Fix keyboard not hiding on RN 62+ (#592)

android/src/main/java/com/swmansion/rnscreens/ScreenFragment.java

@@ -1,11 +1,13 @@
 package com.swmansion.rnscreens;
 
 import android.annotation.SuppressLint;
+import android.content.Context;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewParent;
+import android.view.inputmethod.InputMethodManager;
 import android.widget.FrameLayout;
 
 import com.facebook.react.bridge.ReactContext;
@@ -60,6 +62,24 @@ public View onCreateView(LayoutInflater inflater,
     return wrapper;
   }
 
+  @Override
+  public void onDetach() {
+    super.onDetach();
+    // The below line is a workaround for an issue with keyboard handling within fragments. Despite
+    // Android handles input focus on the fragments that leave the screen, the keyboard stays open
+    // in a number of cases. The issue can be best reproduced on Android 5 devices, before some changes
+    // in Android's InputMethodManager have been introduced (specifically around dismissing the
+    // keyboard in onDetachedFromWindow). However, we also noticed the keyboard issue happen
+    // intermittently on recent versions of Android as well. The issue hasn't been previously noticed
+    // as in React Native <= 0.61 there was a logic that'd trigger keyboard dismiss upon a blur event
+    // (the blur even gets dispatched properly, the keyboard just stays open despite that) – note
+    // the change in RN core here: https://github.com/facebook/react-native/commit/e9b4928311513d3cbbd9d875827694eab6cfa932
+    // The workaround is to force-hide keyboard passing the fragment's view token when the given fragment
+    // is detached. It is safe to call this method regardless of whether the keyboard was open or not.
+    ((InputMethodManager) getContext().getSystemService(Context.INPUT_METHOD_SERVICE))
+            .hideSoftInputFromWindow(mScreenView.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
+  }
+
   public Screen getScreen() {
     return mScreenView;
   }