KenBurns.m

//
//  KenBurnsView.m
//  KenBurns
//
//  Created by Javier Berlana on 9/23/11.
//  Copyright (c) 2011, Javier Berlana
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy of this 
//  software and associated documentation files (the "Software"), to deal in the Software 
//  without restriction, including without limitation the rights to use, copy, modify, merge, 
//  publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons 
//  to whom the Software is furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in all copies 
//  or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
//  PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
//  FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//  ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
//  IN THE SOFTWARE.
//

#import "JBKenBurnsView.h"
#include <stdlib.h>

#define enlargeRatio 1.2
#define imageBufer 3

// Private interface
@interface KenBurnsView()
    @property (nonatomic) BOOL animationInCurse;
    @property (nonatomic, strong) NSOperationQueue *queue;

    - (void) _animate:(NSNumber*)num;
    - (void) _startAnimations:(NSArray*)images;
    - (void) _startInternetAnimations:(NSArray *)urls;
    - (UIImage *) _downloadImageFrom:(NSString *)url;
@end


@implementation KenBurnsView

@synthesize imagesArray, timeTransition, isLoop, isLandscape;
@synthesize animationInCurse, currentImage;
@synthesize queue = _queue;

- (NSOperationQueue *)queue{
    if (!_queue){
        _queue = [[NSOperationQueue alloc] init];
    }
    return _queue;
}

- (id)init
{
    self = [super init];
    if (self) {
        self.layer.masksToBounds = YES;
        self.currentImage = 0;
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.layer.masksToBounds = YES;
    }
    return self;
}

- (void) animateWithImages:(NSMutableArray *)images 
        transitionDuration:(float)duration 
                      loop:(BOOL)shouldLoop 
               isLandscape:(BOOL)inLandscape;
{
    self.imagesArray      = images;
    self.timeTransition   = duration;
    self.isLoop           = shouldLoop;
    self.isLandscape      = inLandscape;
    self.animationInCurse = NO;
    
    self.layer.masksToBounds = YES;
    
    
    NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self 
                                                                            selector:@selector(_startAnimations:) 
                                                                              object:images];
    
    [self.queue addOperation:operation];    
}

- (void) animateWithURLs:(NSArray *)urls 
      transitionDuration:(float)duration 
                    loop:(BOOL)shouldLoop 
             isLandscape:(BOOL)inLandscape;
{
    self.imagesArray      = [[NSMutableArray alloc] init];
    self.timeTransition   = duration;
    self.isLoop           = shouldLoop;
    self.isLandscape      = inLandscape;
    self.animationInCurse = NO;
    
    int bufferSize = (imageBufer < urls.count) ? imageBufer : urls.count;
    
    // Fill the buffer.
    for (uint i=0; i<bufferSize; i++) {
        NSString *url = [[NSString alloc] initWithString:[urls objectAtIndex:i]];
        [self.imagesArray addObject:[self _downloadImageFrom:url]];
    }
    
    self.layer.masksToBounds = YES;
    
    NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self 
                                                                            selector:@selector(_startInternetAnimations::) 
                                                                              object:urls];
    
    [self.queue addOperation:operation];
}

- (void)_startAnimations:(NSArray *)images
{
    @autoreleasepool {
    
        for (uint i = 0; i < [images count]; i++) {
            
            self.currentImage = i;
            
            NSOperationQueue *mainQueue      = [NSOperationQueue mainQueue];
            NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
                                                 selector:@selector(_animate:) 
                                                   object:[NSNumber numberWithInt:self.currentImage]];
            [mainQueue addOperations:[NSArray arrayWithObject:operation] waitUntilFinished:YES];
            
            sleep(self.timeTransition);
            i = (i == [images count]-1) && isLoop ? -1 : i; 
        }

    }
}

- (UIImage *) _downloadImageFrom:(NSString *) url
{
    UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]];
    return image;
}

- (void) _startInternetAnimations:(NSArray *)urls
{
    @autoreleasepool {
        BOOL wrapping = NO;
        int bufferIndex = 0;
        
        for (int urlIndex=self.imagesArray.count; urlIndex < [urls count]; urlIndex++) {
             
            NSOperationQueue *mainQueue      = [NSOperationQueue mainQueue];
            NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
                                                                                    selector:@selector(_animate:) 
                                                                                      object:[NSNumber numberWithInt:0]];
            [mainQueue addOperations:[NSArray arrayWithObject:operation] waitUntilFinished:YES];

            [self.imagesArray removeObjectAtIndex:0];
            [self.imagesArray addObject:[self _downloadImageFrom:[urls objectAtIndex: urlIndex]]];
            
            if ( bufferIndex == self.imagesArray.count -1)
            {
                NSLog(@"Wrapping!!");
                wrapping = YES;
                bufferIndex = -1;
            }
            
            bufferIndex++;
            urlIndex = (urlIndex == [urls count]-1) && isLoop ? -1 : urlIndex; 
            
            sleep(self.timeTransition);
        }
    
    }
}

- (void) _animate:(NSNumber*)num
{
    UIImage* image = [self.imagesArray objectAtIndex:[num intValue]];
    UIImageView *imageView;
    
    float resizeRatio   = -1;
    float widthDiff     = -1;
    float heightDiff    = -1;
    float originX       = -1;
    float originY       = -1;
    float zoomInX       = -1;
    float zoomInY       = -1;
    float moveX         = -1;
    float moveY         = -1;
    float frameWidth    = MAX(self.superview.frame.size.height, self.superview.frame.size.width) + 25;
    float frameHeight   = isLandscape? self.frame.size.height : self.frame.size.width;
    
