How do I animate a UIImageView left to right with UIPageControl? - animation

Question

I want to animate a UIImageView left to right with UIPageControl. I have this code but it seems a bit odd...Specifically because what would I do when I reach image 3? I would have to return and that would mess up the mathematical calculations of the views in the pageControl array the way I have it set up:
-(void)createUIViews{
UIImage *image1 = [UIImage imageNamed:#"GiftCard.png"];
firstView = [[UIImageView alloc] initWithImage:image1];
firstView.backgroundColor = [UIColor grayColor];
firstView.tag = 1;
firstView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin);
[self.view addSubview:firstView];
CGRect newFrame = firstView.frame;
newFrame.origin.x += 40; // shift right by 50pts
newFrame.origin.y += 40;
[UIView animateWithDuration:1.0
animations:^{
firstView.frame = newFrame;
}];
UIImage *image2 = [UIImage imageNamed:#"MyCard.png"];
secondView = [[UIImageView alloc] initWithImage:image2];
secondView.backgroundColor = [UIColor grayColor];
secondView.tag = 1;
secondView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin);
UIImage *image3 = [UIImage imageNamed:#"GiftCard.png"];
thirdView = [[UIImageView alloc] initWithImage:image3];
thirdView.backgroundColor = [UIColor grayColor];
thirdView.tag = 1;
thirdView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin);
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self createUIViews];
// Set up the views array with 3 UIImageViews
views = [[NSArray alloc] initWithObjects:firstView, secondView, thirdView, nil];
// Set pageControl's numberOfPages to 3
self.pageControl.numberOfPages = [views count];
// Set pageControl's currentPage to 0
self.pageControl.currentPage = 0;
// Call changePage each time value of pageControl changes
[self.pageControl addTarget:self action:#selector(changePage:) forControlEvents:UIControlEventValueChanged];
}
- (IBAction) changePage:(id)sender {
NSLog(#"pageControl position %d", [self.pageControl currentPage]);
int oldPageControlPosition = [self.pageControl currentPage] - 1;
NSLog(#"old pageControl position %d", oldPageControlPosition);
//0 Get the currentview as referenced by pageControl
UIImageView *oldView = [views objectAtIndex:oldPageControlPosition];
//NSLog(#"views objectAtIndex = %#",[views objectAtIndex:[self.pageControl currentPage]]);
//1 Animate out the old view
CGRect oldViewFrame = oldView.frame;
oldViewFrame.origin.x -= 300;
[UIView animateWithDuration:2.0
delay: 0.5
options: UIViewAnimationOptionCurveEaseIn
animations:^{
oldView.frame = oldViewFrame;
}
completion:nil];
//3 Get next view from array
UIImageView *nextView = [views objectAtIndex:[self.pageControl currentPage]];
//4 Add it to mainview
[self.view addSubview:nextView];
//5 Animate in
CGRect nextViewFrame = nextView.frame;
nextViewFrame.origin.x += 40; // shift right by 50pts
nextViewFrame.origin.y += 40;
[UIView animateWithDuration:1.0
animations:^{
nextView.frame = nextViewFrame;
}];
}
When I reach the end, I try to return, the last position is 2 and oldPosition at that time is 1. Which is correct, array goes from 0 to 1 to 2 for a total of 3 positions. But when I return, the log displays position as 1 instead of 2, which is fine, because I reversed...but old position shows 0 instead of 2.

Answer 1

I couldnt get it to determine direction so I ended up using gesture recognizers with swipe left and swipe right instances. Here is the code:
//Help determine direction of swipe
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeNext:)];
swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
[self.scrollView addGestureRecognizer:swipeLeft];
UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipePrev:)];
swipeRight.direction = UISwipeGestureRecognizerDirectionRight;
[self.scrollView addGestureRecognizer:swipeRight];