Add withNavigation HOC (#137)

examples/NavigationPlayground/js/WithNavigation.js

@@ -0,0 +1,33 @@
+/* @flow */
+
+import React from 'react';
+import {
+  View,
+  Text,
+  Button,
+} from 'react-native';
+import { TabNavigator, withNavigation } from 'react-navigation';
+
+const ButtonWithNavigation = withNavigation(({ navigation, to, ...rest }) => (
+  <Button {...rest} onPress={() => navigation.navigate(to)} />
+));
+
+const createTabWithNavigationButtons = (tabName: string, links: Array<string>) => {
+  const Tab = () => (
+    <View>
+      <Text>This is tab: {tabName}</Text>
+      <Text>You can navigate to:</Text>
+      {links.map(link => (
+        <ButtonWithNavigation key={link} to={link} title={link} />
+      ))}
+    </View>
+  );
+
+  return Tab;
+};
+
+export default TabNavigator({
+  Tab1: { screen: createTabWithNavigationButtons('Tab1', ['Tab2', 'Tab3']) },
+  Tab2: { screen: createTabWithNavigationButtons('Tab2', ['Tab3', 'Tab1']) },
+  Tab3: { screen: createTabWithNavigationButtons('Tab2', ['Tab2', 'Tab1']) },
+});