iOS 循環(huán)滾動(dòng)視圖，包含文字滾動(dòng)骤宣，banner 滾動(dòng)
效果圖：
Demo.gif
demo 地址：
https://github.com/karosLi/KLRecycleScrollView
功能：
- 支持上下滾動(dòng)和左右滾動(dòng)
- 支持自定義子視圖
- 支持分頁和不分頁
- 支持自動(dòng)滾動(dòng)
實(shí)現(xiàn)代碼：
//
// KLRecycleScrollView.m
// KLRecycleScrollView
//
// Created by karos li on 2017/12/25.
// Copyright ? 2017年 karos. All rights reserved.
//
#import "KLRecycleScrollView.h"
@class KLInfiniteScrollView;
@protocol KLInfiniteScrollViewDelegate <NSObject>
- (UIView *)infiniteScrollView:(KLInfiniteScrollView *)infiniteScrollView viewForItemAtIndex:(NSInteger)index;
- (void)infiniteScrollView:(KLInfiniteScrollView *)infiniteScrollView didSelectView:(UIView *)view forItemAtIndex:(NSInteger)index;
@end
@interface KLInfiniteScrollView : UIScrollView
@property (nonatomic, strong, readonly) NSMutableArray *visibleViews;
@property (nonatomic, weak) id<KLInfiniteScrollViewDelegate> infiniteDelegate;
// 是否是水平布局
@property (nonatomic, assign) BOOL isHorLayout;
- (void)reloadData:(NSInteger)numberOfItems;
// 獲取子視圖距離最左邊的距離
- (CGFloat)getDistanceToLeftEdge:(UIView *)view;
// 獲取子視圖距離最上邊的距離
- (CGFloat)getDistanceToTopEdge:(UIView *)view;
@end
@interface KLInfiniteScrollView ()
@property (nonatomic, strong) NSMutableArray *visibleViews;
@property (nonatomic, strong) UIView *containerView;
@property (nonatomic, assign) NSInteger numberOfItems;
@property (nonatomic, assign) NSInteger rightMostVisibleViewIndex;
@property (nonatomic, assign) NSInteger leftMostVisibleViewIndex;
@property (nonatomic, assign) NSInteger topMostVisibleViewIndex;
@property (nonatomic, assign) NSInteger bottomMostVisibleViewIndex;
@end
@implementation KLInfiniteScrollView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
self.isHorLayout = YES;
self.contentSize = CGSizeMake(5000, self.frame.size.height);
self.visibleViews = [[NSMutableArray alloc] init];
self.containerView = [[UIView alloc] init];
self.containerView.frame = CGRectMake(0, 0, self.contentSize.width, self.contentSize.height);
[self addSubview:self.containerView];
self.bounces = NO;
self.showsHorizontalScrollIndicator = NO;
self.showsVerticalScrollIndicator = NO;
return self;
}
#pragma mark - public
- (void)reloadData:(NSInteger)numberOfItems {
self.numberOfItems = numberOfItems;
[self setNeedsLayout];
}
- (void)setIsHorLayout:(BOOL)isHorLayout {
_isHorLayout = isHorLayout;
[self.visibleViews removeAllObjects];
if (isHorLayout) {
self.contentSize = CGSizeMake(5000, self.frame.size.height);
self.containerView.frame = CGRectMake(0, 0, self.contentSize.width, self.contentSize.height);
} else {
self.contentSize = CGSizeMake(self.frame.size.width, 5000);
self.containerView.frame = CGRectMake(0, 0, self.contentSize.width, self.contentSize.height);
}
}
- (CGFloat)getDistanceToLeftEdge:(UIView *)view {
CGRect visibleBounds = [self convertRect:[self bounds] toView:self.containerView];
return CGRectGetMinX(view.frame) - CGRectGetMinX(visibleBounds);
}
- (CGFloat)getDistanceToTopEdge:(UIView *)view {
CGRect visibleBounds = [self convertRect:[self bounds] toView:self.containerView];
return CGRectGetMinY(view.frame) - CGRectGetMinY(visibleBounds);
}
#pragma mark - gesture
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
UIView *hitView;
for (UIView *view in self.containerView.subviews) {
CGPoint point = [touches.anyObject locationInView:view];
BOOL hasHit = [view pointInside:point withEvent:event];
if (hasHit) {
hitView = view;
break;
}
}
if (hitView.tag >= 20000) {
NSInteger index = hitView.tag - 20000;
if ([self.infiniteDelegate respondsToSelector:@selector(infiniteScrollView:didSelectView:forItemAtIndex:)]) {
[self.infiniteDelegate infiniteScrollView:self didSelectView:hitView forItemAtIndex:index];
}
}
}
#pragma mark - Layout
