Slide out navigation programmatically in Swift - ios

Question

I am looking for a slide out navigation. I am not using cocoa pods and storyboard. Any good reference available so that my side view slides on top of the centre view. I followed rayweinderlich sample code however the side menu comes under the main view.Here is the shadow code and animation code
if shouldShowShadow {
centerNavigationController.view.layer.shadowOpacity = 0.8
} else {
centerNavigationController.view.layer.shadowOpacity = 0.0
}
This is the animation method.The centre panel should be at the bottom and side menu should come over
func animateCenterPanelXPosition(targetPosition: CGFloat, completion: ((Bool) -> Void)? = nil) {
UIView.animate(withDuration: 0.5,
delay: 0,
usingSpringWithDamping: 0.8,
initialSpringVelocity: 0,
options: .curveEaseInOut, animations: {
self.centerNavigationController.view.frame.origin.x = targetPosition
}, completion: completion)
}
func animateLeftPanel(shouldExpand: Bool) {
if shouldExpand {
currentState = .leftPanelExpanded
animateCenterPanelXPosition(
targetPosition: centerNavigationController.view.frame.width - centerPanelExpandedOffset)
} else {
animateCenterPanelXPosition(targetPosition: 0) { _ in
self.currentState = .bothCollapsed
self.leftViewController?.view.removeFromSuperview()
self.leftViewController = nil
}
}
}
This is how a side panel is added.MenuViewController is the side panel
func addChildSidePanelController(_ sidePanelController: MenuViewController) {
sidePanelController.delegate = centerViewController
view.insertSubview(sidePanelController.view, at: 0)
addChild(sidePanelController)
sidePanelController.didMove(toParent: self)
}