initial

Pods/MJRefresh/MJRefresh/Base/MJRefreshAutoFooter.h

@@ -0,0 +1,34 @@
+//
+//  MJRefreshAutoFooter.h
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/4/24.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#if __has_include(<MJRefresh/MJRefreshFooter.h>)
+#import <MJRefresh/MJRefreshFooter.h>
+#else
+#import "MJRefreshFooter.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MJRefreshAutoFooter : MJRefreshFooter
+/** 是否自动刷新(默认为YES) */
+@property (assign, nonatomic, getter=isAutomaticallyRefresh) BOOL automaticallyRefresh;
+
+/** 当底部控件出现多少时就自动刷新(默认为1.0，也就是底部控件完全出现时，才会自动刷新) */
+@property (assign, nonatomic) CGFloat appearencePercentTriggerAutoRefresh MJRefreshDeprecated("请使用triggerAutomaticallyRefreshPercent属性");
+
+/** 当底部控件出现多少时就自动刷新(默认为1.0，也就是底部控件完全出现时，才会自动刷新) */
+@property (assign, nonatomic) CGFloat triggerAutomaticallyRefreshPercent;
+
+/** 自动触发次数, 默认为 1, 仅在拖拽 ScrollView 时才生效,
+ 
+ 如果为 -1, 则为无限触发
+ */
+@property (nonatomic) NSInteger autoTriggerTimes;
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshAutoFooter.m

@@ -0,0 +1,216 @@
+//
+//  MJRefreshAutoFooter.m
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/4/24.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#import "MJRefreshAutoFooter.h"
+#import "NSBundle+MJRefresh.h"
+#import "UIView+MJExtension.h"
+#import "UIScrollView+MJExtension.h"
+#import "UIScrollView+MJRefresh.h"
+
+@interface MJRefreshAutoFooter()
+/** 一个新的拖拽 */
+@property (nonatomic) BOOL triggerByDrag;
+@property (nonatomic) NSInteger leftTriggerTimes;
+@end
+
+@implementation MJRefreshAutoFooter
+
+#pragma mark - 初始化
+- (void)willMoveToSuperview:(UIView *)newSuperview
+{
+    [super willMoveToSuperview:newSuperview];
+    
+    if (newSuperview) { // 新的父控件
+        if (self.hidden == NO) {
+            self.scrollView.mj_insetB += self.mj_h;
+        }
+        
+        // 设置位置
+        self.mj_y = _scrollView.mj_contentH;
+    } else { // 被移除了
+        if (self.hidden == NO) {
+            self.scrollView.mj_insetB -= self.mj_h;
+        }
+    }
+}
+
+#pragma mark - 过期方法
+- (void)setAppearencePercentTriggerAutoRefresh:(CGFloat)appearencePercentTriggerAutoRefresh
+{
+    self.triggerAutomaticallyRefreshPercent = appearencePercentTriggerAutoRefresh;
+}
+
+- (CGFloat)appearencePercentTriggerAutoRefresh
+{
+    return self.triggerAutomaticallyRefreshPercent;
+}
+
+#pragma mark - 实现父类的方法
+- (void)prepare
+{
+    [super prepare];
+    
+    // 默认底部控件100%出现时才会自动刷新
+    self.triggerAutomaticallyRefreshPercent = 1.0;
+    
+    // 设置为默认状态
+    self.automaticallyRefresh = YES;
+    
+    self.autoTriggerTimes = 1;
+}
+
+- (void)scrollViewContentSizeDidChange:(NSDictionary *)change
+{
+    [super scrollViewContentSizeDidChange:change];
+    
+    CGSize size = [change[NSKeyValueChangeNewKey] CGSizeValue];
+    CGFloat contentHeight = size.height == 0 ? self.scrollView.mj_contentH : size.height;
+    // 设置位置
+    CGFloat y = contentHeight + self.ignoredScrollViewContentInsetBottom;
+    if (self.mj_y != y) {
+        self.mj_y = y;
+    }
+}
+
+- (void)scrollViewContentOffsetDidChange:(NSDictionary *)change
+{
+    [super scrollViewContentOffsetDidChange:change];
+    
+    if (self.state != MJRefreshStateIdle || !self.automaticallyRefresh || self.mj_y == 0) return;
+    
+    if (_scrollView.mj_insetT + _scrollView.mj_contentH > _scrollView.mj_h) { // 内容超过一个屏幕
+        // 这里的_scrollView.mj_contentH替换掉self.mj_y更为合理
+        if (_scrollView.mj_offsetY >= _scrollView.mj_contentH - _scrollView.mj_h + self.mj_h * self.triggerAutomaticallyRefreshPercent + _scrollView.mj_insetB - self.mj_h) {
+            // 防止手松开时连续调用
+            CGPoint old = [change[@"old"] CGPointValue];
+            CGPoint new = [change[@"new"] CGPointValue];
+            if (new.y <= old.y) return;
+            
+            if (_scrollView.isDragging) {
+                self.triggerByDrag = YES;
+            }
+            // 当底部刷新控件完全出现时，才刷新
+            [self beginRefreshing];
+        }
+    }
+}
+
+- (void)scrollViewPanStateDidChange:(NSDictionary *)change
+{
+    [super scrollViewPanStateDidChange:change];
+    
+    if (self.state != MJRefreshStateIdle) return;
+    
+    UIGestureRecognizerState panState = _scrollView.panGestureRecognizer.state;
+    
+    switch (panState) {
+        // 手松开
+        case UIGestureRecognizerStateEnded: {
+            if (_scrollView.mj_insetT + _scrollView.mj_contentH <= _scrollView.mj_h) {  // 不够一个屏幕
+                if (_scrollView.mj_offsetY >= - _scrollView.mj_insetT) { // 向上拽
+                    self.triggerByDrag = YES;
+                    [self beginRefreshing];
+                }
+            } else { // 超出一个屏幕
+                if (_scrollView.mj_offsetY >= _scrollView.mj_contentH + _scrollView.mj_insetB - _scrollView.mj_h) {
+                    self.triggerByDrag = YES;
+                    [self beginRefreshing];
+                }
+            }
+        }
+            break;
+            
+        case UIGestureRecognizerStateBegan: {
+            [self resetTriggerTimes];
+        }
+            break;
+            
+        default:
+            break;
+    }
+}
+
+- (BOOL)unlimitedTrigger {
+    return self.leftTriggerTimes == -1;
+}
+
+- (void)beginRefreshing
+{
+    if (self.triggerByDrag && self.leftTriggerTimes <= 0 && !self.unlimitedTrigger) {
+        return;
+    }
+    
+    [super beginRefreshing];
+}
+
+- (void)setState:(MJRefreshState)state
+{
+    MJRefreshCheckState
+    
+    if (state == MJRefreshStateRefreshing) {
+        [self executeRefreshingCallback];
+    } else if (state == MJRefreshStateNoMoreData || state == MJRefreshStateIdle) {
+        if (self.triggerByDrag) {
+            if (!self.unlimitedTrigger) {
+                self.leftTriggerTimes -= 1;
+            }
+            self.triggerByDrag = NO;
+        }
+        
+        if (MJRefreshStateRefreshing == oldState) {
+            if (self.scrollView.pagingEnabled) {
+                CGPoint offset = self.scrollView.contentOffset;
+                offset.y -= self.scrollView.mj_insetB;
+                [UIView animateWithDuration:self.slowAnimationDuration animations:^{
+                    self.scrollView.contentOffset = offset;
+                    
+                    if (self.endRefreshingAnimationBeginAction) {
+                        self.endRefreshingAnimationBeginAction();
+                    }
+                } completion:^(BOOL finished) {
+                    if (self.endRefreshingCompletionBlock) {
+                        self.endRefreshingCompletionBlock();
+                    }
+                }];
+                return;
+            }
+            
+            if (self.endRefreshingCompletionBlock) {
+                self.endRefreshingCompletionBlock();
+            }
+        }
+    }
+}
+
+- (void)resetTriggerTimes {
+    self.leftTriggerTimes = self.autoTriggerTimes;
+}
+
+- (void)setHidden:(BOOL)hidden
+{
+    BOOL lastHidden = self.isHidden;
+    
+    [super setHidden:hidden];
+    
+    if (!lastHidden && hidden) {
+        self.state = MJRefreshStateIdle;
+        
+        self.scrollView.mj_insetB -= self.mj_h;
+    } else if (lastHidden && !hidden) {
+        self.scrollView.mj_insetB += self.mj_h;
+        
+        // 设置位置
+        self.mj_y = _scrollView.mj_contentH;
+    }
+}
+
+- (void)setAutoTriggerTimes:(NSInteger)autoTriggerTimes {
+    _autoTriggerTimes = autoTriggerTimes;
+    self.leftTriggerTimes = autoTriggerTimes;
+}
+@end

