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keyBoard/Class/Vender/BMLongPressDragCellCollectionView/BMLongPressDragCellCollectionView.h

@@ -0,0 +1,71 @@
+//    MIT License
+//
+//    Copyright (c) 2019 https://liangdahong.com
+//
+//    Permission is hereby granted, free of charge, to any person obtaining a copy
+//    of this software and associated documentation files (the "Software"), to deal
+//    in the Software without restriction, including without limitation the rights
+//    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//    copies of the Software, and to permit persons to whom the Software is
+//    furnished to do so, subject to the following conditions:
+//
+//    The above copyright notice and this permission notice shall be included in all
+//    copies or substantial portions of the Software.
+//
+//    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//    SOFTWARE.
+
+////////////////////
+/// v3.1.4
+////////////////////
+
+#import <UIKit/UIKit.h>
+#import "BMLongPressDragCellCollectionViewDelegate.h"
+#import "BMLongPressDragCellCollectionViewDataSource.h"
+
+/*
+ - (NSArray<NSArray<id> *> *)dataSourceWithDragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView {
+     return self.dataSourceArray;
+     // 此协议方法里返回数据源
+ }
+
+ - (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView newDataArrayAfterMove:(nullable NSArray <NSArray <id> *> *)newDataArray {
+     self.dataSourceArray = [newDataArray mutableCopy];
+     // 此协议方法里保存数据源
+ }
+ */
+@interface BMLongPressDragCellCollectionView : UICollectionView
+
+@property (nonatomic, weak) id<BMLongPressDragCellCollectionViewDelegate> delegate;
+@property (nonatomic, weak) id<BMLongPressDragCellCollectionViewDataSource> dataSource;
+
+/// 长按触发拖拽所需时间，默认是 0.5 秒。
+@property (nonatomic, assign) NSTimeInterval minimumPressDuration;
+
+/// 是否可以拖拽 默认为 YES。
+@property (nonatomic, assign, getter=isCanDrag) IBInspectable BOOL canDrag;
+
+/// 长按拖拽时拖拽中的的 Cell 缩放比例，默认是 1.2 倍。
+@property (nonatomic, assign) IBInspectable CGFloat dragZoomScale;
+
+/// 拖拽的 Cell 在拖拽移动时的透明度 默认是： 1.0 不透明。
+@property (nonatomic, assign) IBInspectable CGFloat dragCellAlpha;
+
+/// 拖拽到 UICollectionView 边缘时 UICollectionView 的滚动速度
+/// 默认为: 8.0f ，建议设置 5.0f 到 15.0f 之间。
+@property (nonatomic, assign) IBInspectable CGFloat dragSpeed;
+
+/// 拖拽 View 的背景颜色，默认和被拖拽的 Cell 一样。
+@property (nonatomic, strong) IBInspectable UIColor *dragSnapedViewBackgroundColor;
+
+/// 移动到指定位置
+/// @param indexPath 移动到的位置
+/// 内部只会处理当前正在拖拽的情况，会把拖拽的 Cell 移动到指定位置，建议在停止手势时或者认为适当的时候使用。
+- (void)dragMoveItemToIndexPath:(NSIndexPath *)indexPath;
+
+@end

keyBoard/Class/Vender/BMLongPressDragCellCollectionView/BMLongPressDragCellCollectionView.m

@@ -0,0 +1,729 @@
+//    MIT License
+//
+//    Copyright (c) 2019 https://liangdahong.com
+//
+//    Permission is hereby granted, free of charge, to any person obtaining a copy
+//    of this software and associated documentation files (the "Software"), to deal
+//    in the Software without restriction, including without limitation the rights
+//    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//    copies of the Software, and to permit persons to whom the Software is
+//    furnished to do so, subject to the following conditions:
+//
+//    The above copyright notice and this permission notice shall be included in all
+//    copies or substantial portions of the Software.
+//
+//    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//    SOFTWARE.
