package lib.img.downloder;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.methods.HttpGet;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.net.http.AndroidHttpClient;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.ImageView;
public abstract class ImageDownloader {
private static final String LOG_TAG = "ImageDownlader";
public static void download(String url, ImageView imageView){
Context context = imageView.getContext();
Bitmap bitmap = getBitmapFromCache(context, url);
if (bitmap == null)
forceDownload(url, imageView);
else {
cancelPotentialDownload(url, imageView);
imageView.setImageBitmap(bitmap);
}
}
private static void forceDownload(String url, ImageView imageView){
if (url == null) {
imageView.setImageDrawable(null);
return;
}
if (cancelPotentialDownload(url, imageView)) {
BitmapDownloadTask task = new BitmapDownloadTask(url, imageView);
DownloadedDrawable drawable = new DownloadedDrawable(task);
imageView.setImageDrawable(drawable);
imageView.setMinimumHeight(156);
task.execute();
}
}
private static boolean cancelPotentialDownload(String url, ImageView imageView){
BitmapDownloadTask task = getBitmapDownloadTask(imageView);
if (task != null) {
String downloadURL = task.url;
if (downloadURL == null || !downloadURL.equals(url))
task.cancel(true);
return false;
}
return true;
}
private static BitmapDownloadTask getBitmapDownloadTask(ImageView imageView){
if (imageView != null){
Drawable drawable = imageView.getDrawable();
if (drawable instanceof DownloadedDrawable) {
DownloadedDrawable ddrawable = (DownloadedDrawable)drawable;
return ddrawable.getBitmapDownloadTask();
}
}
return null;
}
static Bitmap downloadBitmap(String url){
final AndroidHttpClient client = AndroidHttpClient.newInstance("Android");
final HttpGet getRequest = new HttpGet(url);
try {
HttpResponse response = client.execute(getRequest);
final int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
Log.w("ImageDownloader", "Error " + statusCode + " while retriving bitmap from " + url);
return null;
}
final HttpEntity entity = response.getEntity();
if (entity != null){
InputStream inputStream = null;
try{
inputStream = entity.getContent();
return BitmapFactory.decodeStream(new FlushedInputStream(inputStream));
} finally {
if (inputStream != null)
inputStream.close();
entity.consumeContent();
}
}
} catch(IOException e){
getRequest.abort();
Log.w(LOG_TAG, "I/O error while retriving from url :" + url, e);
} catch (IllegalStateException e) {
getRequest.abort();
Log.w(LOG_TAG, "Incorrect URL: " + url);
} catch (Exception e) {
getRequest.abort();
Log.w(LOG_TAG, "Error while retrieving bitmap from " + url, e);
} finally {
client.close();
}
return null;
}