// recenter content periodically to achieve impression of infinite scrolling
- (void)recenterInHorIfNecessary {
CGPoint currentOffset = [self contentOffset];
CGFloat contentWidth = [self contentSize].width;
CGFloat centerOffsetX = (contentWidth - [self bounds].size.width) / 2.0;
CGFloat distanceFromCenter = fabs(currentOffset.x - centerOffsetX);
if (distanceFromCenter > (contentWidth / 4.0)) {
self.contentOffset = CGPointMake(centerOffsetX, currentOffset.y);
// move content by the same amount so it appears to stay still
for (UIView *label in self.visibleViews) {
CGPoint center = [self.containerView convertPoint:label.center toView:self];
center.x += (centerOffsetX - currentOffset.x);
label.center = [self convertPoint:center toView:self.containerView];
}
}
}
- (void)recenterInVerIfNecessary {
CGPoint currentOffset = [self contentOffset];
CGFloat contentHeight = [self contentSize].height;
CGFloat centerOffsetY = (contentHeight - [self bounds].size.height) / 2.0;
CGFloat distanceFromCenter = fabs(currentOffset.y - centerOffsetY);
if (distanceFromCenter > (contentHeight / 4.0)) {
self.contentOffset = CGPointMake(currentOffset.x, centerOffsetY);
// move content by the same amount so it appears to stay still
for (UIView *label in self.visibleViews) {
CGPoint center = [self.containerView convertPoint:label.center toView:self];
center.y += (centerOffsetY - currentOffset.y);
label.center = [self convertPoint:center toView:self.containerView];
}
}
}
- (void)layoutSubviews {
if (self.numberOfItems > 0) {
if (self.isHorLayout) {
[self recenterInHorIfNecessary];
// tile content in visible bounds
CGRect visibleBounds = [self convertRect:[self bounds] toView:self.containerView];
CGFloat minimumVisibleX = CGRectGetMinX(visibleBounds);
CGFloat maximumVisibleX = CGRectGetMaxX(visibleBounds);
[self tileViewsFromMinX:minimumVisibleX toMaxX:maximumVisibleX];
} else {
[self recenterInVerIfNecessary];
// tile content in visible bounds
CGRect visibleBounds = [self convertRect:[self bounds] toView:self.containerView];
CGFloat minimumVisibleY = CGRectGetMinY(visibleBounds);
CGFloat maximumVisibleY = CGRectGetMaxY(visibleBounds);
[self tileViewsFromMinY:minimumVisibleY toMaxY:maximumVisibleY];
}
}
[super layoutSubviews];
}
#pragma mark - hor View Tiling
- (CGFloat)placeNewViewOnRight:(CGFloat)rightEdge {
_rightMostVisibleViewIndex++;
if (_rightMostVisibleViewIndex == self.numberOfItems) {
_rightMostVisibleViewIndex = 0;
}
UIView *view;
if ([self.infiniteDelegate respondsToSelector:@selector(infiniteScrollView:viewForItemAtIndex:)]) {
view = [self.infiniteDelegate infiniteScrollView:self viewForItemAtIndex:_rightMostVisibleViewIndex];
}
if (!view) {
view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
}
view.tag = 20000 + _rightMostVisibleViewIndex;
[_containerView addSubview:view];
[_visibleViews addObject:view]; // add rightmost label at the end of the array
CGRect frame = [view frame];
frame.origin.x = rightEdge;
frame.origin.y = 0;
[view setFrame:frame];
return CGRectGetMaxX(frame);
}
- (CGFloat)placeNewViewOnLeft:(CGFloat)leftEdge {
_leftMostVisibleViewIndex--;
if (_leftMostVisibleViewIndex < 0) {
_leftMostVisibleViewIndex = self.numberOfItems - 1;
}
UIView *view;
if ([self.infiniteDelegate respondsToSelector:@selector(infiniteScrollView:viewForItemAtIndex:)]) {
view = [self.infiniteDelegate infiniteScrollView:self viewForItemAtIndex:_leftMostVisibleViewIndex];
}
if (!view) {
view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
}
view.tag = 20000 + _leftMostVisibleViewIndex;
[_containerView addSubview:view];
[_visibleViews insertObject:view atIndex:0]; // add leftmost label at the beginning of the array
CGRect frame = [view frame];
frame.origin.x = leftEdge - frame.size.width;
frame.origin.y = 0;
