From a75b607be2416f29a1310e7442665776cc96554e Mon Sep 17 00:00:00 2001
From: closure11 <wmadao11@gmail.com>
Date: Mon, 31 Oct 2022 10:39:46 +0800
Subject: [PATCH] Add didTransition in PanModalPresentable delegate

---
 .../Controller/PanModalPresentationController.swift | 13 ++++++++++---
 .../Presentable/PanModalPresentable+Defaults.swift  |  4 ++++
 PanModal/Presentable/PanModalPresentable.swift      |  7 +++++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/PanModal/Controller/PanModalPresentationController.swift b/PanModal/Controller/PanModalPresentationController.swift
index 05e3e6a6..fa6280e2 100644
--- a/PanModal/Controller/PanModalPresentationController.swift
+++ b/PanModal/Controller/PanModalPresentationController.swift
@@ -259,11 +259,15 @@ public extension PanModalPresentationController {
 
         presentable?.willTransition(to: state)
 
+        let completion: () -> Void = { [weak self] in
+            self?.presentable?.didTransition(to: state)
+        }
+
         switch state {
         case .shortForm:
-            snap(toYPosition: shortFormYPosition)
+            snap(toYPosition: shortFormYPosition, completion: completion)
         case .longForm:
-            snap(toYPosition: longFormYPosition)
+            snap(toYPosition: longFormYPosition, completion: completion)
         }
     }
 
@@ -643,12 +647,15 @@ private extension PanModalPresentationController {
         return (abs(velocity) - (1000 * (1 - Constants.snapMovementSensitivity))) > 0
     }
 
-    func snap(toYPosition yPos: CGFloat) {
+    func snap(toYPosition yPos: CGFloat, completion: (() -> Void)? = nil) {
         PanModalAnimator.animate({ [weak self] in
             self?.adjust(toYPosition: yPos)
             self?.isPresentedViewAnimating = true
         }, config: presentable) { [weak self] didComplete in
             self?.isPresentedViewAnimating = !didComplete
+            if didComplete {
+                completion?()
+            }
         }
     }
 
diff --git a/PanModal/Presentable/PanModalPresentable+Defaults.swift b/PanModal/Presentable/PanModalPresentable+Defaults.swift
index 76a0679f..e9b82ef6 100644
--- a/PanModal/Presentable/PanModalPresentable+Defaults.swift
+++ b/PanModal/Presentable/PanModalPresentable+Defaults.swift
@@ -117,6 +117,10 @@ public extension PanModalPresentable where Self: UIViewController {
 
     }
 
+    func didTransition(to state: PanModalPresentationController.PresentationState) {
+
+    }
+
     func panModalWillDismiss() {
 
     }
diff --git a/PanModal/Presentable/PanModalPresentable.swift b/PanModal/Presentable/PanModalPresentable.swift
index 76c15015..1cd9b301 100644
--- a/PanModal/Presentable/PanModalPresentable.swift
+++ b/PanModal/Presentable/PanModalPresentable.swift
@@ -220,6 +220,13 @@ public protocol PanModalPresentable: AnyObject {
      */
     func willTransition(to state: PanModalPresentationController.PresentationState)
 
+    /**
+     Notifies the delegate that the pan modal transitioned to a new state.
+
+     Default value is an empty implementation.
+     */
+    func didTransition(to state: PanModalPresentationController.PresentationState)
+
     /**
      Notifies the delegate that the pan modal is about to be dismissed.