How to create view based animation in objective c? - ios

Question

I have to add the following animation in my iOS app, I have used a scroll bar along with UITableView and achieved the top and bottom animation, but I'm still stuck at the middle animation part where the 4 UIViews come in a single horizontal line. Any suggestions?
http://www.image-maps.com/m/private/0/af8u4ulika9siddnf6k6hhrtg2_untitled-2.gif
Code:-
#implementation AnimatedView {
UIScrollView *mainScroll;
UIScrollView *backgroundScrollView;
UILabel *_textLabel;
UITableView *_commentsTableView;
UIView *menuView;
UIView *_commentsViewContainer;
UIView *fadeView;
UIImageView *imageView;
NSMutableArray *comments;
}
- (id)init {
self = [super init];
if (self) {
_mainScrollView = [[UIScrollView alloc] initWithFrame:[UIApplication sharedApplication].keyWindow.frame];
self.view = _mainScrollView;
_backgroundScrollView = [[UIScrollView alloc] initWithFrame:HEADER_INIT_FRAME];
imageView = [[UIImageView alloc] initWithFrame:HEADER_INIT_FRAME];
fadeView = [[UIView alloc] initWithFrame:imageView.frame];
_textLabel = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 100.0f, 150.0f, 25.0f)];
menuView = [[UIView alloc] initWithFrame:CGRectMake(0,_textLabel.frame.size.height+150, self.view.frame.size.width+30, 180)];
[_backgroundScrollView addSubview:imageView];
[_backgroundScrollView addSubview:fadeView];
[_backgroundScrollView addSubview:menuView];
[_backgroundScrollView addSubview:_textLabel];
_commentsViewContainer = [[UIView alloc] init];
_commentsTableView = [[UITableView alloc] init];
_commentsTableView.scrollEnabled = NO;
_commentsTableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
[self.view addSubview:_backgroundScrollView];
[_commentsViewContainer addSubview:_commentsTableView];
[self.view addSubview:_commentsViewContainer];
// fake data!
comments = [#[#"Array for tableview"] mutableCopy];
}
return self;
}
#pragma mark Scroll
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat delta = 0.0f;
CGRect rect = HEADER_INIT_FRAME;
// Here is where I do the "Zooming" image and the quick fade out the text and toolbar
if (scrollView.contentOffset.y < 0.0f) {
delta = fabs(MIN(0.0f, _mainScrollView.contentOffset.y));
_backgroundScrollView.frame = CGRectMake(CGRectGetMinX(rect) - delta / 2.0f, CGRectGetMinY(rect) - delta, CGRectGetWidth(rect) + delta, CGRectGetHeight(rect) + delta);
[_commentsTableView setContentOffset:(CGPoint){0,0} animated:NO];
} else {
delta = _mainScrollView.contentOffset.y;
_textLabel.alpha = 1.0f;
CGFloat backgroundScrollViewLimit = _backgroundScrollView.frame.size.height - kBarHeight;
// Here I check whether or not the user has scrolled passed the limit where I want to stick the header, if they have then I move the frame with the scroll view
// to give it the sticky header look
if (delta > backgroundScrollViewLimit) {
_backgroundScrollView.frame = (CGRect) {.origin = {0, delta - _backgroundScrollView.frame.size.height + kBarHeight}, .size = {self.view.frame.size.width, HEADER_HEIGHT}};
_commentsViewContainer.frame = (CGRect){.origin = {0, CGRectGetMinY(_backgroundScrollView.frame) + CGRectGetHeight(_backgroundScrollView.frame)}, .size = _commentsViewContainer.frame.size };
_commentsTableView.contentOffset = CGPointMake (0, delta - backgroundScrollViewLimit);
CGFloat contentOffsetY = -backgroundScrollViewLimit * kBackgroundParallexFactor;
[_backgroundScrollView setContentOffset:(CGPoint){0,contentOffsetY} animated:NO];
}
else {
_backgroundScrollView.frame = rect;
_commentsViewContainer.frame = (CGRect){.origin = {0, CGRectGetMinY(rect) + CGRectGetHeight(rect)}, .size = _commentsViewContainer.frame.size };
[_commentsTableView setContentOffset:(CGPoint){0,0} animated:NO];
[_backgroundScrollView setContentOffset:CGPointMake(0, -delta * kBackgroundParallexFactor)animated:NO];
}
}
}
- (void)viewDidAppear:(BOOL)animated {
_mainScrollView.contentSize = CGSizeMake(CGRectGetWidth(self.view.frame), _commentsTableView.contentSize.height + CGRectGetHeight(_backgroundScrollView.frame));
}

Answer 1

You don't need any scrollview to implement this really. All you need is 1 UITableView with 2 sections. First section has a single empty element (but set the row height to 0), and enable the header for both sections. You can use UIViews for the headerViews. Then, you only need to change the header height (with icon positioning) based on tableview Delegate scrollViewDidScroll. scrollViewDidScroll is also a delegate of UITableView since one of TableView's element inherits from UIScrollView.