/*******************************************************************************
* Copyright 2013 PAR Works, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.parworks.mars.utils;
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;
public class ImageLoader
{
public interface ImageLoaderListener {
public void imageLoaded();
}
public static String TAG = ImageLoader.class.getName();
// 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)
{
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
cacheDir = Utilities.GetCacheDir(context);
}
public void DisplayImage(String url, Activity activity, ImageView imageView,ImageLoaderListener listener) {
DisplayImage(url,activity,imageView,null,listener);
}
public void DisplayImage(String url, Activity activity, ImageView imageView, Integer bitmapWidth,ImageLoaderListener listener)
{
imageView.setTag(url);
Log.i(TAG, url);
if (cache.containsKey(url)) {
Bitmap bitmap = cache.get(url);
if(bitmapWidth != null) {
bitmap = Bitmap.createScaledBitmap(bitmap, bitmapWidth, calculateHeight(bitmapWidth,bitmap), true);
}
imageView.setImageBitmap(bitmap);
listener.imageLoaded();
} else
{
queuePhoto(url, activity, imageView,listener,bitmapWidth);
}
}
private int calculateHeight(Integer width,Bitmap bitmap) {
float startingWidth = bitmap.getWidth();
float startingHeight = bitmap.getHeight();
float widthHeightRatio = startingWidth/startingHeight;
return Math.round(width / widthHeightRatio);
}
private void queuePhoto(String url, Activity activity, ImageView imageView,ImageLoaderListener listener, Integer bitmapWidth)
{
// 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, listener, bitmapWidth);
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(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);
// IOUtils.copy(is, os);
Utilities.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex)
{
ex.printStackTrace();
return null;
}
}
// decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f)
{
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 = 70;
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;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e)
{
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad
{
public String url;
public ImageView imageView;
public ImageLoaderListener listener;
public Integer width;
public PhotoToLoad(String u, ImageView i,ImageLoaderListener l, Integer w)
{
url = u;
imageView = i;
listener = l;
width = w;
}
}
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);
Object tag = photoToLoad.imageView.getTag();
if (tag != null && ((String) tag).equals(photoToLoad.url))
{
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad.imageView,photoToLoad.listener,photoToLoad.width);
Activity a = (Activity) photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
}
PhotosLoader photoLoaderThread = new PhotosLoader();
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
Bitmap bitmap;
ImageView imageView;
ImageLoaderListener listener;
Integer width;
public BitmapDisplayer(Bitmap b, ImageView i, ImageLoaderListener l, Integer w)
{
bitmap = b;
imageView = i;
listener = l;
width = w;
}
public void run()
{
Log.i(TAG, "BitmapDisplayer run()");
if (bitmap != null) {
if(width != null) {
bitmap = Bitmap.createScaledBitmap(bitmap, width, calculateHeight(width,bitmap), true);
}
imageView.setImageBitmap(bitmap);
listener.imageLoaded();
}
}
}
public void clearCache()
{
// clear memory cache
cache.clear();
// clear SD cache
File[] files = cacheDir.listFiles();
for (File f : files)
f.delete();
}
}