Pods/MJRefresh/MJRefresh/Base/MJRefreshBackFooter.h

@@ -0,0 +1,21 @@
+//
+//  MJRefreshBackFooter.h
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/4/24.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#if __has_include(<MJRefresh/MJRefreshFooter.h>)
+#import <MJRefresh/MJRefreshFooter.h>
+#else
+#import "MJRefreshFooter.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MJRefreshBackFooter : MJRefreshFooter
+
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshBackFooter.m

@@ -0,0 +1,158 @@
+//
+//  MJRefreshBackFooter.m
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/4/24.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#import "MJRefreshBackFooter.h"
+#import "NSBundle+MJRefresh.h"
+#import "UIView+MJExtension.h"
+#import "UIScrollView+MJExtension.h"
+#import "UIScrollView+MJRefresh.h"
+
+@interface MJRefreshBackFooter()
+@property (assign, nonatomic) NSInteger lastRefreshCount;
+@property (assign, nonatomic) CGFloat lastBottomDelta;
+@end
+
+@implementation MJRefreshBackFooter
+
+#pragma mark - 初始化
+- (void)willMoveToSuperview:(UIView *)newSuperview
+{
+    [super willMoveToSuperview:newSuperview];
+    
+    [self scrollViewContentSizeDidChange:nil];
+}
+
+#pragma mark - 实现父类的方法
+- (void)scrollViewContentOffsetDidChange:(NSDictionary *)change
+{
+    [super scrollViewContentOffsetDidChange:change];
+    
+    // 如果正在刷新，直接返回
+    if (self.state == MJRefreshStateRefreshing) return;
+    
+    _scrollViewOriginalInset = self.scrollView.mj_inset;
+    
+    // 当前的contentOffset
+    CGFloat currentOffsetY = self.scrollView.mj_offsetY;
+    // 尾部控件刚好出现的offsetY
+    CGFloat happenOffsetY = [self happenOffsetY];
+    // 如果是向下滚动到看不见尾部控件，直接返回
+    if (currentOffsetY <= happenOffsetY) return;
+    
+    CGFloat pullingPercent = (currentOffsetY - happenOffsetY) / self.mj_h;
+    
+    // 如果已全部加载，仅设置pullingPercent，然后返回
+    if (self.state == MJRefreshStateNoMoreData) {
+        self.pullingPercent = pullingPercent;
+        return;
+    }
+    
+    if (self.scrollView.isDragging) {
+        self.pullingPercent = pullingPercent;
+        // 普通 和 即将刷新 的临界点
+        CGFloat normal2pullingOffsetY = happenOffsetY + self.mj_h;
+        
+        if (self.state == MJRefreshStateIdle && currentOffsetY > normal2pullingOffsetY) {
+            // 转为即将刷新状态
+            self.state = MJRefreshStatePulling;
+        } else if (self.state == MJRefreshStatePulling && currentOffsetY <= normal2pullingOffsetY) {
+            // 转为普通状态
+            self.state = MJRefreshStateIdle;
+        }
+    } else if (self.state == MJRefreshStatePulling) {// 即将刷新 && 手松开
+        // 开始刷新
+        [self beginRefreshing];
+    } else if (pullingPercent < 1) {
+        self.pullingPercent = pullingPercent;
+    }
+}
+
+- (void)scrollViewContentSizeDidChange:(NSDictionary *)change
+{
+    [super scrollViewContentSizeDidChange:change];
+    
+    CGSize size = [change[NSKeyValueChangeNewKey] CGSizeValue];
+    CGFloat contentHeight = size.height == 0 ? self.scrollView.mj_contentH : size.height;
+    // 内容的高度
+    contentHeight += self.ignoredScrollViewContentInsetBottom;
+    // 表格的高度
+    CGFloat scrollHeight = self.scrollView.mj_h - self.scrollViewOriginalInset.top - self.scrollViewOriginalInset.bottom + self.ignoredScrollViewContentInsetBottom;
+    // 设置位置
+    CGFloat y = MAX(contentHeight, scrollHeight);
+    if (self.mj_y != y) {
+        self.mj_y = y;
+    }
+}
+
+- (void)setState:(MJRefreshState)state
+{
+    MJRefreshCheckState
+    
+    // 根据状态来设置属性
+    if (state == MJRefreshStateNoMoreData || state == MJRefreshStateIdle) {
+        // 刷新完毕
+        if (MJRefreshStateRefreshing == oldState) {
+            [UIView animateWithDuration:self.slowAnimationDuration animations:^{
+                if (self.endRefreshingAnimationBeginAction) {
+                    self.endRefreshingAnimationBeginAction();
+                }
+                
+                self.scrollView.mj_insetB -= self.lastBottomDelta;
+                // 自动调整透明度
+                if (self.isAutomaticallyChangeAlpha) self.alpha = 0.0;
+            } completion:^(BOOL finished) {
+                self.pullingPercent = 0.0;
+                
+                if (self.endRefreshingCompletionBlock) {
+                    self.endRefreshingCompletionBlock();
+                }
+            }];
+        }
+        
+        CGFloat deltaH = [self heightForContentBreakView];
+        // 刚刷新完毕
+        if (MJRefreshStateRefreshing == oldState && deltaH > 0 && self.scrollView.mj_totalDataCount != self.lastRefreshCount) {
+            self.scrollView.mj_offsetY = self.scrollView.mj_offsetY;
+        }
+    } else if (state == MJRefreshStateRefreshing) {
+        // 记录刷新前的数量
+        self.lastRefreshCount = self.scrollView.mj_totalDataCount;
+        
+        [UIView animateWithDuration:self.fastAnimationDuration animations:^{
+            CGFloat bottom = self.mj_h + self.scrollViewOriginalInset.bottom;
+            CGFloat deltaH = [self heightForContentBreakView];
+            if (deltaH < 0) { // 如果内容高度小于view的高度
+                bottom -= deltaH;
+            }
+            self.lastBottomDelta = bottom - self.scrollView.mj_insetB;
+            self.scrollView.mj_insetB = bottom;
+            self.scrollView.mj_offsetY = [self happenOffsetY] + self.mj_h;
+        } completion:^(BOOL finished) {
+            [self executeRefreshingCallback];
+        }];
+    }
+}
+#pragma mark - 私有方法
+#pragma mark 获得scrollView的内容 超出 view 的高度
+- (CGFloat)heightForContentBreakView
+{
+    CGFloat h = self.scrollView.frame.size.height - self.scrollViewOriginalInset.bottom - self.scrollViewOriginalInset.top;
+    return self.scrollView.contentSize.height - h;
+}
+
+#pragma mark 刚好看到上拉刷新控件时的contentOffset.y
+- (CGFloat)happenOffsetY
+{
+    CGFloat deltaH = [self heightForContentBreakView];
+    if (deltaH > 0) {
+        return deltaH - self.scrollViewOriginalInset.top;
+    } else {
+        return - self.scrollViewOriginalInset.top;
+    }
+}
+@end

