Add showInAppNotification position param support for Android (#693)

android/app/src/main/java/com/reactnativenavigation/animation/PeekingAnimator.java

 import android.view.View;
 import android.view.animation.OvershootInterpolator;
 
+import com.reactnativenavigation.params.SlidingOverlayParams.Position;
+
 import static android.view.View.TRANSLATION_Y;
 
 public class PeekingAnimator {
 
     private final Animator animator;
 
-    public PeekingAnimator(View view, final boolean show) {
-        final int heightPixels = view.getLayoutParams().height;
+    public PeekingAnimator(View view, Position position, final boolean show) {
+        final int offsetPixels = view.getLayoutParams().height * (position == Position.Top ? -1 : 1);
 
         this.animator = show ?
-                createSlideInAnimator(view, heightPixels) :
-                createSlideOutAnimator(view, heightPixels);
+                createSlideInAnimator(view, offsetPixels) :
+                createSlideOutAnimator(view, offsetPixels);
     }
 
     public void addListener(Animator.AnimatorListener listener) {
         animator.start();
     }
 
-    private ObjectAnimator createSlideInAnimator(View view, int heightPixels) {
-        view.setTranslationY(-heightPixels);
+    private ObjectAnimator createSlideInAnimator(View view, int offset) {
+
+        view.setTranslationY(offset);
 
         ObjectAnimator slideIn = ObjectAnimator.ofFloat(view, TRANSLATION_Y, 0);
         slideIn.setDuration(SLIDE_IN_DURATION);
         return slideIn;
     }
 
-    private ObjectAnimator createSlideOutAnimator(View view, int heightPixels) {
-        ObjectAnimator slideOut = ObjectAnimator.ofFloat(view, TRANSLATION_Y, -heightPixels);
+    private ObjectAnimator createSlideOutAnimator(View view, int offset) {
+        ObjectAnimator slideOut = ObjectAnimator.ofFloat(view, TRANSLATION_Y, offset);
         slideOut.setDuration(SLIDE_OUT_DURATION);
         return slideOut;
     }

android/app/src/main/java/com/reactnativenavigation/params/SlidingOverlayParams.java

 package com.reactnativenavigation.params;
 
 public class SlidingOverlayParams {
+    public enum Position {
+        Top, Bottom;
+
+        public static Position fromString(String string) {
+            switch(string) {
+                case "bottom":
+                    return Position.Bottom;
+                case "top":
+                default:
+                    return Position.Top;
+            }
+        }
+    }
+
     public String screenInstanceId;
     public NavigationParams navigationParams;
+    public Position position;
 }

android/app/src/main/java/com/reactnativenavigation/params/parsers/SlidingOverlayParamsParser.java

         final SlidingOverlayParams result = new SlidingOverlayParams();
         result.screenInstanceId = bundle.getString("screen");
         result.navigationParams = new NavigationParams(bundle.getBundle("navigationParams"));
+        result.position = SlidingOverlayParams.Position.fromString(bundle.getString("position", "top"));
         return result;
     }
 }

android/app/src/main/java/com/reactnativenavigation/views/slidingOverlay/SlidingOverlay.java

 
 import com.reactnativenavigation.animation.PeekingAnimator;
 import com.reactnativenavigation.params.SlidingOverlayParams;
+import com.reactnativenavigation.params.SlidingOverlayParams.Position;
 import com.reactnativenavigation.screens.Screen;
 import com.reactnativenavigation.utils.ViewUtils;
 import com.reactnativenavigation.views.ContentView;
     public void show() {
         parent.addView(view);
 
-        final PeekingAnimator animator = new PeekingAnimator(view, true);
+        final PeekingAnimator animator = new PeekingAnimator(view, params.position, true);
         animator.addListener(new AnimatorListenerAdapter() {
             @Override
             public void onAnimationCancel(Animator animator) {
     }
 
     public void hide() {
-        final PeekingAnimator animator = new PeekingAnimator(view, false);
+        final PeekingAnimator animator = new PeekingAnimator(view, params.position, false);
         animator.addListener(new AnimatorListenerAdapter() {
             @Override
             public void onAnimationCancel(Animator animator) {
         final float heightPixels = ViewUtils.convertDpToPixel(100);
 
         final RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, (int) heightPixels);
-        lp.addRule(RelativeLayout.ALIGN_PARENT_TOP);
+        lp.addRule(params.position == Position.Top ? RelativeLayout.ALIGN_PARENT_TOP : RelativeLayout.ALIGN_PARENT_BOTTOM);
 
         final ContentView view = new ContentView(parent.getContext(), params.screenInstanceId, params.navigationParams);
         view.setLayoutParams(lp);

example/src/screens/SideMenu.js

   onShowInAppNotification() {
     this._toggleDrawer();
     this.props.navigator.showInAppNotification({
-      screen: "example.InAppNotification"
+      screen: "example.InAppNotification",
+      //position: "bottom",
     });
   }