package com.sxt.mygps;

import java.util.Iterator;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.GpsSatellite;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.provider.Settings;
import android.text.style.UpdateLayout;
import android.util.Log;
import android.widget.EditText;
import android.widget.Toast;

public class GpsActivity extends Activity {
	int num=1;
	private EditText editText;
	private EditText et;
	private LocationManager im;
	private static final String TAG = "GpsActivity";
	
	@Override
	protected void onDestroy() {
		super.onDestroy();
		im.removeUpdates(locationListener);
	}
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_gps);
		
		editText = (EditText) findViewById(R.id.editText);
		et = (EditText) findViewById(R.id.et);
		im = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
		
		//判断GPS是否正常启动
		if(!im.isProviderEnabled(LocationManager.GPS_PROVIDER)){
			Toast.makeText(this,"请开启GPS导航",Toast.LENGTH_SHORT).show();
			 //返回开启GPS导航设置界面 
			Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
			startActivityForResult(intent,0);
			return;
		}
		
		
	    //为获取地理位置信息时设置查询条件
		String bestProvider = im.getBestProvider(getCriteria(), true);
	    //获取位置信息
        //如果不设置查询要求，getLastKnownLocation方法传人的参数为LocationManager.GPS_PROVIDER
		Location location = im.getLastKnownLocation(bestProvider);
		updateView(location);
		//监听状态
		im.addGpsStatusListener(listener);
		 //绑定监听，有4个参数    
        //参数1，设备：有GPS_PROVIDER和NETWORK_PROVIDER两种
        //参数2，位置信息更新周期，单位毫秒    
        //参数3，位置变化最小距离：当位置距离变化超过此值时，将更新位置信息    
        //参数4，监听    
        //备注：参数2和3，如果参数3不为0，则以参数3为准；参数3为0，则通过时间来定时更新；两者为0，则随时刷新   
        // 1秒更新一次，或最小位移变化超过1米更新一次；
        //注意：此处更新准确度非常低，推荐在service里面启动一个Thread，在run中sleep(10000);然后执行handler.sendMessage(),更新位置
	    im.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000,1,locationListener);
	}
	
	private LocationListener locationListener = new LocationListener() {
		/**
         * GPS状态变化时触发
         */
		@Override
		public void onStatusChanged(String provider, int status, Bundle extras) {
			switch (status) {
				//GPS状态为可见时
				case LocationProvider.AVAILABLE:
					Log.i(TAG,"当前GPS状态为可见状态");
					break;
				//GPS状态为服务区外时
				case LocationProvider.OUT_OF_SERVICE:
					Log.i(TAG, "当前GPS状态为服务区外状态");
					break;
				//GPS状态为暂停服务时
				case LocationProvider.TEMPORARILY_UNAVAILABLE:
					Log.i(TAG,"当前GPS状态为暂停服务状态");
					break;
			}
		}
		/**
		 * GPS开启时触发
		 */
		@Override
		public void onProviderEnabled(String provider) {
			Location location = im.getLastKnownLocation(provider);
			updateView(location);
		}
		/**
		 * GPS禁用时触发
		 */
		@Override
		public void onProviderDisabled(String provider) {
			updateView(null);
		}
		
		/**
		 * 位置信息变化触发
		 * @return
		 */
		public void onLocationChanged(Location location){
			updateView(location);
			Log.i(TAG, "时间："+location.getTime());
			Log.i(TAG, "经度："+location.getLongitude());
			Log.i(TAG, "纬度："+location.getLatitude());
			Log.i(TAG, "海拔："+location.getAltitude());
		}
	};
	
	/**
	 * 状态监听
	 */
	GpsStatus.Listener listener = new GpsStatus.Listener() {
		public void onGpsStatusChanged(int event) {
			switch(event){
			//第一次定位
				case GpsStatus.GPS_EVENT_FIRST_FIX:
					Log.i(TAG,"第一次定位");
					Toast.makeText(GpsActivity.this,"第一次定位",Toast.LENGTH_SHORT).show();
					break;
			//卫星状态改变
				case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
					Log.i(TAG,"卫星状态改变");
					//获取当前状态
					GpsStatus gpsStatus = im.getGpsStatus(null);
	                //获取卫星颗数的默认最大值
					int maxSatellites = gpsStatus.getMaxSatellites();
					//创建一个迭代器保存所有卫星 
					Iterator<GpsSatellite> iters = gpsStatus.getSatellites().iterator();
					int count = 0;
					while (iters.hasNext() && count <= maxSatellites) {
						GpsSatellite  s = iters.next();
						count++;
					}
					System.out.println("搜索到："+count+"颗卫星球");
					
					et.setText("已搜索次数"+num+"\n搜索到："+count+"颗卫星球");
					num++;
					
					Log.i(TAG,"搜索到："+count+"颗卫星球");
					break;
			//定位启动
				case GpsStatus.GPS_EVENT_STARTED:
					Log.i(TAG,"定位启动");
					Toast.makeText(GpsActivity.this,"定位启动",Toast.LENGTH_SHORT).show();
					break;
			//定位结束
				case GpsStatus.GPS_EVENT_STOPPED:
					Log.i(TAG,"定位结束");
					Toast.makeText(GpsActivity.this,"定位结束",Toast.LENGTH_SHORT).show();
					break;
			}
		}
	};
	
	
	
	/**
	 * 实时更新文本内容
	 * @param location
	 */
	private void updateView(Location location) {
	    if(location!=null){
	    	editText.setText("设备位置信息\n\n经度：");
	    	editText.append(String.valueOf(location.getLongitude()));
	    	editText.append("\n纬度：");
	    	editText.append(String.valueOf(location.getLatitude()));
	    } else {
	    	//清空EditText对象
	    	editText.getEditableText().clear();
	    }
	}
	
	/**
	 * 返回查询条件
	 * @return
	 */
	private Criteria getCriteria() {
	  Criteria criteria = new Criteria();
	  //设置定位精确度 Criteria.ACCURACY_COARSE比较粗略，Criteria.ACCURACY_FINE则比较精细
	  criteria.setAccuracy(Criteria.ACCURACY_FINE);
	  //设置是否要求速度
	  criteria.setSpeedRequired(false);
	  // 设置是否允许运营商收费  
	  criteria.setCostAllowed(true);
	  //设置是否需要方位信息
	  criteria.setAltitudeRequired(true);
	  // 设置对电源的需求
	  criteria.setPowerRequirement(Criteria.POWER_LOW);
	  return criteria;
	}

}