iboss-mini-ios/IBOSSmini/DKPhotoLib/KDPhotoBrowser/Views/DKPhotoPickerBrowserPhotoScrollView.m

//
//  ZLPhotoPickerBrowserPhotoScrollView.m
//  ZLAssetsPickerDemo
//
//

#import "DKPhotoPickerBrowserPhotoScrollView.h"
#import "DKPhotoPickerDatas.h"
#import "UIImageView+WebCache.h"
#import "DACircularProgressView.h"
#import "DKPhotoPickerCommon.h"

// Private methods and properties
@interface DKPhotoPickerBrowserPhotoScrollView ()<UIActionSheetDelegate> {
    DKPhotoPickerBrowserPhotoView *_tapView; // for background taps
    DKPhotoPickerBrowserPhotoImageView *_photoImageView;
}

@property (assign,nonatomic) CGFloat progress;
@property (strong,nonatomic) DACircularProgressView *progressView;

@end

@implementation DKPhotoPickerBrowserPhotoScrollView

- (DACircularProgressView *)progressView{
    if (!_progressView) {
        DACircularProgressView *progressView = [[DACircularProgressView alloc] init];
        
        progressView.frame = CGRectMake(0, 0, ZLPickerProgressViewW, ZLPickerProgressViewH);
        progressView.center = CGPointMake([UIScreen mainScreen].bounds.size.width * 0.5, [UIScreen mainScreen].bounds.size.height * 0.5);
        progressView.roundedCorners = YES;
        if (iOS7gt) {
            progressView.thicknessRatio = 0.1;
            progressView.roundedCorners = NO;
        } else {
            progressView.thicknessRatio = 0.2;
            progressView.roundedCorners = YES;
        }
        
        [self addSubview:progressView];
        self.progressView = progressView;
    }
    return _progressView;
}

- (id)init{
    if ((self = [super init])) {
        
        // Setup
        // Tap view for background
        _tapView = [[DKPhotoPickerBrowserPhotoView alloc] initWithFrame:self.bounds];
        _tapView.tapDelegate = self;
        _tapView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
        _tapView.backgroundColor = [UIColor blackColor];
        [self addSubview:_tapView];
        
        // Image view
        _photoImageView = [[DKPhotoPickerBrowserPhotoImageView alloc] initWithFrame:CGRectZero];
        _photoImageView.tapDelegate = self;
        _photoImageView.contentMode = UIViewContentModeCenter;
        _photoImageView.backgroundColor = [UIColor blackColor];
        [self addSubview:_photoImageView];
        
        // Setup
        self.backgroundColor = [UIColor blackColor];
        self.delegate = self;
        self.showsHorizontalScrollIndicator = NO;
        self.showsVerticalScrollIndicator = NO;
        self.decelerationRate = UIScrollViewDecelerationRateFast;
        self.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
        
        UILongPressGestureRecognizer *longGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longGesture:)];
        [self addGestureRecognizer:longGesture];
        
    }
    return self;
}

- (void)longGesture:(UILongPressGestureRecognizer *)gesture{
    if (gesture.state == UIGestureRecognizerStateBegan) {
        
        if (!self.sheet) {
            self.sheet = [[UIActionSheet alloc] initWithTitle:@"提示" delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:@"保存到相册" otherButtonTitles:nil, nil];
        }

        [self.sheet showInView:self];
    }
}

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{
    if (buttonIndex == 0){
        UIImageWriteToSavedPhotosAlbum(_photoImageView.image, nil, nil, nil);
    }
}

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)setPhoto:(DKPhotoPickerBrowserPhoto *)photo{
    _photo = photo;
    
    __weak typeof(self) weakSelf = self;
    if (photo.photoURL.absoluteString.length) {
        // 本地相册
        NSRange photoRange = [photo.photoURL.absoluteString rangeOfString:@"assets-library"];
        if (photoRange.location != NSNotFound){
            [[DKPhotoPickerDatas defaultPicker] getAssetsPhotoWithURLs:photo.photoURL callBack:^(UIImage *obj) {
                _photoImageView.image = obj;
                [weakSelf displayImage];
            }];
        }else{
            UIImage *thumbImage = photo.thumbImage;
            if (thumbImage == nil) {
                thumbImage = _photoImageView.image;
            }else{
                _photoImageView.image = thumbImage;
            }
            
            _photoImageView.contentMode = UIViewContentModeScaleAspectFit;
            _photoImageView.frame = [self setMaxMinZoomScalesForCurrentBounds:_photoImageView];
            
