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?

CustomListView : Image is changing when scrolling a ListView

I know that this question is asked many times.. But I cant get any proper solution, In my app I use AsyncTask for loading a image. I use AsyncTask because I want smooth scrolling listview.. and after implement AsyncTask My listView get smoothly scrolling.. But now problem is that Image is changing after scrolling... What should I do?
MyAdapter Class
package com.example.adapter;
public class DisplayAllFeedAdapter extends ArrayAdapter<DisplayAllFeedItem> {
private final List<DisplayAllFeedItem> list;
private final Activity context;
ExifInterface exif;
public DisplayAllFeedAdapter(Activity context, List<DisplayAllFeedItem> list) {
super(context, R.layout.feed_screen, list);
this.context = context;
this.list = list;
}
static class ViewHolder {
public TextView optionalDesc, reportedBy;
public LinearLayout layout;
public ImageView displayFeedimg, channelIcon;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView == null) {
LayoutInflater inflater = context.getLayoutInflater();
convertView = inflater.inflate(R.layout.display_all_feed_listitem, null);
viewHolder = new ViewHolder();
viewHolder.optionalDesc = (TextView) convertView.findViewById(R.id.txtFeedOptionalDesc);
viewHolder.reportedBy = (TextView) convertView.findViewById(R.id.txtFeedReportedBy);
viewHolder.displayFeedimg = (ImageView) convertView
.findViewById(R.id.imgFeedDisplayImage);
viewHolder.layout = (LinearLayout) convertView.findViewById(R.id.layoutChannelImgView);
convertView.setTag(viewHolder);
convertView.setTag(R.id.txtFeedOptionalDesc, viewHolder.optionalDesc);
convertView.setTag(R.id.txtFeedReportedBy, viewHolder.reportedBy);
convertView.setTag(R.id.imgFeedDisplayImage, viewHolder.displayFeedimg);
convertView.setTag(R.id.layoutChannelImgView, viewHolder.layout);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
String temp;
String drawableImagePath = list.get(position).getMediaChannelName();
List<String> channelList = new ArrayList<String>();
while (drawableImagePath.length() > 0) {
if (drawableImagePath.indexOf(",") == -1) {
temp = drawableImagePath.substring(0);
channelList.add(temp);
break;
} else {
temp = drawableImagePath.substring(0, drawableImagePath.indexOf(","));
}
channelList.add(temp);
drawableImagePath = drawableImagePath.substring(drawableImagePath.indexOf(",") + 1);
}
viewHolder.layout.removeAllViews();
for (int i = 0; i < channelList.size(); i++) {
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(dpToPx(30),
dpToPx(30));
ImageView imageView = new ImageView(context);
layoutParams.setMargins(0, 0, 10, 0);
imageView.setLayoutParams(layoutParams);
imageView.setImageResource(Integer.parseInt(channelList.get(i)));
viewHolder.layout.addView(imageView);
}
String tempPath = list.get(position).getMediaPath();
File mediaFile = new File(tempPath);
Bitmap bitmap;
viewHolder.optionalDesc.setText(list.get(position).getMediaDesc());
viewHolder.reportedBy.setText("Reported By " + list.get(position).getMediaDisplayName());
if (viewHolder != null) {
new LoadImage(viewHolder).execute(tempPath);
}
return convertView;
}
private class LoadImage extends AsyncTask<String, String, Bitmap> {
// File mediaFile = new File(tempPath);
Bitmap bitmap, displayBitmap;
File mediaFile;
String mediaPath;
private final ViewHolder imageViewReference;
public LoadImage(ViewHolder viewHolder) {
imageViewReference = viewHolder;
}
#Override
protected Bitmap doInBackground(String... params) {
// File f = new File(params[0]);
mediaPath = params[0];
mediaFile = new File(mediaPath);
if (mediaFile.exists()) {
if (isImage(mediaPath)) {
Bitmap myBitmap = BitmapFactory.decodeFile(mediaFile.getAbsolutePath());
int height = (myBitmap.getHeight() * 512 / myBitmap.getWidth());
Bitmap scale = Bitmap.createScaledBitmap(myBitmap, 512, height, true);
int rotate = 0;
try {
exif = new ExifInterface(mediaFile.getAbsolutePath());
} catch (IOException e) {
e.printStackTrace();
}
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_UNDEFINED);
switch (orientation) {
case ExifInterface.ORIENTATION_NORMAL:
rotate = 0;
break;
case ExifInterface.ORIENTATION_ROTATE_270:
rotate = 270;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
rotate = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_90:
rotate = 90;
break;
}
Matrix matrix = new Matrix();
matrix.postRotate(rotate);
displayBitmap = Bitmap.createBitmap(scale, 0, 0, scale.getWidth(),
scale.getHeight(), matrix, true);
} else {
displayBitmap = ThumbnailUtils.createVideoThumbnail(mediaPath,
Thumbnails.MICRO_KIND);
}
}
return displayBitmap;
}
#Override
protected void onPostExecute(Bitmap result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if (imageViewReference != null) {
imageViewReference.displayFeedimg.setImageBitmap(result);
}
// tempView.displayFeedimg.setImageBitmap(result);
}
}
public int dpToPx(int dp) {
DisplayMetrics displayMetrics = getContext().getResources().getDisplayMetrics();
int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
return px;
}
public static boolean isImage(String str) {
boolean temp = false;
String[] arr = { ".jpeg", ".jpg", ".png", ".bmp", ".gif" };
for (int i = 0; i < arr.length; i++) {
temp = str.endsWith(arr[i]);
if (temp) {
break;
}
}
return temp;
}
}

