Why should we call super class onCreate() method from my activity's onCreate()?
What is the reason behind calling super class methods from every life cycle method? Could you please clarify me ?
You can see what each method does by looking at the source. For example, you can see what happens in Activity.onCreate here (line #879):
if (DEBUG_LIFECYCLE) Slog.v(TAG, "onCreate " + this + ": " + savedInstanceState);
if (mLastNonConfigurationInstances != null) {
mAllLoaderManagers = mLastNonConfigurationInstances.loaders;
}
if (mActivityInfo.parentActivityName != null) {
if (mActionBar == null) {
mEnableDefaultActionBarUp = true;
} else {
mActionBar.setDefaultDisplayHomeAsUpEnabled(true);
}
}
if (savedInstanceState != null) {
Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);
mFragments.restoreAllState(p, mLastNonConfigurationInstances != null
? mLastNonConfigurationInstances.fragments : null);
}
mFragments.dispatchCreate();
getApplication().dispatchActivityCreated(this, savedInstanceState);
mCalled = true;
Related
The code I tried to start callback for my background service.
public class PushService extends JobIntentService implements MethodCallHandler {
private static FlutterEngine backgroundFlutterEngine = null;
private void startPushService(Context context) {
synchronized (serviceStarted) {
if (backgroundFlutterEngine == null) {
final Long callbackHandle = PushStore.getInstance().getPreferenceLongValue(
PushPlugin.CALLBACK_DISPATCHER_ID, 0L);
if (callbackHandle == 0L) {
Log.e(TAG, "Fatal: no callback registered.");
return;
}
final FlutterCallbackInformation callbackInfo =
FlutterCallbackInformation.lookupCallbackInformation(callbackHandle);
if (callbackInfo == null) {
Log.e(TAG, "Fatal: failed to find callback info.");
return;
}
Log.i(TAG, "Starting PushService...");
backgroundFlutterEngine = new FlutterEngine(context);
DartCallback args = DartCallback(context.getAssets(), FlutterMain.findAppBundlePath(context), callbackInfo);
backgroundFlutterEngine.getDartExecutor().executeDartCallback(args);
...
}
}
}
}
But the FlutterMain is deprecated, how to do the new way to execute dart callback?
FlutterMain has been replaced by FlutterLoader, from what I understand.
Edit:
On the FlutterMain documentation page, right underneath the first horizontal divider, it mentions this replacement.
I'm new to Webrtc, I'm using the AWS Webrtc demo with Android Nav Component. When I exited the app with the back button, I can see that Webrtc is still running or I can see the following log:
EglRenderer: cameraSurfaceViewDropping frame - No surface
In my fragment at the onStop method my code is as follow:
Thread.setDefaultUncaughtExceptionHandler(null)
if (rootEglBase != null) {
rootEglBase!!.release()
rootEglBase = null
}
if (remoteView != null) {
remoteView!!.release()
remoteView = null
}
if (localPeer != null) {
localPeer!!.dispose()
localPeer = null
}
if (videoSource != null) {
videoSource!!.dispose()
videoSource = null
}
if (videoCapturer != null) {
try {
videoCapturer?.stopCapture()
videoCapturer?.dispose()
} catch (e: InterruptedException) {
Timber.e("Failed to stop webrtc video capture. $e ")
}
videoCapturer = null
}
if (client != null) {
this.client!!.disconnect()
this.client = null
}
peerConnectionFoundMap.clear()
pendingIceCandidatesMap.clear()
However, I can see the problem only when I exited the app through the back button, if I killed the app, I don't get the log. Has anyone experienced this?
Thank you.
This is the way you should destroy your WebRTC session on onDestroy() or onStop().
if (videoCaptureAndroid != null) {
videoCaptureAndroid?.stopCapture()
videoCaptureAndroid = null
}
if (localPeer != null) {
localPeer?.close()
localPeer = null
}
if (videoSource != null) {
videoSource?.dispose()
videoSource = null
}
if (audioSource != null) {
audioSource?.dispose()
audioSource = null
}
if (localAudioTrack != null) {
localAudioTrack?.dispose()
localAudioTrack = null
}
if (currentRemoteMediaStream != null) {
currentRemoteMediaStream?.dispose()
currentRemoteMediaStream = null
}
if (localVideoView != null) {
localVideoView?.release()
localVideoView = null
}
if (remoteVideoView != null) {
remoteVideoView?.release()
remoteVideoView = null
}
rootEglBase.release();
Is private copy ofBundle is passed to Fragment and the parent Activity?
I try to save key,value pair in onSaveInstanceState of Fragment and try to retrieve it in the onCreate of Activity. It is absent there.
But there also seems to be a connection between the two.
When I pass null to super.onCreate of Activity the Bundle passed to Fragment's onCreate is also null.
Bundle wich is sent to onCreate for Activity and Fragment are completely different. If you're sending null to super.onCreate -> activity will recreate all the fragments from the scratch. So your Fragment will receive null -> also. Cause this is NEW fragment
This is a part of code of FragmentActivity:
/**
* Perform initialization of all fragments and loaders.
