diff --git a/PanModal/Controller/PanModalPresentationController.swift b/PanModal/Controller/PanModalPresentationController.swift
index 23ae3fd7..525c6ad4 100644
--- a/PanModal/Controller/PanModalPresentationController.swift
+++ b/PanModal/Controller/PanModalPresentationController.swift
@@ -24,7 +24,6 @@ import UIKit
  the presented view can define its layout configuration & presentation.
  */
 open class PanModalPresentationController: UIPresentationController {
-
     /**
      Enum representing the possible presentation states
      */
@@ -36,7 +35,7 @@ open class PanModalPresentationController: UIPresentationController {
     /**
      Constants
      */
-    struct Constants {
+    enum Constants {
         static let indicatorYOffset = CGFloat(8.0)
         static let snapMovementSensitivity = CGFloat(0.7)
         static let dragIndicatorSize = CGSize(width: 36.0, height: 5.0)
@@ -142,7 +141,7 @@ open class PanModalPresentationController: UIPresentationController {
     /**
      Override presented view to return the pan container wrapper
      */
-    public override var presentedView: UIView {
+    override public var presentedView: UIView {
         return panContainerView
     }
 
@@ -152,20 +151,20 @@ open class PanModalPresentationController: UIPresentationController {
      Gesture recognizer to detect & track pan gestures
      */
     private lazy var panGestureRecognizer: UIPanGestureRecognizer = {
-        let gesture = UIPanGestureRecognizer(target: self, action: #selector(didPanOnPresentedView(_ :)))
+        let gesture = UIPanGestureRecognizer(target: self, action: #selector(didPanOnPresentedView(_:)))
         gesture.minimumNumberOfTouches = 1
         gesture.maximumNumberOfTouches = 1
         gesture.delegate = self
         return gesture
     }()
-    
+
     private lazy var swipeDownGestrue: UISwipeGestureRecognizer = {
         let gesture = UISwipeGestureRecognizer(target: self, action: #selector(swipeDownAction))
         gesture.direction = .down
         return gesture
     }()
-    
-    @objc func swipeDownAction(){
+
+    @objc func swipeDownAction() {
         presentedViewController.dismiss(animated: true)
     }
 
@@ -183,9 +182,12 @@ open class PanModalPresentationController: UIPresentationController {
     }
 
     override public func presentationTransitionWillBegin() {
-
         guard let containerView = containerView
-            else { return }
+        else { return }
+
+        if panContainerView.frame == .zero {
+            adjustPresentedViewFrame()
+        }
 
         layoutBackgroundView(in: containerView)
         layoutPresentedView(in: containerView)
@@ -229,7 +231,7 @@ open class PanModalPresentationController: UIPresentationController {
 
     override public func dismissalTransitionDidEnd(_ completed: Bool) {
         if !completed { return }
-        
+
         presentable?.panModalDidDismiss()
     }
 
@@ -243,7 +245,7 @@ open class PanModalPresentationController: UIPresentationController {
             guard
                 let self = self,
                 let presentable = self.presentable
-                else { return }
+            else { return }
 
             self.adjustPresentedViewFrame()
             if presentable.shouldRoundTopCorners {
@@ -251,21 +253,18 @@ open class PanModalPresentationController: UIPresentationController {
             }
         })
     }
-
 }
 
 // MARK: - Public Methods
 
 public extension PanModalPresentationController {
-
     /**
      Transition the PanModalPresentationController
      to the given presentation state
      */
     func transition(to state: PresentationState) {
-
         guard presentable?.shouldTransition(to: state) == true
-            else { return }
+        else { return }
 
         presentable?.willTransition(to: state)
 
@@ -286,9 +285,8 @@ public extension PanModalPresentationController {
      with scroll observation temporarily disabled.
      */
     func performUpdates(_ updates: () -> Void) {
-
         guard let scrollView = presentable?.panScrollable
-            else { return }
+        else { return }
 