I am not clear on your problem (need better clarification) but I know there are issues on loading images about the lag in performance.
Please Look at Google's web Making a Standard Request.
Search for (Universal) Image Loader, text "Use ImageLoader and NetworkImageView".
You can further improve performance by caching, located below that text.
Code snippet from the webpage:
ImageLoader mImageLoader;
ImageView mImageView;
// The URL for the image that is being loaded.
private static final String IMAGE_URL =
"http://developer.android.com/images/training/system-ui.png";
...
mImageView = (ImageView) findViewById(R.id.regularImageView);
// Get the ImageLoader through your singleton class.
mImageLoader = MySingleton.getInstance(this).getImageLoader();
mImageLoader.get(IMAGE_URL, ImageLoader.getImageListener(mImageView,
R.drawable.def_image, R.drawable.err_image));
There seems a good tutorial in Solving the Android image loading problem... by a knowledgeable author.
Have fun with this. And someday I may have to solve this problem as well. Pls keep us posted.

Besides my previous answer, there is another possible solution. But it is somewhat different than Google's recommendation, so beware...
Look at Stackoverflow discussion ListView like in universal image loader sample app. Checkout code in that page. In CarListAdapter:
ImageLoader = ImageLoader.getInstance();
imageLoader.init(ImageLoaderConfiguration.createDefault(context));
...In another method:
imageLoader.displayImage(...);
Both of my answers lead to one point, use the (Universal) Image Loader.

Android: Scanning a directory and displaying pictures (thumbnails) (pictures are not stored in the mediastore)

I have recently done some tests with display pictures using a custom gallery that i designed using the media queries and mediastore... It worked great but i really need to do something custom.
I don't wish the pictures to be scanned or available in the mediastore hence i would like to have my app scan a directory and create thumbnails and display these thumbnails.
I am finding it really thin on the ground to find any good quality examples to do this.
Can anyone help with a small example.
Here is what i am looking to do.
Pictures are stored in a directory of the sdcard.
Using my custom gallery it would scan this directory but "NOT" using the mediastore
I need to display the contents of the directory but as thumbnails i presume i would need to create this thumbnails first?
Clicking on a thumnail would should the full screen image from my custom gallery.
I suppose i just need a little help in getting the pictures from the the directory considering there are not stored int eh mediastore so i can't use a query. THe other thing that concerns me is that i would need to create the thumbnails for each of the these images (on the fly??) because display the images but at a reduced size i would suspect would be pretty bad for the performance.
Can anyone lend a helping hand?
Thanks in advance