            // 网络URL
            [_photoImageView sd_setImageWithURL:photo.photoURL placeholderImage:thumbImage options:SDWebImageRetryFailed progress:^(NSInteger receivedSize, NSInteger expectedSize) {
                _photoImageView.progress = (double)receivedSize / expectedSize;
            } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
                _photoImageView.image = image;
                [weakSelf displayImage];
            }];
            
        }
        
        
    }  else if (photo.photoImage){
        _photoImageView.image = photo.photoImage;
        [self displayImage];
    }
    
}

- (CGRect )setMaxMinZoomScalesForCurrentBounds:(UIImageView *)imageView {
    // Sizes
    CGSize boundsSize = [UIScreen mainScreen].bounds.size;
    CGSize imageSize = imageView.image.size;
    if (imageSize.width == 0 && imageSize.height == 0) {
        return imageView.frame;
    }
    
    CGFloat xScale = boundsSize.width / imageSize.width;    // the scale needed to perfectly fit the image width-wise
    CGFloat yScale = boundsSize.height / imageSize.height;  // the scale needed to perfectly fit the image height-wise
    CGFloat minScale = MIN(xScale, yScale);                 // use minimum of these to allow the image to become fully visible
    // Image is smaller than screen so no zooming!
    if (xScale >= 1 && yScale >= 1) {
        minScale = MIN(xScale, yScale);
    }
    
    CGRect frameToCenter = CGRectMake(0, 0, imageSize.width * minScale, imageSize.height * minScale);
    
    // Horizontally
    if (frameToCenter.size.width < boundsSize.width) {
        frameToCenter.origin.x = floorf((boundsSize.width - frameToCenter.size.width) / 2.0);
    } else {
        frameToCenter.origin.x = 0;
    }
    
    // Vertically
    if (frameToCenter.size.height < boundsSize.height) {
        frameToCenter.origin.y = floorf((boundsSize.height - frameToCenter.size.height) / 2.0);
    } else {
        frameToCenter.origin.y = 0;
    }
    
    return frameToCenter;
}


#pragma mark - setProgress
- (void)setProgress:(CGFloat)progress{
    _progress = progress;
    
    if (progress == 0) return ;
    if (progress / 1.0 != 1.0) {
        [self.progressView setProgress:progress animated:YES];
    }else{
        [self.progressView removeFromSuperview];
        self.progressView = nil;
    }
}


#pragma mark - Image
// Get and display image
- (void)displayImage {
    // Reset
    self.maximumZoomScale = 1;
    self.minimumZoomScale = 1;
    self.zoomScale = 1;
    self.contentSize = CGSizeMake(0, 0);
    
    // Get image from browser as it handles ordering of fetching
    UIImage *img = _photoImageView.image;
    if (img) {
        
        // Set image
        _photoImageView.image = img;
        _photoImageView.hidden = NO;
        
        // Setup photo frame
        CGRect photoImageViewFrame;
        photoImageViewFrame.origin = CGPointZero;
        photoImageViewFrame.size = img.size;
        _photoImageView.frame = photoImageViewFrame;
        self.contentSize = photoImageViewFrame.size;
        
        // Set zoom to minimum zoom
        [self setMaxMinZoomScalesForCurrentBounds];
        
    }
    [self setNeedsLayout];
}

#pragma mark - Loading Progress
#pragma mark - Setup
- (CGFloat)initialZoomScaleWithMinScale {
    CGFloat zoomScale = self.minimumZoomScale;
    if (_photoImageView) {
        // Zoom image to fill if the aspect ratios are fairly similar
        CGSize boundsSize = self.bounds.size;
        CGSize imageSize = _photoImageView.image.size;
        CGFloat boundsAR = boundsSize.width / boundsSize.height;
        CGFloat imageAR = imageSize.width / imageSize.height;
        CGFloat xScale = boundsSize.width / imageSize.width;

        if (ABS(boundsAR - imageAR) < 0.17) {
            zoomScale = xScale;
        }
    }
    return zoomScale;
}

- (void)setMaxMinZoomScalesForCurrentBounds {
    
    // Reset
    self.maximumZoomScale = 1;
    self.minimumZoomScale = 1;
    self.zoomScale = 1;
    
    // Bail if no image
    if (_photoImageView.image == nil) return;
    
    // Reset position
    _photoImageView.frame = CGRectMake(0, 0, _photoImageView.frame.size.width, _photoImageView.frame.size.height);
    
    // Sizes
    CGSize boundsSize = self.bounds.size;
    CGSize imageSize = _photoImageView.image.size;
    
