/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

 import React, { Component } from 'react';
 import {
   AppRegistry,
   StyleSheet,
   Text,
   View,
   Image,
   Platform,
   StatusBar,
 } from 'react-native';

 //引入tabbar支持包
 import TabNavigator from 'react-native-tab-navigator';
//首页
 import Home from './view/Home';

 const TabNavigatorItem =TabNavigator.Item;

 const TAB_NORMAL_1=require('./images/tabbar_1.png');
 const TAB_NORMAL_2=require('./images/tabbar_2.png');
 const TAB_NORMAL_3=require('./images/tabbar_3.png');
 const TAB_NORMAL_4=require('./images/tabbar_4.png');

 const TAB_PRESS_1=require('./images/tabbar_1_press.png');
 const TAB_PRESS_2=require('./images/tabbar_2_press.png');
 const TAB_PRESS_3=require('./images/tabbar_3_press.png');
 const TAB_PRESS_4=require('./images/tabbar_4_press.png');

 export default class toutiao extends Component {

   constructor(){
     super();
     this.state={
       selectedTab:'Home',
     }
   }

   /**
   tab点击方法
   **/
   onPress(tabName){
     if(tabName){
       this.setState(
         {
           selectedTab:tabName,
         }
       );
     }
   }
    /**
    渲染每项
    **/
    renderTabView(title,tabName,tabContent,isBadge){
      var tabNomal;
      var tabPress;
      switch (tabName) {
        case 'Home':
          tabNomal=TAB_NORMAL_1;
          tabPress=TAB_PRESS_1;
          break;
      case 'Video':
        tabNomal=TAB_NORMAL_2;
        tabPress=TAB_PRESS_2;
        break;
      case 'Follow':
        tabNomal=TAB_NORMAL_3;
        tabPress=TAB_PRESS_3;
        break;
      case 'Mine':
        tabNomal=TAB_NORMAL_4;
        tabPress=TAB_PRESS_4;
        break;
        default:

      }
      return(
        <TabNavigatorItem
         title={title}
         renderIcon={()=><Image style={styles.tabIcon} source={tabNomal}/>}
         renderSelectedIcon={()=><Image style={styles.tabIcon} source={tabPress}/>}
         selected={this.state.selectedTab===tabName}
         selectedTitleStyle={{color:'#f85959'}}
         onPress={()=>this.onPress(tabName)}
         renderBadge={()=>isBadge?<View style={styles.badgeView}><Text style={styles.badgeText}>15</Text></View>:null}
        >
        {
          tabName=='Home'?<Home/>:
          <View style={{flex:1,justifyContent:'center',alignItems:'center'}}><Text>{tabContent}</Text></View>
        }
        </TabNavigatorItem>
      );
    }

    /**
    自定义tabbar
    **/
   tabBarView(){
     return (
       <View style={{flex:1}}>
       <TabNavigator
        tabBarStyle={styles.tab}
       >
       {this.renderTabView('头条','Home','头条板块',true)}
       {this.renderTabView('视频','Video','视频板块',false)}
       {this.renderTabView('关注','Follow','关注板块',false)}
       {this.renderTabView('我的','Mine','我的板块',false)}
       </TabNavigator>
       </View>
     );
   }


   render() {
     var tabBarView=this.tabBarView();
     return (
       <View style={styles.container}>
         {tabBarView}
       </View>
     );
   }
 }

 const styles = StyleSheet.create({
   container: {
     flex: 1,
     backgroundColor: '#F5FCFF',

   },
   welcome: {
     fontSize: 20,
     textAlign: 'center',
     margin: 10,
   },
   instructions: {
     textAlign: 'center',
     color: '#333333',
     marginBottom: 5,
   },
   tab:{
     height: 52,
     alignItems:'center',
     backgroundColor:'#f4f5f6',
   },
   tabIcon:{
     width:25,
     height:25,
   },
   badgeView:{
     width:22,
     height:14 ,
     backgroundColor:'#f85959',
     borderWidth:1,
     marginLeft:10,
     marginTop:5,
     borderColor:'#FFF',
     alignItems:'center',
     justifyContent:'center',
     borderRadius:8,
   },
   badgeText:{
     color:'#fff',
     fontSize:8,
   }
 });