[view setFrame:frame];
return CGRectGetMinX(frame);
}
- (void)tileViewsFromMinX:(CGFloat)minimumVisibleX toMaxX:(CGFloat)maximumVisibleX {
// the upcoming tiling logic depends on there already being at least one label in the visibleLabels array, so
// to kick off the tiling we need to make sure there's at least one label
if ([_visibleViews count] == 0) {
_rightMostVisibleViewIndex = -1;
_leftMostVisibleViewIndex = 0;
[self placeNewViewOnRight:minimumVisibleX];
}
// add labels that are missing on right side
UIView *lastView = [_visibleViews lastObject];
CGFloat rightEdge = CGRectGetMaxX([lastView frame]);
while (rightEdge < maximumVisibleX) {
rightEdge = [self placeNewViewOnRight:rightEdge];
}
// add labels that are missing on left side
UIView *firstView = _visibleViews[0];
CGFloat leftEdge = CGRectGetMinX([firstView frame]);
while (leftEdge > minimumVisibleX) {
leftEdge = [self placeNewViewOnLeft:leftEdge];
}
// remove labels that have fallen off right edge
lastView = [_visibleViews lastObject];
while ([lastView frame].origin.x > maximumVisibleX) {
[lastView removeFromSuperview];
[_visibleViews removeLastObject];
lastView = [_visibleViews lastObject];
_rightMostVisibleViewIndex--;
if (_rightMostVisibleViewIndex < 0) {
_rightMostVisibleViewIndex = self.numberOfItems - 1;
}
}
// remove labels that have fallen off left edge
firstView = _visibleViews[0];
while (CGRectGetMaxX([firstView frame]) < minimumVisibleX) {
[firstView removeFromSuperview];
[_visibleViews removeObjectAtIndex:0];
firstView = _visibleViews[0];
_leftMostVisibleViewIndex++;
if (_leftMostVisibleViewIndex == self.numberOfItems) {
_leftMostVisibleViewIndex = 0;
}
}
}
#pragma mark - ver View Tiling
- (CGFloat)placeNewViewOnBottom:(CGFloat)bottomEdge {
_bottomMostVisibleViewIndex++;
if (_bottomMostVisibleViewIndex == self.numberOfItems) {
_bottomMostVisibleViewIndex = 0;
}
UIView *view;
if ([self.infiniteDelegate respondsToSelector:@selector(infiniteScrollView:viewForItemAtIndex:)]) {
view = [self.infiniteDelegate infiniteScrollView:self viewForItemAtIndex:_bottomMostVisibleViewIndex];
}
if (!view) {
view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
}
view.tag = 20000 + _bottomMostVisibleViewIndex;
[_containerView addSubview:view];
[_visibleViews addObject:view]; // add rightmost label at the end of the array
CGRect frame = [view frame];
frame.origin.x = 0;
frame.origin.y = bottomEdge;
[view setFrame:frame];
return CGRectGetMaxY(frame);
}
- (CGFloat)placeNewViewOnTop:(CGFloat)topEdge {
_topMostVisibleViewIndex--;
if (_topMostVisibleViewIndex < 0) {
_topMostVisibleViewIndex = self.numberOfItems - 1;
}
UIView *view;
if ([self.infiniteDelegate respondsToSelector:@selector(infiniteScrollView:viewForItemAtIndex:)]) {
view = [self.infiniteDelegate infiniteScrollView:self viewForItemAtIndex:_topMostVisibleViewIndex];
}
if (!view) {
view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
}
view.tag = 20000 + _topMostVisibleViewIndex;
[_containerView addSubview:view];
[_visibleViews insertObject:view atIndex:0]; // add leftmost label at the beginning of the array
CGRect frame = [view frame];
frame.origin.x = 0;
frame.origin.y = topEdge - frame.size.height;
[view setFrame:frame];
return CGRectGetMinY(frame);
}
- (void)tileViewsFromMinY:(CGFloat)minimumVisibleY toMaxY:(CGFloat)maximumVisibleY {
// the upcoming tiling logic depends on there already being at least one label in the visibleLabels array, so
// to kick off the tiling we need to make sure there's at least one label
if ([_visibleViews count] == 0) {
_bottomMostVisibleViewIndex = -1;
_topMostVisibleViewIndex = 0;
[self placeNewViewOnBottom:minimumVisibleY];
}
// add labels that are missing on right side
UIView *lastView = [_visibleViews lastObject];
