Resizing a UIView hides subviews - ios

Question

I have a view controller with a view that doesn't fill the screen and has transparency around the edges. In said view I have a tableview, some buttons and a text field.
I have all of the controls attached to the bottom of the view with constraints and the tableview attached to the top.
Everything resizes fine when the device is put in landscape/portrait mode, but when I manually resize it when the keyboard appears, the bottom of the view just moves up and covers the lowest elements.
Resizing/animation code:
- (void)keyboardDidShow:(NSNotification *)notification {
//Stuff to get keyboard frames
void (^animations)() = ^() {
CGRect mainViewFrame = self.mainView.frame;
CGRect tableViewFrame = self.tableView.frame;
tableViewFrame.size.height = tableViewFrame.size.height - 50;
mainViewFrame.size.height = mainViewFrame.size.height - 50;
CGFloat paddingOffset = self.view.frame.size.height - self.mainView.frame.origin.y - self.mainView.frame.size.height;
mainViewFrame.origin.y = (mainViewFrame.origin.y - keyboardEndFrame.size.height + paddingOffset - 8);
self.mainView.frame = mainViewFrame;
[self.tableView setNeedsLayout];
[self.mainView setNeedsLayout];
};
[UIView animateWithDuration:animationDuration
delay:0.0
options:(animationCurve << 16)
animations:animations
completion:^(BOOL finished){
if (finished) {
NSLog(#"Finished animating");
self.acceptBottomConstraint.constant = 5;
self.cancelBottomConstraint.constant = 5;
}
}];
}
This is my UI in the Storyboard:
This is what it looks like after resizing: