Develop Reference

is really image view set null ?

My problem is when i remove images from image View it remove image but when i monitor memory from android studio motorize tool it increasing memory
i am using Garbage collector .but its not good practice .
help me out with different solution.
private void cleanImages() {
img1.setImageDrawable(null);
}
public void clickClean4(View view) {
cleanImages();
System.runFinalization();
System.gc();
Runtime.getRuntime().gc();
}

You need to not only setImageDrawable(null); , but also recycle the bitmap.
You can do this by
if (!bitmapDrawable.getBitmap().isRecycled()) {
bitmapDrawable.getBitmap().recycle();
}
Hope it helps.

Memory leak at SpenInView Native Stack

I have a screen that overlays the SpenSurfaceView with Android layout components. When the user switches the screen to load different components, the old components leak into this class:
com.samsung.android.sdk.pen.engine.SpenInView
from the native stack according to MAT (Memory Analyzer T)
The overlayed components are custom controllers to take in user input in the form of strokes. They have a reference to the SurfaceView, but it is nulled before the components are deleted.
The problem remains even if I completely exit the application.
I am using example PenSample5_6_TextRecognition as reference.
This is using Samsung Mobile SDK (http://developer.samsung.com/samsung-mobile-sdk)
What strategy should I employ to continue to chase this memory leak ?
The NDK side of the SDK is likely closed source.
Does the SpenObjectBase retains references to the SpenSurfaceView ?
Can somebody with more reputation than I have create the "spen sdk" tag.

Please check onDestroy() from sample application. Do you close all resources?
#Override
protected void onDestroy() {
super.onDestroy();
if (mTextRecognition != null) {
mSpenTextRecognitionManager.destroyRecognition(mTextRecognition);
mSpenTextRecognitionManager.close();
}
if (mSpenSurfaceView != null) {
mSpenSurfaceView.closeControl();
mSpenSurfaceView.close();
mSpenSurfaceView = null;
}
if(mSpenNoteDoc != null) {
try {
mSpenNoteDoc.close();
} catch (Exception e) {
e.printStackTrace();
}
mSpenNoteDoc = null;
}
}
Samples are closing resources in onDestroy. That may happen well after user leaves activity (even never if device has enough memory). Consider releasing resources in onPause and re-creating them in onResume instead.
Finally, in my code I am removing registred callbacks
private void removeListeners() {
spenPageDocContainingNoteDoc.setObjectListener(null);
try {
spensBasicShapeConverter.setResultListener(null);
} catch (Exception e) {
..
}
When investingating heap dumps, I saw my Activity (callback handler) held inside some data structure in Spen API. Removing listeners removed that memory leak.

Why does my WeakReference gets NULL inside my AsyncTask?