Pods/MJRefresh/MJRefresh/Base/MJRefreshComponent.h

@@ -0,0 +1,151 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshComponent.h
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/4.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//  刷新控件的基类
+
+#import <UIKit/UIKit.h>
+#if __has_include(<MJRefresh/MJRefreshConst.h>)
+#import <MJRefresh/MJRefreshConst.h>
+#else
+#import "MJRefreshConst.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** 刷新控件的状态 */
+typedef NS_ENUM(NSInteger, MJRefreshState) {
+    /** 普通闲置状态 */
+    MJRefreshStateIdle = 1,
+    /** 松开就可以进行刷新的状态 */
+    MJRefreshStatePulling,
+    /** 正在刷新中的状态 */
+    MJRefreshStateRefreshing,
+    /** 即将刷新的状态 */
+    MJRefreshStateWillRefresh,
+    /** 所有数据加载完毕，没有更多的数据了 */
+    MJRefreshStateNoMoreData
+};
+
+/** 进入刷新状态的回调 */
+typedef void (^MJRefreshComponentRefreshingBlock)(void) MJRefreshDeprecated("first deprecated in 3.3.0 - Use `MJRefreshComponentAction` instead");
+/** 开始刷新后的回调(进入刷新状态后的回调) */
+typedef void (^MJRefreshComponentBeginRefreshingCompletionBlock)(void) MJRefreshDeprecated("first deprecated in 3.3.0 - Use `MJRefreshComponentAction` instead");
+/** 结束刷新后的回调 */
+typedef void (^MJRefreshComponentEndRefreshingCompletionBlock)(void) MJRefreshDeprecated("first deprecated in 3.3.0 - Use `MJRefreshComponentAction` instead");
+
+/** 刷新用到的回调类型 */
+typedef void (^MJRefreshComponentAction)(void);
+
+/** 刷新控件的基类 */
+@interface MJRefreshComponent : UIView
+{
+    /** 记录scrollView刚开始的inset */
+    UIEdgeInsets _scrollViewOriginalInset;
+    /** 父控件 */
+    __weak UIScrollView *_scrollView;
+}
+
+#pragma mark - 刷新动画时间控制
+/** 快速动画时间(一般用在刷新开始的回弹动画), 默认 0.25 */
+@property (nonatomic) NSTimeInterval fastAnimationDuration;
+/** 慢速动画时间(一般用在刷新结束后的回弹动画), 默认 0.4*/
+@property (nonatomic) NSTimeInterval slowAnimationDuration;
+/** 关闭全部默认动画效果, 可以简单粗暴地解决 CollectionView 的回弹动画 bug */
+- (instancetype)setAnimationDisabled;
+
+#pragma mark - 刷新回调
+/** 正在刷新的回调 */
+@property (copy, nonatomic, nullable) MJRefreshComponentAction refreshingBlock;
+/** 设置回调对象和回调方法 */
+- (void)setRefreshingTarget:(id)target refreshingAction:(SEL)action;
+
+/** 回调对象 */
+@property (weak, nonatomic) id refreshingTarget;
+/** 回调方法 */
+@property (assign, nonatomic) SEL refreshingAction;
+/** 触发回调（交给子类去调用） */
+- (void)executeRefreshingCallback;
+
+#pragma mark - 刷新状态控制
+/** 进入刷新状态 */
+- (void)beginRefreshing;
+- (void)beginRefreshingWithCompletionBlock:(void (^)(void))completionBlock;
+/** 开始刷新后的回调(进入刷新状态后的回调) */
+@property (copy, nonatomic, nullable) MJRefreshComponentAction beginRefreshingCompletionBlock;
+/** 带动画的结束刷新的回调 */
+@property (copy, nonatomic, nullable) MJRefreshComponentAction endRefreshingAnimateCompletionBlock MJRefreshDeprecated("first deprecated in 3.3.0 - Use `endRefreshingAnimationBeginAction` instead");
+@property (copy, nonatomic, nullable) MJRefreshComponentAction endRefreshingAnimationBeginAction;
+/** 结束刷新的回调 */
+@property (copy, nonatomic, nullable) MJRefreshComponentAction endRefreshingCompletionBlock;
+/** 结束刷新状态 */
+- (void)endRefreshing;
+- (void)endRefreshingWithCompletionBlock:(void (^)(void))completionBlock;
+/** 是否正在刷新 */
+@property (assign, nonatomic, readonly, getter=isRefreshing) BOOL refreshing;
+
+/** 刷新状态 一般交给子类内部实现 */
+@property (assign, nonatomic) MJRefreshState state;
+
+#pragma mark - 交给子类去访问
+/** 记录scrollView刚开始的inset */
+@property (assign, nonatomic, readonly) UIEdgeInsets scrollViewOriginalInset;
+/** 父控件 */
+@property (weak, nonatomic, readonly) UIScrollView *scrollView;
+
+#pragma mark - 交给子类们去实现
+/** 初始化 */
+- (void)prepare NS_REQUIRES_SUPER;
+/** 摆放子控件frame */
+- (void)placeSubviews NS_REQUIRES_SUPER;
+/** 当scrollView的contentOffset发生改变的时候调用 */
+- (void)scrollViewContentOffsetDidChange:(nullable NSDictionary *)change NS_REQUIRES_SUPER;
+/** 当scrollView的contentSize发生改变的时候调用 */
+- (void)scrollViewContentSizeDidChange:(nullable NSDictionary *)change NS_REQUIRES_SUPER;
+/** 当scrollView的拖拽状态发生改变的时候调用 */
+- (void)scrollViewPanStateDidChange:(nullable NSDictionary *)change NS_REQUIRES_SUPER;
+
+/** 多语言配置 language 发生变化时调用
+ 
+ `MJRefreshConfig.defaultConfig.language` 发生改变时调用.
+ 
+ ⚠️ 父类会调用 `placeSubviews` 方法, 请勿在 placeSubviews 中调用本方法, 造成死循环. 子类在需要重新布局时, 在配置完修改后, 最后再调用 super 方法, 否则可能导致配置修改后, 定位先于修改执行.
+ */
+- (void)i18nDidChange NS_REQUIRES_SUPER;
+
+#pragma mark - 其他
+/** 拉拽的百分比(交给子类重写) */
+@property (assign, nonatomic) CGFloat pullingPercent;
+/** 根据拖拽比例自动切换透明度 */
+@property (assign, nonatomic, getter=isAutoChangeAlpha) BOOL autoChangeAlpha MJRefreshDeprecated("请使用automaticallyChangeAlpha属性");
+/** 根据拖拽比例自动切换透明度 */
+@property (assign, nonatomic, getter=isAutomaticallyChangeAlpha) BOOL automaticallyChangeAlpha;
+@end
+
+@interface UILabel(MJRefresh)
++ (instancetype)mj_label;
+- (CGFloat)mj_textWidth;
+@end
+
+@interface MJRefreshComponent (ChainingGrammar)
+
+#pragma mark - <<< 为 Swift 扩展链式语法 >>> -
+/// 自动变化透明度
+- (instancetype)autoChangeTransparency:(BOOL)isAutoChange;
+/// 刷新开始后立即调用的回调
+- (instancetype)afterBeginningAction:(MJRefreshComponentAction)action;
+/// 刷新动画开始后立即调用的回调
+- (instancetype)endingAnimationBeginningAction:(MJRefreshComponentAction)action;
+/// 刷新结束后立即调用的回调
+- (instancetype)afterEndingAction:(MJRefreshComponentAction)action;
+
+
+/// 需要子类必须实现
+/// @param scrollView 赋值给的 ScrollView 的 Header/Footer/Trailer
+- (instancetype)linkTo:(UIScrollView *)scrollView;
+
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshComponent.m

