Added UIScrollToSelection script

--HG--
branch : zero3growlithe

Scripts/UIScrollToSelection.cs

@@ -0,0 +1,106 @@
+/// sourced from: http://forum.unity3d.com/threads/scripts-useful-4-6-scripts-collection.264161/page-2#post-2011648
+
+/*USAGE:
+Simply place the script on the ScrollRect that contains the selectable children we'll be scroling to
+and drag'n'drop the RectTransform of the options "container" that we'll be scrolling.*/
+
+using UnityEngine;
+using System.Collections;
+using UnityEngine.UI;
+using UnityEngine.EventSystems;
+
+public class UIScrollToSelection : MonoBehaviour {
+
+/* ### VARIABLES ============================================================== */
+
+	// settings
+	public float scrollSpeed = 10f;
+	
+	[SerializeField]
+	private RectTransform layoutListGroup;
+
+	// temporary variables
+	private RectTransform targetScrollObject;
+	private bool scrollToSelection = true;
+
+	// references
+	private RectTransform scrollWindow;
+	private RectTransform currentCanvas;
+	private ScrollRect targetScrollRect;
+	
+
+/* ### MAIN METHODS =========================================================== */
+	// Use this for initialization
+	private void Start () {
+		targetScrollRect = GetComponent<ScrollRect>();
+		scrollWindow = targetScrollRect.GetComponent<RectTransform>();
+		currentCanvas = transform.root.GetComponent<RectTransform>();
+	}
+	
+	// Update is called once per frame
+	private void Update () {
+		ScrollRectToLevelSelection();
+	}
+
+	private void ScrollRectToLevelSelection (){
+		// check main references
+		bool referencesAreIncorrect =
+			(targetScrollRect == null || layoutListGroup == null || scrollWindow == null);
+		if (referencesAreIncorrect == true){
+			return;
+		}
+
+		// get calculation references
+		EventSystem events = EventSystem.current;
+		RectTransform selection = events.currentSelectedGameObject != null ?
+			events.currentSelectedGameObject.GetComponent<RectTransform>() :
+			null;
+		RectTransform lastSelection = events.lastSelectedGameObject != null ?
+			events.lastSelectedGameObject.GetComponent<RectTransform>() :
+			selection;
+
+		if (selection != targetScrollObject)
+			scrollToSelection = true;
+
+		// check if scrolling is possible
+		bool isScrollDirectionUnknown =
+			(selection == null || lastSelection == null || scrollToSelection == false);
+
+		if (isScrollDirectionUnknown == true || selection.transform.parent != layoutListGroup.transform)
+			return;
+
+		// move the current scroll rect to correct position
+		float selectionPos = -selection.anchoredPosition.y;
+		int direction =	(int)Mathf.Sign(selection.anchoredPosition.y - lastSelection.anchoredPosition.y);
+
+		float elementHeight = layoutListGroup.sizeDelta.y / layoutListGroup.transform.childCount;
+		float maskHeight = currentCanvas.sizeDelta.y + scrollWindow.sizeDelta.y;
+		float listPixelAnchor = layoutListGroup.anchoredPosition.y;
+
+		// get the element offset value depending on the cursor move direction
+		float offlimitsValue = 0;
+		if (direction > 0 && selectionPos < listPixelAnchor)
+		{
+			offlimitsValue = listPixelAnchor - selectionPos;
+		}
+		if (direction < 0 && selectionPos + elementHeight > listPixelAnchor + maskHeight)
+		{
+			offlimitsValue = (listPixelAnchor + maskHeight) - (selectionPos + elementHeight);
+		}
+		// move the target scroll rect
+		targetScrollRect.verticalNormalizedPosition +=
+			(offlimitsValue / layoutListGroup.sizeDelta.y) * Time.deltaTime * scrollSpeed;
+		// check if we reached our destination
+		if (Mathf.Abs(offlimitsValue) < 2f)
+			scrollToSelection = false;
+		// save last object we were "heading to" to prevent blocking
+		targetScrollObject = selection;
+	}
+
+/* ### ENUMS ================================================================== */
+	
+
+/* ### CUSTOM TYPES =========================================================== */
+	
+	
+}