*/
#SuppressWarnings("deprecation")
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
mFragments.attachHost(null /*parent*/);
super.onCreate(savedInstanceState);
NonConfigurationInstances nc =
(NonConfigurationInstances) getLastNonConfigurationInstance();
if (nc != null) {
mFragments.restoreLoaderNonConfig(nc.loaders);
}
if (savedInstanceState != null) {
Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);
mFragments.restoreAllState(p, nc != null ? nc.fragments : null);
// Check if there are any pending onActivityResult calls to descendent Fragments.
if (savedInstanceState.containsKey(NEXT_CANDIDATE_REQUEST_INDEX_TAG)) {
mNextCandidateRequestIndex =
savedInstanceState.getInt(NEXT_CANDIDATE_REQUEST_INDEX_TAG);
int[] requestCodes = savedInstanceState.getIntArray(ALLOCATED_REQUEST_INDICIES_TAG);
String[] fragmentWhos = savedInstanceState.getStringArray(REQUEST_FRAGMENT_WHO_TAG);
if (requestCodes == null || fragmentWhos == null ||
requestCodes.length != fragmentWhos.length) {
Log.w(TAG, "Invalid requestCode mapping in savedInstanceState.");
} else {
mPendingFragmentActivityResults = new SparseArrayCompat<>(requestCodes.length);
for (int i = 0; i < requestCodes.length; i++) {
mPendingFragmentActivityResults.put(requestCodes[i], fragmentWhos[i]);
}
}
}
}
if (mPendingFragmentActivityResults == null) {
mPendingFragmentActivityResults = new SparseArrayCompat<>();
mNextCandidateRequestIndex = 0;
}
mFragments.dispatchCreate();
}
What is the difference between them? As far as I can see they both do the same thing.
If you go to sources, you will find PhoneWindow.class that have implementation of Window.setBackgroundDrawable method:
#Override
public final void setBackgroundDrawable(Drawable drawable) {
if (drawable != mBackgroundDrawable || mBackgroundResource != 0) {
mBackgroundResource = 0;
mBackgroundDrawable = drawable;
if (mDecor != null) {
mDecor.setWindowBackground(drawable);
}
if (mBackgroundFallbackResource != 0) {
mDecor.setBackgroundFallback(drawable != null ? 0 : mBackgroundFallbackResource);
}
}
}
As you can see, it calls different method of DecorView setWindowBackground:
public void setWindowBackground(Drawable drawable) {
if (getBackground() != drawable) {
setBackgroundDrawable(drawable);
if (drawable != null) {
drawable.getPadding(mBackgroundPadding);
} else {
mBackgroundPadding.setEmpty();
}
drawableChanged();
}
}
Which is actually use method DecorView.setBackgroundDrawable but also provides additional logic for Window. So I would suggest you to use getWindow().setBackgroundDrawable().
I need a little help to get an idea of how to refactor my code, but I can't see options besides what's done, I would like to add the objects but not using so many lists (and if's conditions).
Here is my code, if anyone could help, I appreciate. Thanks
#ViewById
BannerHomeViewPager place1, place2, place3, place4, place5, place6, place7,
place8, place9;
The lists:
private List<HomeItem> allHomeItems = new ArrayList<HomeItem>(),
placeItems1 = new ArrayList<HomeItem>(),
placeItems2 = new ArrayList<HomeItem>(),
placeItems3 = new ArrayList<HomeItem>(),
placeItems4 = new ArrayList<HomeItem>(),
placeItems5 = new ArrayList<HomeItem>(),
placeItems6 = new ArrayList<HomeItem>(),
placeItems7 = new ArrayList<HomeItem>(),
placeItems8 = new ArrayList<HomeItem>(),
placeItems9 = new ArrayList<HomeItem>();
1) Items mocked, ok.
2)
#UiThread
void updateUI() {
if (allHomeItems != null && allHomeItems.size() > 0) {
for (HomeItem item : allHomeItems) {
if (item.getPlacement().contains("1")) {
placeItems1.add(item);
} else if (item.getPlacement().contains("2")) {
placeItems2.add(item);
} else if (item.getPlacement().contains("3")) {
placeItems3.add(item);
} else if (item.getPlacement().contains("4")) {
placeItems4.add(item);
} else if (item.getPlacement().contains("5")) {
placeItems5.add(item);
} else if (item.getPlacement().contains("6")) {
placeItems6.add(item);
} else if (item.getPlacement().contains("7")) {
placeItems7.add(item);
} else if (item.getPlacement().contains("8")) {
placeItems8.add(item);
} else {
placeItems9.add(item);
}
}
}
setupAdapters();
}
3) setupAdapters()
private void setupAdapters() {
if (place1 != null)
place1.update(placeItems1);
if (place2 != null)
place2.update(placeItems2);
if (place3 != null)
place3.update(placeItems3);
if (place4 != null)
place4.update(placeItems4);
if (place5 != null)
place5.update(placeItems5);
if (place6 != null)
place6.update(placeItems6);
if (place7 != null)
place7.update(placeItems7);
if (place8 != null)
place8.update(placeItems8);
if (place9 != null)
place9.update(placeItems9);
}
As #DanielBo answer:
private Map<String, ArrayList<HomeItem>> placeItems = new HashMap<String,ArrayList<HomeItem>>();
void updateUI() {
if (allHomeItems != null && allHomeItems.size() > 0) {
for (HomeItem item : allHomeItems) {
if(!placeItems.containsKey(item.getPlacement())){
placeItems.put(item.getPlacement(), new ArrayList<HomeItem>());
}
placeItems.get(item.getPlacement()).add(item);
}
}
setupAdapters();
}
But why are you using so many views? I really can't say if this is correct bcs i don't know the purpose of this, but I can't figure a good use to so many list views in the same layout...