@@ -0,0 +1,323 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshComponent.m
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/4.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#import "MJRefreshComponent.h"
+#import "MJRefreshConst.h"
+#import "MJRefreshConfig.h"
+#import "UIView+MJExtension.h"
+#import "UIScrollView+MJExtension.h"
+#import "UIScrollView+MJRefresh.h"
+#import "NSBundle+MJRefresh.h"
+
+@interface MJRefreshComponent()
+@property (strong, nonatomic) UIPanGestureRecognizer *pan;
+@end
+
+@implementation MJRefreshComponent
+#pragma mark - 初始化
+- (instancetype)initWithFrame:(CGRect)frame
+{
+    if (self = [super initWithFrame:frame]) {
+        // 准备工作
+        [self prepare];
+        
+        // 默认是普通状态
+        self.state = MJRefreshStateIdle;
+        self.fastAnimationDuration = 0.25;
+        self.slowAnimationDuration = 0.4;
+    }
+    return self;
+}
+
+- (void)prepare
+{
+    // 基本属性
+    self.autoresizingMask = UIViewAutoresizingFlexibleWidth;
+    self.backgroundColor = [UIColor clearColor];
+}
+
+- (void)layoutSubviews
+{
+    [self placeSubviews];
+    
+    [super layoutSubviews];
+}
+
+- (void)placeSubviews{}
+
+- (void)willMoveToSuperview:(UIView *)newSuperview
+{
+    [super willMoveToSuperview:newSuperview];
+    
+    // 如果不是UIScrollView，不做任何事情
+    if (newSuperview && ![newSuperview isKindOfClass:[UIScrollView class]]) return;
+    
+    // 旧的父控件移除监听
+    [self removeObservers];
+    
+    if (newSuperview) { // 新的父控件
+        // 记录UIScrollView
+        _scrollView = (UIScrollView *)newSuperview;
+        
+        // 设置宽度
+        self.mj_w = _scrollView.mj_w;
+        // 设置位置
+        self.mj_x = -_scrollView.mj_insetL;
+    
+        // 设置永远支持垂直弹簧效果
+        _scrollView.alwaysBounceVertical = YES;
+        // 记录UIScrollView最开始的contentInset
+        _scrollViewOriginalInset = _scrollView.mj_inset;
+        
+        // 添加监听
+        [self addObservers];
+    }
+}
+
+- (void)drawRect:(CGRect)rect
+{
+    [super drawRect:rect];
+    
+    if (self.state == MJRefreshStateWillRefresh) {
+        // 预防view还没显示出来就调用了beginRefreshing
+        self.state = MJRefreshStateRefreshing;
+    }
+}
+
+#pragma mark - KVO监听
+- (void)addObservers
+{
+    NSKeyValueObservingOptions options = NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld;
+    [self.scrollView addObserver:self forKeyPath:MJRefreshKeyPathContentOffset options:options context:nil];
+    [self.scrollView addObserver:self forKeyPath:MJRefreshKeyPathContentSize options:options context:nil];
+    self.pan = self.scrollView.panGestureRecognizer;
+    [self.pan addObserver:self forKeyPath:MJRefreshKeyPathPanState options:options context:nil];
+    
+    [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(i18nDidChange) name:MJRefreshDidChangeLanguageNotification object:MJRefreshConfig.defaultConfig];
+}
+
+- (void)removeObservers
+{
+    [self.superview removeObserver:self forKeyPath:MJRefreshKeyPathContentOffset];
+    [self.superview removeObserver:self forKeyPath:MJRefreshKeyPathContentSize];
+    [self.pan removeObserver:self forKeyPath:MJRefreshKeyPathPanState];
+    self.pan = nil;
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
+{
+    // 遇到这些情况就直接返回
+    if (!self.userInteractionEnabled) return;
+    
+    // 这个就算看不见也需要处理
+    if ([keyPath isEqualToString:MJRefreshKeyPathContentSize]) {
+        [self scrollViewContentSizeDidChange:change];
+    }
+    
+    // 看不见
+    if (self.hidden) return;
+    if ([keyPath isEqualToString:MJRefreshKeyPathContentOffset]) {
+        [self scrollViewContentOffsetDidChange:change];
+    } else if ([keyPath isEqualToString:MJRefreshKeyPathPanState]) {
+        [self scrollViewPanStateDidChange:change];
+    }
+}
+
+- (void)scrollViewContentOffsetDidChange:(NSDictionary *)change{}
+- (void)scrollViewContentSizeDidChange:(NSDictionary *)change{}
+- (void)scrollViewPanStateDidChange:(NSDictionary *)change{}
+
+- (void)i18nDidChange {
+    [self placeSubviews];
+}
+
+#pragma mark - 公共方法
+#pragma mark 设置回调对象和回调方法
+- (void)setRefreshingTarget:(id)target refreshingAction:(SEL)action
+{
+    self.refreshingTarget = target;
+    self.refreshingAction = action;
+}
+
+- (void)setState:(MJRefreshState)state
+{
+    _state = state;
+    
+    // 加入主队列的目的是等setState:方法调用完毕、设置完文字后再去布局子控件
+    MJRefreshDispatchAsyncOnMainQueue([self setNeedsLayout];)
+}
+
+#pragma mark 进入刷新状态
+- (void)beginRefreshing
+{
+    [UIView animateWithDuration:self.fastAnimationDuration animations:^{
+        self.alpha = 1.0;
+    }];
+    self.pullingPercent = 1.0;
+    // 只要正在刷新，就完全显示
+    if (self.window) {
+        self.state = MJRefreshStateRefreshing;
+    } else {
+        // 预防正在刷新中时，调用本方法使得header inset回置失败
+        if (self.state != MJRefreshStateRefreshing) {
+            self.state = MJRefreshStateWillRefresh;
+            // 刷新(预防从另一个控制器回到这个控制器的情况，回来要重新刷新一下)
+            [self setNeedsDisplay];
+        }
+    }
+}
+
+- (void)beginRefreshingWithCompletionBlock:(void (^)(void))completionBlock
+{
+    self.beginRefreshingCompletionBlock = completionBlock;
+    
+    [self beginRefreshing];
+}
+
+#pragma mark 结束刷新状态
+- (void)endRefreshing
+{
+    MJRefreshDispatchAsyncOnMainQueue(self.state = MJRefreshStateIdle;)
+}
+
+- (void)endRefreshingWithCompletionBlock:(void (^)(void))completionBlock
+{
+    self.endRefreshingCompletionBlock = completionBlock;
+    
+    [self endRefreshing];
+}
+
+#pragma mark 是否正在刷新
+- (BOOL)isRefreshing
+{
+    return self.state == MJRefreshStateRefreshing || self.state == MJRefreshStateWillRefresh;
+}
+
+#pragma mark 自动切换透明度
+- (void)setAutoChangeAlpha:(BOOL)autoChangeAlpha
+{
+    self.automaticallyChangeAlpha = autoChangeAlpha;
+}
+
+- (BOOL)isAutoChangeAlpha
+{
+    return self.isAutomaticallyChangeAlpha;
+}
+
+- (void)setAutomaticallyChangeAlpha:(BOOL)automaticallyChangeAlpha
+{
+    _automaticallyChangeAlpha = automaticallyChangeAlpha;
+    
+    if (self.isRefreshing) return;
+    
+    if (automaticallyChangeAlpha) {
+        self.alpha = self.pullingPercent;
+    } else {
+        self.alpha = 1.0;
+    }
+}
+
+#pragma mark 根据拖拽进度设置透明度
+- (void)setPullingPercent:(CGFloat)pullingPercent
+{
+    _pullingPercent = pullingPercent;
+    
+    if (self.isRefreshing) return;
+    
+    if (self.isAutomaticallyChangeAlpha) {
+        self.alpha = pullingPercent;
+    }
+}
+
+#pragma mark - 内部方法
+- (void)executeRefreshingCallback
+{
+    if (self.refreshingBlock) {
+        self.refreshingBlock();
+    }
+    if ([self.refreshingTarget respondsToSelector:self.refreshingAction]) {
+        MJRefreshMsgSend(MJRefreshMsgTarget(self.refreshingTarget), self.refreshingAction, self);
+    }
+    if (self.beginRefreshingCompletionBlock) {
+        self.beginRefreshingCompletionBlock();
+    }
+}
+
+#pragma mark - 刷新动画时间控制
+- (instancetype)setAnimationDisabled {
+    self.fastAnimationDuration = 0;
+    self.slowAnimationDuration = 0;
+    
+    return self;
+}
+
+#pragma mark - <<< Deprecation compatible function >>> -
+- (void)setEndRefreshingAnimateCompletionBlock:(MJRefreshComponentEndRefreshingCompletionBlock)endRefreshingAnimateCompletionBlock {
+    _endRefreshingAnimationBeginAction = endRefreshingAnimateCompletionBlock;
+}
+@end
+
+@implementation UILabel(MJRefresh)
++ (instancetype)mj_label
+{
+    UILabel *label = [[self alloc] init];
+    label.font = MJRefreshLabelFont;
+    label.textColor = MJRefreshLabelTextColor;
+    label.autoresizingMask = UIViewAutoresizingFlexibleWidth;
+    label.textAlignment = NSTextAlignmentCenter;
+    label.backgroundColor = [UIColor clearColor];
+    return label;
+}
+
+- (CGFloat)mj_textWidth {
+    CGFloat stringWidth = 0;
+    CGSize size = CGSizeMake(MAXFLOAT, MAXFLOAT);
+    
+    if (self.attributedText) {
+        if (self.attributedText.length == 0) { return 0; }
+        stringWidth = [self.attributedText boundingRectWithSize:size
+                                                        options:NSStringDrawingUsesLineFragmentOrigin
+                                                        context:nil].size.width;
+    } else {
+        if (self.text.length == 0) { return 0; }
+        NSAssert(self.font != nil, @"请检查 mj_label's `font` 是否设置正确");
+        stringWidth = [self.text boundingRectWithSize:size
+                                              options:NSStringDrawingUsesLineFragmentOrigin
+                                           attributes:@{NSFontAttributeName:self.font}
+                                              context:nil].size.width;
+    }
+    return stringWidth;
+}
+@end
+
+
+#pragma mark - <<< 为 Swift 扩展链式语法 >>> -
+@implementation MJRefreshComponent (ChainingGrammar)
+
+- (instancetype)autoChangeTransparency:(BOOL)isAutoChange {
+    self.automaticallyChangeAlpha = isAutoChange;
+    return self;
+}
+- (instancetype)afterBeginningAction:(MJRefreshComponentAction)action {
+    self.beginRefreshingCompletionBlock = action;
+    return self;
+}
+- (instancetype)endingAnimationBeginningAction:(MJRefreshComponentAction)action {
+    self.endRefreshingAnimationBeginAction = action;
+    return self;
+}
+- (instancetype)afterEndingAction:(MJRefreshComponentAction)action {
+    self.endRefreshingCompletionBlock = action;
+    return self;
+}
+
+- (instancetype)linkTo:(UIScrollView *)scrollView {
+    return self;
+}
+
+@end

