How to animate deletion of a label? - ios

Question

I have a view controller that have a scroll view that bounce horizontally , and in this scroll view I have a label.
I can now hold the label and scroll it down, and if I release it will bounce up back.
What I want is that: When I scroll the view y coordinate (using myScrollView.contentOffset.y) to some value, lets say -33 and under I can release my fine and the label will animate to the bottom of the screen and disappear, and now I can set the label to be a new value, and It will animate from top to the label original position.
Here a photo of how the view controller looks like:
And this is the relevant method I already implemented (powered by #rebello95):
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (self.myScrollView.contentOffset.y <= -73) {
[UIView animateWithDuration:0.3 animations:^{
self.homeLabel.alpha = 0.0;
} completion:^(BOOL finished) {
[self.homeLabel removeFromSuperview];
self.homeLabel = nil;
}];
}
NSLog(#"%f", self.myScrollView.contentOffset.y);
}
Now I want it to slide to the bottom of the page and fade.
thanks!

Answer 1

EDIT: The animation now moves the label to the bottom of the view controller then fades it out.
You can use an animation block to move the label, then put another block inside the completion block to fade out the label, then remove it after the animation completes.
Example:
[UIView animateWithDuration:0.3 animations:^{
[self.myLabel setFrame:CGRectMake(self.myLabel.frame.origin.x, self.view.frame.size.height - self.myLabel.frame.size.height, self.myLabel.frame.size.width, self.myLabel.frame.size.height)];
self.labelRemoving = YES;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.3 animations:^{
self.myLabel.alpha = 0.0;
} completion:^(BOOL finished) {
[self.myLabel removeFromSuperview];
self.myLabel = nil;
self.labelRemoving = NO;
}];
}];
Sidenote: You should probably be using <= instead of == in your if statement to achieve your desired results. In addition, you may want to set a flag to indicate that your label is being removed (since that method will inevitably be called multiple times). Something like this:
//.h
#property (nonatomic, assign) BOOL labelRemoving;
//.m
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (self.myScrollView.contentOffset.y <= -33 && !self.labelRemoving) {
[UIView animateWithDuration:0.3 animations:^{
[self.myLabel setFrame:CGRectMake(self.myLabel.frame.origin.x, self.view.frame.size.height - self.myLabel.frame.size.height, self.myLabel.frame.size.width, self.myLabel.frame.size.height)];
self.labelRemoving = YES;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.3 animations:^{
self.myLabel.alpha = 0.0;
} completion:^(BOOL finished) {
[self.myLabel removeFromSuperview];
self.myLabel = nil;
self.labelRemoving = NO;
}];
}];
}
NSLog(#"%f", self.myScrollView.contentOffset.y);
}