Added pop

android/app/src/main/java/com/reactnativenavigation/activities/BaseReactActivity.java

 
     public abstract void push(Screen screen);
 
+    public abstract Screen pop(String navID);
+
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         mMenu = menu;
 
     @Override
     public void onBackPressed() {
-        if (mReactInstanceManager != null) {
+        if (mReactInstanceManager != null)
             mReactInstanceManager.onBackPressed();
-        } else {
+        //TODO uncomment and add current navID
+         else //if(pop() == null)
             super.onBackPressed();
-        }
     }
 
     @Override

android/app/src/main/java/com/reactnativenavigation/activities/RootActivity.java

     public void push(Screen screen) {
         //TODO
     }
+
+    @Override
+    public Screen pop(String navID) {
+        return null;
+        //TODO
+    }
 }

android/app/src/main/java/com/reactnativenavigation/activities/SingleScreenActivity.java

     public void push(Screen screen) {
         screenStack.push(screen);
     }
+
+    @Override
+    public Screen pop(String navID) {
+        return screenStack.pop();
+    }
 }

android/app/src/main/java/com/reactnativenavigation/activities/TabActivity.java

         adapter.pushScreen(screen);
     }
 
+    @Override
+    public Screen pop(String navID) {
+        return adapter.pop(navID);
+    }
+
     private void setupToolbar() {
         setSupportActionBar(mToolbar);
         mToolbar.setScreens(mScreens);

android/app/src/main/java/com/reactnativenavigation/adapters/ViewPagerAdapter.java

 import android.support.design.widget.TabLayout;
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
+import android.support.v7.widget.Toolbar;
 import android.view.View;
 import android.view.ViewGroup;
 
     private final Map<String, ScreenStack> stacksByNavId;
 
 
-    public ViewPagerAdapter(BaseReactActivity context, ViewPager viewPager, RnnToolBar toolbar,
+    public ViewPagerAdapter(BaseReactActivity context, ViewPager viewPager, Toolbar toolbar,
                             ArrayList<Screen> screens) {
         mContext = context;
         mViewPager = viewPager;
         stack.push(screen);
     }
 
+    public Screen pop(String navID){
+        ScreenStack stack = stacksByNavId.get(navID);
+        if(stack != null)
+            return stack.pop();
+        return null;
+    }
+
     @Override
     public Object instantiateItem(ViewGroup container, int position) {
         ScreenStack view = screenStacks.get(position);
         Screen screen = screenStacks.get(position).peek();
         params.putString(Screen.KEY_NAVIGATOR_EVENT_ID, screen.navigatorEventId);
 
-        mToolbar.setupToolbarButtonsAsync(mScreens.get(position));
+//        mToolbar.setupToolbarButtonsAsync(mScreens.get(position));
 
         RctManager.getInstance().sendEvent(EVENT_ON_TAB_SELECTED, screen.navigatorEventId, params);
     }

android/app/src/main/java/com/reactnativenavigation/modules/RctActivityModule.java

     }
 
     @ReactMethod
-    public void navigatorPush(ReadableMap screen) {
-        BaseReactActivity context = ContextProvider.getActivityContext();
+    public void navigatorPush(final ReadableMap screen) {
+        final BaseReactActivity context = ContextProvider.getActivityContext();
          if (context != null && !context.isFinishing()) {
-             context.push(new Screen(screen));
+             context.runOnUiThread(new Runnable() {
+                 @Override
+                 public void run() {
+                     context.push(new Screen(screen));
+                 }
+             });
+        }
+    }
+
+    @ReactMethod
+    public void navigatorPop(final ReadableMap navigator) {
+        final String navID = navigator.getString("navigatorID");
+        final BaseReactActivity context = ContextProvider.getActivityContext();
+        if (context != null && !context.isFinishing()) {
+            context.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    context.pop(navID);
+                }
+            });
         }
     }
 }

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

 package com.reactnativenavigation.views;
 
 import android.animation.LayoutTransition;
+import android.view.View;
 import android.widget.FrameLayout;
 
 import com.facebook.react.ReactInstanceManager;
     }
 
     public void push(Screen screen){
+        View oldView = null;
+        if(!stack.isEmpty())
+            oldView = stack.peek().view;
         RctView view = new RctView(reactActivity, mReactInstanceManager, screen);
         addView(view, MATCH_PARENT, MATCH_PARENT);
+        if(oldView!=null)
+            removeView(oldView);
         stack.push(new ScreenView(screen, view));
     }
 
     public Screen pop(){
+        //TODO maybe return null if size is 1?
+        if(stack.isEmpty())
+            return null;
         ScreenView popped = stack.pop();
         removeView(popped.view);
+        if(!stack.isEmpty());
+        addView(stack.peek().view);
         return popped.screen;
     }
 

src/platformSpecific.android.js

   RctActivity.navigatorPush(params);
 }
 
+function navigatorPop(navigator, params) {
+  RctActivity.navigatorPop(navigator);
+}
+
 function addNavigatorParams(screen, navigator = null, idx = '') {
   screen.navigatorID = navigator ? navigator.navigatorID : utils.getRandomId() + '_nav' + idx;
   screen.screenInstanceID = utils.getRandomId();
 export default {
   startSingleScreenApp,
   startTabBasedApp,
-  navigatorPush
+  navigatorPush,
+  navigatorPop
 }