This is the animation while loading images from server. Put couple images in drawable.
Image Loader Class:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
public class ImageLoader
{
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Context mContext;
Bitmap bitmap;
AnimationDrawable frameAnimation;
private int i_size = 320;
public ImageLoader(Context context)
{
fileCache = new FileCache(context);
mContext = context;
executorService = Executors.newFixedThreadPool(5);
}
private int mTag = 0;
/**
* LoadImage method for load image from web
*@param url
*@param imageView
*@param tag
* pass int value (1,2,3) for<br/>
* 1 = thumbImage (ScaleType.FIT_XY),<br/>
* 2 = fullImage (ScaleType.FIT_XY),<br/>
* 3 = fullImage (ScaleType.FIT_START)
*/
public synchronized void DisplayImage(String url, ImageView imageView, int tag)
{
this.mTag = tag;
if(mTag == 1 || mTag == 4)
{
i_size =Constant.MAX_ThumbImage_SIZE;
}
else
{
i_size =Constant.MAX_Image_SIZE;
}
imageViews.put(imageView, url);
bitmap = memoryCache.get(url);
if (bitmap != null)
{
Log.i("memoryCache", "bitmap");
imageView.setImageBitmap(bitmap);
}
else
{
Log.i("memoryCache_touch", "bitmap null");
queuePhoto(url, imageView);
frameAnimation = (AnimationDrawable)mContext.getResources().getDrawable(R.anim.animation_loding);
imageView.setScaleType(ScaleType.CENTER);
imageView.setImageDrawable(frameAnimation);
Timer timer = new Timer();
timer.schedule(new TimerTask()
{
@Override
public void run()
{
frameAnimation.start();
}
}, 0);
}
}
private void queuePhoto(String url, ImageView imageView)
{
PhotoToLoad p = new PhotoToLoad(url, imageView);
//executor.execute(new PhotosLoader(p));
executorService.submit(new PhotosLoader(p));
}
public Bitmap getBitmap(String url)
{
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
}
catch (Throwable ex)
{
ex.printStackTrace();
if(ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// decodes image and scales it to reduce memory consumption
public Bitmap decodeFile(File f)
{
try
{
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1=new FileInputStream(f);
BitmapFactory.decodeStream(stream1,null,o);
stream1.close();
//Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE=i_size;
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*=2;
}
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
FileInputStream stream2=new FileInputStream(f);
Bitmap bitmap=BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
}catch (Throwable e) {
// TODO: handle exception
e.printStackTrace();
if(e instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// Task for the queue
private class PhotoToLoad
{
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i)
{
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable
{
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad)
{
this.photoToLoad = photoToLoad;
}
@Override
public void run()
{
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
if(bmp != null)
{
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
Activity a = (Activity) photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad)
{
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p)
{
bitmap = b;
photoToLoad = p;
}
public void run()
{
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
{
photoToLoad.imageView.setBackgroundResource(0);
photoToLoad.imageView.setImageBitmap(bitmap);
if(mTag==1 || mTag == 2)
{
photoToLoad.imageView.setScaleType(ScaleType.FIT_XY);
}
else if (mTag == 4)
{
photoToLoad.imageView.setScaleType(ScaleType.FIT_CENTER);
}
else if (mTag == 5)
{
photoToLoad.imageView.setScaleType(ScaleType.CENTER_CROP);
}
else
{
photoToLoad.imageView.setScaleType(ScaleType.FIT_START);
}
}
else
{
Drawable drawable = mContext.getResources().getDrawable(R.drawable.no_image);
photoToLoad.imageView.setImageDrawable(drawable);
}
}
}
public void clearCache()
{
memoryCache.clear();
fileCache.clear();
}
}
FileCache:
import java.io.File;
import android.content.Context;
public class FileCache {
private File cacheDir;
public FileCache(Context context){
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"ImageLoader");
else
cacheDir=context.getCacheDir();
if(!cacheDir.exists())
cacheDir.mkdirs();
}
public File getFile(String url){
String filename=String.valueOf(url.hashCode());
File f = new File(cacheDir, filename);
return f;
}
public void clear(){
File[] files=cacheDir.listFiles();
if(files==null)
return;
for(File f:files)
f.delete();
}
}
MemoryCache:
import java.lang.ref.SoftReference;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import android.graphics.Bitmap;
public class MemoryCache {
private Map<String, SoftReference<Bitmap>> cache=Collections.synchronizedMap(new HashMap<String, SoftReference<Bitmap>>());
public Bitmap get(String id)
{
if(!cache.containsKey(id))
return null;
SoftReference<Bitmap> ref=cache.get(id);
return ref.get();
}
public void put(String id, Bitmap bitmap){
cache.put(id, new SoftReference<Bitmap>(bitmap));
}
public void clear() {
cache.clear();
}
}
Utils:
import java.io.InputStream;
import java.io.OutputStream;
public class Utils {
public static void CopyStream(InputStream is, OutputStream os)
{
final int buffer_size=1024;
try
{
byte[] bytes=new byte[buffer_size];
for(;;)
{
int count=is.read(bytes, 0, buffer_size);
if(count==-1)
break;
os.write(bytes, 0, count);
}
}
catch(Exception ex){}
}
}
Constant:
public class Constant
{
public static int MAX_Image_SIZE = 320;
public static int MAX_ThumbImage_SIZE = 125;
}
MainActivity:
import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.widget.ImageView;
public class MainActivity extends Activity
{
ImageLoader img_loader;
ImageView imgPhoto=null;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
img_loader =new ImageLoader(MainActivity.this);
imgPhoto = (ImageView)findViewById(R.id.imgPhoto);
getImagesSize();
img_loader.DisplayImage("http://talkingpointsmemo.com/images/google-android-mascot.jpg",imgPhoto,4);
}
private void getImagesSize()
{
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
int w = dm.widthPixels;
int h = dm.heightPixels;
if(w <= 240 && h <= 320)
{
Constant.MAX_ThumbImage_SIZE = 100;
Constant.MAX_Image_SIZE = 400;
}
else if(w <= 320 && h <= 480)
{
Constant.MAX_ThumbImage_SIZE = 100;
Constant.MAX_Image_SIZE = 600;
}
else if(w <= 480 && h <= 854)
{
Constant.MAX_ThumbImage_SIZE = 150;
Constant.MAX_Image_SIZE = 900;
}
else
{
Constant.MAX_ThumbImage_SIZE = 200;
Constant.MAX_Image_SIZE = 1000;
}
}
}
Permission:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Download Sample:
