package net.yunstudio.demo;

 import java.io.File;

 import java.text.Collator;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Comparator;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Locale;

 import java.util.Map;

 import android.app.Dialog;

 import android.content.Context;

 import android.os.Environment;

 import android.text.TextUtils;

 import android.util.Log;

 import android.view.View;

 import android.widget.AdapterView;

 import android.widget.AdapterView.OnItemClickListener;

 import android.widget.ListView;

 import android.widget.SimpleAdapter;

 public class FilePickerDialog extends Dialog implements OnItemClickListener{

     public FilePickerDialog(Context context) {

         super(context);

         init();

     }

     private ListView lv_file;

     private SimpleAdapter simpleAdapter;

     private List<Map<String, Object>> dataList;

     private OnFileSelectListener listener;

     //通过获取sd卡的父级，可以兼容双sd卡的情况

     private static final File rootPath=

             Environment.getExternalStorageDirectory().getParentFile(); 

     private static final String SRC="src";

     private static final String NAME="name";

     private static final String FILE="file";

     private static final String IS_BAK="isBak";

     private void init() {

         getChildren2dataList(rootPath);

         simpleAdapter=new SimpleAdapter(getContext(),dataList , R.layout.list_item_choosefile,

                 new String[]{SRC,NAME}, new int[]{R.id.iv_file_type,R.id.tv_file_name});

         lv_file=new ListView(getContext());

         lv_file.setAdapter(simpleAdapter);

         lv_file.setOnItemClickListener(this);

         setContentView(lv_file);

         setCanceledOnTouchOutside(true);

         this.setTitle("请选择文件");

     }

     /**

      * 设置选择文件的监听器

      * @param listener

      */

     public void setOnFileSelectListener(OnFileSelectListener listener) {

         this.listener = listener;

     }

     /**

      * 将本目录的子文件的信息赋值给dataList字段

      * @param dir

      */

     private void getChildren2dataList(File dir) {

         File[] children=dir.listFiles();

         if(dataList==null){

             dataList=new ArrayList<Map<String,Object>>();

         }else {

             dataList.clear();

         }    

         if(!rootPath.equals(dir)){

             Map<String, Object> map=new HashMap<String, Object>();

             map.put(SRC, R.drawable.folder);

             map.put(NAME, "..");

             map.put(FILE, dir.getParentFile());

             map.put(IS_BAK, true);

             dataList.add(map);

         }

         if(children==null) return ;//避免空目录引起的空指针错误

         for (File file : children) {

             Map<String, Object> map=new HashMap<String, Object>();

             map.put(SRC, file.isDirectory()

                                 ?R.drawable.folder

                                 :R.drawable.file);

             map.put(NAME, file.getName());

             map.put(FILE, file);

             dataList.add(map);

         }

         Collections.sort(dataList, new Comparator<Map<String, Object>>() {

             @Override

             public int compare(Map<String, Object> lhs, Map<String, Object> rhs) {

                 int result=0;

                 if(lhs.get(IS_BAK)!=null){

                     result = -1;

                 }else if (rhs.get(IS_BAK)!=null) {

                     result = 1;

                 }else {

                     File lhsFile=(File) lhs.get(FILE);

                     File rhsFile=(File) rhs.get(FILE);  

                     if(lhsFile.isDirectory()&&rhsFile.isFile()){

                         result = -1;

                     }else if (lhsFile.isFile()&&rhsFile.isDirectory()) {

                         result = 1;

                     }else {

                         Collator cmp = Collator.getInstance(Locale.getDefault());

                         result = cmp.compare(lhs.get(NAME), rhs.get(NAME));

                     }

                 }

                 return result;

             }

         });

     }

     @Override

     public void onItemClick(AdapterView<?> parent, View view, int position,

             long id) {

         File file=(File)dataList.get(position).get(FILE);

         if(file.isDirectory()){

             getChildren2dataList(file);

             simpleAdapter.notifyDataSetChanged();

         }else {

             if(listener!=null){

                 listener.onFileSelect(file);

                 this.dismiss();

             }

         }

     }

     public static interface OnFileSelectListener{

         void onFileSelect(File file);

     }

 }