import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.Stack;
 
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.ImageView;
 
import com.skuup.R;
 
public class ImageLoader {
	private String TAG = ImageLoader.class.getSimpleName();
	public static final String PREFIX_IMG = "img_";
 
	// the simplest in-memory cache implementation. This should be replaced with
	// something like SoftReference or BitmapOptions.inPurgeable(since 1.6)
	private HashMap<String, Bitmap> cache = new HashMap<String, Bitmap>();
 
	private File cacheDir;
 
	public ImageLoader(Context context) {
		// Make the background thead low priority. This way it will not affect the
		// UI performance
		photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
 
		// Find the dir to save cached images
		if (android.os.Environment.getExternalStorageState().equals(
				android.os.Environment.MEDIA_MOUNTED))
			cacheDir = new File(android.os.Environment.getExternalStorageDirectory(),
					context.getResources().getString(R.string.temp_image_folder));
		else
			cacheDir = context.getCacheDir();
		if (!cacheDir.exists())
			cacheDir.mkdirs();
	}
 
	final int stub_id = R.drawable.icon;
 
	public void DisplayImage(String url, Activity activity, ImageView imageView) {
		if (cache.containsKey(url))
			imageView.setImageBitmap(cache.get(url));
		else {
			queuePhoto(url, activity, imageView);
			imageView.setImageResource(stub_id);
		}
	}
 
	private void queuePhoto(String url, Activity activity, ImageView imageView) {
		// This ImageView may be used for other images before. So there may be some
		// old tasks in the queue. We need to discard them.
		photosQueue.Clean(imageView);
		PhotoToLoad p = new PhotoToLoad(url, imageView);
		synchronized (photosQueue.photosToLoad) {
			photosQueue.photosToLoad.push(p);
			photosQueue.photosToLoad.notifyAll();
		}
 
		// start thread if it's not started yet
		if (photoLoaderThread.getState() == Thread.State.NEW)
			photoLoaderThread.start();
	}
 
	private Bitmap getBitmap(String url) {
		// I identify images by hashcode. Not a perfect solution, good for the demo.
		String filename = String.valueOf(PREFIX_IMG + Utils.md5(url) + ".jpg");
		// String filename=String.valueOf(url.hashCode());
		File f = new File(cacheDir, filename);
 
		// from SD cache
		Bitmap b = decodeFile(f);
		if (b != null) {
			return b;
		}
 
		// from web
		try {
			Bitmap bitmap = null;
			InputStream is = new URL(url).openStream();
			OutputStream os = new FileOutputStream(f);
			Utils.CopyStream(is, os);
			os.close();
			bitmap = decodeFile(f);
			return bitmap;
		} catch (Exception ex) {
			Log.e(TAG, "ERROR", ex);
			return null;
		}
	}
 
	// decodes image and scales it to reduce memory consumption
	private Bitmap decodeFile(File f) {
		Bitmap result = null;
		try {
			// decode image size
			BitmapFactory.Options o = new BitmapFactory.Options();
			o.inJustDecodeBounds = true;
			BitmapFactory.decodeStream(new FileInputStream(f), null, o);
 
			// Find the correct scale value. It should be the power of 2.
			final int REQUIRED_SIZE = 150;
			int width_tmp = o.outWidth, height_tmp = o.outHeight;
			int scale = 1;
			while (true) {
				if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
					break;
				width_tmp /= 2;
				height_tmp /= 2;
				scale++;
			}
 
			// decode with inSampleSize
			BitmapFactory.Options o2 = new BitmapFactory.Options();
			o2.inSampleSize = scale;
			result = BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
			return result;
		} catch (FileNotFoundException e) {
			Log.e(TAG, "ERROR", e);
		}
		return result;
	}
 
	// Task for the queue
	private class PhotoToLoad {
		public String url;
		public ImageView imageView;
 
		public PhotoToLoad(String u, ImageView i) {
			url = u;
			imageView = i;
		}
	}
 
	PhotosQueue photosQueue = new PhotosQueue();
 
	public void stopThread() {
		photoLoaderThread.interrupt();
	}
 
	// stores list of photos to download
	class PhotosQueue {
		private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
 
		// removes all instances of this ImageView
		public void Clean(ImageView image) {
			for (int j = 0; j < photosToLoad.size();) {
				if (photosToLoad.get(j).imageView == image)
					photosToLoad.remove(j);
				else
					++j;
			}
		}
	}
 
	class PhotosLoader extends Thread {
		public void run() {
			try {
				while (true) {
					// thread waits until there are any images to load in the queue
					if (photosQueue.photosToLoad.size() == 0)
						synchronized (photosQueue.photosToLoad) {
							photosQueue.photosToLoad.wait();
						}
					if (photosQueue.photosToLoad.size() != 0) {
						PhotoToLoad photoToLoad;
						synchronized (photosQueue.photosToLoad) {
							photoToLoad = photosQueue.photosToLoad.pop();
						}
						Bitmap bmp = getBitmap(photoToLoad.url);
						cache.put(photoToLoad.url, bmp);
						if (((String) photoToLoad.imageView.getTag())
								.equals(photoToLoad.url)) {
							BitmapDisplayer bd = new BitmapDisplayer(bmp,
									photoToLoad.imageView);
							Activity a = (Activity) photoToLoad.imageView.getContext();
							a.runOnUiThread(bd);
						}
					}
					if (Thread.interrupted())
						break;
				}
			} catch (InterruptedException e) {
				// allow thread to exit
				Log.e(TAG, "ERROR", e);
			}
		}
	}
 
	PhotosLoader photoLoaderThread = new PhotosLoader();
 
	// Used to display bitmap in the UI thread
	class BitmapDisplayer implements Runnable {
		Bitmap bitmap;
		ImageView imageView;
 
		public BitmapDisplayer(Bitmap b, ImageView i) {
			bitmap = b;
			imageView = i;
		}
 
		public void run() {
			if (bitmap != null)
				imageView.setImageBitmap(bitmap);
			else
				imageView.setImageResource(stub_id);
		}
	}
 
	public void clearCache() {
		// clear memory cache
		cache.clear();
 
		// clear SD cache
		File[] files = cacheDir.listFiles();
		for (File f : files)
			f.delete();
	}
 
}

public static void setListViewHeightBasedOnChildren(ListView listView) {
		ListAdapter listAdapter = listView.getAdapter();
		if (listAdapter == null) {
			// pre-condition
			return;
		}
 
		int totalHeight = 0;
		int desiredWidth = MeasureSpec.makeMeasureSpec(listView.getWidth(), MeasureSpec.AT_MOST);
		for (int i = 0; i < listAdapter.getCount(); i++) {
			View listItem = listAdapter.getView(i, null, listView);
			listItem.measure(desiredWidth, MeasureSpec.UNSPECIFIED);
			totalHeight += listItem.getMeasuredHeight();
		}
 
		ViewGroup.LayoutParams params = listView.getLayoutParams();
		params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
		listView.setLayoutParams(params);
		listView.requestLayout();
 
	}