Fixed PageChanged event for HSS/VSS

Fixed WorldSpace use of HSS/VSS (also created a new feature :D)
Minor editor options fix for boxslider

--HG--
branch : develop_5.3

Editor/UIExtensionsMenuOptions.cs

@@ -1654,6 +1654,42 @@ namespace UnityEditor.UI
 			Selection.activeGameObject = go;
 		}
 
+        #region BoxSlider
+        [MenuItem("GameObject/UI/Extensions/Box Slider", false)]
+        static public void AddBoxSlider(MenuCommand menuCommand)
+        {
+
+            GameObject uiboxSliderRoot = CreateUIElementRoot("Box Slider", menuCommand, s_ImageGUIElementSize);
+
+            GameObject handleSlideArea = CreateUIObject("Handle Slide Area", uiboxSliderRoot);
+
+            GameObject handle = CreateUIObject("Handle", handleSlideArea);
+
+            // Set RectTransform to stretch
+            SetAnchorsAndStretch(uiboxSliderRoot);
+            Image backgroundImage = uiboxSliderRoot.AddComponent<Image>();
+            backgroundImage.sprite = AssetDatabase.GetBuiltinExtraResource<Sprite>(kBackgroundSpriteResourcePath);
+            backgroundImage.type = Image.Type.Sliced;
+            backgroundImage.fillCenter = false;
+            backgroundImage.color = new Color(1f, 1f, 1f, 0.392f);
+
+            RectTransform handleRect = SetAnchorsAndStretch(handle); 
+            handleRect.sizeDelta = new Vector2(25, 25);
+            Image handleImage = handle.AddComponent<Image>();
+            handleImage.sprite = AssetDatabase.GetBuiltinExtraResource<Sprite>(kKnobPath);
+            handleImage.type = Image.Type.Simple;
+            handleImage.fillCenter = false;
+            handleImage.color = new Color(1f, 1f, 1f, 0.392f);
+
+
+            BoxSlider selectableArea = uiboxSliderRoot.AddComponent<BoxSlider>();
+            selectableArea.HandleRect = handle.GetComponent<RectTransform>();
+            selectableArea.ValueX = selectableArea.ValueY = 0.5f;
+
+            Selection.activeGameObject = uiboxSliderRoot;
+        }
+        #endregion
+
         #endregion
 
         #region Helper Functions
@@ -1787,6 +1823,15 @@ namespace UnityEditor.UI
 			return buttonRoot;
 		}
 
+        private static RectTransform SetAnchorsAndStretch(GameObject root)
+        {
+            RectTransform rectTransformRoot = root.GetComponent<RectTransform>();
+            rectTransformRoot.anchorMin = new Vector2(0.5f, 0.5f);
+            rectTransformRoot.anchorMax = new Vector2(0.5f, 0.5f);
+            rectTransformRoot.anchoredPosition = Vector2.zero;
+            return rectTransformRoot;
+        }
+
         #endregion
 
     }

Scripts/Layout/ScrollSnapBase.cs

@@ -80,12 +80,16 @@ namespace UnityEngine.UI.Extensions
                 {
                     _previousPage = _currentPage;
                     _currentPage = value;
-                    ChangeBulletsInfo(_currentPage);
                     if(MaskArea) UpdateVisible();
+                    ScreenChange();
+                    ChangeBulletsInfo(_currentPage);
                 }
             }
         }
 
+        [Tooltip("(Experimental)\nBy default, child array objects will use the parent transform\nHowever you can disable this for some interesting effects")]
+        public bool UseParentTransform = true;
+
         [Tooltip("Scroll Snap children. (optional)\nEither place objects in the scene as children OR\nPrefabs in this array, NOT BOTH")]
         public GameObject[] ChildObjects;
         
@@ -156,10 +160,21 @@ namespace UnityEngine.UI.Extensions
         internal void InitialiseChildObjectsFromArray()
         {
             int childCount = ChildObjects.Length;
+            RectTransform childRect;
+            GameObject child;
             for (int i = 0; i < childCount; i++)
             {
-                ChildObjects[i] = GameObject.Instantiate(ChildObjects[i]);
+                child = GameObject.Instantiate(ChildObjects[i]);
-                ChildObjects[i].transform.SetParent(_screensContainer.transform);
+                //Optionally, use original GO transform when initialising, by default will use parent RectTransform position/rotation
+                if (UseParentTransform)
+                {
+                    childRect = child.GetComponent<RectTransform>();
+                    childRect.rotation = _screensContainer.rotation;
+                    childRect.localScale = _screensContainer.localScale;
+                    childRect.position = _screensContainer.position;
+                }
+                child.transform.SetParent(_screensContainer.transform);
+                ChildObjects[i] = child;
                 if (MaskArea && ChildObjects[i].activeSelf)
                 {
                     ChildObjects[i].SetActive(false);
@@ -306,9 +321,8 @@ namespace UnityEngine.UI.Extensions
             OnSelectionChangeStartEvent.Invoke();
         }
 
-        internal void ScreenChange(int previousScreen)
+        internal void ScreenChange()
         {
-
             OnSelectionPageChangedEvent.Invoke(_currentPage);
         }