- enabling disabling prev/next button based on position of scrollsnap

- linking items size with scrollrect scroll sensitivity

--HG--
branch : xesenix_upgrades
release
Paweł Kapalla 2015-10-17 18:34:31 +02:00
parent 0c15f75001
commit 0c68f929f6
1 changed files with 558 additions and 0 deletions

558
Scripts/ScrollSnap.cs Normal file
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/// Credit BinaryX
/// Sourced from - http://forum.unity3d.com/threads/scripts-useful-4-6-scripts-collection.264161/page-2#post-1945602
/// Updated by ddreaper - removed dependency on a custom ScrollRect script. Now implements drag interfaces and standard Scroll Rect.
/// Update by xesenix - rewrited almost entire code
/// - configuration for direction move instead of 2 concurrent class (easiear to change direction in editor)
/// - supports list layouted with horizontal or vertical layout need to match direction with type of layout used
/// - dynamicly checks if scrolled list size changes and recalculates anchor positions
/// and item size based on itemsVisibleAtOnce and size of root container
/// if you dont wish to use this auto resize turn of autoLayoutItems
/// - fixed current page made it independant from pivot
/// - replaced pagination with delegate function
using System;
using UnityEngine.EventSystems;
namespace UnityEngine.UI.Extensions
{
[ExecuteInEditMode]
[RequireComponent(typeof(ScrollRect))]
[AddComponentMenu("UI/Extensions/Scroll Snap")]
public class ScrollSnap : MonoBehaviour, IBeginDragHandler, IEndDragHandler, IDragHandler
{
// needed becouse of reversed behavior of axis Y compared to X
// (positions of children lower in children list in horizontal directions grows when in vertical it gets smaller)
public enum ScrollDirection
{
Horizontal,
Vertical
}
public delegate void PageSnapChange(int page);
public event PageSnapChange onPageChange;
public ScrollDirection direction = ScrollDirection.Horizontal;
protected ScrollRect scrollRect;
protected RectTransform scrollRectTransform;
protected Transform listContainerTransform;
protected RectTransform rectTransform;
int pages;
protected int startingPage = 0;
// anchor points to lerp to to see child on certain indexes
protected Vector3[] pageAnchorPositions;
protected Vector3 lerpTarget;
protected bool lerp;
// item list related
protected float listContainerMinPosition;
protected float listContainerMaxPosition;
protected float listContainerSize;
protected RectTransform listContainerRectTransform;
protected Vector2 listContainerCachedSize;
protected float itemSize;
protected int itemsCount = 0;
[Tooltip("Button to go to the next page. (optional)")]
public Button nextButton;
[Tooltip("Button to go to the previous page. (optional)")]
public Button prevButton;
[Tooltip("Number of items visible in one page of scroll frame.")]
[RangeAttribute(1,100)]
public int itemsVisibleAtOnce = 1;
[Tooltip("Sets minimum width of list items to 1/itemsVisibleAtOnce.")]
public bool autoLayoutItems = true;
[Tooltip("If you wish to update scrollbar numberOfSteps to number of active children on list.")]
public bool linkScrolbarSteps = false;
[Tooltip("If you wish to update scrollrect sensitivity to size of list element.")]
public bool linkScrolrectScrollSensitivity = false;
public Boolean useFastSwipe = true;
public int fastSwipeThreshold = 100;
// drag related
protected bool startDrag = true;
protected Vector3 positionOnDragStart = new Vector3();
protected int pageOnDragStart;
protected bool fastSwipeTimer = false;
protected int fastSwipeCounter = 0;
protected int fastSwipeTarget = 10;
// Use this for initialization
void Awake()
{
lerp = false;
scrollRect = gameObject.GetComponent<ScrollRect>();
scrollRectTransform = gameObject.GetComponent<RectTransform>();
listContainerTransform = scrollRect.content;
listContainerRectTransform = listContainerTransform.GetComponent<RectTransform>();
rectTransform = listContainerTransform.gameObject.GetComponent<RectTransform>();
UpdateListItemsSize();
UpdateListItemPositions();
ChangePage(CurrentPage());
if (nextButton)
{
nextButton.GetComponent<Button>().onClick.AddListener(() => {
NextScreen(); });
}
if (prevButton)
{
prevButton.GetComponent<Button>().onClick.AddListener(() => {
PreviousScreen(); });
}
}
void Start()
{
Awake();
}
public void UpdateListItemsSize()
{
float size = 0;
float currentSize = 0;
if (direction == ScrollSnap.ScrollDirection.Horizontal)
{
size = scrollRectTransform.rect.width / itemsVisibleAtOnce;