Pods/MJRefresh/MJRefresh/Base/MJRefreshFooter.h

@@ -0,0 +1,37 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshFooter.h
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/5.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//  上拉刷新控件
+
+#if __has_include(<MJRefresh/MJRefreshComponent.h>)
+#import <MJRefresh/MJRefreshComponent.h>
+#else
+#import "MJRefreshComponent.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MJRefreshFooter : MJRefreshComponent
+/** 创建footer */
++ (instancetype)footerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock;
+/** 创建footer */
++ (instancetype)footerWithRefreshingTarget:(id)target refreshingAction:(SEL)action;
+
+/** 提示没有更多的数据 */
+- (void)endRefreshingWithNoMoreData;
+- (void)noticeNoMoreData MJRefreshDeprecated("使用endRefreshingWithNoMoreData");
+
+/** 重置没有更多的数据（消除没有更多数据的状态） */
+- (void)resetNoMoreData;
+
+/** 忽略多少scrollView的contentInset的bottom */
+@property (assign, nonatomic) CGFloat ignoredScrollViewContentInsetBottom;
+
+/** 自动根据有无数据来显示和隐藏（有数据就显示，没有数据隐藏。默认是NO） */
+@property (assign, nonatomic, getter=isAutomaticallyHidden) BOOL automaticallyHidden MJRefreshDeprecated("已废弃此属性，开发者请自行控制footer的显示和隐藏");
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshFooter.m

@@ -0,0 +1,71 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshFooter.m
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/5.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#import "MJRefreshFooter.h"
+#import "UIScrollView+MJRefresh.h"
+#import "UIView+MJExtension.h"
+
+@interface MJRefreshFooter()
+
+@end
+
+@implementation MJRefreshFooter
+#pragma mark - 构造方法
++ (instancetype)footerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock
+{
+    MJRefreshFooter *cmp = [[self alloc] init];
+    cmp.refreshingBlock = refreshingBlock;
+    return cmp;
+}
++ (instancetype)footerWithRefreshingTarget:(id)target refreshingAction:(SEL)action
+{
+    MJRefreshFooter *cmp = [[self alloc] init];
+    [cmp setRefreshingTarget:target refreshingAction:action];
+    return cmp;
+}
+
+#pragma mark - 重写父类的方法
+- (void)prepare
+{
+    [super prepare];
+    
+    // 设置自己的高度
+    self.mj_h = MJRefreshFooterHeight;
+    
+    // 默认不会自动隐藏
+//    self.automaticallyHidden = NO;
+}
+
+#pragma mark . 链式语法部分 .
+
+- (instancetype)linkTo:(UIScrollView *)scrollView {
+    scrollView.mj_footer = self;
+    return self;
+}
+
+#pragma mark - 公共方法
+- (void)endRefreshingWithNoMoreData
+{
+    MJRefreshDispatchAsyncOnMainQueue(self.state = MJRefreshStateNoMoreData;)
+}
+
+- (void)noticeNoMoreData
+{
+    [self endRefreshingWithNoMoreData];
+}
+
+- (void)resetNoMoreData
+{
+    MJRefreshDispatchAsyncOnMainQueue(self.state = MJRefreshStateIdle;)
+}
+
+- (void)setAutomaticallyHidden:(BOOL)automaticallyHidden
+{
+    _automaticallyHidden = automaticallyHidden;
+}
+@end