I have spent a lot of hours trying to reproduce and understand the cause of this problem, with no success in either of these goals.
I have tried to leave only the code related to the problem, but I believe a few minutes are still necessary to understand the problem and context. I hope that someone will be able to spot the problem in my implementation or at least help me understand the cause.
Description of the application:
Word game where you play against the computer. After the computer has laid a word on the board, the definition of this word is fetched online in an AsyncTask and displayed in a TextView
How I discovered the issue:
I use ACRA for crash and error reporting (great free tool by the way). It sends me reports for each unexpected situtation (this one does not lead to a crash). I have been receiving many reports of errors 1,2,3 and 4 (see code)
Some bad reviews on Google Play tend to show that some users do not see the definition even though they are connected to Internet. (I am pretty sure this functional bug is related to the previously mentioned errors, though I cannot prove it)
A word on the code design:
After reading a lot on memory leaks in Android, I have decided to make the AsyncTask that retrieves the definition online a static inner class (even though my main activty currently does not support rotations, which are the main causes of leaks: I put in my Manifest android:screenOrientation="portrait").
I need access to the parent Activity from this AsyncTask because I retrieve strings from the resources, and perform some changes on the UI in onPostExecute().
Hence, I use a WeakReference in the AsyncTask which is pointing to the parent Activity. This should prevent memory leaks in case the Activity is recreated or killed while theAsyncTask` is still running.
What exactly is the problem:
The WeakReference or the return of its get() method is null in
some unexplained situations (I suspect it impacts more than 1% of the games or
players) (see code)
All kinds of devices and Android versions are impacted, and I often see several occurences coming from the same device)
I have never been able to reproduce these errors (the most obvious try was exiting the activity while the definition is being downloaded, but this didn't cause any error)
Meaningful parts of my code:
public class GameActivity extends Activity {
private TextView _definition; //inflated from XML in onCreate()
private ProgressDialog _pDialog; //created in onCreate()
private Handler _handlerToDelayDroidMove = new Handler();
private Handler _handlerToDelayProgressDialog = new Handler();
private Handler _handlerToDelayDefinitionClosure = new Handler();
public void onClickValidatePlayerMoveAndTriggerDroidMove(View v) {
int score = _arbitre.validatePlayerMoveAndReturnScore(_listOfLetters);
toast(String.format(getResources().getString(R.string.player_word_score), score));
// ***** Only start Droid move when previous toast has been displayed ****
timedDroidPlayWithSpinner();
}
private void timedDroidPlayWithSpinner() {
_handlerToDelayProgressDialog.removeCallbacks(_droidThinkingDialogRunnable);
_handlerToDelayDroidMove.removeCallbacks(_droidPlayRunnable);
_handlerToDelayProgressDialog.postDelayed(_droidThinkingDialogRunnable, 1500);
_handlerToDelayDroidMove.postDelayed(_droidPlayRunnable, 1500 + DUMMY_DELAY);
}
private Runnable _droidThinkingDialogRunnable = new Runnable() { //Show a "Droid is thinking spinner dialog"
public void run() {
_pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
_pDialog.setMessage(getResources().getString(R.string.droid_thinking));
_pDialog.setCancelable(false);
_pDialog.show();
}
};
private Runnable _droidPlayRunnable = new Runnable() {
public void run() {
String word = playBestMoveAndUpdateGUI(); // Droid move (CPU intensive, can take several seconds)
saveGameStateToPrefs();
_pDialog.dismiss(); //Hide "Thinking dialog")
new SearchDefinitionTask(GameActivity.this).execute(word);
}
};
private Runnable _hideDefinitionRunnable = new Runnable() {
public void run() {
_definition.startAnimation(_slideUpAnim);
_definition.setVisibility(View.GONE);
}
};
// Made static so we are sure if does not reference the Activity (risk of leak)
public static class SearchDefinitionTask extends AsyncTask<String, Void, String[]> {
private WeakReference<GameActivity> weakRefToGameActivity;
public SearchDefinitionTask(GameActivity context) { //Save a weak reference to the Activity
super();
weakRefToGameActivity = new WeakReference<GameActivity>(context);
}
protected String[] doInBackground(String... words) {
try {
DefFetcherInterface defFetcher = null;
Language l = weakRefToGameActivity.get()._dictionaryId;
defFetcher = new OnlineDefinitionFetcher(l);
return defFetcher.getDefinition(words[0]);
} catch (Exception e) { // Typical exceptions are due to lack of internet connectivity
Log.e("Definition fetch error: ", e.toString());
String[] ret = { "", "" };
ret[0] = mots[0];
if (weakRefToGameActivity == null) { // !!! This occurs in ~0.3% of the games !!!
ErrorReporter.getInstance().handleSilentException(new Exception("Silent ERROR 1: weakRef is NULL"));
return ret;
}
if (weakRefToGameActivity.get() == null) { !!! This occurs in ~1% of the games !!!
ErrorReporter.getInstance().handleSilentException(new Exception("Silent ERROR 2: weakRef.get() is NULL"));
return ret;
}
// If we get here we still have a reference on our Activit/context, so let's show a decent error message
ret[1] = weakRefToGameActivity.get().getResources().getString(R.string.no_connection);
return ret;
}
}
protected void onPostExecute(String[] result) {
if (result[0] != "") { //Don't send another error report if WeakRef was already NULL in doInBackground()
if (weakRefToGameActivity == null) { !!! This occurs in ~0.5% of the games !!!
ErrorReporter.getInstance().handleSilentException(new Exception("Silent ERROR 3: weakRef is NULL"));
} else if (weakRefToGameActivity.get() == null) { !!!!!!!! This occurs in ~1% of the games !!!!!!!!
ErrorReporter.getInstance().handleSilentException(new Exception("Silent ERROR 4: weakRef.get() is NULL"));
} else {
// Everything is fine, show a box with the definition of the word for a few seconds
//(with animation to make the box appearing from the top of the screen)
weakRefToGameActivity.get()._definition.setVisibility(ImageView.VISIBLE);
weakRefToGameActivity.get()._handlerToDelayDefinitionClosure.removeCallbacks(weakRefToGameActivity.get()._hideDefinitionRunnable);
weakRefToGameActivity.get()._definition.setText(Html.fromHtml("<b>" + result[0].toUpperCase() + "</b> " + result[1]));
weakRefToGameActivity.get()._definition.startAnimation(weakRefToGameActivity.get()._slideDownAnim);
weakRefToGameActivity.get()._handlerToDelayDefinitionClosure.postDelayed(weakRefToGameActivity.get()._hideDefinitionRunnable,
DURATION_OF_DEFINITION);
}
}
}
}
}
Any idea of what could go wrong or how to reproduce?