currentSize = listContainerRectTransform.rect.width / itemsCount;
}
else
{
size = scrollRectTransform.rect.height / itemsVisibleAtOnce;
currentSize = listContainerRectTransform.rect.height / itemsCount;
}
itemSize = size;
if (linkScrolrectScrollSensitivity)
{
scrollRect.scrollSensitivity = itemSize;
}
if (autoLayoutItems && currentSize != size && itemsCount > 0)
{
if (direction == ScrollSnap.ScrollDirection.Horizontal)
{
foreach (var tr in listContainerTransform)
{
GameObject child = ((Transform) tr).gameObject;
if (child.activeInHierarchy)
{
var childLayout = child.GetComponent<LayoutElement>();
if (childLayout == null)
{
childLayout = child.AddComponent<LayoutElement>();
}
childLayout.minWidth = itemSize;
}
}
}
else
{
foreach (var tr in listContainerTransform)
{
GameObject child = ((Transform) tr).gameObject;
if (child.activeInHierarchy)
{
var childLayout = child.GetComponent<LayoutElement>();
if (childLayout == null)
{
childLayout = child.AddComponent<LayoutElement>();
}
childLayout.minHeight = itemSize;
}
}
}
}
}
public void UpdateListItemPositions()
{
if (!listContainerRectTransform.rect.size.Equals(listContainerCachedSize))
{
// checking how many children of list are active
int activeCount = 0;
foreach (var tr in listContainerTransform)
{
if (((Transform) tr).gameObject.activeInHierarchy)
{
activeCount++;
}
}
// if anything changed since last check reinitialize anchors list
itemsCount = 0;
Array.Resize(ref pageAnchorPositions, activeCount);
if (activeCount > 0)
{
pages = Mathf.Max(activeCount - itemsVisibleAtOnce + 1, 1);
if (direction == ScrollDirection.Horizontal)
{
//Debug.Log ("-------------looking for list spanning range----------------");
// looking for list spanning range min/max
scrollRect.horizontalNormalizedPosition = 0;
listContainerMaxPosition = listContainerTransform.localPosition.x;
scrollRect.horizontalNormalizedPosition = 1;
listContainerMinPosition = listContainerTransform.localPosition.x;
listContainerSize = listContainerMaxPosition - listContainerMinPosition;
//itemSize = pages > 1 ? listContainerSize / (float)(pages - 1) : listContainerSize / activeCount;
//itemSize *= (pages + itemsVisibleAtOnce) / (pages + 1);
for (var i = 0; i < pages; i ++)
{
pageAnchorPositions[i] = new Vector3(
listContainerMaxPosition - itemSize * i,
listContainerTransform.localPosition.y,
listContainerTransform.localPosition.z
);
}
//Debug.Log (String.Format("min:{0:0.0}, max:{1:0.0}, pages: {2:0}, width: {3:0}", listContainerMinPosition, listContainerMaxPosition, pages, listContainerSize/pages));
}
else
{
//Debug.Log ("-------------looking for list spanning range----------------");
// looking for list spanning range
scrollRect.verticalNormalizedPosition = 1;
listContainerMinPosition = listContainerTransform.localPosition.y;
scrollRect.verticalNormalizedPosition = 0;
listContainerMaxPosition = listContainerTransform.localPosition.y;
listContainerSize = listContainerMaxPosition - listContainerMinPosition;
//itemSize = pages > 1 ? listContainerSize / (float)(pages - 1) : listContainerSize / activeCount;
//itemSize *= (pages + itemsVisibleAtOnce) / (pages + 1);
for (var i = 0; i < pages; i ++)
{
pageAnchorPositions[i] = new Vector3(
listContainerTransform.localPosition.x,
listContainerMinPosition + itemSize * i,
listContainerTransform.localPosition.z
);
//Debug.Log (String.Format("pos[{0:0}]={1} {2:0%}", i, pageAnchorPositions[i], pages > 1 ? i/(float)(pages-1) : (float)i));
}
//Debug.Log (String.Format("min:{0:0.0}, max:{1:0.0}, pages: {2:0}, width: {3:0}", listContainerMinPosition, listContainerMaxPosition, pages, listContainerSize/pages));
}
UpdateScrollbar(linkScrolbarSteps);
startingPage = Mathf.Min(startingPage, pages);
ResetPage();
}
if (itemsCount != activeCount)
{
ChangePage(CurrentPage());
}
itemsCount = activeCount;
listContainerCachedSize.Set(listContainerRectTransform.rect.size.x, listContainerRectTransform.rect.size.y);
}
}
public void ResetPage()
{
if (direction == ScrollDirection.Horizontal)
{
scrollRect.horizontalNormalizedPosition = pages > 1 ? (float) startingPage / (float) (pages - 1) : 0;
}
else
{
scrollRect.verticalNormalizedPosition = pages > 1 ? (float) (pages - startingPage - 1) / (float) (pages - 1) : 0;
}
}
protected void UpdateScrollbar(bool linkSteps)
{
if (linkSteps)
{
if (direction == ScrollDirection.Horizontal)
{
if (scrollRect.horizontalScrollbar != null)
{
scrollRect.horizontalScrollbar.numberOfSteps = pages;
}
}
else
{
if (scrollRect.verticalScrollbar != null)
{
scrollRect.verticalScrollbar.numberOfSteps = pages;
