Resize UIScrollView on Long Press Gesture

Question

I have a UIScrollView at the very top (just below the navigation bar) of a UITableViewController using Storyboards. The UIScrollView's default size is 320x50. When the user holds the scrollView for at least 1 second, I want the UIScrollView to get twice as big (320x100) in order to show additional details with an animation. The UITableView right below it should animate with it if possible and move down 50.

Holding the UIScrollView for at least 1 second when it's in the bigger setting will result in the opposite animation, and the UIScrollView will animate back to its original size.

How would I do this? Thank you ahead of time! Here's what I have so far:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.featureScrollExpanded = NO;
    UILongPressGestureRecognizer* featureHold = [[UILongPressGestureRecognizer alloc] initWithTarget:self  action:@selector (longHold:)];

    [featureHold setDelaysTouchesBegan : YES];
    featureHold.minimumPressDuration = 0.6;
    featureHold.numberOfTouchesRequired = 1;
    [self.featureScrollView addGestureRecognizer:featureHold];
    [featureHold release];
}

- (void)longHold:(UIGestureRecognizer*)sender {
    if (self.featureScrollExpanded==NO) {
        self.featureScrollExpanded=YES;
        //make it bigger

    }
    else {
        self.featureScrollExpanded=NO;
        //make it smaller

    }
}

what would i put where it says '//make it bigger' and '//make it smaller' in order to resize 'self.featureScrollView' with an animation? I'm just not sure what to do there. — felix_xiao

Ron Ron · Accepted Answer · 2012-12-20T03:15:32

Do an animation:

CGRect frame = yourScrollView.frame;
frame.size.height += 50;
[UIView animateWithDuration:0.6
                     animations:^{
                         yourScrollView.frame = frame;
                     } completion:^(BOOL finished) {
                            //do your other animation here if you want to 
                            //or do them both together and lose this block
                     }
     ];

Or if you want it a bit more with an overview:

CGRect frame = yourScrollView.frame;
frame.size.height += 50;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.6];

[self.yourScrollView setFrame:frame];

[UIView commitAnimations];

Resize UIScrollView on Long Press Gesture

1 Answers