Develop Reference

Android outofmemory bitmap

I have used the following animation class because i have multiple images to make an animation. After the 7th animation i get OutofMemoryError. androidgraphics.Bitmap.createBitmap
public class AnimationsContainer {
public int FPS = 30; // animation FPS
// single instance procedures
private static AnimationsContainer mInstance;
private AnimationsContainer() {
};
public static AnimationsContainer getInstance() {
if (mInstance == null)
mInstance = new AnimationsContainer();
return mInstance;
}
// animation progress dialog frames
private int[] mProgressAnimFrames = {};
// animation splash screen frames
/**
* #param imageView
* #return progress dialog animation
*/
public FramesSequenceAnimation createProgressDialogAnim(ImageView imageView) {
return new FramesSequenceAnimation(imageView, mProgressAnimFrames);
}
/**
* #param imageView
* #return splash screen animation
*/
public FramesSequenceAnimation createSplashAnim(ImageView imageView, int[] n) {
return new FramesSequenceAnimation(imageView, n);
}
/**
* AnimationPlayer. Plays animation frames sequence in loop
*/
public class FramesSequenceAnimation {
private int[] mFrames; // animation frames
private int mIndex; // current frame
private boolean mShouldRun; // true if the animation should continue running. Used to stop the animation
private boolean mIsRunning; // true if the animation currently running. prevents starting the animation twice
private SoftReference<ImageView> mSoftReferenceImageView; // Used to prevent holding ImageView when it should be dead.
private Handler mHandler;
private int mDelayMillis;
private OnAnimationStoppedListener mOnAnimationStoppedListener;
private Bitmap mBitmap = null;
private BitmapFactory.Options mBitmapOptions;
public FramesSequenceAnimation(ImageView imageView, int[] frames) {
mHandler = new Handler();
mFrames = frames;
mIndex = -1;
mSoftReferenceImageView = new SoftReference<ImageView>(imageView);
mShouldRun = false;
mIsRunning = false;
mDelayMillis = 50;
imageView.setImageResource(mFrames[0]);
// use in place bitmap to save GC work (when animation images are the same size & type)
if (Build.VERSION.SDK_INT >= 11) {
Bitmap bmp = ((BitmapDrawable) imageView.getDrawable()).getBitmap();
int width = bmp.getWidth();
int height = bmp.getHeight();
Bitmap.Config config = bmp.getConfig();
mBitmap = Bitmap.createBitmap(width, height, config);
mBitmapOptions = new BitmapFactory.Options();
// setup bitmap reuse options.
mBitmapOptions.inBitmap = mBitmap;
mBitmapOptions.inMutable = true;
mBitmapOptions.inSampleSize = 1;
}
}
private int getNext() {
mIndex++;
if (mIndex == mFrames.length){
mIndex = mIndex - 1;
mShouldRun = false;
}
return mFrames[mIndex];
}
/**
* Starts the animation
*/
public synchronized void start() {
mShouldRun = true;
if (mIsRunning)
return;
Runnable runnable = new Runnable() {
#Override
public void run() {
ImageView imageView = mSoftReferenceImageView.get();
if (!mShouldRun || imageView == null) {
mIsRunning = false;
if (mOnAnimationStoppedListener != null) {
mOnAnimationStoppedListener.onAnimationStopped();
}
return;
}
mIsRunning = true;
mHandler.postDelayed(this, mDelayMillis);
if (imageView.isShown()) {
int imageRes = getNext();
if (mBitmap != null) { // so Build.VERSION.SDK_INT >= 11
Bitmap bitmap = null;
try {
bitmap = BitmapFactory.decodeResource(imageView.getResources(), imageRes, mBitmapOptions);
} catch (Exception e) {
e.printStackTrace();
}
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
} else {
imageView.setImageResource(imageRes);
mBitmap.recycle();
mBitmap = null;
}
} else {
imageView.setImageResource(imageRes);
}
}
}
};
mHandler.post(runnable);
}
/**
* Stops the animation
*/
public synchronized void stop() {
mShouldRun = false;
}
}
}
Can anyone explain me why and tell me how to fix it? I already added
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
to my manifest file.

It might help to be sure that you are not keeping references to unneeded images. This is happening because you probably have the "standard" memory heap of 32MB or something similar (maybe 64MB or maybe 16MB). If you consider that most images are 5MB or more, it's not surprising you are out of memory.
You can increase the heap size using android:largeHeap="true" like this:
How to increase heap size of an android application?

Android How to run an AsyncTask every second?