+
+#import "BMLongPressDragCellCollectionView.h"
+
+typedef NS_ENUM(NSUInteger, BMLongPressDragCellCollectionViewScrollDirection) {
+    BMLongPressDragCellCollectionViewScrollDirectionNone  = 0,
+    BMLongPressDragCellCollectionViewScrollDirectionLeft  = 1,
+    BMLongPressDragCellCollectionViewScrollDirectionRight = 2,
+    BMLongPressDragCellCollectionViewScrollDirectionUp    = 3,
+    BMLongPressDragCellCollectionViewScrollDirectionDown  = 4,
+};
+
+@interface BMLongPressDragCellCollectionView ()
+
+/// 长按手势
+@property (nonatomic, strong, nullable) UILongPressGestureRecognizer *longGesture;
+/// 截图快照
+@property (nonatomic, strong, nullable) UIView *snapedView;
+/// 定时器
+@property (nonatomic, strong, nullable) CADisplayLink *edgeTimer;
+/// 旧的IndexPath
+@property (nonatomic, strong, nullable) NSIndexPath *oldIndexPath;
+/// 当前路径
+@property (nonatomic, strong, nullable) NSIndexPath *currentIndexPath;
+
+@property (nonatomic, assign) BOOL    isEndDrag; ///< 是否已经停止拖动
+@property (nonatomic, assign) BOOL    banReload; ///< 禁止刷新
+@property (nonatomic, assign) CGPoint oldPoint;  ///< 旧的位置
+@property (nonatomic, assign) CGPoint lastPoint; ///< 最后的触摸点
+
+@end
+
+@implementation BMLongPressDragCellCollectionView
+
+@dynamic delegate, dataSource;
+
+- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout {
+    if (self = [super initWithFrame:frame collectionViewLayout:layout]) {
+        [self initConfiguration];
+    }
+    return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder *)aDecoder {
+    if (self = [super initWithCoder:aDecoder]) {
+        [self initConfiguration];
+    }
+    return self;
+}
+
+- (void)dealloc {
+    [self _stopEdgeTimer];
+}
+
+#pragma mark - getters setters
+
+- (void)setCanDrag:(BOOL)canDrag {
+    _canDrag = canDrag;
+    self.longGesture.enabled = _canDrag;
+}
+
+- (void)setMinimumPressDuration:(NSTimeInterval)minimumPressDuration {
+    _minimumPressDuration = minimumPressDuration;
+    self.longGesture.minimumPressDuration = minimumPressDuration;
+}
+
+- (void)setDragZoomScale:(CGFloat)dragZoomScale {
+    if (dragZoomScale < 0.1) {
+        dragZoomScale = 1.2;
+    }
+    _dragZoomScale = dragZoomScale;
+}
+
+- (void)setDragSpeed:(CGFloat)dragSpeed {
+    if (dragSpeed < 0.5) {
+        dragSpeed = 8.0;
+    }
+    _dragSpeed = dragSpeed;
+}
+
+- (void)setDragSnapedViewBackgroundColor:(UIColor *)dragSnapedViewBackgroundColor {
+    _dragSnapedViewBackgroundColor = dragSnapedViewBackgroundColor;
+    _snapedView.backgroundColor = dragSnapedViewBackgroundColor;
+}
+
+- (UILongPressGestureRecognizer *)longGesture {
+    if (!_longGesture) {
+        _longGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)];
+        _longGesture.minimumPressDuration = _minimumPressDuration;
+    }
+    return _longGesture;
+}
+
+// iOS 10 新特性 对UICollectionView做了优化，但是这里如果使用了会导致bug,重写此方法是为了让其无法修改
+// https://developer.apple.com/documentation/uikit/uicollectionview/1771771-prefetchingenabled
+// https://sxgfxm.github.io/blog/2016/10/18/uicollectionview-ios10-new-features
+- (void)setPrefetchingEnabled:(BOOL)prefetchingEnabled {
+    [super setPrefetchingEnabled:NO];
+}
+
+#pragma mark - 私有方法
+
+- (void)initConfiguration {
+    _canDrag              = YES;
+    _minimumPressDuration = 0.5;
+    _dragZoomScale = 1.2;
+    _dragCellAlpha = 1.0;
+    _dragSpeed     = 8.0;
+    [self addGestureRecognizer:self.longGesture];
+    // iOS 10 新特性 对 UICollectionView 做了优化，但是这里如果使用了会导致bug
+    // https://developer.apple.com/documentation/uikit/uicollectionview/1771771-prefetchingenabled
+    // https://sxgfxm.github.io/blog/2016/10/18/uicollectionview-ios10-new-features
+    if (@available(iOS 10.0, *)) {
+        self.prefetchingEnabled = NO;
+    }
+}
+
+- (void)reloadData {
+    if (_banReload) {
+        return;
+    }
+    [super reloadData];
+}
+
+- (void)insertSections:(NSIndexSet *)sections {
+    if (_banReload) {
+        return;
+    }
+    [super insertSections:sections];
+}
+
+- (void)deleteSections:(NSIndexSet *)sections {
+    if (_banReload) {
+        return;
+    }
+    [super deleteSections:sections];
+}
+
+- (void)reloadSections:(NSIndexSet *)sections {
+    if (_banReload) {
+        return;
+    }
+    [super reloadSections:sections];
+}
+
+- (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection {
+    if (_banReload) {
+        return;
+    }
+    [super moveSection:section toSection:newSection];
+}
+
+- (void)insertItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths {
+    if (_banReload) {
+        return;
+    }
+    [super insertItemsAtIndexPaths:indexPaths];
+}
+
+- (void)deleteItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths {
+   if (_banReload) {
+       return;
+   }
+    [super deleteItemsAtIndexPaths:indexPaths];
+}
+
+- (void)reloadItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths {
+    if (_banReload) {
+        return;
+    }
+    [super reloadItemsAtIndexPaths:indexPaths];
+}
+
+- (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath {
+    if (_banReload) {
+        return;
+    }
+    [super moveItemAtIndexPath:indexPath toIndexPath:newIndexPath];
+}
+
+- (__kindof UICollectionViewCell *)dequeueReusableCellWithReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath {
+    UICollectionViewCell *cell = [super dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];
+    // 处理复用时的问题，为了保证显示的正确性
+    if (_isEndDrag) {
+        cell.hidden = NO;
+    } else {
+        cell.hidden = (self.oldIndexPath
+                       && self.oldIndexPath.item == indexPath.item
+                       && self.oldIndexPath.section == indexPath.section);
+    }
+    return cell;
+}
+
+- (nullable NSIndexPath *)_getChangedNullIndexPath {
+    __block NSIndexPath *index = nil;
+    CGPoint point = [self.longGesture locationInView:self];
+    NSInteger number = self.numberOfSections;
+    while (number--) {
+        NSInteger row = [self.dataSource collectionView:self numberOfItemsInSection:number];
+        if (row == 0) {
+            // 如果这组是空的
+            CGRect headerFrame = [self layoutAttributesForSupplementaryElementOfKind:UICollectionElementKindSectionHeader atIndexPath:[NSIndexPath indexPathForItem:0 inSection:number]].frame;
+            CGRect footerFrame = [self layoutAttributesForSupplementaryElementOfKind:UICollectionElementKindSectionFooter atIndexPath:[NSIndexPath indexPathForItem:0 inSection:number]].frame;
+            CGRect frame = CGRectZero;
+            if (((UICollectionViewFlowLayout *)self.collectionViewLayout).scrollDirection == UICollectionViewScrollDirectionHorizontal) {
+                // 水平方向
+                frame = CGRectMake(CGRectGetMinX(headerFrame),
+                                   CGRectGetMinY(headerFrame),
+                                   CGRectGetMaxX(footerFrame) - CGRectGetMidX(headerFrame),
+                                   CGRectGetWidth(footerFrame));
+                
+                if (frame.size.width < 10.0) {
+                    // 如果这组的宽度小于 10.0，就设置一个默认值 10.0，主要是为了判断触摸点缩放在这组内。
+                    frame.size.width  = 10.0;
+                    frame.size.height = CGRectGetHeight(self.frame);
+                    frame.origin.x    -= 5.0;
+                }
+            } else {
+                // 垂直方向
+                frame = CGRectMake(CGRectGetMinX(headerFrame),
+                                   CGRectGetMinY(headerFrame),
+                                   CGRectGetWidth(footerFrame),
+                                   CGRectGetMaxY(footerFrame) - CGRectGetMidY(headerFrame));
+                
+                if (frame.size.height < 10.0) {
+                    // 如果这组的高度小于 10.0，就设置一个默认值 10.0，主要是为了判断触摸点缩放在这组内。
+                    frame.size.height = 10.0;
+                    frame.size.width  = CGRectGetWidth(self.frame);
+                    frame.origin.y    -= 5.0;
+                }
+            }
+            
+            if (CGRectContainsPoint(frame, point)) {
+                // 触摸点在空的组内
+                return [NSIndexPath indexPathForItem:0 inSection:number];
+            }
+        }
+    }
+    return index;
+}
+
+- (nullable NSIndexPath *)_getChangedIndexPath {
+    __block NSIndexPath *index = nil;
+    CGPoint point = [self.longGesture locationInView:self];
+    // 遍历拖拽的 Cell 的中心点在哪一个 Cell 里
+    [[self visibleCells] enumerateObjectsUsingBlock:^(__kindof UICollectionViewCell * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
+        if (CGRectContainsPoint(obj.frame, point)) {
+            index = [self indexPathForCell:obj];
+            *stop = YES;
+        }
+    }];
+    // 找到而且不是当前的 Cell 就返回此 index
+    if (index) {
+        if ((index.section == self.oldIndexPath.section) && (index.item == self.oldIndexPath.item)) {
+            return nil;
+        }
+        return index;
+    }
+    
+    // 获取最应该交换的 Cell
+    __block CGFloat width = MAXFLOAT;
+    __weak typeof(self) weakSelf = self;
+    [[self visibleCells] enumerateObjectsUsingBlock:^(__kindof UICollectionViewCell * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
+        if (CGRectContainsPoint(obj.frame, point)) {
+            index = [self indexPathForCell:obj];
+            *stop = YES;
+        }
+        __strong typeof(weakSelf) self = weakSelf;
+        CGPoint p1 = self.snapedView.center;
+        CGPoint p2 = obj.center;
