HeavenStudioPlus/Assets/Plugins/com.unity.uiextensions/Runtime/Scripts/Layout/VerticalScrollSnap.cs

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2022-01-06 00:11:33 +00:00
/// Credit BinaryX, SimonDarksideJ
/// Sourced from - http://forum.unity3d.com/threads/scripts-useful-4-6-scripts-collection.264161/page-2#post-1945602
/// Updated by SimonDarksideJ - removed dependency on a custom ScrollRect script. Now implements drag interfaces and standard Scroll Rect.
/// Updated by SimonDarksideJ - major refactoring on updating current position and scroll management
using System;
using UnityEngine.EventSystems;
namespace UnityEngine.UI.Extensions
{
[RequireComponent(typeof(ScrollRect))]
[AddComponentMenu("Layout/Extensions/Vertical Scroll Snap")]
public class VerticalScrollSnap : ScrollSnapBase
{
private bool updated = true;
void Start()
{
_isVertical = true;
_childAnchorPoint = new Vector2(0.5f,0);
_currentPage = StartingScreen;
panelDimensions = gameObject.GetComponent<RectTransform>().rect;
UpdateLayout();
}
void Update()
{
updated = false;
if (!_lerp && _scroll_rect.velocity == Vector2.zero)
{
if (!_settled && !_pointerDown)
{
if (!IsRectSettledOnaPage(_screensContainer.anchoredPosition))
{
ScrollToClosestElement();
}
}
return;
}
else if (_lerp)
{
_screensContainer.anchoredPosition = Vector3.Lerp(_screensContainer.anchoredPosition, _lerp_target, transitionSpeed * (UseTimeScale ? Time.deltaTime : Time.unscaledDeltaTime));
if (Vector3.Distance(_screensContainer.anchoredPosition, _lerp_target) < 0.1f)
{
_screensContainer.anchoredPosition = _lerp_target;
_lerp = false;
EndScreenChange();
}
}
if (UseHardSwipe) return;
CurrentPage = GetPageforPosition(_screensContainer.anchoredPosition);
//If the container is moving check if it needs to settle on a page
if (!_pointerDown)
{
if (_scroll_rect.velocity.y > 0.01 || _scroll_rect.velocity.y < -0.01)
{
// if the pointer is released and is moving slower than the threshold, then just land on a page
if (IsRectMovingSlowerThanThreshold(0))
{
ScrollToClosestElement();
}
}
}
}
private bool IsRectMovingSlowerThanThreshold(float startingSpeed)
{
return (_scroll_rect.velocity.y > startingSpeed && _scroll_rect.velocity.y < SwipeVelocityThreshold) ||
(_scroll_rect.velocity.y < startingSpeed && _scroll_rect.velocity.y > -SwipeVelocityThreshold);
}
public void DistributePages()
{
_screens = _screensContainer.childCount;
_scroll_rect.verticalNormalizedPosition = 0;
float _offset = 0;
float _dimension = 0;
Rect panelDimensions = gameObject.GetComponent<RectTransform>().rect;
float currentYPosition = 0;
var pageStepValue = _childSize = (int)panelDimensions.height * ((PageStep == 0) ? 3 : PageStep);
for (int i = 0; i < _screensContainer.transform.childCount; i++)
{
RectTransform child = _screensContainer.transform.GetChild(i).gameObject.GetComponent<RectTransform>();
currentYPosition = _offset + i * pageStepValue;
child.sizeDelta = new Vector2(panelDimensions.width, panelDimensions.height);
child.anchoredPosition = new Vector2(0f, currentYPosition);
child.anchorMin = child.anchorMax = child.pivot = _childAnchorPoint;
}
_dimension = currentYPosition + _offset * -1;
_screensContainer.GetComponent<RectTransform>().offsetMax = new Vector2(0f, _dimension);
}
/// <summary>
/// Add a new child to this Scroll Snap and recalculate it's children
/// </summary>
/// <param name="GO">GameObject to add to the ScrollSnap</param>
public void AddChild(GameObject GO)
{
AddChild(GO, false);
}
/// <summary>
/// Add a new child to this Scroll Snap and recalculate it's children
/// </summary>
/// <param name="GO">GameObject to add to the ScrollSnap</param>
/// <param name="WorldPositionStays">Should the world position be updated to it's parent transform?</param>
public void AddChild(GameObject GO, bool WorldPositionStays)
{
_scroll_rect.verticalNormalizedPosition = 0;
GO.transform.SetParent(_screensContainer, WorldPositionStays);
InitialiseChildObjectsFromScene();
DistributePages();
if (MaskArea) UpdateVisible();
SetScrollContainerPosition();
}
/// <summary>
/// Remove a new child to this Scroll Snap and recalculate it's children
/// *Note, this is an index address (0-x)
/// </summary>
/// <param name="index">Index element of child to remove</param>
/// <param name="ChildRemoved">Resulting removed GO</param>