         // Pause scroll observer
         scrollObserver?.invalidate()
@@ -315,20 +313,19 @@ public extension PanModalPresentationController {
         observe(scrollView: presentable?.panScrollable)
         configureScrollViewInsets()
     }
-
 }
 
 // MARK: - Presented View Layout Configuration
 
 private extension PanModalPresentationController {
-
     /**
      Boolean flag to determine if the presented view is anchored
      */
     var isPresentedViewAnchored: Bool {
-        if !isPresentedViewAnimating
-            && extendsPanScrolling
-            && presentedView.frame.minY.rounded() <= anchoredYPosition.rounded() {
+        if !isPresentedViewAnimating,
+           extendsPanScrolling,
+           presentedView.frame.minY.rounded() <= anchoredYPosition.rounded()
+        {
             return true
         }
 
@@ -341,13 +338,12 @@ private extension PanModalPresentationController {
      based on the pan modal presentable.
      */
     func layoutPresentedView(in containerView: UIView) {
-
         /**
          If the presented view controller does not conform to pan modal presentable
          don't configure
          */
         guard let presentable = presentable
-            else { return }
+        else { return }
 
         /**
          ⚠️ If this class is NOT used in conjunction with the PanModalPresentationAnimator
@@ -355,15 +351,15 @@ private extension PanModalPresentationController {
          in the presentation animator instead of here
          */
         containerView.addSubview(presentedView)
-        
+
         if presentable.noNeedGes == false {
             if presentable.canDrag {
                 containerView.addGestureRecognizer(panGestureRecognizer)
-            }else{
+            } else {
                 containerView.addGestureRecognizer(swipeDownGestrue)
             }
         }
-        
+
         if presentable.showDragIndicator {
             addDragIndicatorView(to: presentedView)
         }
@@ -375,21 +371,18 @@ private extension PanModalPresentationController {
         setNeedsLayoutUpdate()
         adjustPanContainerBackgroundColor()
     }
-    
-    
 
     /**
      Reduce height of presentedView so that it sits at the bottom of the screen
      */
     func adjustPresentedViewFrame() {
-
         guard let frame = containerView?.frame
-            else { return }
+        else { return }
 
         let adjustedSize = CGSize(width: frame.size.width, height: frame.size.height - anchoredYPosition)
         let panFrame = panContainerView.frame
         panContainerView.frame.size = frame.size
-        
+
         if ![shortFormYPosition, longFormYPosition].contains(panFrame.origin.y) {
             // if the container is already in the correct position, no need to adjust positioning
             // (rotations & size changes cause positioning to be out of sync)
@@ -440,9 +433,8 @@ private extension PanModalPresentationController {
      Calculates & stores the layout anchor points & options
      */
     func configureViewLayout() {
-
         guard let layoutPresentable = presentedViewController as? PanModalPresentable.LayoutType
-            else { return }
+        else { return }
 
         shortFormYPosition = layoutPresentable.shortFormYPos
         longFormYPosition = layoutPresentable.longFormYPos
@@ -456,11 +448,10 @@ private extension PanModalPresentationController {
      Configures the scroll view insets
      */
     func configureScrollViewInsets() {
-
         guard
             let scrollView = presentable?.panScrollable,
             !scrollView.isScrolling
-            else { return }
+        else { return }
 
         /**
          Disable vertical scroll indicator until we start to scroll
@@ -483,24 +474,21 @@ private extension PanModalPresentationController {
             scrollView.contentInsetAdjustmentBehavior = .never
         }
     }
-
 }
 
 // MARK: - Pan Gesture Event Handler
 
 private extension PanModalPresentationController {
-
     /**
      The designated function for handling pan gesture events
      */
     @objc func didPanOnPresentedView(_ recognizer: UIPanGestureRecognizer) {
-
         guard
             shouldRespond(to: recognizer),
             let containerView = containerView
-            else {
-                recognizer.setTranslation(.zero, in: recognizer.view)
-                return
+        else {
+            recognizer.setTranslation(.zero, in: recognizer.view)
+            return
         }
 
         switch recognizer.state {
@@ -514,7 +502,7 @@ private extension PanModalPresentationController {
             /**
              If presentedView is translated above the longForm threshold, treat as transition
              */
-            if presentedView.frame.origin.y == anchoredYPosition && extendsPanScrolling {
+            if presentedView.frame.origin.y == anchoredYPosition, extendsPanScrolling {
                 presentable?.willTransition(to: .longForm)
             }
 