I'm new in Android and not really knowing how to deal this problem: I have an AsyncTask which reads a position (X,Y,Z) from a XML file. As this position changes every second, I want, after I push a button (called with "StartListener") to read and draw every new position CONTINUOUSLY and stop reading it when I press the button again...
Somebody can help me? - Here is a part of my MainActivity
(For the moment my app reads and draws a position only when I press the button...)
private OnClickListener StartListener = new OnClickListener() {
#Override
public void onClick(View v) {
TextView ButText = (TextView)findViewById(R.id.buttonStart);
String value=ButText.getText().toString();
if(value.equals("Start positioning")){
ButText.setText("Stop positioning");
new PositionAsync().execute(); //read data from XML file
}
else if(value.equals("Stop positioning")){
ButText.setText("Start positioning");
//new PositionAsync().cancel(true);
}
}
}; // END LISTENER START BUTTON
// READ XML FILE
class PositionAsync extends AsyncTask<Void, Void, Void> {
XMLHelper helper;
#Override
protected Void doInBackground(Void... arg0) {
helper = new XMLHelper();
helper.get();
return null;
}
#Override
protected void onPostExecute(Void result) {
Paint paintBlack = new Paint(); paintBlack.setAntiAlias(true); paintBlack.setColor(Color.BLACK);
BitmapFactory.Options myOptions = new BitmapFactory.Options();
myOptions.inDither = true;
myOptions.inScaled = false;
myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// important
myOptions.inPurgeable = true;
File ImageSource = new File("/sdcard/app_background3.jpg");
Bitmap bitmap2 = BitmapFactory.decodeFile(ImageSource.getAbsolutePath(),myOptions);
Bitmap workingBitmap = Bitmap.createBitmap(bitmap2);
Bitmap mutableBitmap2 = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas2 = new Canvas(mutableBitmap2);
float RoomWidthPx = canvas2.getWidth();
float RoomHeightPx = canvas2.getHeight();
float RoomXmeter = (float) 9.3;
float RoomZmeter = (float) 14.7;
for (PositionValue position : helper.positions) {
String PosX = position.getPositionX(); String PosY = position.getPositionY(); String PosZ = position.getPositionZ();
float x = Float.valueOf(PosX); float y = Float.valueOf(PosY); float z = Float.valueOf(PosZ);
float xm = x*RoomWidthPx/RoomXmeter;
float zm = z*RoomHeightPx/RoomZmeter;
canvas2.drawCircle(xm, zm, 25, paintBlack);
ImageView imageView = (ImageView)findViewById(R.id.imageView1);
imageView.setAdjustViewBounds(true);
imageView.setImageBitmap(mutableBitmap2);
// SAVE DRAWINGS INTO FILE
FileOutputStream fos = null;
try {
fos = new FileOutputStream ("/sdcard/app_background3.jpg");
mutableBitmap2.compress (Bitmap.CompressFormat.JPEG, 95, fos);
} catch (Throwable ex) {ex.printStackTrace (); }
};
}
} //END READ XML FILE

I think you are doing too many task in just one second. You could, instead, prepare all heavy staff in the onPreExecute() of the AsyncTask, read the XML and do the painting in the doInBackground(), resfresh the ImageView in the onProgressUpdate() and finally, when the task is done, save the image to the sdcard.
I've modified your Asynctask to accomplish the above scenario, I've not tested it but it gives you the idea.
In the onCreate() method of your activity you start the AsyncTask just once. It stays executing or sleeping until you set the Quit_Task variable to true. When the button is pressed you toggle the variable Do_Drawing: Do_Drawing=!Do_Drawing; and that's it.
private boolean Do_Drawing = false;
private boolean Quit_Task = false;
// READ XML FILE
class PositionAsync extends AsyncTask<Void, Void, Void>
{
Paint paintBlack;
BitmapFactory.Options myOptions;
Bitmap mutableBitmap2;
Canvas canvas2;
XMLHelper helper;
void Sleep(int ms)
{
try
{
Thread.sleep(ms);
}
catch (Exception e)
{
}
}
#Override
protected void onPreExecute()
{
// Prepare everything for doInBackground thread
paintBlack = new Paint();
paintBlack.setAntiAlias(true);
paintBlack.setColor(Color.BLACK);
myOptions = new BitmapFactory.Options();
myOptions.inDither = true;
myOptions.inScaled = false;
myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// important
myOptions.inPurgeable = true;
File ImageSource = new File("/sdcard/app_background3.jpg");
Bitmap bitmap2 = BitmapFactory.decodeFile(ImageSource.getAbsolutePath(), myOptions);
Bitmap workingBitmap = Bitmap.createBitmap(bitmap2);
mutableBitmap2 = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);
canvas2 = new Canvas(mutableBitmap2);
helper = new XMLHelper();
}
#Override
protected Void doInBackground(Void... arg0)
{
while (!Quit_Task)
{
// Sleep until button is pressed or quit
while (!Do_Drawing)
{
Sleep(1000);
if (Quit_Task)
return null;
}
float RoomWidthPx = canvas2.getWidth();
float RoomHeightPx = canvas2.getHeight();
float RoomXmeter = (float) 9.3;
float RoomZmeter = (float) 14.7;
// keep drawing until button is pressed again or quit
while (Do_Drawing)
{
if (Quit_Task)
return null;
helper.get();
for (PositionValue position : helper.positions)
{
String PosX = position.getPositionX();
String PosY = position.getPositionY();
String PosZ = position.getPositionZ();
float x = Float.valueOf(PosX);
float y = Float.valueOf(PosY);
float z = Float.valueOf(PosZ);
float xm = x * RoomWidthPx / RoomXmeter;
float zm = z * RoomHeightPx / RoomZmeter;
canvas2.drawCircle(xm, zm, 25, paintBlack);
}
this.publishProgress((Void) null);
Sleep(1000);
}
}
return null;
}
#Override
protected void onProgressUpdate(Void... progress)
{
// once all points are read & drawn refresh the imageview
try
{
ImageView imageView = (ImageView) findViewById(R.id.imageView1);
imageView.setAdjustViewBounds(true);
imageView.setImageBitmap(mutableBitmap2);
}
catch (Exception e)
{
e.printStackTrace();
}
}
#Override
protected void onPostExecute(Void result)
{
// SAVE DRAWINGS INTO FILE once the task is done.
FileOutputStream fos = null;
try
{
fos = new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "app_background3.jpg");
mutableBitmap2.compress(Bitmap.CompressFormat.JPEG, 95, fos);
}
catch (Throwable ex)
{
ex.printStackTrace();
}
}
} // END READ XML FILE

