Unity 擴充套件UGUI ScrollRect 實現水平迴圈拖動。
阿新 • • 發佈:2019-01-04
目前UGUI的ScrollRect不支援迴圈滑動,這裡提供一種水平迴圈滑動的方法
簡單描述一下思路:
(1)檢測第一個物件的左邊界和右邊界,和Viewport的左邊界比較。
(2)檢測當前是向左滑動還是向右滑動
(3)修改Content的中心和邊界,使Content的矩形隨著具體內容的變化而變化
(4)左迴圈時把左邊第一個元素放置到最右邊
(5)右迴圈時把右邊第一個元素放置到最左邊。
直接放程式碼,使用方式和ScrollRect基本一致,注意設定列舉為HorizonLoop即可。
using System; using UnityEngine.Events; using UnityEngine.EventSystems; namespace UnityEngine.UI { /// <summary> /// Modified By HawkWang at 2017-04-07 /// All right not reserverd. /// Copy and distribute and modify and delete at free will. /// Too laze to support vertical loop scroll(and infact it is not as useful as horizon loop scroll). /// </summary> [AddComponentMenu("UI/Scroll Rect", 37)] [SelectionBase] [ExecuteInEditMode] [DisallowMultipleComponent] [RequireComponent(typeof(RectTransform))] public class ScrollRectExt : UIBehaviour, IInitializePotentialDragHandler, IBeginDragHandler, IEndDragHandler, IDragHandler, IScrollHandler, ICanvasElement, ILayoutElement, ILayoutGroup { /// <summary> /// Question One:研究哪裡真正改變了Content的位置! /// </summary> #region ################ AddOn Content ########################################## public enum EScrollType { HorizonLoop, Horizon, Vertical, } [SerializeField] private EScrollType m_scrollType = EScrollType.HorizonLoop; public enum EHorizonScrollDirection { Left, Still, Right, } EHorizonScrollDirection m_horizonDirection = EHorizonScrollDirection.Still; public enum EMoveSiblingType { MoveFirstToLast, MoveLastToFirst, } EMoveSiblingType m_moveSiblingType = EMoveSiblingType.MoveFirstToLast; RectTransform FirstChild { get { return m_Content.GetChild(0) as RectTransform; } } RectTransform LastChild { get { return m_Content.GetChild(m_Content.childCount - 1) as RectTransform; } } float m_halfSize; Vector2 m_viewPortWorldBound;//x 表示左邊界,下邊界,y表示右邊界,上邊界。 void InitExtContent() { if( horizontal && vertical == false ) { HorizontalLayoutGroup hlg = m_Content.gameObject.GetComponent<HorizontalLayoutGroup>(); if( hlg != null ) { m_halfSize = ( FirstChild.sizeDelta.x + hlg.spacing ) * 0.5f; m_viewPortWorldBound = RectTransformUtility.WorldToScreenPoint(Camera.main, viewport.position); m_viewPortWorldBound.y = m_viewPortWorldBound.x + viewport.sizeDelta.x; } } if(vertical && horizontal == false) { VerticalLayoutGroup vlg = m_Content.gameObject.GetComponent<VerticalLayoutGroup>(); if( vlg != null ) { //預設左上角對齊,所以下邊界,採用的是x,上邊界才是y m_halfSize = (FirstChild.sizeDelta.y + vlg.spacing) * 0.5f; m_viewPortWorldBound = RectTransformUtility.WorldToScreenPoint(Camera.main, viewport.position); m_viewPortWorldBound.x = m_viewPortWorldBound.y - viewport.sizeDelta.y; } } } public bool horizontalLoop { get { return m_scrollType == EScrollType.HorizonLoop; } } public bool horizontal { get { return m_scrollType == EScrollType.HorizonLoop || m_scrollType == EScrollType.Horizon; } } public bool vertical { get { return m_scrollType == EScrollType.Vertical; } } #endregion ######################################################################## public enum MovementType { Unrestricted, // Unrestricted movement -- can scroll forever Elastic, // Restricted but flexible -- can go past the edges, but springs back in place Clamped, // Restricted movement where it's not possible to go past the edges } public enum ScrollbarVisibility { Permanent, AutoHide, AutoHideAndExpandViewport, } [Serializable] public class ScrollRectEvent : UnityEvent<Vector2> { } [SerializeField] private RectTransform m_Content; public RectTransform content { get { return m_Content; } set { m_Content = value; } } [SerializeField] private MovementType m_MovementType = MovementType.Elastic; public MovementType movementType { get { return m_MovementType; } set { m_MovementType = value; } } [SerializeField] private float m_Elasticity = 0.1f; // Only used for MovementType.Elastic public float elasticity { get { return m_Elasticity; } set { m_Elasticity = value; } } [SerializeField] private bool m_Inertia = true; public bool inertia { get { return m_Inertia; } set { m_Inertia = value; } } [SerializeField] private float m_DecelerationRate = 0.135f; // Only used when inertia is enabled public float decelerationRate { get { return m_DecelerationRate; } set { m_DecelerationRate = value; } } [SerializeField] private float m_ScrollSensitivity = 1.0f; public float scrollSensitivity { get { return m_ScrollSensitivity; } set { m_ScrollSensitivity = value; } } [SerializeField] private RectTransform m_Viewport; public RectTransform viewport { get { return m_Viewport; } set { m_Viewport = value; SetDirtyCaching(); } } [SerializeField] private Scrollbar m_HorizontalScrollbar; public Scrollbar horizontalScrollbar { get { return m_HorizontalScrollbar; } set { if (m_HorizontalScrollbar) m_HorizontalScrollbar.onValueChanged.RemoveListener(SetHorizontalNormalizedPosition); m_HorizontalScrollbar = value; if (m_HorizontalScrollbar) m_HorizontalScrollbar.onValueChanged.AddListener(SetHorizontalNormalizedPosition); SetDirtyCaching(); } } [SerializeField] private Scrollbar m_VerticalScrollbar; public Scrollbar verticalScrollbar { get { return m_VerticalScrollbar; } set { if (m_VerticalScrollbar) m_VerticalScrollbar.onValueChanged.RemoveListener(SetVerticalNormalizedPosition); m_VerticalScrollbar = value; if (m_VerticalScrollbar) m_VerticalScrollbar.onValueChanged.AddListener(SetVerticalNormalizedPosition); SetDirtyCaching(); } } [SerializeField] private ScrollbarVisibility m_HorizontalScrollbarVisibility; public ScrollbarVisibility horizontalScrollbarVisibility { get { return m_HorizontalScrollbarVisibility; } set { m_HorizontalScrollbarVisibility = value; SetDirtyCaching(); } } [SerializeField] private ScrollbarVisibility m_VerticalScrollbarVisibility; public ScrollbarVisibility verticalScrollbarVisibility { get { return m_VerticalScrollbarVisibility; } set { m_VerticalScrollbarVisibility = value; SetDirtyCaching(); } } [SerializeField] private float m_HorizontalScrollbarSpacing; public float horizontalScrollbarSpacing { get { return m_HorizontalScrollbarSpacing; } set { m_HorizontalScrollbarSpacing = value; SetDirty(); } } [SerializeField] private float m_VerticalScrollbarSpacing; public float verticalScrollbarSpacing { get { return m_VerticalScrollbarSpacing; } set { m_VerticalScrollbarSpacing = value; SetDirty(); } } [SerializeField] private ScrollRectEvent m_OnValueChanged = new ScrollRectEvent(); public ScrollRectEvent onValueChanged { get { return m_OnValueChanged; } set { m_OnValueChanged = value; } } // The offset from handle position to mouse down position private Vector2 m_PointerStartLocalCursor = Vector2.zero; // 這個位置,記錄的是,按下一瞬間,Content相對於錨點的位置,比如水平模式下 // 記錄的是Content左上角,相對於ViewPort的左上角的位置。 // 作用: private Vector2 m_ContentStartPosition = Vector2.zero; private RectTransform m_ViewRect; protected RectTransform viewRect { get { if (m_ViewRect == null) m_ViewRect = m_Viewport; if (m_ViewRect == null) m_ViewRect = (RectTransform)transform; return m_ViewRect; } } private Bounds m_ContentBounds; private Bounds m_ViewBounds; private Vector2 m_Velocity; public Vector2 velocity { get { return m_Velocity; } set { m_Velocity = value; } } private bool m_Dragging; private Vector2 m_PrevPosition = Vector2.zero; private Bounds m_PrevContentBounds; private Bounds m_PrevViewBounds; [NonSerialized] private bool m_HasRebuiltLayout = false; private bool m_HSliderExpand; private bool m_VSliderExpand; private float m_HSliderHeight; private float m_VSliderWidth; [System.NonSerialized] private RectTransform m_Rect; private RectTransform rectTransform { get { if (m_Rect == null) m_Rect = GetComponent<RectTransform>(); return m_Rect; } } private RectTransform m_HorizontalScrollbarRect; private RectTransform m_VerticalScrollbarRect; private DrivenRectTransformTracker m_Tracker; protected ScrollRectExt() { flexibleWidth = -1; } public virtual void Rebuild(CanvasUpdate executing) { if (executing == CanvasUpdate.Prelayout) { UpdateCachedData(); } if (executing == CanvasUpdate.PostLayout) { UpdateBounds(); UpdateScrollbars(Vector2.zero); UpdatePrevData(); m_HasRebuiltLayout = true; } } public virtual void LayoutComplete() { } public virtual void GraphicUpdateComplete() { } void UpdateCachedData() { Transform transform = this.transform; m_HorizontalScrollbarRect = m_HorizontalScrollbar == null ? null : m_HorizontalScrollbar.transform as RectTransform; m_VerticalScrollbarRect = m_VerticalScrollbar == null ? null : m_VerticalScrollbar.transform as RectTransform; // These are true if either the elements are children, or they don't exist at all. bool viewIsChild = (viewRect.parent == transform); bool hScrollbarIsChild = (!m_HorizontalScrollbarRect || m_HorizontalScrollbarRect.parent == transform); bool vScrollbarIsChild = (!m_VerticalScrollbarRect || m_VerticalScrollbarRect.parent == transform); bool allAreChildren = (viewIsChild && hScrollbarIsChild && vScrollbarIsChild); m_HSliderExpand = allAreChildren && m_HorizontalScrollbarRect && horizontalScrollbarVisibility == ScrollbarVisibility.AutoHideAndExpandViewport; m_VSliderExpand = allAreChildren && m_VerticalScrollbarRect && verticalScrollbarVisibility == ScrollbarVisibility.AutoHideAndExpandViewport; m_HSliderHeight = (m_HorizontalScrollbarRect == null ? 0 : m_HorizontalScrollbarRect.rect.height); m_VSliderWidth = (m_VerticalScrollbarRect == null ? 0 : m_VerticalScrollbarRect.rect.width); } protected override void OnEnable() { base.OnEnable(); if (m_HorizontalScrollbar) m_HorizontalScrollbar.onValueChanged.AddListener(SetHorizontalNormalizedPosition); if (m_VerticalScrollbar) m_VerticalScrollbar.onValueChanged.AddListener(SetVerticalNormalizedPosition); CanvasUpdateRegistry.RegisterCanvasElementForLayoutRebuild(this); InitExtContent(); } protected override void OnDisable() { CanvasUpdateRegistry.UnRegisterCanvasElementForRebuild(this); if (m_HorizontalScrollbar) m_HorizontalScrollbar.onValueChanged.RemoveListener(SetHorizontalNormalizedPosition); if (m_VerticalScrollbar) m_VerticalScrollbar.onValueChanged.RemoveListener(SetVerticalNormalizedPosition); m_HasRebuiltLayout = false; m_Tracker.Clear(); m_Velocity = Vector2.zero; LayoutRebuilder.MarkLayoutForRebuild(rectTransform); base.OnDisable(); } public override bool IsActive() { return base.IsActive() && m_Content != null; } private void EnsureLayoutHasRebuilt() { if (!m_HasRebuiltLayout && !CanvasUpdateRegistry.IsRebuildingLayout()) Canvas.ForceUpdateCanvases(); } public virtual void StopMovement() { m_Velocity = Vector2.zero; } //支援滑鼠中輪轉動來旋轉。 