Get thumbnails (in MediaStore.Images.Thumbnails) associated with MediaStore.Images.Media

Last exercise demonstrate how to "Get path of image in MediaStore.Images.Media from SimpleCursorAdapter". In this exercise, the associated thumbnails (in MediaStore.Images.Thumbnails) can be retrieved via the Cursor.

package com.example.androidlistimages;

import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v4.content.CursorLoader;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

public class MainActivity extends ListActivity {
 
 //define source of MediaStore.Images.Media, internal or external storage
 final Uri sourceUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
 final Uri thumbUri = MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI;
 final String thumb_DATA = MediaStore.Images.Thumbnails.DATA;
 final String thumb_IMAGE_ID = MediaStore.Images.Thumbnails.IMAGE_ID;

 SimpleCursorAdapter mySimpleCursorAdapter;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_main);
        
        String[] from = {MediaStore.MediaColumns.TITLE};
        int[] to = {android.R.id.text1};

        CursorLoader cursorLoader = new CursorLoader(
          this, 
          sourceUri, 
          null, 
          null, 
          null, 
          MediaStore.Audio.Media.TITLE);
        
        Cursor cursor = cursorLoader.loadInBackground();
        
        mySimpleCursorAdapter = new SimpleCursorAdapter(
          this, 
          android.R.layout.simple_list_item_1, 
          cursor, 
          from, 
          to, 
          CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        
        setListAdapter(mySimpleCursorAdapter);
        
        getListView().setOnItemClickListener(myOnItemClickListener);
    }
    
    OnItemClickListener myOnItemClickListener
    = new OnItemClickListener(){

  @Override
  public void onItemClick(AdapterView<?> parent, View view, int position,
    long id) {
   Cursor cursor = mySimpleCursorAdapter.getCursor();
   cursor.moveToPosition(position);

   int int_ID = cursor.getInt(cursor.getColumnIndex(MediaStore.Images.Media._ID));
   getThumbnail(int_ID);
  }};
 
 private Bitmap getThumbnail(int id){

  String[] thumbColumns = {thumb_DATA, thumb_IMAGE_ID};

  CursorLoader thumbCursorLoader = new CursorLoader(
          this, 
          thumbUri, 
    thumbColumns, 
    thumb_IMAGE_ID + "=" + id, 
    null, 
    null);
        
        Cursor thumbCursor = thumbCursorLoader.loadInBackground();
        
        Bitmap thumbBitmap = null;
        if(thumbCursor.moveToFirst()){
   int thCulumnIndex = thumbCursor.getColumnIndex(thumb_DATA);
   
   String thumbPath = thumbCursor.getString(thCulumnIndex);
   
   Toast.makeText(getApplicationContext(), 
     thumbPath, 
     Toast.LENGTH_LONG).show();
   
   thumbBitmap = BitmapFactory.decodeFile(thumbPath);
   
   //Create a Dialog to display the thumbnail
   AlertDialog.Builder thumbDialog = new AlertDialog.Builder(MainActivity.this);
   ImageView thumbView = new ImageView(MainActivity.this);
   thumbView.setImageBitmap(thumbBitmap);
   LinearLayout layout = new LinearLayout(MainActivity.this);
         layout.setOrientation(LinearLayout.VERTICAL);
         layout.addView(thumbView);
         thumbDialog.setView(layout);
         thumbDialog.show();
   
  }else{
   Toast.makeText(getApplicationContext(), 
     "NO Thumbnail!", 
     Toast.LENGTH_LONG).show();
  }
        
        return thumbBitmap;
 }
}

Download the files.


Next:
- List Images with thumbnails, implementing custom SimpleCursorAdapter.