Leaks in my UIScrollView helper class - ios

Question

I want to publish tutorial about how to easily create an UIScrollView on http://www.xprogress.com/ and I just want to check with you guys if the code is alright before I publish anything. Any help will be appreciated and I'll put your name / website on the bottom of the article :)
Thanks a lot :)
Ondrej
header file:
///
/// IGUIScrollViewImage.h
///
/// IGUILibrary
///
/// Created by Ondrej Rafaj on 7.4.10.
///
/// Copyright 2010 Home. All rights reserved.
///
/// #todo enable margin and center the image to the middle of the view
/**
<b>Examples:</b>
<i>This is just a short example how to use this class</i>
<pre>
- (NSArray *)getImages {
NSMutableArray *arr = [[[NSMutableArray alloc] init] autorelease];
[arr addObject:[UIImage imageNamed:#"image-1.jpg"]];
[arr addObject:[UIImage imageNamed:#"image-2.png"]];
[arr addObject:[UIImage imageNamed:#"image-3.png"]];
[arr addObject:[UIImage imageNamed:#"image-4.jpg"]];
return (NSArray *)arr;
}
- (void)viewDidLoad {
IGUIScrollViewImage *svimage = [[IGUIScrollViewImage alloc] init];
[svimage setSizeFromScrollView:self.scrView]; // takes size of the scroll view you've already placed on stage via Interface Builder
// or
//[svimage setWidth:320 andHeight:240]; // half screen
[svimage enablePositionMemory]; // enables position (pagination) memory for this scroll view
// or
//[svimage enablePositionMemoryWithIdentifier:#"myIdentifier"]; if you have more instances of this scroll view in your application
[svimage enablePageControlOnBottom];
// or
//[svimage enablePageControlOnTop];
[self.myUIView addSubview:[svimage get]]; // and place it on the stage :)
[super viewDidLoad];
}
</pre>
*/
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#interface IGUIScrollViewImage : NSObject <UIScrollViewDelegate> {
UIScrollView *scrollView;
UIPageControl *pageControl;
CGRect rectScrollView;
CGRect rectPageControl;
int scrollWidth;
int scrollHeight;
NSArray *contentArray;
UIColor *bcgColor;
BOOL pageControlEnabledTop;
BOOL pageControlEnabledBottom;
BOOL rememberPosition;
NSString *positionIdentifier;
}
#property (nonatomic, retain) UIScrollView *scrollView;
- (int)getScrollViewWidth;
- (void)setWidth:(int)width andHeight:(int)height;
- (void)setSizeFromScrollView:(UIScrollView *)scView;
- (void)setBackGroudColor:(UIColor *)color;
- (void)setContentArray:(NSArray *)images;
- (void)enablePageControlOnTop;
- (void)enablePageControlOnBottom;
- (void)enablePositionMemory;
- (void)enablePositionMemoryWithIdentifier:(NSString *)identifier;
- (UIScrollView *)getWithPosition:(int)page;
- (UIScrollView *)getWithPositionMemoryIdentifier:(NSString *)identifier;
- (UIScrollView *)get;
#end
And the implementation file:
//
// IGUIScrollViewImage.m
// IGUILibrary
//
// Created by Ondrej Rafaj on 7.4.10.
// Copyright 2010 Home. All rights reserved.
//
#import "IGUIScrollViewImage.h"
#define kIGUIScrollViewImagePageIdentifier #"kIGUIScrollViewImagePageIdentifier"
#define kIGUIScrollViewImageDefaultPageIdentifier #"Default"
#implementation IGUIScrollViewImage
#synthesize scrollView;
- (int)getScrollViewWidth {
return ([contentArray count] * scrollWidth);
}
- (void)setWidth:(int)width andHeight:(int)height {
scrollWidth = width;
scrollHeight = height;
if (!width || !height) rectScrollView = [[UIScreen mainScreen] applicationFrame];
else rectScrollView = CGRectMake(0, 0, width, height);
}
- (void)setSizeFromScrollView:(UIScrollView *)scView {
scrollWidth = scView.frame.size.width;
scrollHeight = scView.frame.size.height;
rectScrollView = CGRectMake(0, 0, scrollWidth, scrollHeight);
}
- (void)setContentArray:(NSArray *)images {