+        // 计算距离
+        CGFloat distance = sqrt(pow((p1.x - p2.x), 2) + pow((p1.y - p2.y), 2));
+        if (distance < width) {
+            width = distance;
+            index = [self indexPathForCell:obj];
+        }
+    }];
+    if (!index) {
+        return nil;
+    }
+    if ((index.section == self.oldIndexPath.section) && (index.item == self.oldIndexPath.item)) {
+        // 最近的就是隐藏的 Cell 时, return nil
+        return nil;
+    }
+    return index;
+}
+
+// 处理临界点问题
+- (BMLongPressDragCellCollectionViewScrollDirection)_setScrollDirection {
+    if (((self.bounds.size.height + self.contentOffset.y - _snapedView.center.y) < (_snapedView.bounds.size.height / 2))
+        && ((self.bounds.size.height + self.contentOffset.y) < self.contentSize.height)) {
+        return BMLongPressDragCellCollectionViewScrollDirectionDown;
+        
+    } else if (((_snapedView.center.y - self.contentOffset.y) < (_snapedView.bounds.size.height / 2))
+               && self.contentOffset.y > 0) {
+        return BMLongPressDragCellCollectionViewScrollDirectionUp;
+        
+    } else if (((self.bounds.size.width + self.contentOffset.x) - (_snapedView.center.x)) < (_snapedView.bounds.size.width / 2)
+               && (self.bounds.size.width + self.contentOffset.x) < self.contentSize.width) {
+        return BMLongPressDragCellCollectionViewScrollDirectionRight;
+        
+    } else if (((_snapedView.center.x - self.contentOffset.x) < (_snapedView.bounds.size.width) / 2)
+               && self.contentOffset.x > 0) {
+        return BMLongPressDragCellCollectionViewScrollDirectionLeft;
+    }
+    
+    return BMLongPressDragCellCollectionViewScrollDirectionNone;
+}
+
+// 处理 UICollectionView 数据源
+- (void)_updateSourceData {
+    // 获取数据源
+    NSMutableArray *array = [self.dataSource dataSourceWithDragCellCollectionView:self].mutableCopy;
+    // 处理数据
+    BOOL dataTypeCheck = ([self numberOfSections] != 1 || ([self  numberOfSections] == 1 && [array[0] isKindOfClass:NSArray.class]));
+    if (dataTypeCheck) {
+        for (int i = 0; i < array.count; i ++) {
+            // 如果是嵌套数组 就把数组里面的数组换为 NSMutableArray。
+            [array replaceObjectAtIndex:i withObject:[array[i] mutableCopy]];
+        }
+    }
+    if (_currentIndexPath.section == _oldIndexPath.section) {
+
+        NSMutableArray *orignalSection = dataTypeCheck ? array[_oldIndexPath.section] : array;
+        
+        if (_currentIndexPath.item > _oldIndexPath.item) {
+            for (NSUInteger i = _oldIndexPath.item; i < _currentIndexPath.item ; i ++) {
+                [orignalSection exchangeObjectAtIndex:i withObjectAtIndex:i + 1];
+            }
+            
+        } else {
+            for (NSUInteger i = _oldIndexPath.item; i > _currentIndexPath.item ; i --) {
+                [orignalSection exchangeObjectAtIndex:i withObjectAtIndex:i - 1];
+            }
+        }
+        
+    } else {
+        NSMutableArray *orignalSection = array[_oldIndexPath.section];
+        NSMutableArray *currentSection = array[_currentIndexPath.section];
+        [currentSection insertObject:orignalSection[_oldIndexPath.item] atIndex:_currentIndexPath.item];
+        // https://github.com/liangdahong/BMLongPressDragCellCollectionView/issues/16
+        // 这里之前删除指定对象会有问题，如果数据源中的对象为 [字符串 而且是一样的时候, 因为 OC 中对字符串的内存做了特殊处理 ]，会把相同的字符串全部删除导致崩溃
+        // [orignalSection removeObject:orignalSection[_oldIndexPath.item]];
+        [orignalSection removeObjectAtIndex:_oldIndexPath.item];
+    }
+    // ==========处理数据
+    // 更新外面的数据源
+    // 这里会触发外面的使用者修改数据源，但外面的使用者可以会在此调用 reloadData 相关方法，所以做了拦截操作
+    // https://github.com/liangdahong/BMLongPressDragCellCollectionView/issues/14
+    self.banReload = YES;
+    [self.delegate dragCellCollectionView:self newDataArrayAfterMove:array];
+    self.banReload = NO;
+}
+
+- (void)_setEdgeTimer{
+    if (!_edgeTimer) {
+        _edgeTimer = [CADisplayLink displayLinkWithTarget:self selector:@selector(_edgeScroll)];
+        [_edgeTimer addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
+    }
+}
+
+- (void)_stopEdgeTimer{
+    if (_edgeTimer) {
+        [_edgeTimer invalidate];
+        _edgeTimer = nil;
+    }
+}
+
+- (void)_edgeScroll {
+    BMLongPressDragCellCollectionViewScrollDirection scrollDirection = [self _setScrollDirection];
+
+    if (BMLongPressDragCellCollectionViewScrollDirectionNone == scrollDirection) {
+        return;
+    }
+
+    switch (scrollDirection) {
+        case BMLongPressDragCellCollectionViewScrollDirectionLeft:{
+            // 这里的动画必须设为 NO
+            [self setContentOffset:CGPointMake(self.contentOffset.x - _dragSpeed, self.contentOffset.y) animated:NO];
