Android Open Source - unmp Image Loader

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Back to project page unmp.
License

The source code is released under:
MIT License
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Java Source Code

package com.parnswir.unmp.core;
/*from  w  ww  . ja  v a 2 s . c  o m*/
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.widget.ImageView;

import com.parnswir.unmp.R;

public class ImageLoader {
  
  public static final boolean DO_COMPRESS = true;
  public static final boolean DO_NOT_COMPRESS = false;
  
  private static final int STUB_ID = R.drawable.default_image;
  private static final int REQUIRED_SIZE = 64;
    
    private MemoryCache memoryCache = new MemoryCache();
    private Map<ImageView, String> imageViews = Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
    private ExecutorService executorService;
    private Handler handler = new Handler();
    private SQLiteDatabase DB;
    
    public ImageLoader(Context context, SQLiteDatabase db){
        executorService = Executors.newFixedThreadPool(1);
        DB = db;
    }
    
    public void displayAlbumImage(String name, ImageView imageView, boolean compress, ImageRetriever handler)
    {
        imageViews.put(imageView, name);
        Bitmap bitmap = memoryCache.get(name);
        if(bitmap != null) {
            imageView.setImageBitmap(bitmap);
        } else {
            queuePhoto(name, imageView, compress, handler);
        }
    }
        
    private void queuePhoto(String albumName, ImageView imageView, boolean compress, ImageRetriever handler)
    {
        PhotoToLoad p = new PhotoToLoad(albumName, imageView, compress, handler);
        executorService.submit(new PhotosLoader(p));
    }
    
    public static Bitmap decodeBitmap(byte[] b, boolean compress){
      if (b == null)
        return null;
      
      int scale = 1;
      
      if (compress) {
      BitmapFactory.Options o = new BitmapFactory.Options();
      o.inJustDecodeBounds = true;
      BitmapFactory.decodeByteArray(b, 0, b.length, o);
      
      int width_tmp = o.outWidth, height_tmp=o.outHeight;
      while(true){
          if(width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
              break;
          width_tmp /= 2;
          height_tmp /= 2;
          scale *= 2;
      }
      }
    
    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize = scale;
    return BitmapFactory.decodeByteArray(b, 0, b.length, o2);
    }
    
    private class PhotoToLoad
    {
        public String albumName;
        public ImageView imageView;
        public boolean doCompress;
        public ImageRetriever handler;
        
        public PhotoToLoad(String albumName, ImageView imageView, boolean compress, ImageRetriever handler){
            this.albumName = albumName; 
            this.imageView = imageView;
            this.doCompress = compress;
            this.handler = handler;
        }
    }
    
    class PhotosLoader implements Runnable {
        PhotoToLoad photoToLoad;
        PhotosLoader(PhotoToLoad photoToLoad){
            this.photoToLoad=photoToLoad;
        }
        
        @Override
        public void run() {
            try{
                if(imageViewReused(photoToLoad))
                    return;
                Bitmap bmp = decodeBitmap(photoToLoad.handler.getBitmap(photoToLoad.albumName, DB), photoToLoad.doCompress);
                memoryCache.put(photoToLoad.albumName, bmp);
                if(imageViewReused(photoToLoad))
                    return;
                BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
                handler.post(bd);
            }catch(Throwable th){
                th.printStackTrace();
            }
        }
    }
    
    boolean imageViewReused(PhotoToLoad photoToLoad){
        String tag = imageViews.get(photoToLoad.imageView);
        if(tag==null || !tag.equals(photoToLoad.albumName))
            return true;
        return false;
    }
    
    class BitmapDisplayer implements Runnable
    {
        Bitmap bitmap;
        PhotoToLoad coverToLoad;
        
        public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
          bitmap = b; 
          coverToLoad = p;
        }
        
        public void run()
        {
            if(imageViewReused(coverToLoad))
                return;
            if(bitmap != null)
                coverToLoad.imageView.setImageBitmap(bitmap);
            else
                coverToLoad.imageView.setImageResource(STUB_ID);
        }
    }

    public void clearCache() {
        memoryCache.clear();
    }

}
Java Source Code List