you can use Handlers to deal with this:
private boolean isBusy = false;//this flag to indicate whether your async task completed or not
private boolean stop = false;//this flag to indicate whether your button stop clicked
private Handler handler = new Handler();
public void startHandler()
{
handler.postDelayed(new Runnable()
{
#Override
public void run()
{
if(!isBusy) callAysncTask();
if(!stop) startHandler();
}
}, 1000);
}
private void callAysncTask()
{
//TODO
new PositionAsync().execute();
}
set isBusy to true when the async task in doInBackground and set it back to false in the last line of onPostExecute.
when you click stop button set stop to true, when click start button set stop to false

Example using Androids lrucache

I need help understanding androids LruCache. I want to use to load images into my gridview in order make the loading/scrolling better. Can someone post an example code using LruCache please. Thanks in advance.

Below is a class I made for using LruCache, this is based on the presentation Doing More With Less: Being a Good Android Citizen given at Google I/O 2012.
Check out the movie for more information about what I'm doing in the TCImageLoader class:
public class TCImageLoader implements ComponentCallbacks2 {
private TCLruCache cache;
public TCImageLoader(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(
Context.ACTIVITY_SERVICE);
int maxKb = am.getMemoryClass() * 1024;
int limitKb = maxKb / 8; // 1/8th of total ram
cache = new TCLruCache(limitKb);
}
public void display(String url, ImageView imageview, int defaultresource) {
imageview.setImageResource(defaultresource);
Bitmap image = cache.get(url);
if (image != null) {
imageview.setImageBitmap(image);
}
else {
new SetImageTask(imageview).execute(url);
}
}
private class TCLruCache extends LruCache<String, Bitmap> {
public TCLruCache(int maxSize) {
super(maxSize);
}
#Override
protected int sizeOf(ImagePoolKey key, Bitmap value) {
int kbOfBitmap = value.getByteCount() / 1024;
return kbOfBitmap;
}
}
private class SetImageTask extends AsyncTask<String, Void, Integer> {
private ImageView imageview;
private Bitmap bmp;
public SetImageTask(ImageView imageview) {
this.imageview = imageview;
}
#Override
protected Integer doInBackground(String... params) {
String url = params[0];
try {
bmp = getBitmapFromURL(url);
if (bmp != null) {
cache.put(url, bmp);
}
else {
return 0;
}
} catch (Exception e) {
e.printStackTrace();
return 0;
}
return 1;
}
#Override
protected void onPostExecute(Integer result) {
if (result == 1) {
imageview.setImageBitmap(bmp);
}
super.onPostExecute(result);
}
private Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection
= (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
}
#Override
public void onLowMemory() {
}
#Override
public void onTrimMemory(int level) {
if (level >= TRIM_MEMORY_MODERATE) {
cache.evictAll();
}
else if (level >= TRIM_MEMORY_BACKGROUND) {
cache.trimToSize(cache.size() / 2);
}
}
}

