UIView (MotionEffect)

#import <UIKit/UIKit.h>


@interface UIView (MotionEffect)
//UIMotionEffect和Home页背景视差效果
- (void) addCenterMotionEffectsXYWithOffset:(CGFloat)offset;
@end


@interface UIView (Window)

//把View加在Window上
- (void) addToWindowWithAnimation:(void(^)())animation;

@end

@interface UIView (Screenshot)

//View截图
- (UIImage*) screenshot;

//ScrollView截图 contentOffset
- (UIImage*) screenshotForScrollViewWithContentOffset:(CGPoint)contentOffset;

//View按Rect截图
- (UIImage*) screenshotInFrame:(CGRect)frame;

@end

#import "UIView+Category.h"
#import <QuartzCore/QuartzCore.h>
#import <objc/runtime.h>

@implementation UIView (MotionEffect)

NSString *const centerX = @"center.x";
NSString *const centerY = @"center.y";

#pragma mark - Motion Effect
- (void)addCenterMotionEffectsXYWithOffset:(CGFloat)offset {
    
    //    if(!IS_OS_7_OR_LATER) return;
    if(floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) return;
    
    UIInterpolatingMotionEffect *xAxis;
    UIInterpolatingMotionEffect *yAxis;
    
    xAxis = [[UIInterpolatingMotionEffect alloc] initWithKeyPath:centerX
                                                            type:UIInterpolatingMotionEffectTypeTiltAlongHorizontalAxis];
    xAxis.maximumRelativeValue = @(offset);
    xAxis.minimumRelativeValue = @(-offset);
    
    yAxis = [[UIInterpolatingMotionEffect alloc] initWithKeyPath:centerY
                                                            type:UIInterpolatingMotionEffectTypeTiltAlongVerticalAxis];
    yAxis.minimumRelativeValue = @(-offset);
    yAxis.maximumRelativeValue = @(offset);
    
    UIMotionEffectGroup *group = [[UIMotionEffectGroup alloc] init];
    group.motionEffects = @[xAxis, yAxis];
    
    [self addMotionEffect:group];
}

@end



@implementation UIView (AddToWindow)

- (void) addToWindowWithAnimation:(void(^)())animation
{
    id appDelegate = [[UIApplication sharedApplication] delegate];
    if ([appDelegate respondsToSelector:@selector(window)])
    {
        UIWindow * window = (UIWindow *) [appDelegate performSelector:@selector(window)];
        [window addSubview:self];
        [UIView animateWithDuration:0.3 animations:^{
            animation();
        } completion:^(BOOL finished) {
            
        }];
    }
}


@end


@implementation UIView (Screenshot)

- (UIImage*) screenshot {
    
    UIGraphicsBeginImageContext(self.bounds.size);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    // helps w/ our colors when blurring
    // feel free to adjust jpeg quality (lower = higher perf)
    NSData *imageData = UIImageJPEGRepresentation(image, 0.75);
    image = [UIImage imageWithData:imageData];
    
    return image;
    
}

- (UIImage *) screenshotForScrollViewWithContentOffset:(CGPoint)contentOffset {
    UIGraphicsBeginImageContext(self.bounds.size);
    //need to translate the context down to the current visible portion of the scrollview
    CGContextTranslateCTM(UIGraphicsGetCurrentContext(), 0.0f, -contentOffset.y);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    // helps w/ our colors when blurring
    // feel free to adjust jpeg quality (lower = higher perf)
    NSData *imageData = UIImageJPEGRepresentation(image, 0.55);
    image = [UIImage imageWithData:imageData];
    
    return image;
}

- (UIImage*) screenshotInFrame:(CGRect)frame {
    UIGraphicsBeginImageContext(frame.size);
    CGContextTranslateCTM(UIGraphicsGetCurrentContext(), frame.origin.x, frame.origin.y);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    // helps w/ our colors when blurring
    // feel free to adjust jpeg quality (lower = higher perf)
    NSData *imageData = UIImageJPEGRepresentation(image, 0.75);
    image = [UIImage imageWithData:imageData];
    
    return image;
}

@end