Fixes #2288

Author: aksonov

dist/navigationStore.js

@@ -318,8 +318,8 @@ return null;
 }
 var res={};
 var order=[];var _scene$props=
-scene.props,navigator=_scene$props.navigator,contentComponent=_scene$props.contentComponent,tabBarPosition=_scene$props.tabBarPosition,lazy=_scene$props.lazy,duration=_scene$props.duration,parentProps=_objectWithoutProperties(_scene$props,['navigator','contentComponent','tabBarPosition','lazy','duration']);var
-tabs=parentProps.tabs,modal=parentProps.modal,lightbox=parentProps.lightbox,overlay=parentProps.overlay,drawer=parentProps.drawer,tabBarComponent=parentProps.tabBarComponent,transitionConfig=parentProps.transitionConfig;
+scene.props,navigator=_scene$props.navigator,contentComponent=_scene$props.contentComponent,lazy=_scene$props.lazy,duration=_scene$props.duration,parentProps=_objectWithoutProperties(_scene$props,['navigator','contentComponent','lazy','duration']);var
+tabs=parentProps.tabs,modal=parentProps.modal,lightbox=parentProps.lightbox,overlay=parentProps.overlay,tabBarPosition=parentProps.tabBarPosition,drawer=parentProps.drawer,tabBarComponent=parentProps.tabBarComponent,transitionConfig=parentProps.transitionConfig;
 if(scene.type===_Modal2.default){
 modal=true;
 }else if(scene.type===_Drawer2.default){
@@ -436,6 +436,9 @@ if(!tabBarComponent){
 tabBarComponent=tabBarPosition==='top'?function(props){return _react2.default.createElement(_reactNavigation.TabBarTop,_extends({},props,commonProps,{__source:{fileName:_jsxFileName,lineNumber:436}}));}:
 function(props){return _react2.default.createElement(_reactNavigation.TabBarBottom,_extends({},props,commonProps,{__source:{fileName:_jsxFileName,lineNumber:437}}));};
 }
+if(!tabBarPosition){
+tabBarPosition=_reactNative.Platform.OS==='android'?'top':'bottom';
+}
 return(0,_reactNavigation.TabNavigator)(res,_extends({lazy:lazy,tabBarComponent:tabBarComponent,tabBarPosition:tabBarPosition,initialRouteName:initialRouteName,initialRouteParams:initialRouteParams,order:order},commonProps,{
 tabBarOptions:createTabBarOptions(commonProps),navigationOptions:createNavigationOptions(commonProps)}));
 }else if(drawer){

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-router-flux",
-  "version": "4.0.0-beta.20",
+  "version": "4.0.0-beta.21",
   "description": "React Native Router using Flux architecture",
   "repository": {
     "type": "git",

src/navigationStore.js

@@ -2,7 +2,7 @@ import React from 'react';
 import { observable, action } from 'mobx';
 import * as ActionConst from './ActionConst';
 import { OnEnter, OnExit, assert } from './Util';
-import { View, Image, Animated, Easing } from 'react-native';
+import { View, Image, Animated, Easing, Platform } from 'react-native';
 import { TabNavigator, DrawerNavigator, StackNavigator, NavigationActions, TabBarTop, TabBarBottom } from 'react-navigation';
 import { LeftButton, RightButton, BackButton } from './NavBar';
 import LightboxNavigator from './LightboxNavigator';
@@ -318,8 +318,8 @@ class NavigationStore {
     }
     const res = {};
     const order = [];
-    const { navigator, contentComponent, tabBarPosition, lazy, duration, ...parentProps } = scene.props;
-    let { tabs, modal, lightbox, overlay, drawer, tabBarComponent, transitionConfig } = parentProps;
+    const { navigator, contentComponent, lazy, duration, ...parentProps } = scene.props;
+    let { tabs, modal, lightbox, overlay, tabBarPosition, drawer, tabBarComponent, transitionConfig } = parentProps;
     if (scene.type === Modal) {
       modal = true;
     } else if (scene.type === Drawer) {
@@ -436,6 +436,9 @@ class NavigationStore {
         tabBarComponent = tabBarPosition === 'top' ? (props) => <TabBarTop {...props} {...commonProps} /> :
           (props) => <TabBarBottom {...props} {...commonProps} />;
       }
+      if (!tabBarPosition) {
+        tabBarPosition = Platform.OS === 'android' ? 'top' : 'bottom';
+      }
       return TabNavigator(res, { lazy, tabBarComponent, tabBarPosition, initialRouteName, initialRouteParams, order, ...commonProps,
         tabBarOptions: createTabBarOptions(commonProps), navigationOptions: createNavigationOptions(commonProps) });
     } else if (drawer) {