@@ -526,7 +514,6 @@ private extension PanModalPresentationController {
             let velocity = recognizer.velocity(in: presentedView)
 
             if isVelocityWithinSensitivityRange(velocity.y) {
-
                 /**
                  If velocity is within the sensitivity range,
                  transition to a presentation state or dismiss entirely.
@@ -538,7 +525,8 @@ private extension PanModalPresentationController {
                     transition(to: .longForm)
 
                 } else if (nearest(to: presentedView.frame.minY, inValues: [longFormYPosition, containerView.bounds.height]) == longFormYPosition
-                    && presentedView.frame.minY < shortFormYPosition) || presentable?.allowsDragToDismiss == false {
+                    && presentedView.frame.minY < shortFormYPosition) || presentable?.allowsDragToDismiss == false
+                {
                     transition(to: .shortForm)
 
                 } else {
@@ -546,7 +534,6 @@ private extension PanModalPresentationController {
                 }
 
             } else {
-
                 /**
                  The `containerView.bounds.height` is used to determine
                  how close the presented view is to the bottom of the screen
@@ -577,11 +564,11 @@ private extension PanModalPresentationController {
     func shouldRespond(to panGestureRecognizer: UIPanGestureRecognizer) -> Bool {
         guard
             presentable?.shouldRespond(to: panGestureRecognizer) == true ||
-                !(panGestureRecognizer.state == .began || panGestureRecognizer.state == .cancelled)
-            else {
-                panGestureRecognizer.isEnabled = false
-                panGestureRecognizer.isEnabled = true
-                return false
+            !(panGestureRecognizer.state == .began || panGestureRecognizer.state == .cancelled)
+        else {
+            panGestureRecognizer.isEnabled = false
+            panGestureRecognizer.isEnabled = true
+            return false
         }
         return !shouldFail(panGestureRecognizer: panGestureRecognizer)
     }
@@ -616,7 +603,6 @@ private extension PanModalPresentationController {
      from one view to another in the same pan gesture so don't cancel
      */
     func shouldFail(panGestureRecognizer: UIPanGestureRecognizer) -> Bool {
-
         /**
          Allow api consumers to override the internal conditions &
          decide if the pan gesture recognizer should be prioritized.
@@ -634,8 +620,8 @@ private extension PanModalPresentationController {
             isPresentedViewAnchored,
             let scrollView = presentable?.panScrollable,
             scrollView.contentOffset.y > 0
-            else {
-                return false
+        else {
+            return false
         }
 
         let loc = panGestureRecognizer.location(in: presentedView)
@@ -672,7 +658,7 @@ private extension PanModalPresentationController {
      */
     func adjust(toYPosition yPos: CGFloat) {
         presentedView.frame.origin.y = max(yPos, anchoredYPosition)
-        
+
         guard presentedView.frame.origin.y > shortFormYPosition else {
             backgroundView.dimState = .max
             return
@@ -696,7 +682,7 @@ private extension PanModalPresentationController {
      */
     func nearest(to number: CGFloat, inValues values: [CGFloat]) -> CGFloat {
         guard let nearestVal = values.min(by: { abs(number - $0) < abs(number - $1) })
-            else { return number }
+        else { return number }
         return nearestVal
     }
 }
@@ -704,7 +690,6 @@ private extension PanModalPresentationController {
 // MARK: - UIScrollView Observer
 
