UUEnt/UU_Ent/UU_Ent/Utils/WebView/YRWebView.m

//
//  YRWebView.m
//  UU_Ent
//
//  Created by liujl on 2019/8/22.
//  Copyright © 2019 UAS. All rights reserved.
//

#import "YRWebView.h"

@interface YRWebView()<WKNavigationDelegate>

@property (nonatomic, strong) UIGestureRecognizer* popGesture;

@property (nonatomic, weak) id <WKNavigationDelegate> originDelegate;

@property (nonatomic, strong)UIImageView *historyView;

@property (nonatomic, strong) NSMutableArray *historyStack;

@property (nonatomic, assign) CGFloat panStartX;

/**
 用来判断是返回还是
 */
@property (nonatomic, strong) NSMutableArray<NSString *> *urlStack;

@end

@implementation YRWebView

- (instancetype)initWithFrame:(CGRect)frame configuration:(WKWebViewConfiguration *)configuration{
    
    self = [super initWithFrame:frame configuration:configuration];
    
    if (self) {
        
        [self defualtSet];
        
    }
    
    return self;
}

-(void)defualtSet{
    
    self.popGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];
    
    [self addGestureRecognizer:self.popGesture];
    
    [super setNavigationDelegate:self];
    
    [YRWebView addShadowToView:self];
    
    [self addObserver:self forKeyPath:@"URL" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];
    
}


+ (UIImage *)screenshotOfView:(UIView *)view {
    
    UIGraphicsBeginImageContextWithOptions(view.frame.size, YES, 0.0);
    
    
    
    if ([view respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
        
        [view drawViewHierarchyInRect:view.bounds afterScreenUpdates:YES];
        
    }
    
    else{
        
        [view.layer renderInContext:UIGraphicsGetCurrentContext()];
        
    }
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return image;
    
}



+ (void)addShadowToView:(UIView *)view{
    
    CALayer *layer = view.layer;
    
    UIBezierPath *path = [UIBezierPath bezierPathWithRect:layer.bounds];
    
    layer.shadowPath = path.CGPath;
    
    layer.shadowColor = [UIColor blackColor].CGColor;
    
    layer.shadowOffset = CGSizeZero;
    
    layer.shadowOpacity = 0.4f;
    
    layer.shadowRadius = 8.0f;
    
}



- (void)setDelegate:(id<WKNavigationDelegate>)delegate{
    
    self.originDelegate = delegate;
    
}



- (id<WKNavigationDelegate>)delegate{
    
    return self.originDelegate;
    
}



- (void)goBack{
    
    [super goBack];
    
    [self.historyStack removeLastObject];
    [self.urlStack removeLastObject];
    
}



- (void)setEnablePanGesture:(BOOL)enablePanGesture{
    
    self.popGesture.enabled = enablePanGesture;
    
}



- (BOOL)enablePanGesture{
    
    return self.popGesture.enabled;
    
}



- (NSMutableArray *)historyStack {
    
    if (!_historyStack) {
        
        _historyStack = [NSMutableArray array];
        
    }
    
    return _historyStack;
    
}



- (UIImageView *)historyView{
    
    if (!_historyView) {
        
        if (self.superview) {
            
            _historyView = [[UIImageView alloc] initWithFrame:self.bounds];
            
            [self.superview insertSubview:_historyView belowSubview:self];
            
        }
        
    }
    
    
    
    return _historyView;
    
}

- (void)dealloc {
    
    
    [self removeObserver:self forKeyPath:@"URL"];
    
    if (self.historyView) {
        
        [self.historyView removeFromSuperview];
        
        self.historyView = nil;
        
    }
    
}



- (void)layoutSubviews {
    
    [super layoutSubviews];
    
    self.historyView.frame = self.bounds;
    
}

#pragma mark === gesture===

- (void)panGesture:(UIPanGestureRecognizer *)sender{
    
    if (![self canGoBack] || self.historyStack.count == 0) {
        
        if (self.panDelegate && [self.panDelegate respondsToSelector:@selector(panableWebView:panPopGesture:)]) {
            
            [self.panDelegate panableWebView:self panPopGesture:sender];
            
        }
        
        
        
        return;
        
    }
    
    
    
    CGPoint point = [sender translationInView:self];
    
    if (sender.state == UIGestureRecognizerStateBegan) {
        
        _panStartX = point.x;
        
    }
    
    else if (sender.state == UIGestureRecognizerStateChanged){
        
        CGFloat deltaX = point.x - _panStartX;
        
        if (deltaX > 0) {
            
            if ([self canGoBack]) {
                
                assert(self.historyStack.count > 0);
                
                NSDictionary *history = self.historyStack.lastObject;
                
                self.historyView.image = [history objectForKey:@"preview"];
                
                self.x = deltaX;
                
                self.historyView.x = -self.width / 2.0f + deltaX / 2.0f;
                
            }
            
        }
        
    }
    
    else if (sender.state == UIGestureRecognizerStateEnded){
        
        CGFloat deltaX = point.x - _panStartX;
        
        CGFloat duration = .5f;
        
        if ([self canGoBack]) {
            
            if (deltaX > self.width / 4.0f) {
                
                [UIView animateWithDuration:(1.0f - deltaX / self.width) * duration animations:^{
                    
                    
                    self.x = self.width;
                    
                    self.historyView.x = 0;
                    
                    [self goBack];
                    
                    
                } completion:^(BOOL finished) {
                    
                    self.x = 0;
                    
                    [self.historyView removeFromSuperview];
                    
                    self.historyView = nil;
                    
                    
                    
                }];
                
            }
            
            else{
                
                [UIView animateWithDuration:(deltaX/self.bounds.size.width)*duration animations:^{
                    
                    CGRect rc = self.frame;
                    
                    rc.origin.x = 0;
                    
                    self.frame = rc;
                    
                    rc.origin.x = -self.bounds.size.width/2.0f;
                    
                    self.historyView.frame = rc;
                    
                } completion:^(BOOL finished) {
                    
                    
                    
                }];
                
            }
            
        }
        
    }
    
}


-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context{
    
    if ([keyPath isEqualToString:@"URL"]) {
        
        NSString *newUrl = [NSString stringWithFormat:@"%@",change[@"new"]];
        //执行的是跳入新页面的操作
         if (![self.urlStack containsObject:newUrl] && [newUrl containsString:@"http"]) {
                
               [self.urlStack addObject:newUrl];
                
        }
        
    }
    
}



-(void)setUrl:(NSString *)url{
    
    _url = url;
    
    [self.urlStack addObject:url];
    
    
}

-(NSMutableArray<NSString *> *)urlStack{
    
    if (!_urlStack) {
        
        _urlStack = [NSMutableArray new];
        
    }
    
    return _urlStack;
}



@end