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mandarinx/ScrollRectAutoScroll.cs

Forked from QubitsDev/ScrollRectAutoScroll.cs
Created August 22, 2017 11:30
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Revisions

  1. @QubitsDev QubitsDev created this gist Aug 19, 2017.
    89 changes: 89 additions & 0 deletions ScrollRectAutoScroll.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,89 @@
    using System.Collections.Generic;
    using UnityEngine;
    using UnityEngine.EventSystems;
    using UnityEngine.UI;
    [RequireComponent(typeof(ScrollRect))]
    public class ScrollRectAutoScroll : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
    {
    public float scrollSpeed = 10f;
    private bool mouseOver = false;

    private List<Selectable> m_Selectables = new List<Selectable>();
    private ScrollRect m_ScrollRect;

    private Vector2 m_NextScrollPosition = Vector2.up;
    void OnEnable()
    {
    if (m_ScrollRect)
    {
    m_ScrollRect.content.GetComponentsInChildren(m_Selectables);
    }
    }
    void Awake()
    {
    m_ScrollRect = GetComponent<ScrollRect>();
    }
    void Start()
    {
    if (m_ScrollRect)
    {
    m_ScrollRect.content.GetComponentsInChildren(m_Selectables);
    }
    ScrollToSelected(true);
    }
    void Update()
    {
    // Scroll via input.
    InputScroll();
    if (!mouseOver)
    {
    // Lerp scrolling code.
    m_ScrollRect.normalizedPosition = Vector2.Lerp(m_ScrollRect.normalizedPosition, m_NextScrollPosition, scrollSpeed * Time.deltaTime);
    }
    else
    {
    m_NextScrollPosition = m_ScrollRect.normalizedPosition;
    }
    }
    void InputScroll()
    {
    if (m_Selectables.Count > 0)
    {
    if (Input.GetButtonDown("Horizontal") || Input.GetButtonDown("Vertical") || Input.GetButton("Horizontal") || Input.GetButton("Vertical"))
    {
    ScrollToSelected(false);
    }
    }
    }
    void ScrollToSelected(bool quickScroll)
    {
    int selectedIndex = -1;
    Selectable selectedElement = EventSystem.current.currentSelectedGameObject ? EventSystem.current.currentSelectedGameObject.GetComponent<Selectable>() : null;

    if (selectedElement)
    {
    selectedIndex = m_Selectables.IndexOf(selectedElement);
    }
    if (selectedIndex > -1)
    {
    if (quickScroll)
    {
    m_ScrollRect.normalizedPosition = new Vector2(0, 1 - (selectedIndex / ((float)m_Selectables.Count - 1)));
    m_NextScrollPosition = m_ScrollRect.normalizedPosition;
    }
    else
    {
    m_NextScrollPosition = new Vector2(0, 1 - (selectedIndex / ((float)m_Selectables.Count - 1)));
    }
    }
    }
    public void OnPointerEnter(PointerEventData eventData)
    {
    mouseOver = true;
    }
    public void OnPointerExit(PointerEventData eventData)
    {
    mouseOver = false;
    ScrollToSelected(false);
    }
    }