Pods/MJRefresh/MJRefresh/Base/MJRefreshHeader.h

@@ -0,0 +1,35 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshHeader.h
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/4.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//  下拉刷新控件:负责监控用户下拉的状态
+
+#if __has_include(<MJRefresh/MJRefreshComponent.h>)
+#import <MJRefresh/MJRefreshComponent.h>
+#else
+#import "MJRefreshComponent.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MJRefreshHeader : MJRefreshComponent
+/** 创建header */
++ (instancetype)headerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock;
+/** 创建header */
++ (instancetype)headerWithRefreshingTarget:(id)target refreshingAction:(SEL)action;
+
+/** 这个key用来存储上一次下拉刷新成功的时间 */
+@property (copy, nonatomic) NSString *lastUpdatedTimeKey;
+/** 上一次下拉刷新成功的时间 */
+@property (strong, nonatomic, readonly, nullable) NSDate *lastUpdatedTime;
+
+/** 忽略多少scrollView的contentInset的top */
+@property (assign, nonatomic) CGFloat ignoredScrollViewContentInsetTop;
+
+/** 默认是关闭状态, 如果遇到 CollectionView 的动画异常问题可以尝试打开 */
+@property (nonatomic) BOOL isCollectionViewAnimationBug;
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshHeader.m

@@ -0,0 +1,297 @@
+//  代码地址: https://github.com/CoderMJLee/MJRefresh
+//  MJRefreshHeader.m
+//  MJRefresh
+//
+//  Created by MJ Lee on 15/3/4.
+//  Copyright (c) 2015年 小码哥. All rights reserved.
+//
+
+#import "MJRefreshHeader.h"
+#import "UIView+MJExtension.h"
+#import "UIScrollView+MJExtension.h"
+#import "UIScrollView+MJRefresh.h"
+
+NSString * const MJRefreshHeaderRefreshing2IdleBoundsKey = @"MJRefreshHeaderRefreshing2IdleBounds";
+NSString * const MJRefreshHeaderRefreshingBoundsKey = @"MJRefreshHeaderRefreshingBounds";
+
+@interface MJRefreshHeader() <CAAnimationDelegate>
+@property (assign, nonatomic) CGFloat insetTDelta;
+@end
+
+@implementation MJRefreshHeader
+#pragma mark - 构造方法
++ (instancetype)headerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock
+{
+    MJRefreshHeader *cmp = [[self alloc] init];
+    cmp.refreshingBlock = refreshingBlock;
+    return cmp;
+}
++ (instancetype)headerWithRefreshingTarget:(id)target refreshingAction:(SEL)action
+{
+    MJRefreshHeader *cmp = [[self alloc] init];
+    [cmp setRefreshingTarget:target refreshingAction:action];
+    return cmp;
+}
+
+#pragma mark - 覆盖父类的方法
+- (void)prepare
+{
+    [super prepare];
+    
+    // 设置key
+    self.lastUpdatedTimeKey = MJRefreshHeaderLastUpdatedTimeKey;
+    
+    // 设置高度
+    self.mj_h = MJRefreshHeaderHeight;
+}
+
+- (void)placeSubviews
+{
+    [super placeSubviews];
+    
+    // 设置y值(当自己的高度发生改变了，肯定要重新调整Y值，所以放到placeSubviews方法中设置y值)
+    self.mj_y = - self.mj_h - self.ignoredScrollViewContentInsetTop;
+}
+
+- (void)resetInset {
+    if (@available(iOS 11.0, *)) {
+    } else {
+        // 如果 iOS 10 及以下系统在刷新时, push 新的 VC, 等待刷新完成后回来, 会导致顶部 Insets.top 异常, 不能 resetInset, 检查一下这种特殊情况
+        if (!self.window) { return; }
+    }
+    
+    // sectionheader停留解决
+    CGFloat insetT = - self.scrollView.mj_offsetY > _scrollViewOriginalInset.top ? - self.scrollView.mj_offsetY : _scrollViewOriginalInset.top;
+    insetT = insetT > self.mj_h + _scrollViewOriginalInset.top ? self.mj_h + _scrollViewOriginalInset.top : insetT;
+    self.insetTDelta = _scrollViewOriginalInset.top - insetT;
+    // 避免 CollectionView 在使用根据 Autolayout 和 内容自动伸缩 Cell, 刷新时导致的 Layout 异常渲染问题
+    if (self.scrollView.mj_insetT != insetT) {
+        self.scrollView.mj_insetT = insetT;
+    }
+}
+
+- (void)scrollViewContentOffsetDidChange:(NSDictionary *)change
+{
+    [super scrollViewContentOffsetDidChange:change];
+    
+    // 在刷新的refreshing状态
+    if (self.state == MJRefreshStateRefreshing) {
+        [self resetInset];
+        return;
+    }
+    
+    // 跳转到下一个控制器时，contentInset可能会变
+    _scrollViewOriginalInset = self.scrollView.mj_inset;
+    
+    // 当前的contentOffset
+    CGFloat offsetY = self.scrollView.mj_offsetY;
+    // 头部控件刚好出现的offsetY
+    CGFloat happenOffsetY = - self.scrollViewOriginalInset.top;
+    
+    // 如果是向上滚动到看不见头部控件，直接返回
+    // >= -> >
+    if (offsetY > happenOffsetY) return;
+    
+    // 普通 和 即将刷新 的临界点
+    CGFloat normal2pullingOffsetY = happenOffsetY - self.mj_h;
+    CGFloat pullingPercent = (happenOffsetY - offsetY) / self.mj_h;
+    
+    if (self.scrollView.isDragging) { // 如果正在拖拽
+        self.pullingPercent = pullingPercent;
+        if (self.state == MJRefreshStateIdle && offsetY < normal2pullingOffsetY) {
+            // 转为即将刷新状态
+            self.state = MJRefreshStatePulling;
+        } else if (self.state == MJRefreshStatePulling && offsetY >= normal2pullingOffsetY) {
+            // 转为普通状态
+            self.state = MJRefreshStateIdle;
+        }
+    } else if (self.state == MJRefreshStatePulling) {// 即将刷新 && 手松开
+        // 开始刷新
+        [self beginRefreshing];
+    } else if (pullingPercent < 1) {
+        self.pullingPercent = pullingPercent;
+    }
+}
+
+- (void)setState:(MJRefreshState)state
+{
+    MJRefreshCheckState
+    
+    // 根据状态做事情
+    if (state == MJRefreshStateIdle) {
+        if (oldState != MJRefreshStateRefreshing) return;
+        
+        [self headerEndingAction];
+    } else if (state == MJRefreshStateRefreshing) {
+        [self headerRefreshingAction];
+    }
+}
+
+- (void)headerEndingAction {
+    // 保存刷新时间
+    [[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:self.lastUpdatedTimeKey];
+    [[NSUserDefaults standardUserDefaults] synchronize];
+    
+    // 默认使用 UIViewAnimation 动画
+    if (!self.isCollectionViewAnimationBug) {
+        // 恢复inset和offset
+        [UIView animateWithDuration:self.slowAnimationDuration animations:^{
+            self.scrollView.mj_insetT += self.insetTDelta;
+            
+            if (self.endRefreshingAnimationBeginAction) {
+                self.endRefreshingAnimationBeginAction();
+            }
+            // 自动调整透明度
+            if (self.isAutomaticallyChangeAlpha) self.alpha = 0.0;
+        } completion:^(BOOL finished) {
+            self.pullingPercent = 0.0;
+            
+            if (self.endRefreshingCompletionBlock) {
+                self.endRefreshingCompletionBlock();
+            }
+        }];
+        
+        return;
+    }
+    
+    /**
+     这个解决方法的思路出自 https://github.com/CoderMJLee/MJRefresh/pull/844
+     修改了用+ [UIView animateWithDuration: animations:]实现的修改contentInset的动画
+     fix issue#225 https://github.com/CoderMJLee/MJRefresh/issues/225
+     另一种解法 pull#737 https://github.com/CoderMJLee/MJRefresh/pull/737
+     
+     同时, 处理了 Refreshing 中的动画替换.
+    */
+    