static class FlushedInputStream extends FilterInputStream {
public FlushedInputStream(InputStream inputStream) {
super(inputStream);
}
@Override
public long skip(long n) throws IOException {
long totalBytesSkipped = 0L;
while (totalBytesSkipped <>
long bytesSkipped = in.skip(n - totalBytesSkipped);
if (bytesSkipped == 0L) {
int b = read();
if (b <>
break; // we reached EOF
} else {
bytesSkipped = 1; // we read one byte
}
}
totalBytesSkipped += bytesSkipped;
}
return totalBytesSkipped;
}
}
public static class BitmapDownloadTask extends AsyncTask {
private String url;
private final WeakReference imageViewRef;
public BitmapDownloadTask(String url, ImageView imageView) {
imageViewRef = new WeakReference(imageView);
this.url = url;
}
protected void onPostExecute(Bitmap bitmap){
if (this.isCancelled()) {
bitmap = null;
}
ImageView imageView = imageViewRef.get();
if (imageView != null) {
Context ctx = imageView.getContext();
addBitmapToCache(ctx, url, bitmap);
if (imageViewRef != null) {
BitmapDownloadTask task = getBitmapDownloadTask(imageView);
if (this == task) {
imageView.setImageBitmap(bitmap);
}
}
}
}
@Override
protected Bitmap doInBackground(Void... params) {
return downloadBitmap(url);
}
}
static class DownloadedDrawable extends ColorDrawable {
private final WeakReference taskRef;
public DownloadedDrawable(BitmapDownloadTask task){
super(Color.BLACK);
taskRef = new WeakReference(task);
}
public BitmapDownloadTask getBitmapDownloadTask(){
return taskRef.get();
}
}
private static void addBitmapToCache(Context context, String url, Bitmap bitmap){
if (bitmap != null) {
if (context != null) {
File dir = context.getCacheDir();
String fileName = url.hashCode() + ".png";
File f = new File(dir, fileName);
FileOutputStream out = null;
try {
out = new FileOutputStream(f);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
} catch (FileNotFoundException e) {
Log.w(LOG_TAG, "Error save bitmap from url: " + url + " to " + f);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
}
}
}
}
}
}
private static Bitmap getBitmapFromCache(Context context, String url) {
if (url != null) {
if (context != null) {
File dir = context.getCacheDir();
String fileName = url.hashCode() + ".png";
File f = new File(dir, fileName);
if (f.exists()) {
return BitmapFactory.decodeFile(f.toString());
}
}
}
return null;
}
}
// ImageAdapter.java
package lib.img.downloder;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
public class ImageAdapter extends BaseAdapter{
private static final String[] URLS = {
"http://lh5.ggpht.com/_mrb7w4gF8Ds/TCpetKSqM1I/AAAAAAAAD2c/Qef6Gsqf12Y/s144-c/_DSC4374%20copy.jpg",
"http://lh5.ggpht.com/_Z6tbBnE-swM/TB0CryLkiLI/AAAAAAAAVSo/n6B78hsDUz4/s144-c/_DSC3454.jpg",
"http://lh3.ggpht.com/_GEnSvSHk4iE/TDSfmyCfn0I/AAAAAAAAF8Y/cqmhEoxbwys/s144-c/_MG_3675.jpg",
"http://lh6.ggpht.com/_Nsxc889y6hY/TBp7jfx-cgI/AAAAAAAAHAg/Rr7jX44r2Gc/s144-c/IMGP9775a.jpg",
"http://lh3.ggpht.com/_lLj6go_T1CQ/TCD8PW09KBI/AAAAAAAAQdc/AqmOJ7eg5ig/s144-c/Juvenile%20Gannet%20despute.jpg",
"http://lh6.ggpht.com/_ZN5zQnkI67I/TCFFZaJHDnI/AAAAAAAABVk/YoUbDQHJRdo/s144-c/P9250508.JPG",
"http://lh4.ggpht.com/_XjNwVI0kmW8/TCOwNtzGheI/AAAAAAAAC84/SxFJhG7Scgo/s144-c/0014.jpg",
"http://lh6.ggpht.com/_lnDTHoDrJ_Y/TBvKsJ9qHtI/AAAAAAAAG6g/Zll2zGvrm9c/s144-c/000007.JPG",
"http://lh6.ggpht.com/_qvCl2efjxy0/TCIVI-TkuGI/AAAAAAAAOUY/vbk9MURsv48/s144-c/DSC_0844.JPG",
"http://lh4.ggpht.com/_TPlturzdSE8/TBv4ugH60PI/AAAAAAAAMsI/p2pqG85Ghhs/s144-c/_MG_3963.jpg",
"http://lh4.ggpht.com/_4f1e_yo-zMQ/TCe5h9yN-TI/AAAAAAAAXqs/8X2fIjtKjmw/s144-c/IMG_1786.JPG",
"http://lh6.ggpht.com/_iFt5VZDjxkY/TB9rQyWnJ4I/AAAAAAAADpU/lP2iStizJz0/s144-c/DSCF1014.JPG",
"http://lh5.ggpht.com/_hepKlJWopDg/TB-_WXikaYI/AAAAAAAAElI/715k4NvBM4w/s144-c/IMG_0075.JPG",
"http://lh6.ggpht.com/_OfRSx6nn68g/TCzsQic_z3I/AAAAAAABOOI/5G4Kwzb2qhk/s144-c/EASTER%20ISLAND_Hanga%20Roa_31.5.08_46.JPG",
"http://lh6.ggpht.com/_ZGv_0FWPbTE/TB-_GLhqYBI/AAAAAAABVxs/cVEvQzt0ke4/s144-c/IMG_1288_hf.jpg",
"http://lh6.ggpht.com/_a29lGRJwo0E/TBqOK_tUKmI/AAAAAAAAVbw/UloKpjsKP3c/s144-c/31012332.jpg",
"http://lh3.ggpht.com/_55Lla4_ARA4/TB6xbyxxJ9I/AAAAAAABTWo/GKe24SwECns/s144-c/Bluebird%20049.JPG",
"http://lh3.ggpht.com/_iVnqmIBYi4Y/TCaOH6rRl1I/AAAAAAAA1qg/qeMerYQ6DYo/s144-c/Kwiat_100626_0016.jpg",
"http://lh6.ggpht.com/_QFsB_q7HFlo/TCItd_2oBkI/AAAAAAAAFsk/4lgJWweJ5N8/s144-c/3705226938_d6d66d6068_o.jpg",
"http://lh5.ggpht.com/_JTI0xxNrKFA/TBsKQ9uOGNI/AAAAAAAChQg/z8Exh32VVTA/s144-c/CRW_0015-composite.jpg",
"http://lh6.ggpht.com/_loGyjar4MMI/S-InVNkTR_I/AAAAAAAADJY/Fb5ifFNGD70/s144-c/Moving%20Rock.jpg",
"http://lh4.ggpht.com/_L7i4Tra_XRY/TBtxjScXLqI/AAAAAAAAE5o/ue15HuP8eWw/s144-c/opera%20house%20II.jpg",
"http://lh3.ggpht.com/_rfAz5DWHZYs/S9cstBTv1iI/AAAAAAAAeYA/EyZPUeLMQ98/s144-c/DSC_6425.jpg",
"http://lh6.ggpht.com/_iGI-XCxGLew/S-iYQWBEG-I/AAAAAAAACB8/JuFti4elptE/s144-c/norvig-polar-bear.jpg",
"http://lh3.ggpht.com/_M3slUPpIgmk/SlbnavqG1cI/AAAAAAAACvo/z6-CnXGma7E/s144-c/mf_003.jpg",
"http://lh4.ggpht.com/_loGyjar4MMI/S-InQvd_3hI/AAAAAAAADIw/dHvCFWfyHxQ/s144-c/Rainbokeh.jpg",
"http://lh4.ggpht.com/_yy6KdedPYp4/SB5rpK3Zv0I/AAAAAAAAOM8/mokl_yo2c9E/s144-c/Point%20Reyes%20road%20.jpg",
"http://lh5.ggpht.com/_6_dLVKawGJA/SMwq86HlAqI/AAAAAAAAG5U/q1gDNkmE5hI/s144-c/mobius-glow.jpg",
"http://lh3.ggpht.com/_QFsB_q7HFlo/TCItc19Jw3I/AAAAAAAAFs4/nPfiz5VGENk/s144-c/4551649039_852be0a952_o.jpg",
"http://lh6.ggpht.com/_TQY-Nm7P7Jc/TBpjA0ks2MI/AAAAAAAABcI/J6ViH98_poM/s144-c/IMG_6517.jpg",
