Fixed MessagesCollectionView's bottom inset when hardware keyboard is connected

zhongwuzw · zhongwuzw · commit d2fee1851fb7 · 2018-05-31T16:34:45.000+08:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,9 @@ The changelog for `MessageKit`. Also see the [releases](https://github.com/Messa
 
 ### Fixed
 
+- Fixed `MessagesCollectionView`'s bottom inset when hardware keyboard is connected. Do not adjust `MessagesCollection`'s inset when being popped.
+[#707](https://github.com/MessageKit/MessageKit/pull/707) by [@zhongwuzw](https://github.com/zhongwuzw).
+
 - Fixed `LabelAlignment` initializer which has default internal access control.
 [#705](https://github.com/MessageKit/MessageKit/pull/705) by [@zhongwuzw](https://github.com/zhongwuzw).
 
diff --git a/Sources/Controllers/MessagesViewController+Keyboard.swift b/Sources/Controllers/MessagesViewController+Keyboard.swift
@@ -53,22 +53,19 @@ extension MessagesViewController {
     @objc
     private func handleKeyboardDidChangeState(_ notification: Notification) {
         guard let keyboardEndFrame = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? CGRect else { return }
-
-        if (keyboardEndFrame.origin.y + keyboardEndFrame.size.height) > UIScreen.main.bounds.height {
-            // Hardware keyboard is found
-            messageCollectionViewBottomInset = view.frame.size.height - keyboardEndFrame.origin.y - iPhoneXBottomInset
-        } else {
-            //Software keyboard is found
-            let afterBottomInset = keyboardEndFrame.height > keyboardOffsetFrame.height ? (keyboardEndFrame.height - iPhoneXBottomInset) : keyboardOffsetFrame.height
-            let differenceOfBottomInset = afterBottomInset - messageCollectionViewBottomInset
-
-            if maintainPositionOnKeyboardFrameChanged && differenceOfBottomInset != 0 {
-                let contentOffset = CGPoint(x: messagesCollectionView.contentOffset.x, y: messagesCollectionView.contentOffset.y + differenceOfBottomInset)
-                messagesCollectionView.setContentOffset(contentOffset, animated: false)
-            }
-
-            messageCollectionViewBottomInset = afterBottomInset
+        
+        guard !isMessagesControllerBeingDismissed else { return }
+        
+        let newBottomInset = view.frame.height - keyboardEndFrame.minY - iPhoneXBottomInset
+        
+        let differenceOfBottomInset = newBottomInset - messageCollectionViewBottomInset
+        
+        if maintainPositionOnKeyboardFrameChanged && differenceOfBottomInset != 0 {
+            let contentOffset = CGPoint(x: messagesCollectionView.contentOffset.x, y: messagesCollectionView.contentOffset.y + differenceOfBottomInset)
+            messagesCollectionView.setContentOffset(contentOffset, animated: false)
         }
+        
+        messageCollectionViewBottomInset = newBottomInset
     }
 
     @objc
diff --git a/Sources/Controllers/MessagesViewController.swift b/Sources/Controllers/MessagesViewController.swift
@@ -60,6 +60,8 @@ UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
     }
 
     private var isFirstLayout: Bool = true
+    
+    internal var isMessagesControllerBeingDismissed: Bool = false
 
     internal var selectedIndexPathForMenu: IndexPath?
 
@@ -82,6 +84,16 @@ UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
         addObservers()
     }
     
+    open override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+        isMessagesControllerBeingDismissed = false
+    }
+    
+    open override func viewWillDisappear(_ animated: Bool) {
+        super.viewWillDisappear(animated)
+        isMessagesControllerBeingDismissed = true
+    }
+    
     open override func viewDidLayoutSubviews() {
         // Hack to prevent animation of the contentInset after viewDidAppear
         if isFirstLayout {
