VICMAImageView.m

//
//  VIAnimatableImageView.m
//  VIAnimatableImageViewDemo
//
//  Created by Vito on 12/30/14.
//  Copyright (c) 2014 Vito. All rights reserved.
// 	project can be found at: https://github.com/vitoziv/VICMAImageView

#import "VICMAImageView.h"

@interface VICMAImageView ()

@property (nonatomic, strong) UIImageView *imageView;

@end

@implementation VICMAImageView

- (void)commonInit
{
	self.clipsToBounds = YES;
	self.contentMode = UIViewContentModeScaleAspectFit;
	
	if (!_imageView) {
		UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.frame];
		imageView.contentMode = UIViewContentModeScaleToFill;
		[self addSubview:imageView];
		_imageView = imageView;
	}
}

- (instancetype)initWithImage:(UIImage *)image
{
	self = [super init];
	if (self) {
		[self commonInit];
		_imageView.image = image;
	}
	
	return self;
}

- (instancetype)initWithFrame:(CGRect)frame
{
	self = [super initWithFrame:frame];
	if (self) {
		[self commonInit];
	}
	
	return self;
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
	self = [super initWithCoder:aDecoder];
	if (self) {
		[self commonInit];
	}
	
	return self;
}

- (CGSize)presentationImageSize
{
	return self.imageView.bounds.size;
}

- (void)setImage:(UIImage *)image
{
	self.imageView.image = image;
	[self updateView];
}

- (UIImage *)image
{
	return self.imageView.image;
}

- (void)setFrame:(CGRect)frame
{
	[super setFrame:frame];
	[self updateView];
}

- (void)setContentMode:(UIViewContentMode)contentMode
{
	[super setContentMode:contentMode];
	[self updateView];
}

- (void)updateView
{
	if (self.bounds.size.width == 0 || self.bounds.size.height == 0 ||
		self.image.size.width == 0 || self.image.size.height == 0) {
		return;
	}
	
	switch (self.contentMode) {
		case UIViewContentModeScaleAspectFit:
			[self updateViewToAspectFit];
			break;
			
		case UIViewContentModeScaleAspectFill:
			[self updateViewToAspectFill];
			break;
			
		case UIViewContentModeScaleToFill:
			[self updateViewToScaleToFill];
			break;
			
		case UIViewContentModeCenter:
			[self updateViewToCenter];
			break;
			
		case UIViewContentModeBottom:
			[self updateViewToBottom];
			break;
			
		case UIViewContentModeBottomLeft:
			[self updateViewToBottomLeft];
			break;
			
		case UIViewContentModeBottomRight:
			[self updateViewToBottomRight];
			break;
			
		case UIViewContentModeLeft:
			[self updateViewToLeft];
			break;
			
		case UIViewContentModeRight:
			[self updateViewToRight];
			break;
			
		case UIViewContentModeTop:
			[self updateViewToTop];
			break;
			
		case UIViewContentModeTopLeft:
			[self updateViewToTopLeft];
			break;
			
		case UIViewContentModeTopRight:
			[self updateViewToTopRight];
			break;
			
		case UIViewContentModeRedraw:
			[self updateViewToScaleToFill];
			break;
			
		default:
			break;
	}
}

- (void)updateViewToAspectFit
{
	CGSize imageSize = CGSizeMake(self.imageView.image.size.width / self.imageView.image.scale,
								  self.imageView.image.size.height / self.imageView.image.scale);
	
	CGFloat widthRatio = imageSize.width / self.bounds.size.width;
	CGFloat heightRatio = imageSize.height / self.bounds.size.height;
	
	if (widthRatio > heightRatio) {
		imageSize = CGSizeMake(imageSize.width / widthRatio, imageSize.height / widthRatio);
	} else {
		imageSize = CGSizeMake(imageSize.width / heightRatio, imageSize.height / heightRatio);
	}
	
	self.imageView.bounds = CGRectMake(0, 0, imageSize.width, imageSize.height);
	self.imageView.center = CGPointMake(self.bounds.size.width / 2, self.bounds.size.height / 2);
}

- (void)updateViewToAspectFill
{
	CGSize imageSize = CGSizeMake(self.imageView.image.size.width / self.imageView.image.scale,
								  self.imageView.image.size.height / self.imageView.image.scale);
	
	CGFloat widthRatio = imageSize.width / self.bounds.size.width;
	CGFloat heightRatio = imageSize.height / self.bounds.size.height;
	
	if (widthRatio > heightRatio) {
		imageSize = CGSizeMake(imageSize.width / heightRatio, imageSize.height / heightRatio);
	} else {
		imageSize = CGSizeMake(imageSize.width / widthRatio, imageSize.height / widthRatio);
	}
	
	self.imageView.bounds = CGRectMake(0, 0, imageSize.width, imageSize.height);
	[self centerImageViewToSuperView];
}

- (void)updateViewToScaleToFill
{
	self.imageView.bounds = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height);
	[self centerImageViewToSuperView];
}

- (void)updateViewToCenter
{
	[self fitImageViewSizeToImageSize];
	[self centerImageViewToSuperView];
}

- (void)updateViewToBottom
{
	[self fitImageViewSizeToImageSize];
	self.imageView.center = CGPointMake(self.bounds.size.width / 2,
										self.bounds.size.height - self.image.size.height / 2);
}

- (void)updateViewToBottomLeft
{
	[self fitImageViewSizeToImageSize];
	
	self.imageView.center = CGPointMake(self.image.size.width / 2,
										self.bounds.size.height - self.image.size.height / 2);
}

- (void)updateViewToBottomRight
{
	[self fitImageViewSizeToImageSize];
	self.imageView.center = CGPointMake(self.bounds.size.width - self.image.size.width / 2,
										self.bounds.size.height - self.image.size.height / 2);
}

- (void)updateViewToLeft
{
	[self fitImageViewSizeToImageSize];
	
	self.imageView.center = CGPointMake(self.image.size.width / 2,
										self.bounds.size.height / 2);
}

- (void)updateViewToRight
{
	[self fitImageViewSizeToImageSize];
	
	self.imageView.center = CGPointMake(self.bounds.size.width - self.image.size.width / 2,
										self.bounds.size.height / 2);
}

- (void)updateViewToTop
{
	[self fitImageViewSizeToImageSize];
	
	self.imageView.center = CGPointMake(self.bounds.size.width / 2,
										self.image.size.height / 2);
}

- (void)updateViewToTopLeft
{
	[self fitImageViewSizeToImageSize];
	
	self.imageView.center = CGPointMake(self.image.size.width / 2,
										self.image.size.height / 2);
}

- (void)updateViewToTopRight
{
	[self fitImageViewSizeToImageSize];
	self.imageView.center = CGPointMake(self.bounds.size.width - self.image.size.width / 2,
										self.image.size.height / 2);
}

#pragma mark - Helper

- (void)fitImageViewSizeToImageSize
{
	CGSize imageSize = CGSizeMake(self.imageView.image.size.width / self.imageView.image.scale,
								  self.imageView.image.size.height / self.imageView.image.scale);
	
	self.imageView.bounds = CGRectMake(0, 0, imageSize.width, imageSize.height);
}

- (void)centerImageViewToSuperView
{
	self.imageView.center = CGPointMake(self.bounds.size.width / 2, self.bounds.size.height / 2);
}

@end