99 lines
3.0 KiB
C#
99 lines
3.0 KiB
C#
using System;
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using System.Collections.Generic;
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using UnityEngine;
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using UnityEngine.EventSystems;
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using UnityEngine.UI;
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public class UIPageable : MonoBehaviour, IBeginDragHandler, IEndDragHandler
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{
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private float _startDragHorizontal;
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private bool _isDrag = false; //是否拖拽结束
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private bool _moving = false;
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private float _startTime;
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private float _fixedSmooting = 4;//基本滑动速度
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public float _smooting = 4; //滑动速度
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private float _targethorizontal = 0; //滑动的起始坐标
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private List<float> _posList;//求出每页的临界角，页索引从0开始
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public float _dragMaxDeltaOfScreen = 0.3f; //最大滑动距离(超出后按一页)
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private int _currentPageIndex = 0;
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private ScrollRect _scrollRect;
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private bool _invokeDelegatePageChanged = true;
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public System.Action OnBeginDragDelegate;
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public System.Action OnEndDragDelegate;
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public System.Action<int> DelegatePageChanged;
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public bool Moving { get => _moving; }
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public void Init(ScrollRect scrollRect, int cellCount, int initIndex)
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{
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_scrollRect = scrollRect;
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_posList = new List<float>(cellCount);
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for (var i = 0; i < cellCount; i++)
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{
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_posList.Add(i * (1f / (cellCount - 1)));
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}
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GotoPage(initIndex, 100f);
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}
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public void Update()
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{
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if (!_isDrag && _moving)
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{
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_startTime += 0.05f;
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var t = _startTime * _smooting;
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_scrollRect.horizontalNormalizedPosition = Mathf.Lerp(_scrollRect.horizontalNormalizedPosition, _targethorizontal, t);
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if (t >= 1)
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{
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_moving = false;
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_smooting = _fixedSmooting;
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if (_invokeDelegatePageChanged) DelegatePageChanged?.Invoke(_currentPageIndex);
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}
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}
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}
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public void GotoPage(int index, float smooting = -1)
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{
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index = Mathf.Clamp(index, 0, _posList.Count - 1);
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_invokeDelegatePageChanged = _currentPageIndex != index;
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_targethorizontal = _posList[index];
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_isDrag = false;
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_startTime = 0;
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_moving = true;
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_currentPageIndex = index;
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_smooting = Math.Abs(smooting + 1) < 0.01 ? _fixedSmooting : smooting;
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}
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void IBeginDragHandler.OnBeginDrag(PointerEventData eventData)
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{
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_moving = true;
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_isDrag = true;
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_startDragHorizontal = _scrollRect.horizontalNormalizedPosition;
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OnBeginDragDelegate?.Invoke();
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}
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void IEndDragHandler.OnEndDrag(PointerEventData eventData)
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{
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OnEndDragDelegate?.Invoke();
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var posX = _scrollRect.horizontalNormalizedPosition;
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var delta = _scrollRect.horizontalNormalizedPosition - _startDragHorizontal;
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var sign = Mathf.Sign(delta);
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delta = Mathf.Abs(delta);
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delta *= _posList.Count;
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var targetIndex = _currentPageIndex;
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if (delta >= _dragMaxDeltaOfScreen)
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{
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targetIndex += (int)sign;
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}
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GotoPage(targetIndex, _fixedSmooting);
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}
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} |