public void RemoveChild(int index, out GameObject ChildRemoved)
{
RemoveChild(index, false, out ChildRemoved);
}
/// <summary>
/// Remove a new child to this Scroll Snap and recalculate it's children
/// *Note, this is an index address (0-x)
/// </summary>
/// <param name="index">Index element of child to remove</param>
/// <param name="WorldPositionStays">If true, the parent-relative position, scale and rotation are modified such that the object keeps the same world space position, rotation and scale as before</param>
/// <param name="ChildRemoved">Resulting removed GO</param>
public void RemoveChild(int index, bool WorldPositionStays, out GameObject ChildRemoved)
{
ChildRemoved = null;
if (index < 0 || index > _screensContainer.childCount)
{
return;
}
_scroll_rect.verticalNormalizedPosition = 0;
Transform child = _screensContainer.transform.GetChild(index);
child.SetParent(null, WorldPositionStays);
ChildRemoved = child.gameObject;
InitialiseChildObjectsFromScene();
DistributePages();
if (MaskArea) UpdateVisible();
if (_currentPage > _screens - 1)
{
CurrentPage = _screens - 1;
}
SetScrollContainerPosition();
}
/// <summary>
/// Remove all children from this ScrollSnap
/// </summary>
/// <param name="ChildrenRemoved">Array of child GO's removed</param>
public void RemoveAllChildren(out GameObject[] ChildrenRemoved)
{
RemoveAllChildren(false, out ChildrenRemoved);
}
/// <summary>
/// Remove all children from this ScrollSnap
/// </summary>
/// <param name="WorldPositionStays">If true, the parent-relative position, scale and rotation are modified such that the object keeps the same world space position, rotation and scale as before</param>
/// <param name="ChildrenRemoved">Array of child GO's removed</param>
public void RemoveAllChildren(bool WorldPositionStays, out GameObject[] ChildrenRemoved)
{
var _screenCount = _screensContainer.childCount;
ChildrenRemoved = new GameObject[_screenCount];
for (int i = _screenCount - 1; i >= 0; i--)
{
ChildrenRemoved[i] = _screensContainer.GetChild(i).gameObject;
ChildrenRemoved[i].transform.SetParent(null, WorldPositionStays);
}
_scroll_rect.verticalNormalizedPosition = 0;
CurrentPage = 0;
InitialiseChildObjectsFromScene();
DistributePages();
if (MaskArea) UpdateVisible();
}
private void SetScrollContainerPosition()
{
_scrollStartPosition = _screensContainer.anchoredPosition.y;
_scroll_rect.verticalNormalizedPosition = (float)(_currentPage) / (_screens - 1);
OnCurrentScreenChange(_currentPage);
}
/// <summary>
/// used for changing / updating between screen resolutions
/// </summary>
public void UpdateLayout()
{
_lerp = false;
DistributePages();
if (MaskArea) UpdateVisible();
SetScrollContainerPosition();
OnCurrentScreenChange(_currentPage);
}
private void OnRectTransformDimensionsChange()
{
if (_childAnchorPoint != Vector2.zero)
{
UpdateLayout();
}
}
private void OnEnable()
{
InitialiseChildObjectsFromScene();
DistributePages();
if (MaskArea)
UpdateVisible();
if (JumpOnEnable || !RestartOnEnable)
SetScrollContainerPosition();
if (RestartOnEnable)
GoToScreen(StartingScreen);
}
/// <summary>
/// Release screen to swipe
/// </summary>
/// <param name="eventData"></param>
public override void OnEndDrag(PointerEventData eventData)
{
if (updated)
{
return;
}
// to prevent double dragging, only act on EndDrag once per frame
updated = true;
_pointerDown = false;
if (_scroll_rect.vertical)
{
if (UseSwipeDeltaThreshold && Math.Abs(eventData.delta.y) < SwipeDeltaThreshold)
{
ScrollToClosestElement();
}
else
{
var distance = Vector3.Distance(_startPosition, _screensContainer.anchoredPosition);
if (UseHardSwipe)
{
_scroll_rect.velocity = Vector3.zero;
if (distance > FastSwipeThreshold)
{
if (_startPosition.y - _screensContainer.anchoredPosition.y > 0)
{
NextScreen();
}
else
{
PreviousScreen();
}
}
else
{
ScrollToClosestElement();
}
}
else
{
if (UseFastSwipe && distance < panelDimensions.height + FastSwipeThreshold && distance >= 1f)
{
_scroll_rect.velocity = Vector3.zero;
if (_startPosition.y - _screensContainer.anchoredPosition.y > 0)
{
if (_startPosition.y - _screensContainer.anchoredPosition.y > _childSize / 3)
{
ScrollToClosestElement();
}
else
{
NextScreen();
}
}
else
{
if (_startPosition.y - _screensContainer.anchoredPosition.y > -_childSize / 3)
{
ScrollToClosestElement();
}
else
{
PreviousScreen();
}
}
}
}
}
}
}
}
}