"http://lh3.ggpht.com/_rfAz5DWHZYs/S9cLAeKuueI/AAAAAAAAeYU/E19G8DOlJRo/s144-c/DSC_4397_8_9_tonemapped2.jpg",
"http://lh4.ggpht.com/_TQY-Nm7P7Jc/TBpi6rKfFII/AAAAAAAABbg/79FOc0Dbq0c/s144-c/david_lee_sakura.jpg",
"http://lh3.ggpht.com/_TQY-Nm7P7Jc/TBpi8EJ4eDI/AAAAAAAABb0/AZ8Cw1GCaIs/s144-c/Hokkaido%20Swans.jpg",
"http://lh3.ggpht.com/_1aZMSFkxSJI/TCIjB6od89I/AAAAAAAACHM/CLWrkH0ziII/s144-c/079.jpg",
"http://lh5.ggpht.com/_loGyjar4MMI/S-InWuHkR9I/AAAAAAAADJE/wD-XdmF7yUQ/s144-c/Colorado%20River%20Sunset.jpg",
"http://lh3.ggpht.com/_0YSlK3HfZDQ/TCExCG1Zc3I/AAAAAAAAX1w/9oCH47V6uIQ/s144-c/3138923889_a7fa89cf94_o.jpg",
"http://lh6.ggpht.com/_K29ox9DWiaM/TAXe4Fi0xTI/AAAAAAAAVIY/zZA2Qqt2HG0/s144-c/IMG_7100.JPG",
"http://lh6.ggpht.com/_0YSlK3HfZDQ/TCEx16nJqpI/AAAAAAAAX1c/R5Vkzb8l7yo/s144-c/4235400281_34d87a1e0a_o.jpg",
"http://lh4.ggpht.com/_8zSk3OGcpP4/TBsOVXXnkTI/AAAAAAAAAEo/0AwEmuqvboo/s144-c/yosemite_forrest.jpg",
"http://lh4.ggpht.com/_6_dLVKawGJA/SLZToqXXVrI/AAAAAAAAG5k/7fPSz_ldN9w/s144-c/coastal-1.jpg",
"http://lh4.ggpht.com/_WW8gsdKXVXI/TBpVr9i6BxI/AAAAAAABhNg/KC8aAJ0wVyk/s144-c/IMG_6233_1_2-2.jpg",
"http://lh3.ggpht.com/_loGyjar4MMI/S-InS0tJJSI/AAAAAAAADHU/E8GQJ_qII58/s144-c/Windmills.jpg",
"http://lh4.ggpht.com/_loGyjar4MMI/S-InbXaME3I/AAAAAAAADHo/4gNYkbxemFM/s144-c/Frantic.jpg",
"http://lh5.ggpht.com/_loGyjar4MMI/S-InKAviXzI/AAAAAAAADHA/NkyP5Gge8eQ/s144-c/Rice%20Fields.jpg",
"http://lh3.ggpht.com/_loGyjar4MMI/S-InZA8YsZI/AAAAAAAADH8/csssVxalPcc/s144-c/Seahorse.jpg",
"http://lh3.ggpht.com/_syQa1hJRWGY/TBwkCHcq6aI/AAAAAAABBEg/R5KU1WWq59E/s144-c/Antelope.JPG",
"http://lh5.ggpht.com/_MoEPoevCLZc/S9fHzNgdKDI/AAAAAAAADwE/UAno6j5StAs/s144-c/c84_7083.jpg",
"http://lh4.ggpht.com/_DJGvVWd7IEc/TBpRsGjdAyI/AAAAAAAAFNw/rdvyRDgUD8A/s144-c/Free.jpg",
"http://lh6.ggpht.com/_iO97DXC99NY/TBwq3_kmp9I/AAAAAAABcz0/apq1ffo_MZo/s144-c/IMG_0682_cp.jpg",
"http://lh4.ggpht.com/_7V85eCJY_fg/TBpXudG4_PI/AAAAAAAAPEE/8cHJ7G84TkM/s144-c/20100530_120257_0273-Edit-2.jpg"
};
public int getCount(){
return URLS.length;
}
public String getItem(int position){
return URLS[position];
}
public long getItemId(int position){
return URLS[position].hashCode();
}
public View getView(int position, View view, ViewGroup parent){
if (view == null){
view = new ImageView(parent.getContext());
view.setPadding(6, 6, 6, 6);
}
ImageDownloader.download(URLS[position], (ImageView)view);
return view;
}
}
//ImageListActivity.java
package lib.img.downloder;
import android.app.ListActivity;
import android.os.Bundle;
public class ImageListActivity extends ListActivity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.imagelist);
this.setListAdapter(new ImageAdapter());
}
}