I've found a really easy way that work perfectly for me...
This is the Cache.java class. In this class, the static getInstance() method enables us to create only one cache instance in the whole application. getLru() method is used to retrieve the cached object, it will be shown later how to use it. This cache is generic, meaning you can save any Object type into it. The cache memory size here is set to 1024. It can be changed if it is too small:
import android.support.v4.util.LruCache;
public class Cache {
private static Cache instance;
private LruCache<Object, Object> lru;
private Cache() {
lru = new LruCache<Object, Object>(1024);
}
public static Cache getInstance() {
if (instance == null) {
instance = new Cache();
}
return instance;
}
public LruCache<Object, Object> getLru() {
return lru;
}
}
This is the code in your activity where you save the bitmap to the cache:
public void saveBitmapToCahche(){
//The imageView that you want to save it's bitmap image resourse
ImageView imageView = (ImageView) findViewById(R.id.imageViewID);
//To get the bitmap from the imageView
Bitmap bitmap = ((BitmapDrawable)imageview.getDrawable()).getBitmap();
//Saving bitmap to cache. it will later be retrieved using the bitmap_image key
Cache.getInstance().getLru().put("bitmap_image", bitmap);
}
This is the code where you retrieve the bitmap from the cache, then set an imageView to this bitmap:
public void retrieveBitmapFromCache(){
//The imageView that you want to set to the retrieved bitmap
ImageView imageView = (ImageView) findViewById(R.id.imageViewID);
//To get bitmap from cache using the key. Must cast retrieved cache Object to Bitmap
Bitmap bitmap = (Bitmap)Cache.getInstance().getLru().get("bitmap_image");
//Setting imageView to retrieved bitmap from cache
imageView.setImageBitmap(bitmap));
}
THAT'S ALL! As you can see this is rather easy and simple.
EXAMPLE:
In my application, All the views are saved in class variables so they can be seen by all the methods in the class. In my first activity, I save the image bitmap to the cache in an onClickButton() method, right before I start a new activity using intent. I also save a string value in my cache:
public void onClickButton(View v){
Bitmap bitmap = ((BitmapDrawable)imageView.getDrawable()).getBitmap();
String name = textEdit.getText().toString();
Cache.getInstance().getLru().put("bitmap_image", bitmap);
Cache.getInstance().getLru().put("name", name);
Intent i = new Intent(FirstActivity.this, SecondActivity.class);
startActivity(i);
}
Then I navigate from the second activity to a third activity also using intents. In the last activity I save other objects into my cache, then go back to the first activity using an intent. Once I'm back in the first activity, the onCreate() method will start. In that method, I check if my cache has any bitmap value or any String value separately (based on my application business):
public ImageView imageView;
public EditText editText;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first);
//...Other code...
//The imageView that you want to save it's bitmap image resourse
imageView = (ImageView) findViewById(R.id.imageViewID);
//The editText that I want to save it's text into cache
editText = (EditText)findViewById(R.id.editTextID);
if(Cache.getInstance().getLru().get("name")!=null){
editText.setText(Cache.getInstance().getLru().get("name").toString());
}
if(Cache.getInstance().getLru().get("bitmap_image")!=null){
imageView.setImageBitmap((Bitmap)Cache.getInstance().getLru().get("bitmap_image"));
}
//...Other code...
}

Take a look at Caching Bitmaps where the use of LruCache is demonstrated.
The relevant portion of the code from the page is as follows:-
private LruCache mMemoryCache;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
// Get memory class of this device, exceeding this amount will throw an
// OutOfMemory exception.
final int memClass = ((ActivityManager) context.getSystemService(
Context.ACTIVITY_SERVICE)).getMemoryClass();
// Use 1/8th of the available memory for this memory cache.
final int cacheSize = 1024 * 1024 * memClass / 8;
mMemoryCache = new LruCache(cacheSize) {
#Override
protected int sizeOf(String key, Bitmap bitmap) {
// The cache size will be measured in bytes rather than number of items.
return bitmap.getByteCount();
}
};
...
}
public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
if (getBitmapFromMemCache(key) == null) {
mMemoryCache.put(key, bitmap);
}
}
public Bitmap getBitmapFromMemCache(String key) {
return mMemoryCache.get(key);
}

