mukarillo / unitydynamicscrollrect

An optimized approach to lists with dozens of elements and a Pooling system

UnityDynamicScrollRect

An optimized approach to lists with dozens of elements.

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.

unitydynamicscrollrect's Issues

Scroll to index?

Hello, i think you might want to add some feature, that will be great: scroll to index
it basically do is that scrolls the scrollview to make the element visible, on center of the scrollRect (if possible), you'll need to pass an index argument to the method and it should animate or jump directly to the scroll position (by an optional bool/speed parameter?)

i have seen that feature in similar assets and i think it will be a great addiction if you can for sure :)

Use IList instead of an array to make solution more flexible

If you make a little change and use IList interface instead of info array list, your solution will be prepared for use in new scenarios.

For example, I can't load all information and store it in an array, because it is too big. But if I can use an IList, I can implement a way to load only information which dynamic scroll needs.

Items are not removed when data list gets shorter?

Hi,

I am trying to integrate this into my project. My items are addable and deletable. When I add or delete them, I do this:

public void UpdateList(ItemData[] listData) //updated list of items, could be more, could be less than before
        {
            if(!dynamicScroll.Initialized) //I added this bool in the DynamicScroll to know if DynamicScroll.Initiate(...) has been called already
            {
                dynamicScroll.spacing = scrollSpacing;
                dynamicScroll.centralizeOnStop = scrollCentralizeOnStop;
                dynamicScroll.Initiate(dynamicScrollRect, listData, 0, sceneObjectTemplate);
            }
            else
            {
                dynamicScroll.ChangeList(listData);
            }
        }

It works for adding new items. But when I remove items, the UI elements are not removed (or hidden).

Am I using this right? How do I do this properly?

Start on the last element of the collection.

Hi, first of all, thank you to sharing this great asset.

The thing is that i need to change the start point of the scroll, by this I mean to start at the end of the list, on the last object, therefore on the end of the scrollrect so you can only start scrolling up.

I saw that on the methods Initialize and ChangeList, there is a startIndex that can be set, but if for example i use the mData.Length - 1 instead of 0, it only shows the last object. Looking why this is happening I found that in the CreateList method is no support for using the the max size of a collection. So I proceeded to modify this and add the functionality to iterate from the last object to the first one but it still not working as I want.

Can you guide me what I need to change/modify on the pooling or the refreshing of objects to achieve this ?

Thanks.

[Feature Request] Elastic Movement

Asset works great from the first look. However I'm missing elastic movement when dragging beyond the end or beginning. Is there a plan to include it?

Compatible with Grid Layout?

Hello,

First, thank you to sharing with us this great project, this is very useful!

Now I would like to apply the same kind of process but for elements inside of a grid layout that is inside a VerticalScrollRect.

Basically, it the almost same thing instead of I have more than one element by row, and it doesn't seem to work well from now.

I will try to update the code to make this possible, but if you have any advice of how you would do it, it will be great! 👍

Consider control adoption in the Unity UI Extensions collection?

Hi

One of the users of the Unity UI Extensions project spotted your control and suggested it would be a good for including in the project.

https://bitbucket.org/UnityUIExtensions/unity-ui-extensions

Would you be ok with your control being uplifted there?

Can't add through Package Manager in Unity 2021.1.19f1

I know there hasn't been much work done to this in years, but I still figured I'd throw the question your way.
Any chance we can have this updated so that one can add the package through the Package Managers "Add package from git URL"?

ScrollRect Content/Elements going very far from origin if the list is very big

The way that it is implemented today doesn't work very well because it changes the position of objects and the scrollrect.velocity gets messed up, so the scroll gets very fast when the offset happens.

Scollbar support?

Hi, thanks for this great component.

I want to show a scrollbar on my UI, which can interact with the ScrollRect.
I set a vertical scrollbar to Dynicamic ScrollRect, but the scrollbar did not work properly.
How can I config the scrollbar?

ScrollObjct is not necessary to derive from MonoBehaviour

I think it's not necessary to add a mono script on each item in scroll list. When driving from monoBehaviour, unity have to execute code in Awake , which is performance-cost.
As a replacement, I prefer to add a virtual methd in PoolingObject like:

public GameObject gameObject { get; set; }

public virtual void AttachView(GameObject go)
{
    gameObject = go;
}

And call it in Pooling.CreateObject:

var go = GameObject.Instantiate(referenceOjbct);
var obj = new T();
obj.AttachView(go);