Fix Modal not disappearing when navigating from inside a Modal to another activity

Reviewed By: achen1

Differential Revision: D6668368

fbshipit-source-id: 809e9c978032e731478bcc8e290eb030e4ee6eca

ReactAndroid/src/main/java/com/facebook/react/views/modal/ReactModalHostView.java

@@ -128,7 +128,10 @@ public class ReactModalHostView extends ViewGroup implements LifecycleEventListe
 
   private void dismiss() {
     if (mDialog != null) {
+      Activity currentActivity = getCurrentActivity();
+      if (mDialog.isShowing() && (currentActivity == null || !currentActivity.isFinishing())) {
         mDialog.dismiss();
+      }
       mDialog = null;
 
       // We need to remove the mHostView from the parent
@@ -168,8 +171,7 @@ public class ReactModalHostView extends ViewGroup implements LifecycleEventListe
 
   @Override
   public void onHostPause() {
-    // We dismiss the dialog and reconstitute it onHostResume
-    dismiss();
+    // do nothing
   }
 
   @Override
@@ -183,6 +185,10 @@ public class ReactModalHostView extends ViewGroup implements LifecycleEventListe
     return mDialog;
   }
 
+  private @Nullable Activity getCurrentActivity() {
+    return ((ReactContext) getContext()).getCurrentActivity();
+  }
+
   /**
    * showOrUpdate will display the Dialog.  It is called by the manager once all properties are set
    * because we need to know all of them before creating the Dialog.  It is also smart during
@@ -209,7 +215,9 @@ public class ReactModalHostView extends ViewGroup implements LifecycleEventListe
     } else if (mAnimationType.equals("slide")) {
       theme = R.style.Theme_FullScreenDialogAnimatedSlide;
     }
-    mDialog = new Dialog(getContext(), theme);
+    Activity currentActivity = getCurrentActivity();
+    Context context = currentActivity == null ? getContext() : currentActivity;
+    mDialog = new Dialog(context, theme);
 
     mDialog.setContentView(getContentView());
     updateProperties();
@@ -247,8 +255,10 @@ public class ReactModalHostView extends ViewGroup implements LifecycleEventListe
     if (mHardwareAccelerated) {
       mDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
     }
+    if (currentActivity == null || !currentActivity.isFinishing()) {
       mDialog.show();
     }
+  }
 
   /**
    * Returns the view that will be the root view of the dialog. We are wrapping this in a