//
|
// MJRefreshBackFooter.m
|
// MJRefreshExample
|
//
|
// Created by MJ Lee on 15/4/24.
|
// Copyright (c) 2015年 小码哥. All rights reserved.
|
//
|
|
#import "MJRefreshBackFooter.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.contentInset;
|
|
// 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];
|
|
// 内容的高度
|
CGFloat contentHeight = self.scrollView.mj_contentH + self.ignoredScrollViewContentInsetBottom;
|
// 表格的高度
|
CGFloat scrollHeight = self.scrollView.mj_h - self.scrollViewOriginalInset.top - self.scrollViewOriginalInset.bottom + self.ignoredScrollViewContentInsetBottom;
|
// 设置位置和尺寸
|
self.mj_y = MAX(contentHeight, scrollHeight);
|
}
|
|
- (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:MJRefreshSlowAnimationDuration animations:^{
|
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;
|
}];
|
}
|
|
CGFloat deltaH = [self heightForContentBreakView];
|
// 刚刷新完毕
|
if (MJRefreshStateRefreshing == oldState && deltaH > 0 && self.scrollView.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.totalDataCount;
|
|
[UIView animateWithDuration:MJRefreshFastAnimationDuration 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 - 公共方法
|
- (void)endRefreshing
|
{
|
if ([self.scrollView isKindOfClass:[UICollectionView class]]) {
|
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
|
[super endRefreshing];
|
});
|
} else {
|
[super endRefreshing];
|
}
|
}
|
|
- (void)noticeNoMoreData
|
{
|
if ([self.scrollView isKindOfClass:[UICollectionView class]]) {
|
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
|
[super noticeNoMoreData];
|
});
|
} else {
|
[super noticeNoMoreData];
|
}
|
}
|
|
#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
|
