UnityDynamicScrollRect

An optimized approach to lists with dozens of elements.

<p align="center"> <img src="https://github.com/Mukarillo/UnityDynamicScrollRect/blob/master/ReadmeAssets/dynamic_list_example.gif?raw=true" alt="Example"/> </p>

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.

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<ExampleData> and implement its abstract members (make sure to call base.updateScrollObject(item, index);) and set the object width and height in currentWidth and currentHeight.

public class ExampleDynamicObject : DynamicScrollObject<ExampleData>
{
  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<RectTransform>().rect.height;
    currentWidth = GetComponent<RectTransform>().rect.width;

    idText = transform.Find("PostId").GetComponent<Text>();
    nameEmailText = transform.Find("NameEmail").GetComponent<Text>();
    bodyText = transform.Find("Body").GetComponent<Text>();         
  }

  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)

public class ExampleScroll : MonoBehaviour
{
  public DynamicScrollRect verticalScroll;
  public GameObject referenceObject;

  private DynamicScroll<ExampleData, ExampleDynamicObject> mVerticalDynamicScroll = new DynamicScroll<ExampleData, ExampleDynamicObject>();

  public IEnumerator Start()
  {
    WWW www = new WWW(@"https://jsonplaceholder.typicode.com/comments");
    yield return www;
    var data = JsonHelper.getJsonArray<ExampleData>(www.text);

    mVerticalDynamicScroll.spacing = 5f;
    mVerticalDynamicScroll.Initiate(verticalScroll, data, 0, referenceObject);
  }      
}

DynamicScroll<T, T1> 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.