+            _snapedView.center = CGPointMake(_snapedView.center.x - _dragSpeed, _snapedView.center.y);
+            _lastPoint.x -= _dragSpeed;
+        }
+            break;
+        case BMLongPressDragCellCollectionViewScrollDirectionRight:{
+            [self setContentOffset:CGPointMake(self.contentOffset.x + _dragSpeed, self.contentOffset.y) animated:NO];
+            _snapedView.center = CGPointMake(_snapedView.center.x + _dragSpeed, _snapedView.center.y);
+            _lastPoint.x += _dragSpeed;
+        }
+            break;
+        case BMLongPressDragCellCollectionViewScrollDirectionUp:{
+            [self setContentOffset:CGPointMake(self.contentOffset.x, self.contentOffset.y - _dragSpeed) animated:NO];
+            _snapedView.center = CGPointMake(_snapedView.center.x, _snapedView.center.y - _dragSpeed);
+            _lastPoint.y -= _dragSpeed;
+        }
+            break;
+        case BMLongPressDragCellCollectionViewScrollDirectionDown:{
+            [self setContentOffset:CGPointMake(self.contentOffset.x, self.contentOffset.y + _dragSpeed) animated:NO];
+            _snapedView.center = CGPointMake(_snapedView.center.x, _snapedView.center.y + _dragSpeed);
+            _lastPoint.y += _dragSpeed;
+        }
+            break;
+        default:
+            break;
+    }
+
+    // 如果Cell 拖拽到了边沿时
+    // 截图视图位置移动
+    [UIView animateWithDuration:0.1 animations:^{
+        self.snapedView.center = self.lastPoint;
+    }];
+    
+    // 获取应该交换的 Cell 的位置
+    NSIndexPath *index1 = [self _getChangedNullIndexPath];
+    NSIndexPath *index = nil;
+
+    index = index1 ? : [self _getChangedIndexPath];
+
+    if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionView:changedDragAtPoint:)]) {
+        [self.delegate dragCellCollectionView:self changedDragAtPoint:_lastPoint];
+    }
+    
+    if (!index) {
+        return;
+    }
+    
+    // 是否可以交换
+    if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionViewShouldBeginExchange:sourceIndexPath:toIndexPath:)]) {
+        if (![self.delegate dragCellCollectionViewShouldBeginExchange:self sourceIndexPath:_oldIndexPath toIndexPath:index]) {
+            return;
+        }
+    }
+    _currentIndexPath = index;
+
+    UICollectionViewCell *cell1 = [self cellForItemAtIndexPath:_currentIndexPath];
+
+    NSIndexPath *sourceIndexPath = _oldIndexPath;
+    NSIndexPath *toIndexPath = _currentIndexPath;
+    if (!index1) {
+        self.oldPoint = cell1.center;
+        // 更新数据源
+        [self _updateSourceData];
+        // 移动 cell
+        [self moveItemAtIndexPath:_oldIndexPath toIndexPath:_currentIndexPath];
+        // 设置移动后的起始 indexPath
+        _oldIndexPath = _currentIndexPath;
+        // 为了防止在缓存池取出的 Cell 已隐藏,
+        // 以后可以优化
+        [self reloadItemsAtIndexPaths:@[_oldIndexPath]];
+        
+    } else {
+        // 更新数据源
+        [self _updateSourceData];
+        // 移动 cell
+        [self moveItemAtIndexPath:_oldIndexPath toIndexPath:_currentIndexPath];
+        self.oldPoint = [self cellForItemAtIndexPath:_currentIndexPath].center;
+        // 设置移动后的起始 indexPath
+        _oldIndexPath = _currentIndexPath;
+        [self reloadItemsAtIndexPaths:@[_oldIndexPath]];
+    }
+
+    // 交换结束时
+    if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionViewShouldEndExchange:sourceIndexPath:toIndexPath:)]) {
+        [self.delegate dragCellCollectionViewShouldEndExchange:self sourceIndexPath:sourceIndexPath toIndexPath:toIndexPath];
+    }
+}
+
+#pragma mark - 事件响应
+
+- (void)handlelongGesture:(UILongPressGestureRecognizer *)longGesture {
+    CGPoint point = [longGesture locationInView:self];
+    NSIndexPath *indexPath = [self indexPathForItemAtPoint:point];
+    switch (longGesture.state) {
+        case UIGestureRecognizerStateBegan: {
+            // 手势开始
+            self.userInteractionEnabled = NO;
+            _oldIndexPath = indexPath;
+            // 判断手势落点位置是否在 Cell 上, 没有按在 cell 上就 break
+            if (_oldIndexPath == nil) {
+                self.longGesture.enabled = NO;
+                dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.25 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+                    if (self.canDrag) {
+                        self.longGesture.enabled = YES;
+                    }
+                });
+                break;
+            }
+            
+            // 将要开始拖拽时，询问此位置的Cell是否可以拖拽
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionViewShouldBeginMove:indexPath:)]) {
+                if (![self.delegate dragCellCollectionViewShouldBeginMove:self indexPath:_oldIndexPath]) {
+                    _oldIndexPath = nil;
+                    self.longGesture.enabled = NO;