    // Widder than screen 
    if (image.size.width > frameWidth) {
        widthDiff  = image.size.width - frameWidth;
        
        // Higher than screen
        if (image.size.height > frameHeight) {
            heightDiff = image.size.height - frameHeight;
            
            if (widthDiff > heightDiff) 
                resizeRatio = frameHeight / image.size.height;
            else
                resizeRatio = frameWidth / image.size.width;
            
        // No higher than screen
        } else {
            heightDiff = frameHeight - image.size.height;
            
            if (widthDiff > heightDiff) 
                resizeRatio = frameWidth / image.size.width;
            else
                resizeRatio = self.bounds.size.height / image.size.height;
        }
        
    // No widder than screen
    } else {
        widthDiff  = frameWidth - image.size.width;
        
        // Higher than screen
        if (image.size.height > frameHeight) {
            heightDiff = image.size.height - frameHeight;
            
            if (widthDiff > heightDiff) 
                resizeRatio = image.size.height / frameHeight;
            else
                resizeRatio = frameWidth / image.size.width;
            
        // No higher than screen
        } else {
            heightDiff = frameHeight - image.size.height;
            
            if (widthDiff > heightDiff) 
                resizeRatio = frameWidth / image.size.width;
            else
                resizeRatio = frameHeight / image.size.height;
        }
    }
    
    // Resize the image.
    float optimusWidth  = (image.size.width * resizeRatio) * enlargeRatio;
    float optimusHeight = (image.size.height * resizeRatio) * enlargeRatio;
    imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, optimusWidth, optimusHeight)];
    
    // Calcule the maximum move allowed.
    float maxMoveX = optimusWidth - frameWidth;
    float maxMoveY = optimusHeight - frameHeight;
    
    float rotation = (arc4random() % 9) / 100;

    switch (arc4random() % 4) {
        case 0:
            originX = 0;
            originY = 0;
            zoomInX = 1.25;
            zoomInY = 1.25;
            moveX   = -maxMoveX;
            moveY   = -maxMoveY;
            break;
            
        case 1:
            originX = 0;
            originY = frameHeight - optimusHeight;
            zoomInX = 1.10;
            zoomInY = 1.10;
            moveX   = -maxMoveX;
            moveY   = maxMoveY;
            break;

            
        case 2:
            originX = frameWidth - optimusWidth;
            originY = 0;
            zoomInX = 1.30;
            zoomInY = 1.30;
            moveX   = maxMoveX;
            moveY   = -maxMoveY;
            break;
            
        case 3:
            originX = frameWidth - optimusWidth;
            originY = frameHeight - optimusHeight;
            zoomInX = 1.20;
            zoomInY = 1.20;
            moveX   = maxMoveX;
            moveY   = maxMoveY;
            break;
            
        default:
            NSLog(@"def");
            break;
    }
    
    CALayer *picLayer    = [CALayer layer];
    picLayer.contents    = (id)image.CGImage;
    picLayer.anchorPoint = CGPointMake(0, 0); 
    picLayer.bounds      = CGRectMake(0, 0, optimusWidth, optimusHeight);
    picLayer.position    = CGPointMake(originX, originY);
    
    [imageView.layer addSublayer:picLayer];
    
    CATransition *animation = [CATransition animation];
    [animation setDuration:1];
    [animation setType:kCATransitionFade];
    [[self layer] addAnimation:animation forKey:nil];
    
    // Remove the previous view
    if ([[self subviews] count] > 0){
        [[[self subviews] objectAtIndex:0] removeFromSuperview];
    }
    
    [self addSubview:imageView];
    
    // Generates the animation
    [UIView animateWithDuration:self.timeTransition + 2
                          delay:0 
                        options:UIViewAnimationOptionCurveEaseIn 
                     animations:^{    
                         CGAffineTransform rotate    = CGAffineTransformMakeRotation(rotation);
                         CGAffineTransform moveRight = CGAffineTransformMakeTranslation(moveX, moveY);
                         CGAffineTransform combo1    = CGAffineTransformConcat(rotate, moveRight);
                         CGAffineTransform zoomIn    = CGAffineTransformMakeScale(zoomInX, zoomInY);
                         CGAffineTransform transform = CGAffineTransformConcat(zoomIn, combo1);
                         imageView.transform         = transform;
                     } 
                     completion:nil];    
}

- (void)pauseLayer
{
    if ([self.subviews count] > 0) {
        CALayer *layer = [[self.subviews objectAtIndex:0] layer];
        CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
        layer.speed = 0.0;
        layer.timeOffset = pausedTime;
    }
}

- (void)resumeLayer
{
    if ([self.subviews count] > 0) {
        CALayer *layer = [[self.subviews objectAtIndex:0] layer];
        CFTimeInterval pausedTime = [layer timeOffset];
        layer.speed = 1.0;
        layer.timeOffset = 0.0;
        layer.beginTime = 0.0;
        CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
        layer.beginTime = timeSincePause;
    }
}

@end