <summary>
/// Calls Dispose() on a Slot and pools it for reuse. This is done at the end of
/// a Dispatch() or when a Slot is removed and no dispatches are occurring.
/// </summary>
/// <param name="slot"></param>
private void DisposeSlot(SlotBase slot)
{
slot.Dispose();
if (!isDisposed)
{
slotsPooled.Push(slot);
}
}
/// <summary>
/// Internal method that is called from Slots when their priority has changed.
/// Keeps the Signal's Slot order up to date. Should NOT be called from anywhere else!
/// </summary>
/// <param name="slot"></param>
/// <param name="current"></param>
/// <param name="previous"></param>
internal void PriorityChanged(SlotBase slot, int current, int previous)
{
slots.Remove(slot);
for (int index = slots.Count; index > 0; --index)
{
if (slots[index - 1].Priority <= slot.Priority)
{
slots.Insert(index, slot);
return;
}
}
slots.Insert(0, slot);
}
/// <summary>
/// Removes the listener from this Signal at the given index.
/// </summary>
/// <param name="index">The index of the Slot to remove. Slots are ordered by priority.</param>
/// <returns></returns>
public bool RemoveAt(int index)
{
if (index < 0)
{
return(false);
}
if (index >= slots.Count)
{
return(false);
}
SlotBase slot = slots[index];
slots.RemoveAt(index);
if (dispatching > 0)
{
slotsRemoved.Push(slot);
}
else
{
DisposeSlot(slot);
}
return(true);
}