Animate Height of UITableView - ios

Question

I am trying to animate the tableviews height when the collection view scrolls. I call the animation function from scrollViewWillBeginDragging. Then I execute an animation block:
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
if expanded == false && scrollView == IBcalendarCollectionView {
expanded = true
expandCollectionView()
}
}
func expandCollectionView() {
let screenSize: CGRect = UIScreen.mainScreen().bounds
UIView.animateWithDuration(3, delay: 0, options: UIViewAnimationOptions.TransitionNone, animations: { () -> Void in
self.IBcalendarTableView.frame = CGRectMake(self.IBcalendarTableView.frame.origin.x, screenSize.height/2, self.IBcalendarTableView.frame.width, screenSize.height/2)
}) { (success) -> Void in
print(self.IBcalendarTableView.frame.origin.y)
}
}
Whats happening is the TableView animates up to the status bar then returns to its original position. I want it to animate down to half the size of the screen. The animation block is only executed once because I set a boolean when the animation function is called.

Answer 1

you say you set a boolean when the animation block is called, is that so the animation is not being called again and again? I also don't see that in your code.
This should work fine.
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
let mainScreen = UIScreen.mainScreen().bounds
if (self.IBcalendarTableView.frame.origin.y != mainScreen.height / 2) {
var frame = self.IBcalendarTableView.frame
frame.origin.y = mainScreen.height / 2
frame.size.height = frame.origin.y
UIView.animateWithDuration(0.5) { () -> Void in
self.IBcalendarTableView.frame = frame
}
}
}
I set a lower animation speed, 3 seconds seems like a lot... I also built the frame differently, I just do it because I find it easier to read.
Please let me know if there is anything else I can do to help.

Answer 2

The issue is with autolayout. You have to also set the height constraint of the tableview in order to keep the tableview at the new height/origin.
For anyone else who may have this issue:
Dynamic UITableView height
This answer helped me solve this problem. My fixed code looks like this:
func expandCollectionView() {
let screenSize: CGRect = UIScreen.mainScreen().bounds
var frame = self.IBcalendarTableView.frame
frame.origin.y = screenSize.height / 2
frame.size.height = frame.origin.y
UIView.animateWithDuration(0.5) { () -> Void in
self.IBcalendarTableView.frame = frame
self.IBtableViewHeightConstraint.constant = screenSize.height/2
}
}