Sebastien, maybe you can try to check the onDestroy is never called for your Activity... The activity can be restarted when the screen is rotated (which you already handle), but there are other configuration changes that may cause the same behavior.
Another pretty common one is to take the keyboard out on some phones, but there are others that are even more obscure to me. You can see the list there
Beside that, I really don't see anything wrong in your code and cannot imagine what else could cause your trouble.
The worst ones are your errors 1 and 3. Can you check in the constructor that weakRefToGameActivity is not null after it is created? (and if it is null, what about the context argument).
Please post updates once you find the root cause of your problem.
Bonne chance.

how to solve OutOfMemoryError in android?

I have prepared no.of drawable animations.when application launch first animation will be start.i have two buttons(next and previous) with same activity.when i click on next button i got exception like,
java.lang.OutOfMemoryError: bitmap size exceeds VM budget
My code is,
For getting drawable animations from drawable,
private void getAnimationForLetters(int mAnim) {
// TODO Auto-generated method stub
String anim = "capital_anim_" + new Integer(mAnim).toString();
final int resID = getApplicationContext().getResources().getIdentifier(
anim, "drawable", "my-package-name");
mImgLetter.clearAnimation();
mImgLetter.setBackgroundResource(resID);
mImgLetter.post(new Runnable() {
public void run() {
loadingAnimation = (AnimationDrawable) mImgLetter
.getBackground();
loadingAnimation.start();
}
});
}
my next button code is,
case R.id.btnNext_:
unbindDrawables(findViewById(R.id.imgLetter));
mLetterNum=mLetterNum+1;
getAnimationForLetters(mLetterNum);
my undind drawable method code is,
private void unbindDrawables(View view) {
if (view.getBackground() != null) {
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup) {
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
finally i got exception java.lang.OutOfMemoryError: bitmap size exceeds VM budget
It is showing exception here mImgLetter.setBackgroundResource(resID);
Please help me.
I have added following code to clear,
loadingAnimation.stop();
for (int i = 0; i < loadingAnimation.getNumberOfFrames(); ++i){
Drawable frame = loadingAnimation.getFrame(i);
if (frame instanceof BitmapDrawable) {
((BitmapDrawable)frame).getBitmap().recycle();
}
frame.setCallback(null);
}
loadingAnimation.setCallback(null);
It is working fine for only next or previous.First time click on next animation move to second animation,second time if i click on previous button i got exception like,
Canvas: trying to use a recycled bitmap android.graphics.Bitmap
please help me.