contentArray = images;
}
- (void)setBackGroudColor:(UIColor *)color {
bcgColor = color;
}
- (void)enablePageControlOnTop {
pageControlEnabledTop = YES;
}
- (void)enablePageControlOnBottom {
pageControlEnabledBottom = YES;
}
- (void)enablePositionMemoryWithIdentifier:(NSString *)identifier {
rememberPosition = YES;
if (!identifier) identifier = kIGUIScrollViewImageDefaultPageIdentifier;
positionIdentifier = identifier;
}
- (void)enablePositionMemory {
[self enablePositionMemoryWithIdentifier:nil];
}
- (UIScrollView *)getWithPosition:(int)page {
if (!contentArray) {
contentArray = [[[NSArray alloc] init] autorelease];
}
if (page > [contentArray count]) page = 0;
if (!scrollWidth || !scrollHeight) {
rectScrollView = [[UIScreen mainScreen] applicationFrame];
scrollWidth = rectScrollView.size.width;
scrollHeight = rectScrollView.size.height;
}
rectScrollView = CGRectMake(0, 0, scrollWidth, scrollHeight);
self.scrollView = [[UIScrollView alloc] initWithFrame:rectScrollView];
self.scrollView.contentSize = CGSizeMake([self getScrollViewWidth], scrollHeight);
if (!bcgColor) bcgColor = [UIColor blackColor];
self.scrollView.backgroundColor = bcgColor;
self.scrollView.alwaysBounceHorizontal = YES;
self.scrollView.contentOffset = CGPointMake(page * scrollWidth, 0);
self.scrollView.pagingEnabled = YES;
UIImageView *imageView;
UIView *main = [[[UIView alloc] initWithFrame:rectScrollView] autorelease];
int i = 0;
for (UIImage *img in contentArray) {
imageView = [[UIImageView alloc] initWithImage:img];
imageView.contentMode = UIViewContentModeScaleAspectFit;
imageView.autoresizingMask = ( UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
imageView.backgroundColor = [UIColor blackColor];
float ratio = img.size.width/rectScrollView.size.width;
CGRect imageFrame = CGRectMake(i, 0, rectScrollView.size.width, (img.size.height / ratio));
imageView.frame = imageFrame;
[self.scrollView addSubview:imageView];
i += scrollWidth;
}
[imageView release];
[main addSubview:scrollView];
if (pageControlEnabledTop) {
rectPageControl = CGRectMake(0, 5, scrollWidth, 15);
}
else if (pageControlEnabledBottom) {
rectPageControl = CGRectMake(0, (scrollHeight - 25), scrollWidth, 15);
}
if (pageControlEnabledTop || pageControlEnabledBottom) {
pageControl = [[[UIPageControl alloc] initWithFrame:rectPageControl] autorelease];
pageControl.numberOfPages = [contentArray count];
pageControl.currentPage = page;
[main addSubview:pageControl];
}
if (pageControlEnabledTop || pageControlEnabledBottom || rememberPosition) self.scrollView.delegate = self;
//if (margin) [margin release];
return (UIScrollView *)main;
}
- (UIScrollView *)get {
return [self getWithPosition:0];
}
- (UIScrollView *)getWithPositionMemoryIdentifier:(NSString *)identifier {
[self enablePositionMemoryWithIdentifier:identifier];
return [self getWithPosition:[[[NSUserDefaults alloc] objectForKey:[NSString stringWithFormat:#"%#%#", kIGUIScrollViewImagePageIdentifier, positionIdentifier]] intValue]];
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sv {
int page = sv.contentOffset.x / sv.frame.size.width;
pageControl.currentPage = page;
if (rememberPosition) {
[[NSUserDefaults alloc] setObject:[NSString stringWithFormat:#"%d", page] forKey:[NSString stringWithFormat:#"%#%#", kIGUIScrollViewImagePageIdentifier, positionIdentifier]];
}
}
- (void)dealloc {
[scrollView release];
[super dealloc];
}
#end

Answer 1

Just a quick glance. You alloc UIImageView multiple times in
-(UIScrollView*)getWithPosition:(int)page and release it only once:
for (UIImage *img in contentArray) {
imageView = [[UIImageView alloc] initWithImage:img];
// ...
}
[imageView release];