duoshoubang/FirstLink/General/GalleryScrol...

//
//  GalleryScrollView.m
//  FirstLink
//
//  Created by Lemon on 14/12/24.
//  Copyright (c) 2014年 FirstLink. All rights reserved.
//

#import "GalleryScrollView.h"


@interface GalleryScrollView () <UIScrollViewDelegate>

@property (nonatomic, strong) UIImageView *imageView;
@property (nonatomic, assign) CGRect scaleOriginalRect;
@property (nonatomic, assign) CGSize imageSize;
@property (nonatomic, assign) CGRect initRect;

@end


@implementation GalleryScrollView

- (id)init
{
    self = [super init];
    if (self)
    {
        _index = 0;
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self)
    {
        self.backgroundColor = [UIColor blackColor];
        self.showsHorizontalScrollIndicator = NO;
        self.showsVerticalScrollIndicator = NO;
//        self.pagingEnabled = YES;
        self.minimumZoomScale = 1.0;
        self.bouncesZoom = YES;
        self.delegate = self;
        
        self.userInteractionEnabled = YES;
        [self addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGalleryImage:)]];
        
        _imageView = [[UIImageView alloc] init];
        _imageView.clipsToBounds = YES;
        _imageView.contentMode = UIViewContentModeScaleAspectFill;
        [self addSubview:_imageView];
    }
    return self;
}

- (void)setContentWithFrame:(CGRect)rect initRect:(CGRect)initRect
{
    _imageView.frame = rect;
    _initRect = initRect;
}

- (void)setAnimationRect
{
    _imageView.frame = _scaleOriginalRect;
}

- (void)resetFrame
{
    self.zoomScale = 1.0;
    _imageView.frame = _initRect;
}

- (void)setImage:(UIImage *)image
{
    if (image)
    {
        _imageView.image = image;
        _imageSize = image.size;
        
        // 判断首先缩放的值
        float scaleX = self.frame.size.width / _imageSize.width;
        float scaleY = self.frame.size.height / _imageSize.height;
        
        // 倍数小的，先到边缘
        if (scaleX > scaleY)
        {
            // Y方向先到边缘
            float imageViewWidth = _imageSize.width * scaleY;
            self.maximumZoomScale = self.frame.size.width / imageViewWidth;
            
            _scaleOriginalRect = (CGRect){self.frame.size.width/2 - imageViewWidth/2, 0, imageViewWidth, self.frame.size.height};
        }
        else
        {
            // X先到边缘
            float imageViewHeight = _imageSize.height * scaleX;
            self.maximumZoomScale = self.frame.size.height / imageViewHeight;
            
            _scaleOriginalRect = (CGRect){0, self.frame.size.height/2 - imageViewHeight/2, self.frame.size.width, imageViewHeight};
        }
    }
}

#pragma mark -
#pragma mark - ScrollView Delegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return _imageView;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView
{
    CGSize boundsSize = scrollView.bounds.size;
    CGRect imageFrame = _imageView.frame;
    CGSize contentSize = scrollView.contentSize;
    
    CGPoint centerPoint = CGPointMake(contentSize.width/2, contentSize.height/2);
    
    // center horizontally
    if (imageFrame.size.width <= boundsSize.width)
    {
        centerPoint.x = boundsSize.width/2;
    }
    
    // center vertically
    if (imageFrame.size.height <= boundsSize.height)
    {
        centerPoint.y = boundsSize.height/2;
    }
    
    _imageView.center = centerPoint;
}

#pragma mark -
#pragma mark - Gesture
- (IBAction)tapGalleryImage:(id)sender
{
    if (self.touchCallBack)
    {
        self.touchCallBack(self, self.index);
    }
}

@end