// after uGUI(from 4.6)

#if !(UNITY_4_0 || UNITY_4_1 || UNITY_4_2 || UNITY_4_3 || UNITY_4_4 || UNITY_4_5)

using System;
using UnityEngine;

namespace UniRx.Triggers
{
    [DisallowMultipleComponent]
    public class ObservableRectTransformTrigger : ObservableTriggerBase
    {
        private Subject<Unit> onRectTransformDimensionsChange;

        private Subject<Unit> onRectTransformRemoved;

        // Callback that is sent if an associated RectTransform has it's dimensions changed
        private void OnRectTransformDimensionsChange()
        {
            if (onRectTransformDimensionsChange != null) onRectTransformDimensionsChange.OnNext(Unit.Default);
        }

        /// <summary>Callback that is sent if an associated RectTransform has it's dimensions changed.</summary>
        public IObservable<Unit> OnRectTransformDimensionsChangeAsObservable()
        {
            return onRectTransformDimensionsChange ?? (onRectTransformDimensionsChange = new Subject<Unit>());
        }

        // Callback that is sent if an associated RectTransform is removed
        private void OnRectTransformRemoved()
        {
            if (onRectTransformRemoved != null) onRectTransformRemoved.OnNext(Unit.Default);
        }

        /// <summary>Callback that is sent if an associated RectTransform is removed.</summary>
        public IObservable<Unit> OnRectTransformRemovedAsObservable()
        {
            return onRectTransformRemoved ?? (onRectTransformRemoved = new Subject<Unit>());
        }

        protected override void RaiseOnCompletedOnDestroy()
        {
            if (onRectTransformDimensionsChange != null) onRectTransformDimensionsChange.OnCompleted();
            if (onRectTransformRemoved != null) onRectTransformRemoved.OnCompleted();
        }
    }
}

#endif