http://allseeing-i.com/ASIHTTPRequest/ and the sample code from Apple
ThumbImageView.h
#import "ASIHTTPRequest.h"
@protocol ThumbImageViewDelegate;
@interface ThumbImageView : UIImageView{
id delegate;
NSString *imageName;
CGSize imageSize;
CGRect home;
BOOL dragging;
CGPoint touchLocation; // Location of touch in own coordinates (stays constant during dragging).
}
@property (nonatomic, assign) id delegate;
@property (nonatomic, retain) NSString *imageName;
@property (nonatomic, assign) CGSize imageSize;
@property (nonatomic, assign) CGRect home;
@property (nonatomic, assign) CGPoint touchLocation;
- (void)goHome;
- (void)moveByOffset:(CGPoint)offset;
- (id)initWithImageAtUrl:(NSURL*)theUrl;
@end
@protocol ThumbImageViewDelegate
@optional
- (void)thumbImageViewWasTapped:(ThumbImageView *)tiv;
- (void)thumbImageViewStartedTracking:(ThumbImageView *)tiv;
- (void)thumbImageViewMoved:(ThumbImageView *)tiv;
- (void)thumbImageViewStoppedTracking:(ThumbImageView *)tiv;
@end
ThumbImageView.m
#import "ThumbImageView.h"
#import "MoMagIO.h"
#define DRAG_THRESHOLD 10
#define ACTIVITYVIEW_TAG 123
float distanceBetweenPoints(CGPoint a, CGPoint b);
@interface ThumbImageView(PrivateMethods)
-(void)addLoadingCircle;
-(void)removeLoadingCircle;
-(void)downloadImageWithURL:(NSURL*)theUrl;
@end
@implementation ThumbImageView
@synthesize delegate;
@synthesize imageName;
@synthesize imageSize;
@synthesize home;
@synthesize touchLocation;
- (id)initWithImageAtUrl:(NSURL*)theUrl{
self = [super init];
if (self) {
[self setUserInteractionEnabled:YES];
[self setExclusiveTouch:YES];
self.image = nil;
// Add loading circle
[self addLoadingCircle];
// Asyncronous download image
[self downloadImageWithURL:theUrl];
}
return self;
}
-(void)addLoadingCircle{
UIActivityIndicatorView *indicatorView = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 24, 24)];
indicatorView.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;
indicatorView.center = CGPointMake((152/2),(195/2));
indicatorView.tag = ACTIVITYVIEW_TAG;
[self addSubview:[indicatorView autorelease]];
[indicatorView startAnimating];
}
-(void)removeLoadingCircle{
UIActivityIndicatorView *indicatorView = (UIActivityIndicatorView*)[self viewWithTag:ACTIVITYVIEW_TAG];
[indicatorView stopAnimating];
[indicatorView removeFromSuperview];
}
-(void)downloadImageWithURL:(NSURL*)theUrl{
NSLog(@"Url for download %@",theUrl);
NSString *pathToSave = [[MoMagIO getCacheDirPath] stringByAppendingPathComponent:[[theUrl path] lastPathComponent]];
//
if(imageName != pathToSave){
[imageName release];
imageName = [pathToSave retain];
}
NSFileManager *fm = [NSFileManager defaultManager];
if([fm fileExistsAtPath:self.imageName]){
UIImage *img = [[UIImage alloc] initWithContentsOfFile:imageName];
if(img){
self.image = img;
[self setNeedsDisplay];
}
[img release];
[self removeLoadingCircle];
}else {
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:theUrl];
[request setDelegate:self];
request.didFailSelector = @selector(downloadDidFailed:);
request.didFinishSelector = @selector(downloadDidCompleted:);
request.downloadDestinationPath = imageName;
[request startAsynchronous];
}
}
-(void)downloadDidFailed:(ASIHTTPRequest *)request{
#ifdef DEBUG
NSLog(@"ThumbImageView:-(void)downloadDidFailed:(ASIHTTPRequest *)request %@",[request error]);
#endif
NSBundle *bundle = [NSBundle mainBundle];
NSString *root = [[bundle resourcePath] stringByAppendingPathComponent:@"cover_preload.jpg"];
UIImage *img = [[UIImage alloc] initWithContentsOfFile:root];
if(img){
self.image = img;
[self setNeedsDisplay];
}
[img release];
[self removeLoadingCircle];
}
-(void)downloadDidCompleted:(ASIHTTPRequest *)request{
UIImage *img = [[UIImage alloc] initWithContentsOfFile:imageName];
if(img){
self.image = img;
[self setNeedsDisplay];
}
[img release];
[self removeLoadingCircle];
}
- (id)initWithImage:(UIImage *)image {
self = [super initWithImage:image];
if (self) {
[self setUserInteractionEnabled:YES];
[self setExclusiveTouch:YES];
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
// store the location of the starting touch so we can decide when we've moved far enough to drag
touchLocation = [[touches anyObject] locationInView:self];
if ([delegate respondsToSelector:@selector(thumbImageViewStartedTracking:)])
[delegate thumbImageViewStartedTracking:self];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
// we want to establish a minimum distance that the touch has to move before it counts as dragging,
// so that the slight movement involved in a tap doesn't cause the frame to move.