    // Calculate Min
    CGFloat xScale = boundsSize.width / imageSize.width;    // the scale needed to perfectly fit the image width-wise
    CGFloat yScale = boundsSize.height / imageSize.height;  // the scale needed to perfectly fit the image height-wise
    CGFloat minScale = MIN(xScale, yScale);                 // use minimum of these to allow the image to become fully visible
    
    // Calculate Max
    CGFloat maxScale = 3;
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        // Let them go a bit bigger on a bigger screen!
        maxScale = 4;
    }
    
    // Image is smaller than screen so no zooming!
    if (xScale >= 1 && yScale >= 1) {
        minScale = MIN(xScale, yScale);
    }
    
    // Set min/max zoom
    self.maximumZoomScale = maxScale;
    self.minimumZoomScale = minScale;
    
    // Initial zoom
    self.zoomScale = [self initialZoomScaleWithMinScale];
    
    // If we're zooming to fill then centralise
    if (self.zoomScale != minScale) {
        // Centralise
        self.contentOffset = CGPointMake((imageSize.width * self.zoomScale - boundsSize.width) / 2.0,
                                         (imageSize.height * self.zoomScale - boundsSize.height) / 2.0);
        // Disable scrolling initially until the first pinch to fix issues with swiping on an initally zoomed in photo
        self.scrollEnabled = NO;
    }
    
    // Layout
    [self setNeedsLayout];
    
}

#pragma mark - Layout

- (void)layoutSubviews {
    // Super
    [super layoutSubviews];
    
    // Center the image as it becomes smaller than the size of the screen
    CGSize boundsSize = self.bounds.size;
    CGRect frameToCenter = _photoImageView.frame;
    
    // Horizontally
    if (frameToCenter.size.width < boundsSize.width) {
        frameToCenter.origin.x = floorf((boundsSize.width - frameToCenter.size.width) / 2.0);
    } else {
        frameToCenter.origin.x = 0;
    }
    
    // Vertically
    if (frameToCenter.size.height < boundsSize.height) {
        frameToCenter.origin.y = floorf((boundsSize.height - frameToCenter.size.height) / 2.0);
    } else {
        frameToCenter.origin.y = 0;
    }
    
    // Center
    if (!CGRectEqualToRect(_photoImageView.frame, frameToCenter))
        _photoImageView.frame = frameToCenter;
    
}

#pragma mark - UIScrollViewDelegate

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return _photoImageView;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    [self setNeedsLayout];
    [self layoutIfNeeded];
}

#pragma mark - Tap Detection
- (void)handleDoubleTap:(CGPoint)touchPoint {
    
    // Zoom
    if (self.zoomScale != self.minimumZoomScale && self.zoomScale != [self initialZoomScaleWithMinScale]) {
        
        // Zoom out
        [self setZoomScale:self.minimumZoomScale animated:YES];
        self.contentSize = CGSizeMake(self.frame.size.width, 0);
    } else {
        
        // Zoom in to twice the size
        CGFloat newZoomScale = ((self.maximumZoomScale + self.minimumZoomScale) / 2);
        CGFloat xsize = self.bounds.size.width / newZoomScale;
        CGFloat ysize = self.bounds.size.height / newZoomScale;
        [self zoomToRect:CGRectMake(touchPoint.x - xsize/2, touchPoint.y - ysize/2, xsize, ysize) animated:YES];
        
    }
    
}

- (void)imageView:(UIImageView *)imageView singleTapDetected:(UITouch *)touch{
    [self disMissTap:nil];
}

#pragma mark - disMissTap
- (void) disMissTap:(UITapGestureRecognizer *)tap{
    if (self.callback){
        self.callback(nil);
    }else if ([self.photoScrollViewDelegate respondsToSelector:@selector(pickerPhotoScrollViewDidSingleClick:)]) {
        [self.photoScrollViewDelegate pickerPhotoScrollViewDidSingleClick:self];
    }
}

// Image View
- (void)imageView:(UIImageView *)imageView doubleTapDetected:(UITouch *)touch {
    [self handleDoubleTap:[touch locationInView:imageView]];
}

- (void)view:(UIView *)view singleTapDetected:(UITouch *)touch{
    [self disMissTap:nil];
}

- (void)view:(UIView *)view doubleTapDetected:(UITouch *)touch {
    // Translate touch location to image view location
    CGFloat touchX = [touch locationInView:view].x;
    CGFloat touchY = [touch locationInView:view].y;
    touchX *= 1/self.zoomScale;
    touchY *= 1/self.zoomScale;
    touchX += self.contentOffset.x;
    touchY += self.contentOffset.y;
    [self handleDoubleTap:CGPointMake(touchX, touchY)];
}

@end