CGFloat bottomEdge = CGRectGetMaxY([lastView frame]);
while (bottomEdge < maximumVisibleY) {
bottomEdge = [self placeNewViewOnBottom:bottomEdge];
}
// add labels that are missing on left side
UIView *firstView = _visibleViews[0];
CGFloat topEdge = CGRectGetMinY([firstView frame]);
while (topEdge > minimumVisibleY) {
topEdge = [self placeNewViewOnTop:topEdge];
}
// remove labels that have fallen off right edge
lastView = [_visibleViews lastObject];
while ([lastView frame].origin.y > maximumVisibleY) {
[lastView removeFromSuperview];
[_visibleViews removeLastObject];
lastView = [_visibleViews lastObject];
_bottomMostVisibleViewIndex--;
if (_bottomMostVisibleViewIndex < 0) {
_bottomMostVisibleViewIndex = self.numberOfItems - 1;
}
}
// remove labels that have fallen off left edge
firstView = _visibleViews[0];
while (CGRectGetMaxY([firstView frame]) < minimumVisibleY) {
[firstView removeFromSuperview];
[_visibleViews removeObjectAtIndex:0];
firstView = _visibleViews[0];
_topMostVisibleViewIndex++;
if (_topMostVisibleViewIndex == self.numberOfItems) {
_topMostVisibleViewIndex = 0;
}
}
}
@end
@interface KLRecycleScrollView() <UIScrollViewDelegate, KLInfiniteScrollViewDelegate>
@property (strong, nonatomic) KLInfiniteScrollView *scrollView;
@property (strong, nonatomic) NSMutableArray *containerViews;
@property (assign, nonatomic) NSInteger totalItemsCount;
@property (strong, nonatomic) NSTimer *timer;
@end
@implementation KLRecycleScrollView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
self.scrollInterval = 3.5;
[self setupView];
return self;
}
- (void)setupView {
self.scrollView = [[KLInfiniteScrollView alloc] initWithFrame:self.bounds];
self.scrollView.delegate = self;
self.scrollView.infiniteDelegate = self;
[self addSubview:self.scrollView];
}
#pragma mark - public methods
- (void)reloadData:(NSInteger)totalItemsCount {
self.totalItemsCount = totalItemsCount;
[self.scrollView reloadData:totalItemsCount];
[self startTimer];
}
- (void)setPagingEnabled:(BOOL)pagingEnabled {
_pagingEnabled = pagingEnabled;
self.scrollView.decelerationRate = pagingEnabled ? UIScrollViewDecelerationRateFast : UIScrollViewDecelerationRateNormal;
}
- (void)setDirection:(KLRecycleScrollViewDirection)direction {
_direction = direction;
if (self.direction == KLRecycleScrollViewDirectionLeft || self.direction == KLRecycleScrollViewDirectionRight) {
self.scrollView.isHorLayout = YES;
} else if (self.direction == KLRecycleScrollViewDirectionTop || self.direction == KLRecycleScrollViewDirectionBottom) {
self.scrollView.isHorLayout = NO;
}
}
#pragma mark - timer
- (void)fireTimer {
[UIView animateWithDuration:0.75 delay:0.0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
if (self.direction == KLRecycleScrollViewDirectionLeft) {
CGPoint contentOffset = self.scrollView.contentOffset;
[self.scrollView setContentOffset:CGPointMake(contentOffset.x + self.bounds.size.width, 0) animated:NO];
} else if (self.direction == KLRecycleScrollViewDirectionRight) {
CGPoint contentOffset = self.scrollView.contentOffset;
[self.scrollView setContentOffset:CGPointMake(contentOffset.x - self.bounds.size.width, 0) animated:NO];
} else if (self.direction == KLRecycleScrollViewDirectionTop) {
CGPoint contentOffset = self.scrollView.contentOffset;
[self.scrollView setContentOffset:CGPointMake(0, contentOffset.y + self.bounds.size.height) animated:NO];
} else if (self.direction == KLRecycleScrollViewDirectionBottom) {
CGPoint contentOffset = self.scrollView.contentOffset;
[self.scrollView setContentOffset:CGPointMake(0, contentOffset.y - self.bounds.size.height) animated:NO];
}
} completion:^(BOOL finished) {
}];
}
- (void)configTimer {