+    // 由于修改 Inset 会导致 self.pullingPercent 联动设置 self.alpha, 故提前获取 alpha 值, 后续用于还原 alpha 动画
+    CGFloat viewAlpha = self.alpha;
+    
+    self.scrollView.mj_insetT += self.insetTDelta;
+    // 禁用交互, 如果不禁用可能会引起渲染问题.
+    self.scrollView.userInteractionEnabled = NO;
+
+    //CAAnimation keyPath 不支持 contentInset 用Bounds的动画代替
+    CABasicAnimation *boundsAnimation = [CABasicAnimation animationWithKeyPath:@"bounds"];
+    boundsAnimation.fromValue = [NSValue valueWithCGRect:CGRectOffset(self.scrollView.bounds, 0, self.insetTDelta)];
+    boundsAnimation.duration = self.slowAnimationDuration;
+    //在delegate里移除
+    boundsAnimation.removedOnCompletion = NO;
+    boundsAnimation.fillMode = kCAFillModeBoth;
+    boundsAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
+    boundsAnimation.delegate = self;
+    [boundsAnimation setValue:MJRefreshHeaderRefreshing2IdleBoundsKey forKey:@"identity"];
+
+    [self.scrollView.layer addAnimation:boundsAnimation forKey:MJRefreshHeaderRefreshing2IdleBoundsKey];
+    
+    if (self.endRefreshingAnimationBeginAction) {
+        self.endRefreshingAnimationBeginAction();
+    }
+    // 自动调整透明度的动画
+    if (self.isAutomaticallyChangeAlpha) {
+        CABasicAnimation *opacityAnimation = [CABasicAnimation animationWithKeyPath:@"opacity"];
+        opacityAnimation.fromValue = @(viewAlpha);
+        opacityAnimation.toValue = @(0.0);
+        opacityAnimation.duration = self.slowAnimationDuration;
+        opacityAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
+        [self.layer addAnimation:opacityAnimation forKey:@"MJRefreshHeaderRefreshing2IdleOpacity"];
+
+        // 由于修改了 inset 导致, pullingPercent 被设置值, alpha 已经被提前修改为 0 了. 所以这里不用置 0, 但为了代码的严谨性, 不依赖其他的特殊实现方式, 这里还是置 0.
+        self.alpha = 0;
+    }
+}
+
+- (void)headerRefreshingAction {
+    // 默认使用 UIViewAnimation 动画
+    if (!self.isCollectionViewAnimationBug) {
+        [UIView animateWithDuration:self.fastAnimationDuration animations:^{
+            if (self.scrollView.panGestureRecognizer.state != UIGestureRecognizerStateCancelled) {
+                CGFloat top = self.scrollViewOriginalInset.top + self.mj_h;
+                // 增加滚动区域top
+                self.scrollView.mj_insetT = top;
+                // 设置滚动位置
+                CGPoint offset = self.scrollView.contentOffset;
+                offset.y = -top;
+                [self.scrollView setContentOffset:offset animated:NO];
+            }
+        } completion:^(BOOL finished) {
+            [self executeRefreshingCallback];
+        }];
+        return;
+    }
+    
+    if (self.scrollView.panGestureRecognizer.state != UIGestureRecognizerStateCancelled) {
+        CGFloat top = self.scrollViewOriginalInset.top + self.mj_h;
+        // 禁用交互, 如果不禁用可能会引起渲染问题.
+        self.scrollView.userInteractionEnabled = NO;
+
+        // CAAnimation keyPath不支持 contentOffset 用Bounds的动画代替
+        CABasicAnimation *boundsAnimation = [CABasicAnimation animationWithKeyPath:@"bounds"];
+        CGRect bounds = self.scrollView.bounds;
+        bounds.origin.y = -top;
+        boundsAnimation.fromValue = [NSValue valueWithCGRect:self.scrollView.bounds];
+        boundsAnimation.toValue = [NSValue valueWithCGRect:bounds];
+        boundsAnimation.duration = self.fastAnimationDuration;
+        //在delegate里移除
+        boundsAnimation.removedOnCompletion = NO;
+        boundsAnimation.fillMode = kCAFillModeBoth;
+        boundsAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
+        boundsAnimation.delegate = self;
+        [boundsAnimation setValue:MJRefreshHeaderRefreshingBoundsKey forKey:@"identity"];
+        [self.scrollView.layer addAnimation:boundsAnimation forKey:MJRefreshHeaderRefreshingBoundsKey];
+    } else {
+        [self executeRefreshingCallback];
+    }
+}
+
+#pragma mark . 链式语法部分 .
+
+- (instancetype)linkTo:(UIScrollView *)scrollView {
+    scrollView.mj_header = self;
+    return self;
+}
+
+#pragma mark - CAAnimationDelegate
+- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
+    NSString *identity = [anim valueForKey:@"identity"];
+    if ([identity isEqualToString:MJRefreshHeaderRefreshing2IdleBoundsKey]) {
+        self.pullingPercent = 0.0;
+        self.scrollView.userInteractionEnabled = YES;
+        if (self.endRefreshingCompletionBlock) {
+            self.endRefreshingCompletionBlock();
+        }
+    } else if ([identity isEqualToString:MJRefreshHeaderRefreshingBoundsKey]) {
+        // 避免出现 end 先于 Refreshing 状态
+        if (self.state != MJRefreshStateIdle) {
+            CGFloat top = self.scrollViewOriginalInset.top + self.mj_h;
+            self.scrollView.mj_insetT = top;
+            // 设置最终滚动位置
+            CGPoint offset = self.scrollView.contentOffset;
+            offset.y = -top;
+            [self.scrollView setContentOffset:offset animated:NO];
+         }
+        self.scrollView.userInteractionEnabled = YES;
+        [self executeRefreshingCallback];
+    }
+    
+    if ([self.scrollView.layer animationForKey:MJRefreshHeaderRefreshing2IdleBoundsKey]) {
+        [self.scrollView.layer removeAnimationForKey:MJRefreshHeaderRefreshing2IdleBoundsKey];
+    }
+    
+    if ([self.scrollView.layer animationForKey:MJRefreshHeaderRefreshingBoundsKey]) {
+        [self.scrollView.layer removeAnimationForKey:MJRefreshHeaderRefreshingBoundsKey];
+    }
+}
+
+#pragma mark - 公共方法
+- (NSDate *)lastUpdatedTime
+{
+    return [[NSUserDefaults standardUserDefaults] objectForKey:self.lastUpdatedTimeKey];
+}
+
+- (void)setIgnoredScrollViewContentInsetTop:(CGFloat)ignoredScrollViewContentInsetTop {
+    _ignoredScrollViewContentInsetTop = ignoredScrollViewContentInsetTop;
+    
+    self.mj_y = - self.mj_h - _ignoredScrollViewContentInsetTop;
+}
+
+@end

Pods/MJRefresh/MJRefresh/Base/MJRefreshTrailer.h

@@ -0,0 +1,30 @@
+//
+//  MJRefreshTrailer.h
+//  MJRefresh
+//
+//  Created by kinarobin on 2020/5/3.
+//  Copyright © 2020 小码哥. All rights reserved.
+//
+
+#if __has_include(<MJRefresh/MJRefreshComponent.h>)
+#import <MJRefresh/MJRefreshComponent.h>
+#else
+#import "MJRefreshComponent.h"
+#endif
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MJRefreshTrailer : MJRefreshComponent
+
+/** 创建trailer*/
++ (instancetype)trailerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock;
+/** 创建trailer */
++ (instancetype)trailerWithRefreshingTarget:(id)target refreshingAction:(SEL)action;
+
+/** 忽略多少scrollView的contentInset的right */
+@property (assign, nonatomic) CGFloat ignoredScrollViewContentInsetRight;
+
+
+@end
+
+NS_ASSUME_NONNULL_END