https://techienotes.info/2015/08/28/caching-bitmaps-in-android-using-lrucache/
This link has a full project having sample application to load images into Gridview using LruCache.
This class is using LruCache and taken from the code given in the link
public class ImageAdapter extends BaseAdapter{
private String TAG = getClass().getSimpleName();
Context mContext;
ArrayList<Uri> imageList;
private LruCache<String, Bitmap> mLruCache;
public ImageAdapter (Context context){
mContext = context;
//Find out maximum memory available to application
//1024 is used because LruCache constructor takes int in kilobytes
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
// Use 1/4th of the available memory for this memory cache.
final int cacheSize = maxMemory / 4;
Log.d(TAG, "max memory " + maxMemory + " cache size " + cacheSize);
// LruCache takes key-value pair in constructor
// key is the string to refer bitmap
// value is the stored bitmap
mLruCache = new LruCache<String, Bitmap>(cacheSize) {
#Override
protected int sizeOf(String key, Bitmap bitmap) {
// The cache size will be measured in kilobytes
return bitmap.getByteCount() / 1024;
}
};
imageList = new ArrayList<Uri>();
//Change this directory to where the images are stored
String imagesFolderPath = Environment.getExternalStorageDirectory().getPath()+"/backups/";
File imageSrcDir = new File (imagesFolderPath);
// if directory not present, build it
if (!imageSrcDir.exists()){
imageSrcDir.mkdirs();
}
ArrayList<File> imagesInDir = getImagesFromDirectory(imageSrcDir);
for (File file: imagesInDir){
// imageList will hold Uri of all images
imageList.add(Uri.fromFile(file));
}
}
#Override
public int getCount() {
return imageList.size();
}
#Override
public Object getItem(int position) {
return null;
}
#Override
public long getItemId(int position) {
return 0;
}
/**
*
* #param position The position of the item within the
* adapter's data set of the item whose view we want.
* #param convertView it is the view to be reused
* #param parent The parent that this view will eventually be attached to
* #return a View corresponding to the data at the specified position.
*/
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
Bitmap thumbnailImage = null;
if (convertView == null){
imageView = new ImageView(mContext);
imageView.setLayoutParams(
//150,150 is size of imageview to display image
new GridView.LayoutParams(150, 150));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
}
else {
imageView = (ImageView)convertView;
}
// Use the path as the key to LruCache
final String imageKey = imageList.get(position).toString();
//thumbnailImage is fetched from LRU cache
thumbnailImage = getBitmapFromMemCache(imageKey);
if (thumbnailImage == null){
// if asked thumbnail is not present it will be put into cache
BitmapWorkerTask task = new BitmapWorkerTask(imageView);
task.execute(imageKey);
}
imageView.setImageBitmap(thumbnailImage);
return imageView;
}
/**
* This function returns the files from a directory
* #param parentDirPath source directory in which images are located
* #return list of Files
*/
private ArrayList<File> getImagesFromDirectory (File parentDirPath){
ArrayList <File> listOfImages = new ArrayList<File>();
File [] fileArray = null;
if ( parentDirPath.isDirectory() ){//parentDirPath.exists() &&
// &&
// parentDirPath.canRead()){
fileArray = parentDirPath.listFiles();
}
if (fileArray == null){
return listOfImages; // return empty list
}
for (File file: fileArray){
if (file.isDirectory()){
listOfImages.addAll(getImagesFromDirectory(file));
}
else {
// Only JPEG and PNG formats are included
// for sake of simplicity
if (file.getName().endsWith("png") ||
file.getName().endsWith("jpg")){
listOfImages.add(file);
}
}
}
return listOfImages;
}
/**
* This function will return the scaled version of original image.
* Loading original images into thumbnail is wastage of computation
* and hence we will take put scaled version.
*/
private Bitmap getScaledImage (String imagePath){
Bitmap bitmap = null;
Uri imageUri = Uri.parse (imagePath);
try{
BitmapFactory.Options options = new BitmapFactory.Options();
/**
* inSampleSize flag if set to a value > 1,
* requests the decoder to sub-sample the original image,
* returning a smaller image to save memory.
* This is a much faster operation as decoder just reads
* every n-th pixel from given image, and thus
* providing a smaller scaled image.
* 'n' is the value set in inSampleSize
* which would be a power of 2 which is downside
* of this technique.
*/
options.inSampleSize = 4;
options.inScaled = true;
InputStream inputStream = mContext.getContentResolver().openInputStream(imageUri);
bitmap = BitmapFactory.decodeStream(inputStream, null, options);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return bitmap;
}
public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
if (getBitmapFromMemCache(key) == null) {
mLruCache.put(key, bitmap);
}
}
public Bitmap getBitmapFromMemCache(String key) {
return mLruCache.get(key);
}
class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
public BitmapWorkerTask(ImageView imageView) {
// Use a WeakReference to ensure the ImageView can be garbage collected
imageViewReference = new WeakReference<ImageView>(imageView);
}
#Override
protected Bitmap doInBackground(String... params) {
final Bitmap bitmap = getScaledImage(params[0]);
addBitmapToMemoryCache(String.valueOf(params[0]), bitmap);
return bitmap;
}
// onPostExecute() sets the bitmap fetched by doInBackground();
#Override
protected void onPostExecute(Bitmap bitmap) {
if (imageViewReference != null && bitmap != null) {
final ImageView imageView = (ImageView)imageViewReference.get();
if (imageView != null) {
imageView.setImageBitmap(bitmap);
}
}
}
}
}