public virtual void OnScroll(PointerEventData data) { if (!IsActive()) return; EnsureLayoutHasRebuilt(); UpdateBounds(); Vector2 delta = data.scrollDelta; // Down is positive for scroll events, while in UI system up is positive. delta.y *= -1; if (vertical && !horizontal) { if (Mathf.Abs(delta.x) > Mathf.Abs(delta.y)) delta.y = delta.x; delta.x = 0; } if (horizontal && !vertical) { if (Mathf.Abs(delta.y) > Mathf.Abs(delta.x)) delta.x = delta.y; delta.y = 0; } Vector2 position = m_Content.anchoredPosition; position += delta * m_ScrollSensitivity; if (m_MovementType == MovementType.Clamped) position += CalculateOffset(position - m_Content.anchoredPosition); SetContentAnchoredPosition(position,"Scroll"); UpdateBounds(); } public virtual void OnInitializePotentialDrag(PointerEventData eventData) { if (eventData.button != PointerEventData.InputButton.Left) return; m_Velocity = Vector2.zero; } //開始拖拽 public virtual void OnBeginDrag(PointerEventData eventData) { if (eventData.button != PointerEventData.InputButton.Left) return; if (!IsActive()) return; UpdateBounds(); m_PointerStartLocalCursor = Vector2.zero; RectTransformUtility.ScreenPointToLocalPointInRectangle(viewRect, eventData.position, eventData.pressEventCamera, out m_PointerStartLocalCursor); m_ContentStartPosition = m_Content.anchoredPosition; Debug.Log("Begin Drag Scrollrect ! content start position " + m_ContentStartPosition); m_Dragging = true; } //結束拖拽 public virtual void OnEndDrag(PointerEventData eventData) { if (eventData.button != PointerEventData.InputButton.Left) return; Debug.Log("End Drag ScrollRect !"); m_Dragging = false; } int frame_lock = -1; public virtual void OnDrag(PointerEventData eventData) { if (eventData.button != PointerEventData.InputButton.Left) return; if (!IsActive()) return; Vector2 localCursor; //莫名其妙,基本都是返回True的呀。應該是指,點選ScrollRect,並且點選在viewRect之內的雙重條件。 //官網:當平面被Hit返回true,而不管點是不是在rect之內。這他媽有啥用.... bool result = RectTransformUtility.ScreenPointToLocalPointInRectangle(viewRect, eventData.position, eventData.pressEventCamera, out localCursor); if (!result) return; frame_lock--; //試試在這裡檢測迴圈越界! UpdateBounds(); Vector2 first_child_pos = RectTransformUtility.WorldToScreenPoint(Camera.main, FirstChild.position); Vector2 left_bound_position = first_child_pos + new Vector2(m_halfSize, 0); Vector2 right_bound_position = first_child_pos - new Vector2(m_halfSize, 0); var pointerDelta = localCursor - m_PointerStartLocalCursor; Vector2 position = m_ContentStartPosition + pointerDelta; if (frame_lock < 0 && horizontalLoop) { if (m_horizonDirection == EHorizonScrollDirection.Left && left_bound_position.x < m_viewPortWorldBound.x) { m_ContentStartPosition.x += m_halfSize * 2; m_ContentBounds.center = new Vector3(m_ContentBounds.center.x + m_halfSize * 2, m_ContentBounds.center.y, m_ContentBounds.center.z); m_moveSiblingType = EMoveSiblingType.MoveFirstToLast; UpdateBounds(); frame_lock = 2; Debug.Log("Move One Item To Tail "); } else if (m_horizonDirection == EHorizonScrollDirection.Right && right_bound_position.x > m_viewPortWorldBound.x) { m_ContentStartPosition.x -= m_halfSize * 2; m_ContentBounds.center = new Vector3(m_ContentBounds.center.x - m_halfSize * 2, m_ContentBounds.center.y, m_ContentBounds.center.z); m_moveSiblingType = EMoveSiblingType.MoveLastToFirst; UpdateBounds(); frame_lock = 2; Debug.Log("Move One Item To Front "); } } if (frame_lock == 1) { if (m_moveSiblingType == EMoveSiblingType.MoveFirstToLast) { FirstChild.SetAsLastSibling(); } else if( m_moveSiblingType == EMoveSiblingType.MoveLastToFirst ) { LastChild.SetAsFirstSibling(); } } // Offset to get content into place in the view. Vector2 offset = CalculateOffset(position - m_Content.anchoredPosition); position += offset; if (m_MovementType == MovementType.Elastic) { if (offset.x != 0) position.x = position.x - RubberDelta(offset.x, m_ViewBounds.size.x); if (offset.y != 0) position.y = position.y - RubberDelta(offset.y, m_ViewBounds.size.y); } SetContentAnchoredPosition(position,"OnDrag"); } protected virtual void SetContentAnchoredPosition(Vector2 position, string source = "") { if (!horizontal) position.x = m_Content.anchoredPosition.x; if (!vertical) position.y = m_Content.anchoredPosition.y; if (position != m_Content.anchoredPosition) { m_Content.anchoredPosition = position; UpdateBounds(); } } protected virtual void LateUpdate() { if (!m_Content) return; EnsureLayoutHasRebuilt(); UpdateScrollbarVisibility(); UpdateBounds(); float deltaTime = Time.unscaledDeltaTime; Vector2 offset = CalculateOffset(Vector2.zero); if (!m_Dragging && (offset != Vector2.zero || m_Velocity != Vector2.zero)) { Vector2 position = m_Content.anchoredPosition; for (int axis = 0; axis < 2; axis++) { // Apply spring physics if movement is elastic and content has an offset from the view. if (m_MovementType == MovementType.Elastic && offset[axis] != 0) { float speed = m_Velocity[axis]; position[axis] = Mathf.SmoothDamp(m_Content.anchoredPosition[axis], m_Content.anchoredPosition[axis] + offset[axis], ref speed, m_Elasticity, Mathf.Infinity, deltaTime); m_Velocity[axis] = speed; } // Else move content according to velocity with deceleration applied. else if (m_Inertia) { m_Velocity[axis] *= Mathf.Pow(m_DecelerationRate, deltaTime); if (Mathf.Abs(m_Velocity[axis]) < 1) m_Velocity[axis] = 0; position[axis] += m_Velocity[axis] * deltaTime; } // If we have neither elaticity or friction, there shouldn't be any velocity. else { m_Velocity[axis] = 0; } } if (m_Velocity != Vector2.zero) { if (m_MovementType == MovementType.Clamped) { offset = CalculateOffset(position - m_Content.anchoredPosition); position += offset; } SetContentAnchoredPosition(position,"Late Update!"); } } if (m_Dragging && m_Inertia) { Vector3 newVelocity = (m_Content.anchoredPosition - m_PrevPosition) / deltaTime; m_Velocity = Vector3.Lerp(m_Velocity, newVelocity, deltaTime * 10); } //只要一拖動,立刻就會呼叫OnValueChange,這個Bound到底是什麼東西? if (m_ViewBounds != m_PrevViewBounds || m_ContentBounds != m_PrevContentBounds || m_Content.anchoredPosition != m_PrevPosition) { UpdateScrollbars(offset); m_OnValueChanged.Invoke(normalizedPosition); UpdatePrevData(); } } /// <summary> /// 用於比較上一次的值,來確定是否需要出發OnValueChange等。 /// </summary> private void UpdatePrevData() { if (m_Content == null) m_PrevPosition = Vector2.zero; else { if( m_Content.anchoredPosition.x - m_PrevPosition.x > 0.00001f ) { m_horizonDirection = EHorizonScrollDirection.Right; } else if( m_Content.anchoredPosition.x - m_PrevPosition.x < -0.00001f ) { m_horizonDirection = EHorizonScrollDirection.Left; } else { m_horizonDirection = EHorizonScrollDirection.Still; } Debug.Log(" direction is " + m_horizonDirection); m_PrevPosition = m_Content.anchoredPosition; } m_PrevViewBounds = m_ViewBounds; m_PrevContentBounds = m_ContentBounds; } private void UpdateScrollbars(Vector2 offset) { if (m_HorizontalScrollbar) { if (m_ContentBounds.size.x > 0) m_HorizontalScrollbar.size = Mathf.Clamp01((m_ViewBounds.size.x - Mathf.Abs(offset.x)) / m_ContentBounds.size.x); else