+                    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.25 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+                        if (self.canDrag) {
+                            self.longGesture.enabled = YES;
+                        }
+                    });
+                    break;
+                }
+            }
+            self.isEndDrag = NO;
+            // 取出正在长按的cell
+            UICollectionViewCell *cell = [self cellForItemAtIndexPath:_oldIndexPath];
+            self.oldPoint = cell.center;
+            // 先置 nil
+            if (_snapedView) {
+                _snapedView = nil;
+            }
+            // 是否外部提供拖拽View
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionView: startDragAtIndexPath:)]) {
+                _snapedView = [self.delegate dragCellCollectionView:self startDragAtIndexPath:indexPath];
+            }
+            if (!_snapedView) {
+                // 使用系统截图功能，得到 cell 的快照 view
+                _snapedView = [cell snapshotViewAfterScreenUpdates:NO];
+            }
+            
+            // 修改颜色
+            if (_dragSnapedViewBackgroundColor) {
+                _snapedView.backgroundColor = _dragSnapedViewBackgroundColor;
+            }
+            
+            // 让外面做一些特殊处理
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionView: dragView:indexPath:)]) {
+                [self.delegate dragCellCollectionView:self dragView:_snapedView indexPath:indexPath];
+            }
+            
+            // 设置frame
+            _snapedView.frame = cell.frame;
+            // 添加到 collectionView 不然无法显示
+            [self addSubview:_snapedView];
+            // 截图后隐藏当前 cell
+            cell.hidden = YES;
+            
+            // 获取当前触摸的中心点
+            CGPoint currentPoint = point;
+            
+            // 动画放大和移动到触摸点下面
+            [UIView animateWithDuration:0.25 animations:^{
+                self.snapedView.transform = CGAffineTransformMakeScale(self.dragZoomScale, self.dragZoomScale);
+                self.snapedView.center = CGPointMake(currentPoint.x, currentPoint.y);
+                self.snapedView.alpha = self.dragCellAlpha;
+            }];
+        }
+            break;
+        case UIGestureRecognizerStateChanged: {
+            // 开启 collectionView 的边缘自动滚动检测
+            // https://github.com/liangdahong/BMLongPressDragCellCollectionView/issues/15
+            if (!_edgeTimer) {
+                [self _setEdgeTimer];
+            }
+
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionView:changedDragAtPoint:)]) {
+                [self.delegate dragCellCollectionView:self changedDragAtPoint:point];
+            }
+            // 当前手指位置
+            _lastPoint = point;
+            // 截图视图位置移动
+            [UIView animateWithDuration:0.1 animations:^{
+                self.snapedView.center = self.lastPoint;
+            }];
+            
+            NSIndexPath *index1 = [self _getChangedNullIndexPath];
+            NSIndexPath *index = nil;
+            
+            if (index1) {
+                index = index1;
+            } else {
+                index = [self _getChangedIndexPath];
+            }
+            
+            // 没有取到 || 距离隐藏的 Cell 最近时就返回
+            if (!index) {
+                break;
+            }
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionViewShouldBeginExchange:sourceIndexPath:toIndexPath:)]) {
+                if (![self.delegate dragCellCollectionViewShouldBeginExchange:self sourceIndexPath:_oldIndexPath toIndexPath:index]) {
+                    break;
+                }
+            }
+            
+            _currentIndexPath = index;
+            UICollectionViewCell *cell1 = [self cellForItemAtIndexPath:_currentIndexPath];
+
+            NSIndexPath *sourceIndexPath = _oldIndexPath;
+            NSIndexPath *toIndexPath = _currentIndexPath;
+            if (!index1) {
+                self.oldPoint = cell1.center;
+                // 更新数据源
+                [self _updateSourceData];
+                // 移动 cell
+                [self moveItemAtIndexPath:_oldIndexPath toIndexPath:_currentIndexPath];
+                // 设置移动后的起始 indexPath
+                _oldIndexPath = _currentIndexPath;
+                [self reloadItemsAtIndexPaths:@[_oldIndexPath]];
+                
+            } else {
+                // 更新数据源
+                [self _updateSourceData];
+                // 移动 cell
+                [self moveItemAtIndexPath:_oldIndexPath toIndexPath:_currentIndexPath];
+                self.oldPoint = [self cellForItemAtIndexPath:_currentIndexPath].center;
+                // 设置移动后的起始 indexPath