Utility Class to save and retrieve Bitmap from own Cache.
package com.roomco.android.utils;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
public class MyCache {
private static MyCache instance;
private LruCache<Object, Object> lru;
private MyCache() {
lru = new LruCache<Object, Object>(1024);
}
public static MyCache getInstance() {
if (instance == null) {
instance = new MyCache();
}
return instance;
}
public LruCache<Object, Object> getLru() {
return lru;
}
public void saveBitmapToCahche(String key, Bitmap bitmap){
MyCache.getInstance().getLru().put(key, bitmap);
}
public Bitmap retrieveBitmapFromCache(String key){
Bitmap bitmap = (Bitmap)MyCache.getInstance().getLru().get(key);
return bitmap;
}
}
Usage:
//Save bitmap in cache
MyCache.getInstance().saveBitmapToCahche("your_key",bitmap);
// Get bitmap from cache
MyCache.getInstance().retrieveBitmapFromCache("your_key");

Android List view update

I am struggling to update a list view with data from a database, this works nicely by using a SimpleCursorAdapter. But the image view on the rows is not updated on the activity start, I have to scroll through the list a few times and only then the images are loaded in the image view.
This is the binder i am using for the SimpleCursorAdapter:
private class PromotionViewBinder implements SimpleCursorAdapter.ViewBinder {
private int done;
public boolean setViewValue(View view, Cursor cursor, int index) {
Log.e(""+cursor.getCount(),"");
View tmpview = view;
if (index == cursor.getColumnIndex(PromotionsTable.SEEN_COL)) {
boolean read = cursor.getInt(index) > 0 ? true : false;
TextView title = (TextView) tmpview;
if (!read) {
title.setTypeface(Typeface.DEFAULT_BOLD, 0);
} else {
title.setTypeface(Typeface.DEFAULT);
}
return true;
} else if (tmpview.getId() == R.id.promotions_list_row_image){
String imageURL = cursor.getString(index);
Log.e("",imageURL);
imageRetriever.displayImage(imageURL, (ImageView)tmpview);
return true;
} else {
return false;
}
}
}
The image retriever class is the LazyList example from here. As you will see this is using a runnable to retrieve the images and once the task is done is automatically updating the given imageView...Do you think that the reference to the imageView is lost somewhere on the way?
Thanx in advance,
Nick
package com.tipgain.promotions;
The image retriever class:
/**
* This class is used for retrieving images from a given web link. it uses local
* storage and memory to store the images. Once a image is downloaded
* successfully the UI gets updated automatically.
*
*
*/
public class ImageRetriever {
private final String TAG = ImageRetriever.class.getName();
private MemoryImageCache memoryImgCache = new MemoryImageCache();
private LocalStorageImageCache localFileCache;
private Map<ImageView, String> imageViewHolders = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
private ExecutorService execService;
final int defaultImageID = R.drawable.photo_not_available;
public ImageRetriever(Context context) {
localFileCache = new LocalStorageImageCache(context);
execService = Executors.newFixedThreadPool(5);
}
public void displayImage(String url, ImageView imageView) {
imageViewHolders.put(imageView, url);
Bitmap bmp = memoryImgCache.retrieve(url);
if (bmp != null) {
Log.e("case 1", " " + (bmp != null));
imageView.setImageBitmap(bmp);
} else {
Log.e("case 2", " " + (bmp == null));
addImageToQueue(url, imageView);
imageView.setImageResource(defaultImageID);
}
}
private void addImageToQueue(String url, ImageView imageView) {
NextImageToLoad img = new NextImageToLoad(url, imageView);
execService.submit(new ImagesRetriever(img));
}
/**
* This method is used for retrieving the Bitmap Image.
*
* #param url
* String representing the url pointing to the image.
* #return Bitmap representing the image
*/
private Bitmap getBitmap(String url) {
File imageFile = localFileCache.getFile(url);