exactly - the system knows when to collect garbage, so calling that doesn't help in the least.
You have to really really manage your apps memory. 290x330 may not seem like much, but if you're using full RGBA that's 4 bytes per pixel and your image turns into 380K. If you have several of these you're going to run out of memory. Most Android devices are not like PCs - they have rather limited memory. Some have only 16M or 24M to run everything, including the OS and any other apps the user might be running concurrently.
You might try wrapping your routine to load resources with try/catch
While( ! success ) {
try {
// load resources
} catch (OutOfMemoryError E) {
// do something to use less memory and try again
}
}

It may happen if you use high resolution images for mobiles with less resolution and memory. Make use Drawable-hdpi, Drawable-mdpi, Drawable-ldpi folders and place your images with suitable resolution.
FYI.. mostly you may also see this error in emulator when heapSize is too less. Try to increase heap size using AVD manager
This link might help you
Supporting multiple screen resolutions

Look at the below link the out of memory has been discussed in detail.
Android Out of memory issue
For me Thomas's solution has worked in past.
Hope it helps.

you can use this to free memory:
system.gc();

Android AndEngine - How can I update ChangeableText value

I have a little problem with ChangeableText in AndEngine. I want to know how to update it's text without freezing the screen? For now I'm using this way, but it's freezing my phone for maybe 2-3 seconds :
private void removeFace(final Sprite face) {
hm = getIconNames();
if(face.getUserData().equals("petrol")){
elapsedText.setText(hm.get(25));
final PhysicsConnector facePhysicsConnector = this.mPhysicsWorld.getPhysicsConnectorManager().findPhysicsConnectorByShape(face);
this.mPhysicsWorld.unregisterPhysicsConnector(facePhysicsConnector);
this.mPhysicsWorld.destroyBody(facePhysicsConnector.getBody());
this.mScene.unregisterTouchArea(face);
this.mScene.detachChild(face);
} else {
}
System.gc();
}
Any ideas how to do that?

Remember that when you detachChild you should do this in thread because if you don't it can causes errors. Use this construction
runOnUpdateThread(new Runnable(){
#Override
public void run() {
if(yourSprite.hasParent())
scene.detachChild(yourSprite);
}});
You can put there all code if you want then your phone shouldn't freez
private void removeFace(final Sprite face) {
runOnUpdateThread(new Runnable(){
#Override
public void run() {
hm = getIconNames();
if(face.getUserData().equals("petrol")){
elapsedText.setText(hm.get(25));
final PhysicsConnector facePhysicsConnector = this.mPhysicsWorld.getPhysicsConnectorManager().findPhysicsConnectorByShape(face);
this.mPhysicsWorld.unregisterPhysicsConnector(facePhysicsConnector);
this.mPhysicsWorld.destroyBody(facePhysicsConnector.getBody());
this.mScene.unregisterTouchArea(face);
this.mScene.detachChild(face);
} else {
}
System.gc();
}});
}

Thats probably because you are fetching some information while setting the text.
What you should do is, get your
String hm = hm.get(25); //What ever the correct object is or variable. im guessing its a string or int.
Then
pass it to the Changeable text to be set.
elapsedText.setText(hm); //If its a int make sure you do String.valueOf(hm);

The only 3 methods here that have the possibility to take long are getIconNames() and get(), and System.gc()
The others are usually methods that return immediately, or have a very low complexity. For example, getPhysicsConnectorManager() returns immediately. findPhysicsConnectorByShape, unregisterPhysicsConnector, unregisterTouchArea and detachChild all have complexity of O(n), (And most of the others methods also have complexity of O(1) or O(n)).
I recommend you to look in the LogCat and when System.gc() is called, you will see a Log.i (blue) message of the tag of dalvikvm which will begin with GC_EXPLICIT and will give you some information about how long did the garbage collection took, etc....
If that GC call isn't taking the time, it must be your 2 methods, getIconNames() and hm.get(). You can put a Log.d message after each code line, which will write the last code line executed. This way you can follow the times.