+                _oldIndexPath = _currentIndexPath;
+                [self reloadItemsAtIndexPaths:@[_oldIndexPath]];
+            }
+
+            // 交换结束时
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionViewShouldEndExchange:sourceIndexPath:toIndexPath:)]) {
+                [self.delegate dragCellCollectionViewShouldEndExchange:self sourceIndexPath:sourceIndexPath toIndexPath:toIndexPath];
+            }
+
+            break;
+        }
+            break;
+            
+        default: {
+            self.userInteractionEnabled = YES;
+            if (self.delegate && [self.delegate respondsToSelector:@selector(dragCellCollectionView:endedDragAtPoint:)]) {
+                [self.delegate dragCellCollectionView:self endedDragAtPoint:point];
+            }
+
+            if (longGesture.isEnabled) {
+                
+                if (!self.oldIndexPath) {
+                    return;
+                }
+                UICollectionViewCell *cell = [self cellForItemAtIndexPath:_oldIndexPath];
+                // 结束动画过程中停止交互，防止出问题
+                self.userInteractionEnabled = NO;
+                // 结束拖拽了
+                self.isEndDrag = YES;
+                // 给截图视图一个动画移动到隐藏 cell 的新位置
+                [UIView animateWithDuration:0.25 animations:^{
+                    if (!cell) {
+                        self.snapedView.center = self.oldPoint;
+                    } else {
+                        self.snapedView.center = cell.center;
+                    }
+                    self.snapedView.transform = CGAffineTransformMakeScale(1.0f, 1.0f);
+                    self.snapedView.alpha = 1.0;
+                } completion:^(BOOL finished) {
+                    // 移除截图视图、显示隐藏的 cell 并开启交互
+                    [self.snapedView removeFromSuperview];
+                    self.snapedView = nil;
+                    cell.hidden = NO;
+                    self.userInteractionEnabled = YES;
+                }];
+            }
+            // 关闭定时器
+            self.oldIndexPath = nil;
+            [self _stopEdgeTimer];
+        }
+            break;
+    }
+}
+
+- (void)dragMoveItemToIndexPath:(NSIndexPath *)newIndexPath {
+    if (self.isEndDrag) {
+        return;
+    }
+    self.isEndDrag = YES;
+    self.longGesture.enabled = NO;
+    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.25 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+        if (self.canDrag) {
+            self.longGesture.enabled = YES;
+        }
+    });
+    
+    if (_oldIndexPath) {
+        _currentIndexPath = newIndexPath;
+        // 更新数据源
+        [self _updateSourceData];
+        // 移动 cell
+        [self moveItemAtIndexPath:_oldIndexPath toIndexPath:_currentIndexPath];
+        // 设置移动后的起始 indexPath
+        _oldIndexPath = newIndexPath;
+        [self reloadItemsAtIndexPaths:@[newIndexPath]];
+        
+        UICollectionViewCell *cell = [self cellForItemAtIndexPath:_oldIndexPath];
+        cell.hidden = YES;
+        
+        // 结束动画过程中停止交互，防止出问题
+        self.userInteractionEnabled = NO;
+        // 结束拖拽了
+        self.isEndDrag = YES;
+        // 给截图视图一个动画移动到隐藏 cell 的新位置
+        [UIView animateWithDuration:0.25 animations:^{
+            if (!cell) {
+                self.snapedView.center = self.oldPoint;
+            } else {
+                self.snapedView.center = cell.center;
+            }
+            self.snapedView.transform = CGAffineTransformMakeScale(1.0f, 1.0f);
+            self.snapedView.alpha = 1.0;
+        } completion:^(BOOL finished) {
+            // 移除截图视图、显示隐藏的 cell 并开启交互
+            [self.snapedView removeFromSuperview];
+            cell.hidden = NO;
+            self.userInteractionEnabled = YES;
+        }];
+    }
+
+    // 关闭定时器
+    _oldIndexPath = nil;
+    [self _stopEdgeTimer];
+}
+
+@end

keyBoard/Class/Vender/BMLongPressDragCellCollectionView/BMLongPressDragCellCollectionViewDataSource.h

@@ -0,0 +1,47 @@
+//    MIT License
+//
+//    Copyright (c) 2019 https://liangdahong.com
+//
+//    Permission is hereby granted, free of charge, to any person obtaining a copy
+//    of this software and associated documentation files (the "Software"), to deal
+//    in the Software without restriction, including without limitation the rights
+//    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//    copies of the Software, and to permit persons to whom the Software is
+//    furnished to do so, subject to the following conditions:
+//
+//    The above copyright notice and this permission notice shall be included in all
+//    copies or substantial portions of the Software.
+//
+//    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//    SOFTWARE.
