# UnityDynamicScrollRect An optimized approach to lists with dozens of elements.

Example

## How to use *you can find a pratical example inside this repository in DynamicScrollScene scene* ### 1 - Create a class to store all the information that each element of the list will need. ```c# public class ExampleData { public int postId; public int id; public string name; public string email; public string body; } ``` ### 2 - Create a class that extends `DynamicScrollObject` and implement its abstract members (make sure to call `base.updateScrollObject(item, index);`) and set the object width and height in `currentWidth` and `currentHeight`. ```c# public class ExampleDynamicObject : DynamicScrollObject { public override float currentHeight { get; set; } public override float currentWidth { get; set; } private Text idText; private Text nameEmailText; private Text bodyText; public void Awake() { currentHeight = GetComponent().rect.height; currentWidth = GetComponent().rect.width; idText = transform.Find("PostId").GetComponent(); nameEmailText = transform.Find("NameEmail").GetComponent(); bodyText = transform.Find("Body").GetComponent(); } public override void updateScrollObject(ExampleData item, int index) { base.updateScrollObject(item, index); idText.text = item.id.ToString(); nameEmailText.text = string.Format("{0} ({1})", item.name, item.email); bodyText.text = item.body; } } ``` ### 3 - Create a class to initiate the DynamicList (use DynamicScrollRect instead of ScrollRect) ```c# public class ExampleScroll : MonoBehaviour { public DynamicScrollRect verticalScroll; public GameObject referenceObject; private DynamicScroll mVerticalDynamicScroll = new DynamicScroll(); public IEnumerator Start() { WWW www = new WWW(@"https://jsonplaceholder.typicode.com/comments"); yield return www; var data = JsonHelper.getJsonArray(www.text); mVerticalDynamicScroll.spacing = 5f; mVerticalDynamicScroll.Initiate(verticalScroll, data, 0, referenceObject); } } ``` ## DynamicScroll `public` overview ### Properties |name |type |description | |--|--|--| |`spacing` |**float** |*Value that represent the spacing between elements of the list* | |`centralizeOnStop` |**bool** |*If the list should centralize the closest element to the center of the viewport after stop moving* | |`objectPool` |**readonly Pooling < T1 >** |*The elements of the list* | |`OnDragEvent` |**Action < Vector2 >** |*Event that triggers whenever the user scrolls the list, the parameter represent the velocity of the drag* | |`OnBeginDragEvent` |**UnityEvent < PointerEventData >** |*Event that triggers in the first frame of dragging* | |`OnEndDragEvent` |**UnityEvent < PointerEventData >** |*Event that triggers in the last frame of dragging* | ### Methods > `dynamicScroll.Initiate` - *Description*: Initiate the scroll rect with `objReference` objects applying `infoList` data. - *Parameters*: |name |type |description | |--|--|--| |`scrollRect` |**ScrollRect** |*a reference to the scroll rect* | |`infoList` |**T[]** |*the list with the data information* | |`startIndex` |**int** |*the item of index `startindex` will be the first element of the list* | |`objReference` |**GameObject** |*a reference of the object that will be inside the list* | |`createMoreIfNeeded` |**bool** |*if the list needs more itens, it will create more if `createMoreIfNeeded` == true* | |`forceAmount` |**int?** |*if setted, it will force `forceAmount` objects to be created at start* | > `dynamicScroll.ChangeList` - *Description*: Change the current list of the scroll rect. - *Parameters* : |name |type |description | |--|--|--| |`infoList` |**T[]** |*the list with the data information* | |`startIndex` |**int** |*the item of index `startindex` will be the first element of the list. If -1, the current index will be setted.* | |`resetContentPosition` |**bool** |*reset list position* | > `dynamicScroll.RefreshPosition` - *Description*: Repaint the whole scroll rect. This is useful if any item inside the scroll rect changes the size (`currentWidth` and `currentHeight`). > `dynamicScroll.ToggleScroll` - *Description*: Enable or Disable the ability to scroll the list. - *Parameters* : |name |type |description | |--|--|--| |`active` |**bool** |*enable or Disable the ability to scroll the list* | > `dynamicScroll.CanMove` - *Description*: Returns true if all directions send thro parameter are available. - *Parameters* : |name |type |description | |--|--|--| |`directions` |**ScrollDirection** |*Enum flag with all the directions you want to know if are available* | > `dynamicScroll.MoveToIndex` - *Description*: Tweens the content to centralize the object of index specified in the parameters. - *Parameters* : |name |type |description | |--|--|--| |`i` |**int** |*Index of the element to be centralized* | |`totalTime` |**float?** |*Total time to the animation happen (if you choose to input this value, the next one will be ignored)* | |`timePerElement` |**float?** |*This value will be multiplied by the difference between the current centralized element and the target element to get the totalTime* | > `dynamicScroll.GetCentralizedObject` - *Description*: Returns the closest element to the center of the viewport. > `dynamicScroll.GetLowest` - *Description*: Returns the most left (if horizontal scroll) or most bottom (if vertical scroll) T1 object. > `dynamicScroll.GetHighest` - *Description*: Returns the most right (if horizontal scroll) or most upper (if vertical scroll) T1 object.