self.timer = [NSTimer timerWithTimeInterval:self.scrollInterval target:self selector:@selector(fireTimer) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}
- (void)startTimer {
if (self.timerEnabled && !self.timer) {
[self configTimer];
}
}
- (void)stopTimer {
if (self.timerEnabled) {
[self.timer invalidate];
self.timer = nil;
}
}
#pragma mark - KLInfiniteScrollViewDelegate
- (UIView *)infiniteScrollView:(KLInfiniteScrollView *)infiniteScrollView viewForItemAtIndex:(NSInteger)index {
UIView *subview;
if ([self.delegate respondsToSelector:@selector(recycleScrollView:viewForItemAtIndex:)]) {
subview = [self.delegate recycleScrollView:self viewForItemAtIndex:index];
}
subview.frame = self.bounds;
return subview;
}
- (void)infiniteScrollView:(KLInfiniteScrollView *)infiniteScrollView didSelectView:(UIView *)view forItemAtIndex:(NSInteger)index {
if ([self.delegate respondsToSelector:@selector(recycleScrollView:didSelectView:forItemAtIndex:)]) {
[self.delegate recycleScrollView:self didSelectView:view forItemAtIndex:index];
}
}
#pragma mark - override
- (void)setClipsToBounds:(BOOL)clipsToBounds {
[super setClipsToBounds:clipsToBounds];
self.scrollView.clipsToBounds = clipsToBounds;
}
#pragma mark - scroll view deleaget
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
if (self.pagingEnabled) {
if (self.direction == KLRecycleScrollViewDirectionLeft || self.direction == KLRecycleScrollViewDirectionRight) {
NSInteger width = self.bounds.size.width;
NSInteger extra = 0;
if (velocity.x != 0) {
extra = velocity.x > 0 ? width : -width;
}
CGPoint targetOffset = [self getLeftestViewToLeftEdge];
targetContentOffset->x = targetOffset.x + extra;
targetContentOffset->y = targetOffset.y;
} else if (self.direction == KLRecycleScrollViewDirectionTop || self.direction == KLRecycleScrollViewDirectionBottom) {
NSInteger height = self.bounds.size.height;
NSInteger extra = 0;
if (velocity.y != 0) {
extra = velocity.y > 0 ? height : -height;
}
CGPoint targetOffset = [self getTopestViewToTopEdge];
targetContentOffset->x = targetOffset.x;
targetContentOffset->y = targetOffset.y + extra;
}
}
}
- (CGPoint)getLeftestViewToLeftEdge {
CGPoint offset = self.scrollView.contentOffset;
__block CGFloat minDistanceFromLeftEdge = MAXFLOAT;
__block UIView *minDistanceFromLeftEdgeView;
__weak typeof(self) weakSelf = self;
[self.scrollView.visibleViews enumerateObjectsUsingBlock:^(id _Nonnull view, NSUInteger idx, BOOL * _Nonnull stop) {
CGFloat distanceToLeftEdge = [weakSelf.scrollView getDistanceToLeftEdge:view];
if (distanceToLeftEdge < fabs(minDistanceFromLeftEdge)) {
minDistanceFromLeftEdge = distanceToLeftEdge;
minDistanceFromLeftEdgeView = view;
}
}];
CGFloat targetX = offset.x + minDistanceFromLeftEdge;
CGPoint targetOffset = CGPointMake(targetX, offset.y);
return targetOffset;
}
- (CGPoint)getTopestViewToTopEdge {
CGPoint offset = self.scrollView.contentOffset;
__block CGFloat minDistanceFromTopEdge = MAXFLOAT;
__block UIView *minDistanceFromTopEdgeView;
__weak typeof(self) weakSelf = self;
[self.scrollView.visibleViews enumerateObjectsUsingBlock:^(id _Nonnull view, NSUInteger idx, BOOL * _Nonnull stop) {
CGFloat distanceToTopEdge = [weakSelf.scrollView getDistanceToTopEdge:view];
if (distanceToTopEdge < fabs(minDistanceFromTopEdge)) {
minDistanceFromTopEdge = distanceToTopEdge;
minDistanceFromTopEdgeView = view;
}
}];
CGFloat targetY = offset.y + minDistanceFromTopEdge;
CGPoint targetOffset = CGPointMake(offset.x, targetY);
return targetOffset;
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
[self stopTimer];
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
if (scrollView == self.scrollView) {
if (!decelerate) {
[self startTimer];
}
}
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
if (scrollView == self.scrollView) {
[self startTimer];
}
}
@end
