Fixed screen size calculations when in multi-window view (#1432)

android/app/src/main/java/com/reactnativenavigation/screens/ScreenAnimator.java

 import android.view.animation.AccelerateInterpolator;
 import android.view.animation.DecelerateInterpolator;
 import android.view.animation.LinearInterpolator;
-
 import com.reactnativenavigation.NavigationApplication;
 import com.reactnativenavigation.utils.ViewUtils;
 import com.reactnativenavigation.views.sharedElementTransition.SharedElementsAnimator;
 
+import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.List;
 
-import javax.annotation.Nullable;
-
 class ScreenAnimator {
     private final float translationY;
     private final float translationX;
 
     ScreenAnimator(Screen screen) {
         this.screen = screen;
-        translationY = 0.08f * ViewUtils.getScreenHeight();
-        translationX = 0.08f * ViewUtils.getScreenWidth();
+        translationY = 0.08f * ViewUtils.getWindowHeight(screen.activity);
+        translationX = 0.08f * ViewUtils.getWindowWidth(screen.activity);
     }
 
     public void show(boolean animate, final Runnable onAnimationEnd) {

android/app/src/main/java/com/reactnativenavigation/utils/ViewUtils.java

 package com.reactnativenavigation.utils;
 
-import android.content.Context;
+import android.app.Activity;
 import android.content.res.Resources;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffColorFilter;
 import android.view.ViewGroup;
 import android.view.ViewParent;
 import android.view.ViewTreeObserver;
-import android.view.WindowManager;
 import android.widget.RelativeLayout;
 import android.widget.TextView;
-
 import com.reactnativenavigation.NavigationApplication;
 import com.reactnativenavigation.params.AppStyle;
 import com.reactnativenavigation.screens.Screen;
         }
     }
 
-    public static float getScreenHeight() {
-        WindowManager wm = (WindowManager) NavigationApplication.instance.getSystemService(Context.WINDOW_SERVICE);
+    public static float getWindowWidth(Activity activity) {
         DisplayMetrics metrics = new DisplayMetrics();
-        wm.getDefaultDisplay().getMetrics(metrics);
-        return metrics.heightPixels;
+        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
+        return metrics.widthPixels;
     }
 
-    public static float getScreenWidth() {
-        WindowManager wm = (WindowManager) NavigationApplication.instance.getSystemService(Context.WINDOW_SERVICE);
+    public static float getWindowHeight(Activity activity) {
         DisplayMetrics metrics = new DisplayMetrics();
-        wm.getDefaultDisplay().getMetrics(metrics);
+        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
         return metrics.widthPixels;
     }
 

android/app/src/main/java/com/reactnativenavigation/views/TitleBar.java

 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
+import android.app.Activity;
 import android.content.Context;
+import android.content.ContextWrapper;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.Nullable;
 import android.support.v7.widget.ActionMenuView;
 import android.view.animation.AccelerateDecelerateInterpolator;
 import android.view.animation.AccelerateInterpolator;
 import android.widget.TextView;
-
 import com.reactnativenavigation.params.BaseScreenParams;
 import com.reactnativenavigation.params.BaseTitleBarButtonParams;
 import com.reactnativenavigation.params.StyleParams;
         setVisibility(titleBarHidden ? GONE : VISIBLE);
     }
 
+    private Activity getActivity() {
+        Context context = getContext();
+        while (context instanceof ContextWrapper) {
+            if (context instanceof Activity) {
+                return (Activity)context;
+            }
+            context = ((ContextWrapper)context).getBaseContext();
+        }
+        return null;
+    }
+
     private void centerTitle(final StyleParams params) {
         final View titleView = getTitleView();
         if (titleView == null) {
             @Override
             public void run() {
                 if (params.titleBarTitleTextCentered) {
-                    titleView.setX(ViewUtils.getScreenWidth() / 2 - titleView.getWidth() / 2);
+                    titleView.setX(ViewUtils.getWindowWidth(getActivity()) / 2 - titleView.getWidth() / 2);
                 }
                 
             }