Animation View Code.m

//
//  MYAnimationView.h
//  http://www.cuppadev.co.uk/iphone/animated-images-on-the-iphone-sans-memory-leaks
//
//  A UIView control which animates an image by simply transforming a slide image
//  containing frames of the animation inside a clipped subview.
//  (in other words, like a flip book except instead of flipping pages, 
//   you move them around in a viewport)
//
//  Requirements:
//    - 1 image containing the frames of your animation.
//      (these can be placed sequentially on both the x and y axis)
//    - 1 MYAnimationView instance with the same frame size as your animation
//       (since the slide will be clipped by this view)
//
//  e.g.:
//    
//    MYAnimationView *animView = [[MYAnimationView alloc] initWithFrame:CGRectMake(100, 100, 96, 66)];
//    [window addSubview:animView];
//    animView.currentAnim = @"anim"; // anim.png
//    animView.isPlaying = YES; // i.e. start playing
//
//  Copyright 2009 James Urquhart. All rights reserved.
//  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 <UIKit/UIKit.h>

@class MYAnimationViewSlide;

@interface MYAnimationView : UIView {
    MYAnimationViewSlide *slide;
    
    NSString *currentAnim;
    int currentFrame;
    int numFrames;
    float advanceTime;
    
    bool isPlaying;
    
    NSTimer *animTimer;
    NSTimeInterval lastTime;
}

@property(nonatomic, readonly, retain) UIView *slide;
@property(nonatomic, copy) NSString *currentAnim;
@property(nonatomic, assign) int currentFrame;

@property(nonatomic, assign) bool isPlaying; 

@end


//
//  MYAnimationView.m
//

#import "MYAnimationView.h"
#import "MYAnimationViewSlide.h"

@implementation MYAnimationView

@synthesize slide;
@dynamic currentAnim;
@dynamic currentFrame;

@dynamic isPlaying;


- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        // Add the frame slide as a sub-view
        slide = [[MYAnimationViewSlide alloc] initWithFrame:frame];
        [self addSubview:slide];
        
        // Reset defaults
        currentFrame = 0;
        numFrames = 0;
        currentAnim = nil;
        
        animTimer = nil;
        lastTime = 0;
        
        isPlaying = NO;
        advanceTime = 0.0;
        
        // Make sure we don't see all of the slide, etc
        self.userInteractionEnabled = NO;
        self.clipsToBounds = YES;
    }
    return self;
}


- (NSString*)currentAnim {
    return currentAnim;
}

- (void)setCurrentAnim:(NSString*)aValue {
    [currentAnim autorelease];
    currentAnim = [aValue retain];
    
    // start from fresh 
    NSString *path = [[NSBundle mainBundle] pathForResource:aValue  ofType:@"png"];
    if (path) {
        // Clean transform, set image
        slide.transform = CGAffineTransformMakeTranslation(0, 0);
        slide.image = [UIImage imageWithContentsOfFile:path];
        
        // Set frame length
        CGSize slideSize = slide.bounds.size;
        CGSize viewSize = self.bounds.size;
        numFrames = floor((slideSize.width / viewSize.width) * (slideSize.height / viewSize.height));
        
        // 25fps
        advanceTime = (1.0 / 25.0);
        
        // reset
        self.currentFrame = 0;
        isPlaying = NO;
    }
    
}


- (int)currentFrame
{
    return currentFrame;
}

- (void)setCurrentFrame:(int)aValue
{
    currentFrame = aValue;
    
    if (currentFrame > numFrames) {
        // animation ended
        [animTimer invalidate];
        animTimer = nil;
        isPlaying = NO;
        
        return;
    }
    
    // Transform the slide
    
    CGSize slideSize = slide.bounds.size;
    CGSize viewSize = self.bounds.size;
    
    // Calculate x,y position for the frame
    // (assuming your frames are packed in a block rather than a strip)
    int framesPerRow = floor(slideSize.width / viewSize.width);
    int x = currentFrame % framesPerRow;
    int y = currentFrame / framesPerRow;
    
    slide.transform = CGAffineTransformMakeTranslation(-viewSize.width * x, -viewSize.height * y);
}


- (bool)isPlaying {
    return isPlaying;
}

- (void)setIsPlaying:(bool)aValue {
    if (aValue) {
        // Start timer, etc
        if (animTimer == nil) {
            lastTime = 0;
            animTimer = [NSTimer scheduledTimerWithTimeInterval:advanceTime 
                                 target:self
                                 selector:@selector(animateTimer:)
                                 userInfo:nil repeats:YES];
        }
        self.currentFrame = 0;
    } else {
        // Invalidate timer as we don't need it!
        if (animTimer) {
            [animTimer invalidate];
            animTimer = nil;
        }
    }
    
    isPlaying = aValue;
}


- (void)animateTimer:(NSTimer*)timer
{
    NSTimeInterval timeInterval = timer.timeInterval;
    NSTimeInterval currentTime = [NSDate timeIntervalSinceReferenceDate];
        
    if (lastTime != 0) {
        double delta = (currentTime - lastTime) / timeInterval;
        
        // advance by at least 1 frame, at most frames in delta
        if (delta < 1)
            self.currentFrame += 1;
        else
            self.currentFrame += (int)delta;
    }
        
    lastTime = currentTime;
}


- (void)drawRect:(CGRect)rect {
    // Drawing code
}


- (void)dealloc {
    [slide release];
    
    [currentAnim release];
    if (animTimer)
        [animTimer invalidate];
    
    [super dealloc];
}


@end

//
//  MYAnimationViewSlide.h
//
#import <UIKit/UIKit.h>


@interface MYAnimationViewSlide : UIView {
    UIImage *image;
}

@property(nonatomic, retain) UIImage *image;

@end


//
//  MYAnimationViewSlide.m
//

#import "MYAnimationViewSlide.h"


@implementation MYAnimationViewSlide

@dynamic image;

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        // Initialization code
    }
    return self;
}


- (UIImage*)image {
    return image;
}

- (void)setImage:(UIImage*)aValue {
    [image release];
    image = [aValue retain];
    
    // Resize to fit
    CGSize sz = image.size;
    self.frame = CGRectMake(0, 0, sz.width, sz.height);
    
    [self setNeedsDisplay];
}


- (void)drawRect:(CGRect)rect {
    // Just draw the image!
    [image drawAtPoint:CGPointMake(0, 0)];
    
    // No more need for the image
    [image release];
    image = nil;
}


- (void)dealloc {
    [image release];
    [super dealloc];
}


@end