m_HorizontalScrollbar.size = 1; m_HorizontalScrollbar.value = horizontalNormalizedPosition; } if (m_VerticalScrollbar) { if (m_ContentBounds.size.y > 0) m_VerticalScrollbar.size = Mathf.Clamp01((m_ViewBounds.size.y - Mathf.Abs(offset.y)) / m_ContentBounds.size.y); else m_VerticalScrollbar.size = 1; m_VerticalScrollbar.value = verticalNormalizedPosition; } } public Vector2 normalizedPosition { get { return new Vector2(horizontalNormalizedPosition, verticalNormalizedPosition); } set { SetNormalizedPosition(value.x, 0); SetNormalizedPosition(value.y, 1); } } public float horizontalNormalizedPosition { get { UpdateBounds(); if (m_ContentBounds.size.x <= m_ViewBounds.size.x) return (m_ViewBounds.min.x > m_ContentBounds.min.x) ? 1 : 0; return (m_ViewBounds.min.x - m_ContentBounds.min.x) / (m_ContentBounds.size.x - m_ViewBounds.size.x); } set { SetNormalizedPosition(value, 0); } } public float verticalNormalizedPosition { get { UpdateBounds(); if (m_ContentBounds.size.y <= m_ViewBounds.size.y) return (m_ViewBounds.min.y > m_ContentBounds.min.y) ? 1 : 0; ; return (m_ViewBounds.min.y - m_ContentBounds.min.y) / (m_ContentBounds.size.y - m_ViewBounds.size.y); } set { SetNormalizedPosition(value, 1); } } private void SetHorizontalNormalizedPosition(float value) { SetNormalizedPosition(value, 0); } private void SetVerticalNormalizedPosition(float value) { SetNormalizedPosition(value, 1); } private void SetNormalizedPosition(float value, int axis) { EnsureLayoutHasRebuilt(); UpdateBounds(); // How much the content is larger than the view. float hiddenLength = m_ContentBounds.size[axis] - m_ViewBounds.size[axis]; // Where the position of the lower left corner of the content bounds should be, in the space of the view. float contentBoundsMinPosition = m_ViewBounds.min[axis] - value * hiddenLength; // The new content localPosition, in the space of the view. float newLocalPosition = m_Content.localPosition[axis] + contentBoundsMinPosition - m_ContentBounds.min[axis]; Vector3 localPosition = m_Content.localPosition; if (Mathf.Abs(localPosition[axis] - newLocalPosition) > 0.01f) { localPosition[axis] = newLocalPosition; m_Content.localPosition = localPosition; m_Velocity[axis] = 0; UpdateBounds(); } } private static float RubberDelta(float overStretching, float viewSize) { return (1 - (1 / ((Mathf.Abs(overStretching) * 0.55f / viewSize) + 1))) * viewSize * Mathf.Sign(overStretching); } protected override void OnRectTransformDimensionsChange() { SetDirty(); } private bool hScrollingNeeded { get { if (Application.isPlaying) return m_ContentBounds.size.x > m_ViewBounds.size.x + 0.01f; return true; } } private bool vScrollingNeeded { get { if (Application.isPlaying) return m_ContentBounds.size.y > m_ViewBounds.size.y + 0.01f; return true; } } public virtual void CalculateLayoutInputHorizontal() { } public virtual void CalculateLayoutInputVertical() { } public virtual float minWidth { get { return -1; } } public virtual float preferredWidth { get { return -1; } } public virtual float flexibleWidth { get; private set; } public virtual float minHeight { get { return -1; } } public virtual float preferredHeight { get { return -1; } } public virtual float flexibleHeight { get { return -1; } } public virtual int layoutPriority { get { return -1; } } public virtual void SetLayoutHorizontal() { m_Tracker.Clear(); if (m_HSliderExpand || m_VSliderExpand) { m_Tracker.Add(this, viewRect, DrivenTransformProperties.Anchors | DrivenTransformProperties.SizeDelta | DrivenTransformProperties.AnchoredPosition); // Make view full size to see if content fits. viewRect.anchorMin = Vector2.zero; viewRect.anchorMax = Vector2.one; viewRect.sizeDelta = Vector2.zero; viewRect.anchoredPosition = Vector2.zero; // Recalculate content layout with this size to see if it fits when there are no scrollbars. LayoutRebuilder.ForceRebuildLayoutImmediate(content); m_ViewBounds = new Bounds(viewRect.rect.center, viewRect.rect.size); m_ContentBounds = GetBounds(); } // If it doesn't fit vertically, enable vertical scrollbar and shrink view horizontally to make room for it. if (m_VSliderExpand && vScrollingNeeded) { viewRect.sizeDelta = new Vector2(-(m_VSliderWidth + m_VerticalScrollbarSpacing), viewRect.sizeDelta.y); // Recalculate content layout with this size to see if it fits vertically // when there is a vertical scrollbar (which may reflowed the content to make it taller). LayoutRebuilder.ForceRebuildLayoutImmediate(content); m_ViewBounds = new Bounds(viewRect.rect.center, viewRect.rect.size); m_ContentBounds = GetBounds(); } // If it doesn't fit horizontally, enable horizontal scrollbar and shrink view vertically to make room for it. if (m_HSliderExpand && hScrollingNeeded) { viewRect.sizeDelta = new Vector2(viewRect.sizeDelta.x, -(m_HSliderHeight + m_HorizontalScrollbarSpacing)); m_ViewBounds = new Bounds(viewRect.rect.center, viewRect.rect.size); m_ContentBounds = GetBounds(); } // If the vertical slider didn't kick in the first time, and the horizontal one did, // we need to check again if the vertical slider now needs to kick in. // If it doesn't fit vertically, enable vertical scrollbar and shrink view horizontally to make room for it. if (m_VSliderExpand && vScrollingNeeded && viewRect.sizeDelta.x == 0 && viewRect.sizeDelta.y < 0) { viewRect.sizeDelta = new Vector2(-(m_VSliderWidth + m_VerticalScrollbarSpacing), viewRect.sizeDelta.y); } } public virtual void SetLayoutVertical() { UpdateScrollbarLayout(); m_ViewBounds = new Bounds(viewRect.rect.center, viewRect.rect.size); m_ContentBounds = GetBounds(); } void UpdateScrollbarVisibility() { if (m_VerticalScrollbar && m_VerticalScrollbarVisibility != ScrollbarVisibility.Permanent && m_VerticalScrollbar.gameObject.activeSelf != vScrollingNeeded) m_VerticalScrollbar.gameObject.SetActive(vScrollingNeeded); if (m_HorizontalScrollbar && m_HorizontalScrollbarVisibility != ScrollbarVisibility.Permanent && m_HorizontalScrollbar.gameObject.activeSelf != hScrollingNeeded) m_HorizontalScrollbar.gameObject.SetActive(hScrollingNeeded); } void UpdateScrollbarLayout() { if (m_VSliderExpand && m_HorizontalScrollbar) { m_Tracker.Add(this, m_HorizontalScrollbarRect, DrivenTransformProperties.AnchorMinX | DrivenTransformProperties.AnchorMaxX | DrivenTransformProperties.SizeDeltaX | DrivenTransformProperties.AnchoredPositionX); m_HorizontalScrollbarRect.anchorMin = new Vector2(0, m_HorizontalScrollbarRect.anchorMin.y); m_HorizontalScrollbarRect.anchorMax = new Vector2(1, m_HorizontalScrollbarRect.anchorMax.y); m_HorizontalScrollbarRect.anchoredPosition = new Vector2(0, m_HorizontalScrollbarRect.anchoredPosition.y); if (vScrollingNeeded) m_HorizontalScrollbarRect.sizeDelta = new Vector2(-(m_VSliderWidth + m_VerticalScrollbarSpacing), m_HorizontalScrollbarRect.sizeDelta.y); else m_HorizontalScrollbarRect.sizeDelta = new Vector2(0, m_HorizontalScrollbarRect.sizeDelta.y); } if (m_HSliderExpand && m_VerticalScrollbar) { m_Tracker.Add(this, m_VerticalScrollbarRect, DrivenTransformProperties.AnchorMinY | DrivenTransformProperties.AnchorMaxY | DrivenTransformProperties.SizeDeltaY | DrivenTransformProperties.AnchoredPositionY); m_VerticalScrollbarRect.anchorMin = new Vector2(m_VerticalScrollbarRect.anchorMin.x, 0); m_VerticalScrollbarRect.anchorMax = new Vector2(m_VerticalScrollbarRect.anchorMax.x, 1); m_VerticalScrollbarRect.anchoredPosition = new Vector2(m_VerticalScrollbarRect.anchoredPosition.x, 0); if (hScrollingNeeded) m_VerticalScrollbarRect.sizeDelta = new Vector2(m_VerticalScrollbarRect.sizeDelta.x, -(m_HSliderHeight + m_HorizontalScrollbarSpacing)); else m_VerticalScrollbarRect.sizeDelta = new Vector2(m_VerticalScrollbarRect.sizeDelta.x, 0); } } /// <summary> /// 目前推測,最後HorizonLayout是根據ContentBound來計算每個位置的偏移的 /// </summary> private void UpdateBounds() { m_ViewBounds = new Bounds(viewRect.rect.center, viewRect.rect.size); m_ContentBounds = GetBounds(); if (m_Content == null) return; // Make sure content bounds are at least as large as view by adding padding if not. // One might think at first that if the content is smaller than the view, scrolling should be allowed. // However, that's not how scroll views normally work. // Scrolling is *only* possible when content is *larger* than view. // We use the pivot of the content rect to decide in which directions the content bounds should be expanded. // E.g. if pivot is at top, bounds are expanded downwards. // This also works nicely when ContentSizeFitter is used on the content. Vector3 contentSize = m_ContentBounds.size; Vector3 contentPos = m_ContentBounds.center; Vector3 excess = m_ViewBounds.size - contentSize; if (excess.x > 0) { contentPos.x -= excess.x * (m_Content.pivot.x - 0.5f); contentSize.x = m_ViewBounds.size.x; } if (excess.y > 0) { contentPos.y -= excess.y * (m_Content.pivot.y - 0.5f); contentSize.y = m_ViewBounds.size.y; } m_ContentBounds.size = contentSize; m_ContentBounds.center = contentPos; } private readonly Vector3[] m_Corners = new Vector3[4]; private Bounds GetBounds() { if (m_Content == null) return new Bounds(); var vMin = new Vector3(float.MaxValue, float.MaxValue, float.MaxValue); var vMax = new Vector3(float.MinValue, float.MinValue, float.MinValue); var toLocal = viewRect.worldToLocalMatrix; m_Content.GetWorldCorners(m_Corners); for (int j = 0; j < 4; j++) { Vector3 v = toLocal.MultiplyPoint3x4(m_Corners[j]); vMin = Vector3.Min(v, vMin); vMax = Vector3.Max(v, vMax); } var bounds = new Bounds(vMin, Vector3.zero); bounds.Encapsulate(vMax); return bounds; } private Vector2 CalculateOffset(Vector2 delta) { Vector2 offset = Vector2.zero; if (m_MovementType == MovementType.Unrestricted) return offset; Vector2 min = m_ContentBounds.min; Vector2 max = m_ContentBounds.max; if (horizontal) { min.x += delta.x; max.x += delta.x; if (min.x > m_ViewBounds.min.x) offset.x = m_ViewBounds.min.x - min.x; else if (max.x < m_ViewBounds.max.x) offset.x = m_ViewBounds.max.x - max.x; } if (vertical) { min.y += delta.y; max.y += delta.y; if (max.y < m_ViewBounds.max.y) offset.y = m_ViewBounds.max.y - max.y; else if (min.y > m_ViewBounds.min.y) offset.y = m_ViewBounds.min.y - min.y; } return offset; } protected void SetDirty() { if (!IsActive()) return; LayoutRebuilder.MarkLayoutForRebuild(rectTransform); } protected void SetDirtyCaching() { if (!IsActive()) return; CanvasUpdateRegistry.RegisterCanvasElementForLayoutRebuild(this); LayoutRebuilder.MarkLayoutForRebuild(rectTransform); } #if UNITY_EDITOR protected override void OnValidate() { SetDirtyCaching(); } #endif } }