UIAnchor.cs

using System;
using UnityEngine;

[AddComponentMenu("NGUI/UI/Anchor")]
[ExecuteInEditMode]
public class UIAnchor : MonoBehaviour
{
	public enum Side
	{
		BottomLeft,
		Left,
		TopLeft,
		Top,
		TopRight,
		Right,
		BottomRight,
		Bottom,
		Center
	}

	public Camera uiCamera;

	public GameObject container;

	public Side side = Side.Center;

	public bool runOnlyOnce = true;

	public Vector2 relativeOffset = Vector2.zero;

	public Vector2 pixelOffset = Vector2.zero;

	[HideInInspector]
	[SerializeField]
	private UIWidget widgetContainer;

	private Transform mTrans;

	private Animation mAnim;

	private Rect mRect = default(Rect);

	private UIRoot mRoot;

	private bool mStarted;

	private void Awake()
	{
		mTrans = base.transform;
		mAnim = GetComponent<Animation>();
		UICamera.onScreenResize = (UICamera.OnScreenResize)Delegate.Combine(UICamera.onScreenResize, new UICamera.OnScreenResize(ScreenSizeChanged));
	}

	private void OnDestroy()
	{
		UICamera.onScreenResize = (UICamera.OnScreenResize)Delegate.Remove(UICamera.onScreenResize, new UICamera.OnScreenResize(ScreenSizeChanged));
	}

	private void ScreenSizeChanged()
	{
		if (mStarted && runOnlyOnce)
		{
			Update();
		}
	}

	private void Start()
	{
		if (container == null && widgetContainer != null)
		{
			container = widgetContainer.gameObject;
			widgetContainer = null;
		}
		mRoot = NGUITools.FindInParents<UIRoot>(base.gameObject);
		if (uiCamera == null)
		{
			uiCamera = NGUITools.FindCameraForLayer(base.gameObject.layer);
		}
		Update();
		mStarted = true;
	}

	private void Update()
	{
		if (!(mAnim != null) || !mAnim.enabled || !mAnim.isPlaying)
		{
			bool flag = false;
			UIWidget uIWidget = (!(container == null)) ? container.GetComponent<UIWidget>() : null;
			UIPanel uIPanel = (!(container == null) || !(uIWidget == null)) ? container.GetComponent<UIPanel>() : null;
			if (uIWidget != null)
			{
				Bounds bounds = uIWidget.CalculateBounds(container.transform.parent);
				ref Rect reference = ref mRect;
				Vector3 min = bounds.min;
				reference.x = min.x;
				ref Rect reference2 = ref mRect;
				Vector3 min2 = bounds.min;
				reference2.y = min2.y;
				ref Rect reference3 = ref mRect;
				Vector3 size = bounds.size;
				reference3.width = size.x;
				ref Rect reference4 = ref mRect;
				Vector3 size2 = bounds.size;
				reference4.height = size2.y;
			}
			else if (uIPanel != null)
			{
				if (uIPanel.clipping == UIDrawCall.Clipping.None)
				{
					float num = (!(mRoot != null)) ? 0.5f : ((float)mRoot.activeHeight / (float)Screen.height * 0.5f);
					mRect.xMin = (float)(-Screen.width) * num;
					mRect.yMin = (float)(-Screen.height) * num;
					mRect.xMax = 0f - mRect.xMin;
					mRect.yMax = 0f - mRect.yMin;
				}
				else
				{
					Vector4 finalClipRegion = uIPanel.finalClipRegion;
					mRect.x = finalClipRegion.x - finalClipRegion.z * 0.5f;
					mRect.y = finalClipRegion.y - finalClipRegion.w * 0.5f;
					mRect.width = finalClipRegion.z;
					mRect.height = finalClipRegion.w;
				}
			}
			else if (container != null)
			{
				Transform parent = container.transform.parent;
				Bounds bounds2 = (!(parent != null)) ? NGUIMath.CalculateRelativeWidgetBounds(container.transform) : NGUIMath.CalculateRelativeWidgetBounds(parent, container.transform);
				ref Rect reference5 = ref mRect;
				Vector3 min3 = bounds2.min;
				reference5.x = min3.x;
				ref Rect reference6 = ref mRect;
				Vector3 min4 = bounds2.min;
				reference6.y = min4.y;
				ref Rect reference7 = ref mRect;
				Vector3 size3 = bounds2.size;
				reference7.width = size3.x;
				ref Rect reference8 = ref mRect;
				Vector3 size4 = bounds2.size;
				reference8.height = size4.y;
			}
			else
			{
				if (!(uiCamera != null))
				{
					return;
				}
				flag = true;
				mRect = uiCamera.pixelRect;
			}
			float x = (mRect.xMin + mRect.xMax) * 0.5f;
			float y = (mRect.yMin + mRect.yMax) * 0.5f;
			Vector3 vector = new Vector3(x, y, 0f);
			if (side != Side.Center)
			{
				if (side == Side.Right || side == Side.TopRight || side == Side.BottomRight)
				{
					vector.x = mRect.xMax;
				}
				else if (side == Side.Top || side == Side.Center || side == Side.Bottom)
				{
					vector.x = x;
				}
				else
				{
					vector.x = mRect.xMin;
				}
				if (side == Side.Top || side == Side.TopRight || side == Side.TopLeft)
				{
					vector.y = mRect.yMax;
				}
				else if (side == Side.Left || side == Side.Center || side == Side.Right)
				{
					vector.y = y;
				}
				else
				{
					vector.y = mRect.yMin;
				}
			}
			float width = mRect.width;
			float height = mRect.height;
			vector.x += pixelOffset.x + relativeOffset.x * width;
			vector.y += pixelOffset.y + relativeOffset.y * height;
			if (flag)
			{
				if (uiCamera.orthographic)
				{
					vector.x = Mathf.Round(vector.x);
					vector.y = Mathf.Round(vector.y);
				}
				Vector3 vector2 = uiCamera.WorldToScreenPoint(mTrans.position);
				vector.z = vector2.z;
				vector = uiCamera.ScreenToWorldPoint(vector);
			}
			else
			{
				vector.x = Mathf.Round(vector.x);
				vector.y = Mathf.Round(vector.y);
				if (uIPanel != null)
				{
					vector = uIPanel.cachedTransform.TransformPoint(vector);
				}
				else if (container != null)
				{
					Transform parent2 = container.transform.parent;
					if (parent2 != null)
					{
						vector = parent2.TransformPoint(vector);
					}
				}
				Vector3 position = mTrans.position;
				vector.z = position.z;
			}
			if (mTrans.position != vector)
			{
				mTrans.position = vector;
			}
			if (runOnlyOnce && Application.isPlaying)
			{
				base.enabled = false;
			}
		}
	}
}