// trying to get the bitmap from the local storage first
Bitmap bmp = decodeImageFile(imageFile);
if (bmp != null)
return bmp;
// if the file was not found locally we retrieve it from the web
try {
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(imageFile);
Utils.CopyStream(is, os);
os.close();
bmp = decodeImageFile(imageFile);
return bmp;
} catch (MalformedURLException e) {
Log.e(TAG, e.getMessage());
} catch (FileNotFoundException e) {
Log.e(TAG, e.getMessage());
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
return null;
}
/**
* This method is used for decoding a given image file. Also, to reduce
* memory, the image is also scaled.
*
* #param imageFile
* #return
*/
private Bitmap decodeImageFile(File imageFile) {
try {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(imageFile), null,
options);
// Find the correct scale value. It should be the power of 2.
// Deciding the perfect scaling value. (^2).
final int REQUIRED_SIZE = 100;
int tmpWidth = options.outWidth, tmpHeight = options.outHeight;
int scale = 1;
while (true) {
if (tmpWidth / 2 < REQUIRED_SIZE
|| tmpHeight / 2 < REQUIRED_SIZE)
break;
tmpWidth /= 2;
tmpHeight /= 2;
scale *= 2;
}
// decoding using inSampleSize
BitmapFactory.Options option2 = new BitmapFactory.Options();
option2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(imageFile),
null, option2);
} catch (FileNotFoundException e) {
Log.e(TAG, e.getLocalizedMessage());
}
return null;
}
private boolean reusedImage(NextImageToLoad image) {
Context c = image.imageView.getContext();
c.getContentResolver().notifyChange(PromotionsProvider.CONTENT_URI, null);
String tag = imageViewHolders.get(image.imageView);
if ((tag == null) || (!tag.equals(image.url)))
return true;
return false;
}
/**
* Clears the Memory and Local cache
*/
public void clearCache() {
memoryImgCache.clear();
localFileCache.clear();
}
/**
* This class implements a runnable that is used for updating the promotions
* images on the UI
*
*
*/
class UIupdater implements Runnable {
Bitmap bmp;
NextImageToLoad image;
public UIupdater(Bitmap bmp, NextImageToLoad image) {
this.bmp = bmp;
this.image = image;
Log.e("", "ui updater");
}
public void run() {
Log.e("ui updater", "ui updater");
if (reusedImage(image))
return;
Log.e("nick", "" + (bmp == null) + " chberugv");
if (bmp != null){
image.imageView.setImageBitmap(bmp);
Context c = image.imageView.getContext();
c.getContentResolver().notifyChange(PromotionsProvider.CONTENT_URI, null);
}else
image.imageView.setImageResource(defaultImageID);
}
}
private class ImagesRetriever implements Runnable {
NextImageToLoad image;
ImagesRetriever(NextImageToLoad image) {
this.image = image;
}
public void run() {
Log.e("images retirever", " images retriever");
if (reusedImage(image))
return;
Bitmap bmp = getBitmap(image.url);
memoryImgCache.insert(image.url, bmp);
if (reusedImage(image))
return;
UIupdater uiUpdater = new UIupdater(bmp, image);
Activity activity = (Activity) image.imageView.getContext();
activity.runOnUiThread(uiUpdater);
//Context c = image.imageView.getContext();
//c.getContentResolver().notifyChange(PromotionsProvider.CONTENT_URI, null);
}
}
/**
* This class encapsulates the image being downloaded.
*
* #author Nicolae Anca
*
*/
private class NextImageToLoad {
public String url;
public ImageView imageView;
public NextImageToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
}
Modified Runnable:
class UIupdater implements Runnable {
Bitmap bmp;
NextImageToLoad image;
public UIupdater(Bitmap bmp, NextImageToLoad image) {
this.bmp = bmp;
this.image = image;
}
public void run() {
if (reusedImage(image))
return;
if (bmp != null){
image.imageView.setImageBitmap(bmp);
Context c = image.imageView.getContext();
c.getContentResolver().notifyChange(PromotionsProvider.CONTENT_URI, null);
}else
image.imageView.setImageResource(defaultImageID);
}
}

