Implement custom dialog to open folder

In the old article "JPG File Chooser", custom dialog was implemented to load individual image(jpg). In this article, the custom dialog is used to open folder, instead of individual file. After dismissed, the images(jpg) in the selected folder will be listed.

dialoglayout.xml, layout of the custom dislog.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/customdialog"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="20dp"
    android:minWidth="300dp">
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_launcher"/>
        <Button
            android:id="@+id/up"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Parent folder"/>
    </LinearLayout>
    <Button
        android:id="@+id/selectfolder"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
         
    <ListView
        android:id="@+id/dialoglist"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
 
</LinearLayout>

AndroidGalleryActivity.java, the main code.

package com.AndroidGallery;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.app.Dialog;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.MimeTypeMap;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidGalleryActivity extends Activity {
 
 Button buttonOpenDialog;
 Button buttonUp, buttonSelectFolder;
 TextView jpgList;
   
 String KEY_TEXTPSS = "TEXTPSS";
 static final int CUSTOM_DIALOG_ID = 0;
 
 ListView dialog_ListView;
 
 File root;
 File curFolder;
 
 private List<String> fileList = new ArrayList<String>();
 
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
   
  jpgList = (TextView)findViewById(R.id.jpglist);
   
  buttonOpenDialog = (Button)findViewById(R.id.opendialog);
  buttonOpenDialog.setOnClickListener(new Button.OnClickListener(){
   @Override
   public void onClick(View arg0) {
    showDialog(CUSTOM_DIALOG_ID); 
   }});
   
  root = new File(Environment
    .getExternalStorageDirectory()
    .getAbsolutePath());
   
  curFolder = root;
  ListJpgInFolder(curFolder);
   
 }
  
 @Override
 protected Dialog onCreateDialog(int id) {
   
  Dialog dialog = null;
   
  switch(id) {
  case CUSTOM_DIALOG_ID:
   dialog = new Dialog(AndroidGalleryActivity.this);
   dialog.setContentView(R.layout.dialoglayout);
   dialog.setTitle("Select JPG");
    
   dialog.setCancelable(true);
   dialog.setCanceledOnTouchOutside(true);
    
   buttonUp = (Button)dialog.findViewById(R.id.up);
   buttonUp.setOnClickListener(new OnClickListener(){
     
    @Override
    public void onClick(View v) {
     // TODO Auto-generated method stub
     ListDir(curFolder.getParentFile()); 
    }});
   
   buttonSelectFolder = (Button)dialog.findViewById(R.id.selectfolder);
   buttonSelectFolder.setOnClickListener(new OnClickListener(){
    
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    Toast.makeText(AndroidGalleryActivity.this,
      curFolder + " selected",
      Toast.LENGTH_LONG).show();
    dismissDialog(CUSTOM_DIALOG_ID);
    
    ListJpgInFolder(curFolder);

   }});
   
    
   //Prepare ListView in dialog
   dialog_ListView = (ListView)dialog.findViewById(R.id.dialoglist);
    
   dialog_ListView.setOnItemClickListener(new OnItemClickListener(){
     
    @Override
    public void onItemClick(AdapterView<?> parent, View view,
      int position, long id) {
     File selected = new File(fileList.get(position));
     if(selected.isDirectory()){
      ListDir(selected);  
     }else {
      /*
      Toast.makeText(AndroidGalleryActivity.this,
        selected.toString() + " selected",
        Toast.LENGTH_LONG).show();
      dismissDialog(CUSTOM_DIALOG_ID);
       
      Bitmap bm = BitmapFactory.decodeFile(selected.getAbsolutePath());
      image.setImageBitmap(bm);
      */
     } 
    }});
        
   break;
  }
  return dialog; 
 }
  
 @Override
 protected void onPrepareDialog(int id, Dialog dialog, Bundle bundle) {
  // TODO Auto-generated method stub
  super.onPrepareDialog(id, dialog, bundle);
   
  switch(id) {
  case CUSTOM_DIALOG_ID:
   ListDir(curFolder);
   
   break; 
  } 
 }
  
 void ListDir(File f){
   
  if(f.equals(root)){
   buttonUp.setEnabled(false); 
  }else{
   buttonUp.setEnabled(true); 
  }
   
  curFolder = f;
  buttonSelectFolder.setText("Select Folder " + curFolder);
   
  File[] files = f.listFiles();
  fileList.clear();
  for (File file : files){
   if(file.isDirectory()){
    fileList.add(file.getPath()); 
   }else{
    Uri selectedUri = Uri.fromFile(file);
    String fileExtension
     = MimeTypeMap.getFileExtensionFromUrl(selectedUri.toString());
    if(fileExtension.equalsIgnoreCase("jpg")){
     fileList.add(file.getName()); 
    } 
   } 
  }
   
  ArrayAdapter<String> directoryList
   = new ArrayAdapter<String>(this,
     android.R.layout.simple_list_item_1, fileList);
  dialog_ListView.setAdapter(directoryList); 
 }
 
 private void ListJpgInFolder(File folder){
  String jpgs = "JPG fiels in folder " + folder.getAbsolutePath() + "\n\n";
  File[] files = folder.listFiles();
  for (File file : files){
   if(!file.isDirectory()){
    Uri selectedUri = Uri.fromFile(file);
    String fileExtension
     = MimeTypeMap.getFileExtensionFromUrl(selectedUri.toString());
    if(fileExtension.equalsIgnoreCase("jpg")){
     jpgs += file.getAbsolutePath() + "\n"; 
    } 
   } 
  }
  
  jpgList.setText(jpgs);
 }
  
}

main.xml, the main layout.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
 
    <Button
        android:id="@+id/opendialog"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Load Folder" />
    <TextView
        android:id="@+id/jpglist"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

Next:
- Display photos from SD in android.widget.Gallery