}
}
}
else
{
if (direction == ScrollDirection.Horizontal)
{
if (scrollRect.horizontalScrollbar != null)
{
scrollRect.horizontalScrollbar.numberOfSteps = 0;
}
}
else
{
if (scrollRect.verticalScrollbar != null)
{
scrollRect.verticalScrollbar.numberOfSteps = 0;
}
}
}
}
void LateUpdate()
{
UpdateListItemsSize();
UpdateListItemPositions();
if (lerp)
{
UpdateScrollbar(false);
listContainerTransform.localPosition = Vector3.Lerp(listContainerTransform.localPosition, lerpTarget, 7.5f * Time.deltaTime);
if (Vector3.Distance(listContainerTransform.localPosition, lerpTarget) < 0.001f)
{
listContainerTransform.localPosition = lerpTarget;
lerp = false;
UpdateScrollbar(linkScrolbarSteps);
//Debug.Log(String.Format("Lerp: {0}/{1} page: {2:0}", lerpTarget, listContainerTransform.localPosition, CurrentPage()));
}
//change the info bullets at the bottom of the screen. Just for visual effect
if (Vector3.Distance(listContainerTransform.localPosition, lerpTarget) < 10f)
{
ChangePage(CurrentPage());
}
}
if (fastSwipeTimer)
{
fastSwipeCounter++;
}
//Debug.Log(String.Format("Update: {0}", listContainerTransform.localPosition));
}
private bool fastSwipe = false; //to determine if a fast swipe was performed
//Function for switching screens with buttons
public void NextScreen()
{
UpdateListItemPositions();
if (CurrentPage() < pages - 1)
{
lerp = true;
lerpTarget = pageAnchorPositions[CurrentPage() + 1];
ChangePage(CurrentPage() + 1);
}
}
//Function for switching screens with buttons
public void PreviousScreen()
{
UpdateListItemPositions();
if (CurrentPage() > 0)
{
lerp = true;
lerpTarget = pageAnchorPositions[CurrentPage() - 1];
ChangePage(CurrentPage() - 1);
}
}
//Because the CurrentScreen function is not so reliable, these are the functions used for swipes
private void NextScreenCommand()
{
if (pageOnDragStart < pages - 1)
{
int targetPage = Mathf.Min(pages - 1, pageOnDragStart + itemsVisibleAtOnce);
lerp = true;
lerpTarget = pageAnchorPositions[targetPage];
ChangePage(targetPage);
}
}
//Because the CurrentScreen function is not so reliable, these are the functions used for swipes
private void PrevScreenCommand()
{
if (pageOnDragStart > 0)
{
int targetPage = Mathf.Max(0, pageOnDragStart - itemsVisibleAtOnce);
lerp = true;
lerpTarget = pageAnchorPositions[targetPage];
ChangePage(targetPage);
}
}
//returns the current screen that the is seeing
public int CurrentPage()
{
float pos;
if (direction == ScrollDirection.Horizontal)
{
pos = listContainerMaxPosition - listContainerTransform.localPosition.x;
pos = Mathf.Clamp(pos, 0, listContainerSize);
}
else
{
pos = listContainerTransform.localPosition.y - listContainerMinPosition;
pos = Mathf.Clamp(pos, 0, listContainerSize);
}
float page = pos / itemSize;
//Debug.Log (String.Format("min:{0:0.0}, max:{1:0.0}, current:{2:0.0}/{4:0.0}, page:{3:0.0}, target:{5}", listContainerMinPosition, listContainerMaxPosition, pos, page, listContainerTransform.localPosition.x, pageAnchorPositions[Mathf.RoundToInt(page)]));
return Mathf.Clamp(Mathf.RoundToInt(page), 0, pages);
}
//changes the bullets on the bottom of the page - pagination
private void ChangePage(int currentPage)
{
startingPage = currentPage;
if (nextButton)
{
nextButton.interactable = currentPage < pages - 1;
}
if (prevButton)
{
prevButton.interactable = currentPage > 0;
}
if (onPageChange != null)
{
onPageChange(currentPage);
}
}
#region Interfaces
public void OnBeginDrag(PointerEventData eventData)
{
UpdateScrollbar(false);
fastSwipeCounter = 0;
fastSwipeTimer = true;
positionOnDragStart = eventData.position;
pageOnDragStart = CurrentPage();
//Debug.Log (String.Format("pageOnDragStart:{0:0}", pageOnDragStart));
}
public void OnEndDrag(PointerEventData eventData)
{
startDrag = true;
float change = 0;
if (direction == ScrollDirection.Horizontal)
{
change = positionOnDragStart.x - eventData.position.x;
}
else
{
change = -positionOnDragStart.y + eventData.position.y;
}
if (useFastSwipe)
{
fastSwipe = false;
fastSwipeTimer = false;
if (fastSwipeCounter <= fastSwipeTarget)
{
if (Math.Abs(change) > fastSwipeThreshold)
{
fastSwipe = true;
}
}
if (fastSwipe)
{
if (change > 0)
{
NextScreenCommand();
}
else
{
PrevScreenCommand();
}
}
else
{
lerp = true;
lerpTarget = pageAnchorPositions[CurrentPage()];
}
}
else
{
lerp = true;
lerpTarget = pageAnchorPositions[CurrentPage()];
}
}
public void OnDrag(PointerEventData eventData)
{
lerp = false;
if (startDrag)
{
OnBeginDrag(eventData);
startDrag = false;
}
}
#endregion
}
}