Pods/MJRefresh/MJRefresh/Base/MJRefreshTrailer.m

@@ -0,0 +1,179 @@
+//
+//  MJRefreshTrailer.m
+//  MJRefresh
+//
+//  Created by kinarobin on 2020/5/3.
+//  Copyright © 2020 小码哥. All rights reserved.
+//
+
+#import "MJRefreshTrailer.h"
+#import "UIView+MJExtension.h"
+#import "UIScrollView+MJRefresh.h"
+#import "UIScrollView+MJExtension.h"
+
+@interface MJRefreshTrailer()
+@property (assign, nonatomic) NSInteger lastRefreshCount;
+@property (assign, nonatomic) CGFloat lastRightDelta;
+@end
+
+@implementation MJRefreshTrailer
+
+#pragma mark - 构造方法
++ (instancetype)trailerWithRefreshingBlock:(MJRefreshComponentAction)refreshingBlock {
+    MJRefreshTrailer *cmp = [[self alloc] init];
+    cmp.refreshingBlock = refreshingBlock;
+    return cmp;
+}
+
++ (instancetype)trailerWithRefreshingTarget:(id)target refreshingAction:(SEL)action {
+    MJRefreshTrailer *cmp = [[self alloc] init];
+    [cmp setRefreshingTarget:target refreshingAction:action];
+    return cmp;
+}
+
+- (void)scrollViewContentOffsetDidChange:(NSDictionary *)change {
+    [super scrollViewContentOffsetDidChange:change];
+    
+    // 如果正在刷新，直接返回
+    if (self.state == MJRefreshStateRefreshing) return;
+    
+    _scrollViewOriginalInset = self.scrollView.mj_inset;
+    
+    // 当前的contentOffset
+    CGFloat currentOffsetX = self.scrollView.mj_offsetX;
+    // 尾部控件刚好出现的offsetX
+    CGFloat happenOffsetX = [self happenOffsetX];
+    // 如果是向右滚动到看不见右边控件，直接返回
+    if (currentOffsetX <= happenOffsetX) return;
+    
+    CGFloat pullingPercent = (currentOffsetX - happenOffsetX) / self.mj_w;
+    
+    // 如果已全部加载，仅设置pullingPercent，然后返回
+    if (self.state == MJRefreshStateNoMoreData) {
+        self.pullingPercent = pullingPercent;
+        return;
+    }
+    
+    if (self.scrollView.isDragging) {
+        self.pullingPercent = pullingPercent;
+        // 普通 和 即将刷新 的临界点
+        CGFloat normal2pullingOffsetX = happenOffsetX + self.mj_w;
+        
+        if (self.state == MJRefreshStateIdle && currentOffsetX > normal2pullingOffsetX) {
+            self.state = MJRefreshStatePulling;
+        } else if (self.state == MJRefreshStatePulling && currentOffsetX <= normal2pullingOffsetX) {
+            // 转为普通状态
+            self.state = MJRefreshStateIdle;
+        }
+    } else if (self.state == MJRefreshStatePulling) {// 即将刷新 && 手松开
+        // 开始刷新
+        [self beginRefreshing];
+    } else if (pullingPercent < 1) {
+        self.pullingPercent = pullingPercent;
+    }
+}
+
+- (void)setState:(MJRefreshState)state {
+    MJRefreshCheckState
+    // 根据状态来设置属性
+    if (state == MJRefreshStateNoMoreData || state == MJRefreshStateIdle) {
+        // 刷新完毕
+        if (MJRefreshStateRefreshing == oldState) {
+            [UIView animateWithDuration:self.slowAnimationDuration animations:^{
+                if (self.endRefreshingAnimationBeginAction) {
+                    self.endRefreshingAnimationBeginAction();
+                }
+                
+                self.scrollView.mj_insetR -= self.lastRightDelta;
+                // 自动调整透明度
+                if (self.isAutomaticallyChangeAlpha) self.alpha = 0.0;
+            } completion:^(BOOL finished) {
+                self.pullingPercent = 0.0;
+                
+                if (self.endRefreshingCompletionBlock) {
+                    self.endRefreshingCompletionBlock();
+                }
+            }];
+        }
+        
+        CGFloat deltaW = [self widthForContentBreakView];
+        // 刚刷新完毕
+        if (MJRefreshStateRefreshing == oldState && deltaW > 0 && self.scrollView.mj_totalDataCount != self.lastRefreshCount) {
+            self.scrollView.mj_offsetX = self.scrollView.mj_offsetX;
+        }
+    } else if (state == MJRefreshStateRefreshing) {
+        // 记录刷新前的数量
+        self.lastRefreshCount = self.scrollView.mj_totalDataCount;
+        
+        [UIView animateWithDuration:self.fastAnimationDuration animations:^{
+            CGFloat right = self.mj_w + self.scrollViewOriginalInset.right;
+            CGFloat deltaW = [self widthForContentBreakView];
+            if (deltaW < 0) { // 如果内容宽度小于view的宽度
+                right -= deltaW;
+            }
+            self.lastRightDelta = right - self.scrollView.mj_insetR;
+            self.scrollView.mj_insetR = right;
+            
+            // 设置滚动位置
+            CGPoint offset = self.scrollView.contentOffset;
+            offset.x = [self happenOffsetX] + self.mj_w;
+            [self.scrollView setContentOffset:offset animated:NO];
+        } completion:^(BOOL finished) {
+            [self executeRefreshingCallback];
+        }];
+    }
+}
+
+- (void)scrollViewContentSizeDidChange:(NSDictionary *)change {
+    [super scrollViewContentSizeDidChange:change];
+    
+    // 内容的宽度
+    CGFloat contentWidth = self.scrollView.mj_contentW + self.ignoredScrollViewContentInsetRight;
+    // 表格的宽度
+    CGFloat scrollWidth = self.scrollView.mj_w - self.scrollViewOriginalInset.left - self.scrollViewOriginalInset.right + self.ignoredScrollViewContentInsetRight;
+    // 设置位置和尺寸
+    self.mj_x = MAX(contentWidth, scrollWidth);
+}
+
+- (void)placeSubviews {
+    [super placeSubviews];
+    
+    self.mj_h = _scrollView.mj_h;
+    // 设置自己的宽度
+    self.mj_w = MJRefreshTrailWidth;
+}
+
+- (void)willMoveToSuperview:(UIView *)newSuperview {
+    [super willMoveToSuperview:newSuperview];
+    
+    if (newSuperview) {
+        // 设置支持水平弹簧效果
+        _scrollView.alwaysBounceHorizontal = YES;
+        _scrollView.alwaysBounceVertical = NO;
+    }
+}
+
+#pragma mark . 链式语法部分 .
+
+- (instancetype)linkTo:(UIScrollView *)scrollView {
+    scrollView.mj_trailer = self;
+    return self;
+}
+
+#pragma mark - 刚好看到上拉刷新控件时的contentOffset.x
+- (CGFloat)happenOffsetX {
+    CGFloat deltaW = [self widthForContentBreakView];
+    if (deltaW > 0) {
+        return deltaW - self.scrollViewOriginalInset.left;
+    } else {
+        return - self.scrollViewOriginalInset.left;
+    }
+}
+
+#pragma mark 获得scrollView的内容 超出 view 的宽度
+- (CGFloat)widthForContentBreakView {
+    CGFloat w = self.scrollView.frame.size.width - self.scrollViewOriginalInset.right - self.scrollViewOriginalInset.left;
+    return self.scrollView.contentSize.width - w;
+}
+
+@end