Thats an interesting way to do what you are doing. Have you tried extending the Simple Cursor Adapter?
What you do is implement a ViewHolder and put your imageview in it.
Then in your ImageRetriever, write a Listener which will be called once the image is ready and retrieved.
Implement this listener in the Viewholder.
You create the view in getView() and request for the image in BindView().
Once the image gets loaded, the list will be refreshed automatically.

one way to do it is by calling notifyDataSetChenged on listview, and another was is to have adapter as member variable and when something changes on listview you call a function that assigns new listadapter to member adapter. That way your list will be redraw on change.

I guess, you have to use some handler, calling after image load, which will call notifyDataSetChanged for list adapter

Display images on Android using TextView and Html.ImageGetter asynchronously?

I want to set a TextView with SpannableString which is from the method below:
Html.fromHtml(String source, Html.ImageGetter imageGetter,
Html.TagHandler tagHandler)
But the ImageGetter here need to override the method below:
public abstract Drawable getDrawable(String source)
Because I need to get the drawable from the internet, I have to do it asynchronously and seems it is not.
How to make it work?
Thanks.

These guys did a great job, this is my solution using Square's Picasso library:
//...
final TextView textView = (TextView) findViewById(R.id.description);
Spanned spanned = Html.fromHtml(getIntent().getStringExtra(EXTRA_DESCRIPTION),
new Html.ImageGetter() {
#Override
public Drawable getDrawable(String source) {
LevelListDrawable d = new LevelListDrawable();
Drawable empty = getResources().getDrawable(R.drawable.abc_btn_check_material);;
d.addLevel(0, 0, empty);
d.setBounds(0, 0, empty.getIntrinsicWidth(), empty.getIntrinsicHeight());
new ImageGetterAsyncTask(DetailActivity.this, source, d).execute(textView);
return d;
}
}, null);
textView.setText(spanned);
//...
class ImageGetterAsyncTask extends AsyncTask<TextView, Void, Bitmap> {
private LevelListDrawable levelListDrawable;
private Context context;
private String source;
private TextView t;
public ImageGetterAsyncTask(Context context, String source, LevelListDrawable levelListDrawable) {
this.context = context;
this.source = source;
this.levelListDrawable = levelListDrawable;
}
#Override
protected Bitmap doInBackground(TextView... params) {
t = params[0];
try {
Log.d(LOG_CAT, "Downloading the image from: " + source);
return Picasso.with(context).load(source).get();
} catch (Exception e) {
return null;
}
}
#Override
protected void onPostExecute(final Bitmap bitmap) {
try {
Drawable d = new BitmapDrawable(context.getResources(), bitmap);
Point size = new Point();
((Activity) context).getWindowManager().getDefaultDisplay().getSize(size);
// Lets calculate the ratio according to the screen width in px
int multiplier = size.x / bitmap.getWidth();
Log.d(LOG_CAT, "multiplier: " + multiplier);
levelListDrawable.addLevel(1, 1, d);
// Set bounds width and height according to the bitmap resized size
levelListDrawable.setBounds(0, 0, bitmap.getWidth() * multiplier, bitmap.getHeight() * multiplier);
levelListDrawable.setLevel(1);
t.setText(t.getText()); // invalidate() doesn't work correctly...
} catch (Exception e) { /* Like a null bitmap, etc. */ }
}
}
My 2 cents... Peace!

Now I'm using an AsyncTask to download the images in the ImageGetter:
Spanned spannedContent = Html.fromHtml(htmlString, new ImageGetter() {
#Override
public Drawable getDrawable(String source) {
new ImageDownloadAsyncTask().execute(textView, htmlString, source);
return null;
}
}, null);
And set the text again into the TextView when the image has been downloaded.
Now it works. But It failed when I tried to do the TextView.postInvalidate() to redraw the downloaded images. I have to do setText() again in the AsyncTask.
Does anyone know why?

Here's my code that grabs all images in the html string (it's simplified from the original, so I hope it works):
private HashMap<String, Drawable> mImageCache = new HashMap<String, Drawable>();
private String mDescription = "...your html here...";
private void updateImages(final boolean downloadImages) {
if (mDescription == null) return;
Spanned spanned = Html.fromHtml(mDescription,
new Html.ImageGetter() {
#Override
public Drawable getDrawable(final String source) {
Drawable drawable = mImageCache.get(source);
if (drawable != null) {
return drawable;
} else if (downloadImages) {
new ImageDownloader(new ImageDownloader.ImageDownloadListener() {
#Override
public void onImageDownloadComplete(byte[] bitmapData) {
Drawable drawable = new BitmapDrawable(getResources(),
BitmapFactory.decodeByteArray(bitmapData, 0, bitmapData.length));
try {
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
} catch (Exception ex) {}
mImageCache.put(source, drawable);
updateImages(false);
}
#Override
public void onImageDownloadFailed(Exception ex) {}
}).execute(source);
}
return null;
}
}, null);
tvDescription.setText(spanned);
}
So basically what happens here is the ImageGetter will make a request for every image in the html description. If that image isn't in the mImageCache array and downloadImages is true, we run an async task to download that image. Once it has completed, we add the drawable into the hashmap, and then make a call to this method again (but with downloadImages as false so we don't risk an infinite loop), where the image will be able to be grabbed with the second attempt.
And with that, you'll need the ImageDownloader class that I used:
public class ImageDownloader extends AsyncTask {
public interface ImageDownloadListener {
public void onImageDownloadComplete(byte[] bitmapData);
public void onImageDownloadFailed(Exception ex);
}
private ImageDownloadListener mListener = null;
public ImageDownloader(ImageDownloadListener listener) {
mListener = listener;
}
protected Object doInBackground(Object... urls) {
String url = (String)urls[0];
ByteArrayOutputStream baos = null;
InputStream mIn = null;
try {
mIn = new java.net.URL(url).openStream();
int bytesRead;
byte[] buffer = new byte[64];
baos = new ByteArrayOutputStream();
while ((bytesRead = mIn.read(buffer)) > 0) {
if (isCancelled()) return null;
baos.write(buffer, 0, bytesRead);
}
return new AsyncTaskResult<byte[]>(baos.toByteArray());
} catch (Exception ex) {
return new AsyncTaskResult<byte[]>(ex);
}
finally {
Quick.close(mIn);
Quick.close(baos);
}
}
protected void onPostExecute(Object objResult) {
AsyncTaskResult<byte[]> result = (AsyncTaskResult<byte[]>)objResult;
if (isCancelled() || result == null) return;
if (result.getError() != null) {
mListener.onImageDownloadFailed(result.getError());
}
else if (mListener != null)
mListener.onImageDownloadComplete(result.getResult());
}
}