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class BMLongPressDragCellCollectionView;
+
+@protocol BMLongPressDragCellCollectionViewDataSource <UICollectionViewDataSource>
+
+@required
+
+/**
+ 获取数据源，内部会在合适的时候获取最新的数据源，必须实现
+ 
+ @param dragCellCollectionView dragCellCollectionView
+ @return 最新的数据源
+
+  - (nullable NSArray *)dataSourceWithDragCellCollectionView:(BMLongPressDragCellCollectionView *)dragCellCollectionView {
+    return self.dataArray;
+ }
+ */
+- (nullable NSArray <NSArray <id> *> *)dataSourceWithDragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView;
+
+@end
+
+NS_ASSUME_NONNULL_END

keyBoard/Class/Vender/BMLongPressDragCellCollectionView/BMLongPressDragCellCollectionViewDelegate.h

@@ -0,0 +1,98 @@
+//    MIT License
+//
+//    Copyright (c) 2019 https://liangdahong.com
+//
+//    Permission is hereby granted, free of charge, to any person obtaining a copy
+//    of this software and associated documentation files (the "Software"), to deal
+//    in the Software without restriction, including without limitation the rights
+//    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//    copies of the Software, and to permit persons to whom the Software is
+//    furnished to do so, subject to the following conditions:
+//
+//    The above copyright notice and this permission notice shall be included in all
+//    copies or substantial portions of the Software.
+//
+//    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//    SOFTWARE.
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class BMLongPressDragCellCollectionView;
+
+@protocol BMLongPressDragCellCollectionViewDelegate <UICollectionViewDelegateFlowLayout>
+
+@required
+
+/**
+ Cell 有交换时调用
+ 
+ @param dragCellCollectionView dragCellCollectionView
+ @param newDataArray 最新的数据源，需要使用者保存，在拖拽的时候 Cell 已经移动，需保存最新的数据源
+
+ - (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView newDataArrayAfterMove:(nullable NSArray <NSArray <id> *> *)newDataArray  {
+    self.dataArray = [newDataArray copy];
+ }
+ */
+- (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView newDataArrayAfterMove:(nullable NSArray <NSArray <id> *> *)newDataArray;
+
+@optional
+
+/**
+ 将要开始拖拽时，询问此位置的 Cell 是否能拖拽
+ 
+ @param dragCellCollectionView dragCellCollectionView
+ @param indexPath indexPath
+ @return YES: 正常拖拽和移动 NO:此 Cell 不可拖拽，如：增加按钮等。
+ */
+- (BOOL)dragCellCollectionViewShouldBeginMove:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView indexPath:(NSIndexPath *)indexPath;
+
+/**
+ 将要开始拖拽时，向外面获取需要拖拽的 View，如果不实现就内部自动处理。
+
+ @param dragCellCollectionView dragCellCollectionView
+ @param indexPath indexPath
+ @return dragView
+ */
+- (UIView *)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView startDragAtIndexPath:(NSIndexPath *)indexPath;
+
+/// 开始拖拽时，让外面的使用者可以对拖拽的 View 做额外操作
+/// @param dragCellCollectionView dragCellCollectionView
+/// @param dragView dragView
+/// @param indexPath indexPath
+- (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView dragView:(UIView *)dragView indexPath:(NSIndexPath *)indexPath;
+
+/// 正在拖拽时
+/// @param dragCellCollectionView dragCellCollectionView
+/// @param point 手指触摸点对于 collectionView 的位置
+/// 可以参考 https://github.com/liangdahong/ToutiaoDemo/blob/master/ToutiaoDemo/Classes/Edit/Controller/BMChannelEditVC.m 的使用
+- (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView changedDragAtPoint:(CGPoint)point;
+
+/// cell 将要交换时，询问是否能交换
+/// @param dragCellCollectionView dragCellCollectionView
+/// @param sourceIndexPath 原来的 IndexPath
+/// @param destinationIndexPath 将要交换的 IndexPath
+/// YES: 正常拖拽和移动 NO:此Cell不可拖拽，如：增加按钮等。
+- (BOOL)dragCellCollectionViewShouldBeginExchange:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView sourceIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath;
+
+/// 结束交换时
+/// @param dragCellCollectionView dragCellCollectionView
+/// @param sourceIndexPath 原来的 IndexPath
+/// @param destinationIndexPath 被交换的 IndexPath
+- (void)dragCellCollectionViewShouldEndExchange:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView sourceIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath;
+
+/// 结束拖拽时
+/// @param dragCellCollectionView dragCellCollectionView
+/// @param point 手指触摸点对于 collectionView 的位置
+/// 可以参考 https://github.com/liangdahong/ToutiaoDemo/blob/master/ToutiaoDemo/Classes/Edit/Controller/BMChannelEditVC.m 的使用
+- (void)dragCellCollectionView:(__kindof BMLongPressDragCellCollectionView *)dragCellCollectionView endedDragAtPoint:(CGPoint)point;
+
+@end
+
+NS_ASSUME_NONNULL_END