Widget.cs

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections;
using System.Collections.Generic;


namespace UI
{
    public class Widget : MonoBehaviour
    {
        public LayoutPosition layoutPosition{ private set; get; }
        public Screen layoutScreen = Screen.center;
        public AlignmentH layoutAlignHorizontal = AlignmentH.stretch;
        public AlignmentV layoutAlignVertical = AlignmentV.stretch;
        [Range(0, 99)] public int layoutLayer = 0;

        private Material textMaterial = null;
        private Material imageMaterial = null;

        public void Awake()
        {
            // Make sure my canvas is centered:
            Canvas cv = GetComponentInChildren (typeof(Canvas), true) as Canvas;
            if (cv != null) {
                cv.transform.localPosition = Vector3.zero;
            }

            UpdateMaterials ();
        }

        public void UpdateMaterials()
        {
            if( textMaterial == null )
                textMaterial = new Material (Shader.Find ("Custom/TextShader"));
            if( imageMaterial == null )
                imageMaterial = new Material (Shader.Find ("Custom/UIObject"));

            // Set material for all texts:
            Component[] texts;
            texts = GetComponentsInChildren (typeof(Text), true);
            if (texts != null) {
                foreach (Text t in texts)
                    t.material = textMaterial;
            }

            // Set material for all images:
            Component[] images;
            images = GetComponentsInChildren (typeof(Image), true);
            if (images != null) {
                foreach (Image i in images) {
                    if( i.material.name == "Default UI Material")
                        i.material = imageMaterial;
                }
            }
        }

        public void OnEnable()
        {
            layoutPosition = new LayoutPosition();
            layoutPosition.screen = layoutScreen;
            layoutPosition.alignHorizontal = layoutAlignHorizontal;
            layoutPosition.alignVertical = layoutAlignVertical;
            UI.Core.instance.layoutSystem.addWidget (this);
        }

        public void OnDisable()
        {
            UI.Core.instance.layoutSystem.removeWidget (this);
        }

        public void OnDestroy()
        {
            UI.Core.instance.layoutSystem.removeWidget (this);
        }

        public void setPosition( LayoutPosition newPosition )
        {
            layoutPosition = newPosition;
            UI.Core.instance.layoutSystem.setWidgetPosition( this, newPosition );
        }

        public void highlight()
        {
            imageMaterial.SetInt ("_highlight", 1);

            //GetComponent<RectTransform> ().localScale = activeScale;
            Vector3 pos = transform.localPosition;
            pos.z = 100 - layoutLayer;
            transform.localPosition = pos;
        }

        public void unHighlight()
        {
            imageMaterial.SetInt ("_highlight", 0);

            //GetComponent<RectTransform> ().localScale = inactiveScale;
            Vector3 pos = transform.localPosition;
            pos.z = 200 - layoutLayer;
            transform.localPosition = pos;
        }
    }
}