I did exactly the same a while ago. You have to pass a folder name where your images are to setBaseFolder. This method in turn invokes refresh() which - using a FilenameFilter (code not included but is very easy to implement) gets all images named orig_....jpg from that folder and holds it in mFileList. Then we call notifyDataSetChanged() which in turn will trigger getView() for every cell.
Now, in getView() we either fetch a thumbnail bitmap from a cache if we already have it there, otherwise we make a gray placeholder and start a ThumbnailBuilder to create thumbnail resp. get a bitmap from it.
I think you'll have to change the ThumbnailBuilder a bit, because I create quite large "thumbnails" (500x500) as I need the resized images for other purposes too. Also, as I work with photos taken by the camera there is some stuff there, rotating the image according to the exif information. But basicly, ThumbnailBuilder just checks if there already is a thumbnail image (my thumbnail images are placed the same folder but have prefix small_ instead of orig_) - if the thumbnail picture already exists, we get it as a Bitmap and are done, otherwise the image is generated. Finally, in onPostExecute() the bitmap is set to the ImageView.
public class PhotoAdapter extends BaseAdapter {
private Context mContext;
private int mCellSize;
private File mFolder;
private File[] mFileList;
private Map<Object, Bitmap> mThumbnails = new HashMap<Object, Bitmap>();
private Set<Object> mCreatingTriggered = new HashSet<Object>(); // flag that creating already triggered
public PhotoAdapter(Context context, int cellSize) {
mContext = context;
mCellSize = cellSize;
}
#Override
public int getCount() {
if (mFolder == null) {
return 0; // don't do this
} else {
return mFileList.length;
}
}
#Override
public Object getItem(int position) {
return mFileList[position];
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView view = (ImageView)convertView;
if (view == null) {
view = new ImageView(mContext);
view.setLayoutParams(new GridView.LayoutParams(mCellSize, mCellSize));
view.setScaleType(ImageView.ScaleType.CENTER_CROP);
view.setPadding(8, 8, 8, 8);
view.setBackgroundColor(0xFFC6CCD3);
}
Object item = getItem(position);
Bitmap bm = mThumbnails.get(item);
if (bm == null) {
view.setImageBitmap(null);
if (!mCreatingTriggered.contains(item)) {
mCreatingTriggered.add(item);
new ThumbnailBuilder(view, (File)item).execute();
}
} else {
view.setImageBitmap(bm);
}
return view;
}
public void setBaseFolder(File baseFolder) {
if (baseFolder == null) return;
if (!baseFolder.equals(mFolder)) {
releaseThumbnails();
mFolder = baseFolder;
}
refresh();
}
public void refresh() {
if (mFolder == null) {
return;
}
mFileList = mFolder.listFiles(EtbApplication.origImageFilenameFilter);
if (mFileList == null) mFileList = new File[0];
notifyDataSetChanged();
}
public void releaseThumbnails() {
for (Bitmap bm : mThumbnails.values()) {
bm.recycle();
}
mThumbnails.clear();
}
// ------------------------------------------------------------------------------------ Asynchronous Thumbnail builder
private class ThumbnailBuilder extends AsyncTask<Void, Integer, Bitmap> {
private ImageView mView;
private File mFile;
public ThumbnailBuilder(ImageView view, File file) {
mView = view;
mFile = file;
}
#Override
protected Bitmap doInBackground(Void... params) {
Log.d("adapter", "make small image and thumbnail");
try {
return createThumbnail(mFile.getAbsolutePath());
} catch (Exception e) {
return null;
}
}
#Override
protected void onPostExecute(Bitmap result) {
if (result != null) {
mView.setImageBitmap(result);
mThumbnails.put(mFile, result);
} else {
mView.setImageResource(R.drawable.ic_launcher);
}
}
/**
* Creates Thumbnail (also rotates according to exif-info)
* #param file
* #return
* #throws IOException
*/
private Bitmap createThumbnail(String file) throws IOException {
File thumbnailFile = new File(file.replace("orig_", "small_"));
// If a small image version already exists, just load it and be done.
if (thumbnailFile.exists()) {
return BitmapFactory.decodeFile(thumbnailFile.getAbsolutePath());
}
// Decode image size
BitmapFactory.Options bounds = new BitmapFactory.Options();
bounds.inJustDecodeBounds = true;
BitmapFactory.decodeFile(file, bounds);
if ((bounds.outWidth == -1) || (bounds.outHeight == -1))
return null;
int w, h;
if (bounds.outWidth > bounds.outHeight) { // Querformat
w = 500;
h = 500 * bounds.outHeight / bounds.outWidth;
} else { // Hochformat
h = 500;
w = 500 * bounds.outWidth / bounds.outHeight;
}
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inSampleSize = 4; // resample -- kleiner aber noch nicht die 500 Pixel, die kommen dann unten
Bitmap resizedBitmap = BitmapFactory.decodeFile(file, opts);
resizedBitmap = Bitmap.createScaledBitmap(resizedBitmap, w, h, true);
ExifInterface exif = new ExifInterface(file);
String orientString = exif.getAttribute(ExifInterface.TAG_ORIENTATION);
int orientation = orientString != null ? Integer.parseInt(orientString) : ExifInterface.ORIENTATION_NORMAL;
int rotationAngle = 0;
if (orientation == ExifInterface.ORIENTATION_ROTATE_90) rotationAngle = 90;
if (orientation == ExifInterface.ORIENTATION_ROTATE_180) rotationAngle = 180;
if (orientation == ExifInterface.ORIENTATION_ROTATE_270) rotationAngle = 270;
Matrix matrix = new Matrix();
matrix.setRotate(rotationAngle, (float) resizedBitmap.getWidth() / 2, (float) resizedBitmap.getHeight() / 2);
Bitmap rotatedBitmap = Bitmap.createBitmap(resizedBitmap, 0, 0, w, h, matrix, true);
resizedBitmap.recycle();
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
thumbnailFile.createNewFile();
FileOutputStream fo = new FileOutputStream(thumbnailFile);
fo.write(bytes.toByteArray());
fo.close();
//new File(file).delete(); // Originalbild löschen
return rotatedBitmap;
}
}
}

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