 private extension PanModalPresentationController {
-
     /**
      Creates & stores an observer on the given scroll view's content offset.
      This allows us to track scrolling without overriding the scrollView delegate
@@ -717,7 +702,7 @@ private extension PanModalPresentationController {
              Incase we have a situation where we have two containerViews in the same presentation
              */
             guard self?.containerView != nil
-                else { return }
+            else { return }
 
             self?.didPanOnScrollView(scrollView, change: change)
         }
@@ -733,21 +718,18 @@ private extension PanModalPresentationController {
      which allows us to seamlessly transition scrolling from the panContainerView to the scrollView
      */
     func didPanOnScrollView(_ scrollView: UIScrollView, change: NSKeyValueObservedChange<CGPoint>) {
-
         guard
             !presentedViewController.isBeingDismissed,
             !presentedViewController.isBeingPresented
-            else { return }
+        else { return }
 
         if !isPresentedViewAnchored && scrollView.contentOffset.y > 0 {
-
             /**
              Hold the scrollView in place if we're actively scrolling and not handling top bounce
              */
             haltScrolling(scrollView)
 
         } else if scrollView.isScrolling || isPresentedViewAnimating {
-
             if isPresentedViewAnchored {
                 /**
                  While we're scrolling upwards on the scrollView,
@@ -761,9 +743,9 @@ private extension PanModalPresentationController {
                 haltScrolling(scrollView)
             }
 
-        } else if presentedViewController.view.isKind(of: UIScrollView.self)
-            && !isPresentedViewAnimating && scrollView.contentOffset.y <= 0 {
-
+        } else if presentedViewController.view.isKind(of: UIScrollView.self),
+                  !isPresentedViewAnimating, scrollView.contentOffset.y <= 0
+        {
             /**
              In the case where we drag down quickly on the scroll view and let go,
              `handleScrollViewTopBounce` adds a nice elegant touch.
@@ -802,9 +784,8 @@ private extension PanModalPresentationController {
      So, for example, a UITableViewController.
      */
     func handleScrollViewTopBounce(scrollView: UIScrollView, change: NSKeyValueObservedChange<CGPoint>) {
-
         guard let oldYValue = change.oldValue?.y, scrollView.isDecelerating
-            else { return }
+        else { return }
 
         let yOffset = scrollView.contentOffset.y
         let presentedSize = containerView?.frame.size ?? .zero
@@ -834,7 +815,6 @@ private extension PanModalPresentationController {
 // MARK: - UIGestureRecognizerDelegate
 
 extension PanModalPresentationController: UIGestureRecognizerDelegate {
-
     /**
      Do not require any other gesture recognizers to fail
      */
@@ -854,7 +834,6 @@ extension PanModalPresentationController: UIGestureRecognizerDelegate {
 // MARK: - UIBezierPath
 
 private extension PanModalPresentationController {
-
     /**
      Draws top rounded corners on a given view
      We have to set a custom path for corner rounding
@@ -868,7 +847,7 @@ private extension PanModalPresentationController {
 
         // Draw around the drag indicator view, if displayed
         if presentable?.showDragIndicator == true {
-            let indicatorLeftEdgeXPos = view.bounds.width/2.0 - Constants.dragIndicatorSize.width/2.0
+            let indicatorLeftEdgeXPos = view.bounds.width / 2.0 - Constants.dragIndicatorSize.width / 2.0
             drawAroundDragIndicator(currentPath: path, indicatorLeftEdgeXPos: indicatorLeftEdgeXPos)
         }
 
@@ -886,7 +865,6 @@ private extension PanModalPresentationController {
      Draws a path around the drag indicator view
      */
     func drawAroundDragIndicator(currentPath path: UIBezierPath, indicatorLeftEdgeXPos: CGFloat) {
-
         let totalIndicatorOffset = Constants.indicatorYOffset + Constants.dragIndicatorSize.height
 
         // Draw around drag indicator starting from the left
@@ -900,7 +878,6 @@ private extension PanModalPresentationController {
 // MARK: - Helper Extensions
 
 private extension UIScrollView {
-
     /**
      A flag to determine if a scroll view is scrolling
      */