/**CGPoint newTouchLocation = [[touches anyObject] locationInView:self];
if (dragging) {
float deltaX = newTouchLocation.x - touchLocation.x;
float deltaY = newTouchLocation.y - touchLocation.y;
[self moveByOffset:CGPointMake(deltaX, deltaY)];
}
else if (distanceBetweenPoints(touchLocation, newTouchLocation) > DRAG_THRESHOLD) {
touchLocation = newTouchLocation;
dragging = YES;
}**/
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
if (dragging) {
[self goHome];
dragging = NO;
} else if ([[touches anyObject] tapCount] == 1) {
if ([delegate respondsToSelector:@selector(thumbImageViewWasTapped:)])
[delegate thumbImageViewWasTapped:self];
}
if ([delegate respondsToSelector:@selector(thumbImageViewStoppedTracking:)])
[delegate thumbImageViewStoppedTracking:self];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
[self goHome];
dragging = NO;
if ([delegate respondsToSelector:@selector(thumbImageViewStoppedTracking:)])
[delegate thumbImageViewStoppedTracking:self];
}
- (void)goHome {
float distanceFromHome = distanceBetweenPoints([self frame].origin, [self home].origin); // distance is in pixels
float animationDuration = 0.1 + distanceFromHome * 0.001;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:animationDuration];
[self setFrame:[self home]];
[UIView commitAnimations];
}
- (void)moveByOffset:(CGPoint)offset {
CGRect frame = [self frame];
frame.origin.x += offset.x;
frame.origin.y += offset.y;
[self setFrame:frame];
if ([delegate respondsToSelector:@selector(thumbImageViewMoved:)])
[delegate thumbImageViewMoved:self];
}
@end
float distanceBetweenPoints(CGPoint a, CGPoint b) {
float deltaX = a.x - b.x;
float deltaY = a.y - b.y;
return sqrtf( (deltaX * deltaX) + (deltaY * deltaY) );
}
Then use it
// Left photo
ThumbImageView *thumbViewLeft = [[[ThumbImageView alloc] initWithImageAtUrl:url] autorelease];
thumbViewLeft.userInteractionEnabled = YES;
thumbViewLeft.exclusiveTouch = NO;
thumbViewLeft.layer.borderWidth = 1.0f;
thumbViewLeft.layer.borderColor = [[UIColor lightGrayColor] CGColor];
[thumbViewLeft setDelegate:self];
CGRect frame = [thumbViewLeft frame];
frame.origin.y = IMAGE_PADDING;
frame.origin.x = xPosition;
frame.size = CGSizeMake(imageWidth,IMAGE_HEIGHT);
[thumbViewLeft setFrame:frame];
[thumbViewLeft setHome:frame];
thumbViewLeft.tag = LEFT_IMAGE;
//image =[[UIImage alloc] initWithContentsOfFile:[root stringByAppendingPathComponent:@"cover_preload.jpg"]];
//[thumbViewLeft setImage:[ImagePopulate image:image fitInSize:thumbViewLeft.frame.size]];
//[image release];
[cell.contentView addSubview:thumbViewLeft];
xPosition += (frame.size.width + IMAGE_PADDING);
Happy with programming
