Expose hideDelay option for custom presentation

Author: wtmoose

CHANGELOG.md

@@ -4,7 +4,15 @@ All notable changes to this project will be documented in this file.
 ## 6.0.1
 
 ### Features
-* #257 Add the ability to specify the hide delay on `PhysicsPanHandler`. When `PhysicsPanHandler`'s dismissal gesture determines that the view is out of the container view's bounds, it waits `hideDelay` seconds before calling `SwiftMessages.hide()`. The default value is 0.2, which is what you'll get when using `presentationStyle = .center`. To specify a different delay, use `presentationStyle = .custom(animator:)` and supply an instance of `PhysicsPanHandler` configured to your liking.
+* #257 The `.centered` presentation style, which is a shortcut for a specific configuration of the `PhysicsAnimation` animator, provides a physics-based dismissal gesture where the view can be flung off screen. When the view goes out of the container view's bounds, the animator calls `SwiftMessages.hide()`, which animates the dim view away and concludes the message view's lifecycle. There is currently a small delay of 0.2s before calling `hide()`.
+
+This change adds the ability to configure the delay by customizing the animator. For example, to set the delay to zero, one would do:
+
+````swift
+let animation = PhysicsAnimation()
+animation.panHandler.hideDelay = 0
+config.presentationStyle = .custom(animator: animation)
+````
 
 ## 6.0.0
 

SwiftMessages/PhysicsAnimation.swift

@@ -18,6 +18,8 @@ public class PhysicsAnimation: NSObject, Animator {
 
     public var placement: Placement = .center
 
+    public var panHandler = PhysicsPanHandler()
+
     public weak var delegate: AnimationDelegate?
     weak var messageView: UIView?
     weak var containerView: UIView?
@@ -37,9 +39,9 @@ public class PhysicsAnimation: NSObject, Animator {
 
     public func hide(context: AnimationContext, completion: @escaping AnimationCompletion) {
         NotificationCenter.default.removeObserver(self)
-        if panHandler?.isOffScreen ?? false {
+        if panHandler.isOffScreen {
             context.messageView.alpha = 0
-            panHandler?.state?.stop()
+            panHandler.state?.stop()
         }
         let view = context.messageView
         self.context = context
@@ -114,11 +116,9 @@ public class PhysicsAnimation: NSObject, Animator {
         CATransaction.commit()
     }
 
-    var panHandler: PhysicsPanHandler?
-
     func installInteractive(context: AnimationContext) {
         guard context.interactiveHide else { return }
-        panHandler = PhysicsPanHandler(context: context, animator: self)
+        panHandler.configure(context: context, animator: self)
     }
 }
 

SwiftMessages/PhysicsPanHandler.swift

@@ -10,8 +10,6 @@ import UIKit
 
 open class PhysicsPanHandler {
 
-    /// During the dismiss gesture, specifies the delay between the view
-    /// going out of the screen's bounds and `SwiftMessages.hide()` being called.
     public var hideDelay: TimeInterval = 0.2
 
     public struct MotionSnapshot {
@@ -91,17 +89,23 @@ open class PhysicsPanHandler {
     private(set) public var isOffScreen = false
     private var restingCenter: CGPoint?
 
-    public init(context: AnimationContext, animator: Animator) {
-        messageView = context.messageView
-        containerView = context.containerView
-        self.animator = animator
+    public init() {}
+
+    lazy var pan: UIPanGestureRecognizer = {
         let pan = UIPanGestureRecognizer()
         pan.addTarget(self, action: #selector(pan(_:)))
-        if let view = messageView as? BackgroundViewable {
-            view.backgroundView.addGestureRecognizer(pan)
-        } else {
-            context.messageView.addGestureRecognizer(pan)
+        return pan
+    }()
+
+    func configure(context: AnimationContext, animator: Animator) {
+        if let oldView = (messageView as? BackgroundViewable)?.backgroundView ?? messageView {
+            oldView.removeGestureRecognizer(pan)
         }
+        messageView = context.messageView
+        let view = (messageView as? BackgroundViewable)?.backgroundView ?? messageView
+        view?.addGestureRecognizer(pan)
+        containerView = context.containerView
+        self.animator = animator
     }
 
     @objc func pan(_ pan: UIPanGestureRecognizer) {