Circular Scroll View

Question

Hi all,
I am trying to implement a circular scroll view.
I have added the scroll views and 3 uiview's to the scroll view as the subview.
It is working fine, but after sometimes the scroll view's delegates are not getting called.
// MyScrollViewViewController.h
// MyScrollView
// Created by Biranchi on 26/05/09.
// Copyright PurpleTalk 2009. All rights reserved.
#import <UIKit/UIKit.h>
@interface MyScrollViewViewController : UIViewController <UIScrollViewDelegate> {
IBOutlet UIScrollView *scrollView;
IBOutlet UIView *view1;
IBOutlet UIView *view2;
IBOutlet UIView *view3;
IBOutlet UILabel *label1;
IBOutlet UILabel *label2;
IBOutlet UILabel *label3;
int viewAtIndex;
int currentOffset;
int firstOffset, lastOffset;
int currentContentInset;
int tempOffset;
NSMutableArray *arr;
@end
// MyScrollViewViewController.m
// MyScrollView
// Created by Biranchi on 26/05/09.
// Copyright PurpleTalk 2009. All rights reserved.
#import "MyScrollViewViewController.h"
@implementation MyScrollViewViewController
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
// Custom initialization
return self;
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
//static int j = 0;
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
arr = [[NSMutableArray alloc] init];
[arr addObject:view1];
[arr addObject:view2];
[arr addObject:view3];
//NSLog(@"arr : %@", arr);
scrollView.minimumZoomScale = 1.0f;
scrollView.maximumZoomScale = 2.0f;
scrollView.delegate = self;
//scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
firstOffset = 0;
currentOffset = 320;
lastOffset = 640;
currentContentInset = 320;
CGRect frame;
//Scroll View
frame = [view1 frame];
[view1 setBackgroundColor:[UIColor redColor]];
frame.origin.x = 0;
[view1 setFrame:frame];
frame = [view2 frame];
[view2 setBackgroundColor:[UIColor greenColor]];
frame.origin.x = 320;
[view2 setFrame:frame];
frame = [view3 frame];
[view3 setBackgroundColor:[UIColor blueColor]];
frame.origin.x = 640;
[view3 setFrame:frame];
[scrollView addSubview:view1];
[scrollView addSubview:view2];
[scrollView addSubview:view3];
[scrollView setContentSize:CGSizeMake(3*320, 480)];
[scrollView setContentOffset: CGPointMake(currentOffset,0) animated:NO];
[self.view addSubview:scrollView];
//NSLog(@"Self.view Subviews : %@", [self.view subviews]);
#pragma mark -
#pragma mark ScrollView Delegate
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView1
NSLog(@"Will begin dragging ===");
CGPoint offset = [scrollView1 contentOffset];
tempOffset = offset.x;
NSLog(@"Offset : %@", NSStringFromCGPoint(offset));
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView1
NSLog(@"ScrollView did end decelerating ");
int i, result;
CGPoint offset = [scrollView1 contentOffset];
currentOffset = offset.x;
NSLog(@"Offset : %@", NSStringFromCGPoint(offset));
if( ( (currentOffset - tempOffset) > 0 ) || ( (currentOffset == tempOffset) && (currentOffset == lastOffset) ) )
NSLog(@"Show next page , current : %d, temp : %d", currentOffset, tempOffset);
for(i=0; i<[arr count]; i++)
if( [[arr objectAtIndex:i] frame].origin.x == currentOffset )
NSLog(@"Current view on screen : %d", i);
break;
NSLog(@"Before Current offset : %d, last offset : %d", currentOffset, lastOffset);
if( currentOffset == lastOffset )
result = i-2;
if(result < 0)
result += 3;
NSLog(@"Change the frame of object at index : %d", result);
[[arr objectAtIndex:result] setFrame:CGRectMake(currentOffset + 320, 0, 320, 480)];
[scrollView1 setContentSize:CGSizeMake(currentOffset+640,480) ];
lastOffset += 320;
firstOffset += 320;
NSLog(@"Current offset : %d, first offset : %d , last offset : %d", currentOffset, firstOffset, lastOffset);
else if( ( (currentOffset - tempOffset) < 0 ) || ( (currentOffset == tempOffset) && (currentOffset == firstOffset) ) )
//NSLog(@"Show prev page");
for(i=0; i<[arr count]; i++)
if( [[arr objectAtIndex:i] frame].origin.x == currentOffset )
NSLog(@"==Current view on screen : %d", i);
break;
NSLog(@"==Before Current offset : %d, First offset : %d", currentOffset, firstOffset);
if( currentOffset == firstOffset )
result = i+2;
if(result >= 3)
result -= 3;
NSLog(@"==Change the frame of object at index : %d", result);
[[arr objectAtIndex:result] setFrame:CGRectMake(currentOffset - 320, 0, 320, 480)];
UIEdgeInsets contentInset = {0,currentContentInset,0,0};
[scrollView1 setContentInset:contentInset ];
firstOffset -= 320;
currentContentInset += 320;
lastOffset -= 320;
NSLog(@"==Current offset : %d, first offset : %d, Last Offset : %d", currentOffset, firstOffset, lastOffset);
else
NSLog(@"Error in offset");
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView1
return [[scrollView1 subviews] objectAtIndex:viewAtIndex];
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView1 withView:(UIView *)view atScale:(float)scale
//NSLog(@"View Zoomed : %@, scale : %f", view, scale);
#pragma mark -
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceO rientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview
// Release anything that's not essential, such as cached data
- (void)dealloc {
[super dealloc];
@end
What is the problem?
Thanks for your help in advance...

Answer 1

This problem is solved.