I have multiple instances of the same CustomView inside one fragment.
I implemented savedInstance for this CustomView but the problem is since there are multiple instances of this CustomView, savedInstance of the last one, overrides them all.
for example, if there are 3 instances of this CustomView which has a recyclerview inside, If I scroll the last one, it applies to them all. because i'm using key value pairs and the key is the same for all of them. (I can change the key to differ for each one but I think there is a better way)
Here is the code for savedInstance saving and restoring inside my CustomView:
#Nullable
#Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(SavedInstanceKey.SUPERSTATE.name(), super.onSaveInstanceState());
bundle.putParcelable(SavedInstanceKey.RECYCLERVIEW.name(), recyclerView.getLayoutManager().onSaveInstanceState()); // ... save stuff
return bundle;
}
#Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) // implicit null check
{
Bundle bundle = (Bundle) state;
this.recyclerView.getLayoutManager().onRestoreInstanceState(bundle.getParcelable(SavedInstanceKey.RECYCLERVIEW.name())); // ... load stuff
state = bundle.getParcelable(SavedInstanceKey.SUPERSTATE.name());
}
super.onRestoreInstanceState(state);
}
and here is my fragment's OnCreateView:
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_artist, container, false);
final GridListView gv_new = view.findViewById(R.id.gridlist_new_songs);
final GridListView gv_best = view.findViewById(R.id.gridlist_best);
final GridListView gv_singles = view.findViewById(R.id.gridlist_singles);
final GridListView gv_feats = view.findViewById(R.id.gridlist_feats);
final RecyclerView rc_albums = view.findViewById(R.id.rcview_album);
if(!alreadyInitialized) {
alreadyInitialized = true;
apiService = new ApiService(getContext());
try {
artistID = getArguments().getString(KeyIntent.ARTIST.name());
} catch (Exception e) {
Log.e(TAG, "onCreateView: Artist Fragment doesnt have args.\t", e);
}
apiService.getArtist(artistID, new ApiService.OnArtistReceived() {
#Override
public void onSuccess(Artist artist) {
ArtistFragment.this.artist=artist;
setArtistToViews(artist, view);
}
#Override
public void onFail() {
Toast.makeText(getContext(), "Error on receiving artist.", Toast.LENGTH_LONG).show();
}
});
apiService.getNewSongs(artistID, new ApiService.OnSongsReceived() {
#Override
public void onSuccess(List<Song> songs) {
ArtistFragment.this.newSongs=songs;
List<GridListable> gridListables = new ArrayList<>();
gridListables.addAll(songs);
gv_new.load(gridListables, 1);
}
#Override
public void onFail(ApiService.ApiResponse response) {
Toast.makeText(getContext(), "Error on receiving artist.", Toast.LENGTH_LONG).show();
}
});
apiService.getBestSongs(artistID, new ApiService.OnSongsReceived() {
#Override
public void onSuccess(List<Song> songs) {
ArtistFragment.this.bestSongs=songs;
List<GridListable> gridListables = new ArrayList<>();
gridListables.addAll(songs);
gv_best.load(gridListables, 1);
}
#Override
public void onFail(ApiService.ApiResponse response) {
Toast.makeText(getContext(), "Error on receiving artist.", Toast.LENGTH_LONG).show();
}
});
apiService.getSingleSongs(artistID, new ApiService.OnSongsReceived() {
#Override
public void onSuccess(List<Song> songs) {
ArtistFragment.this.singleSongs=songs;
List<GridListable> gridListables = new ArrayList<>();
gridListables.addAll(songs);
gv_singles.load(gridListables, 1);
}
#Override
public void onFail(ApiService.ApiResponse response) {
}
});
apiService.getFeats(artistID, new ApiService.OnSongsReceived() {
#Override
public void onSuccess(List<Song> songs) {
ArtistFragment.this.feats=songs;
List<GridListable> gridListables = new ArrayList<>();
gridListables.addAll(songs);
gv_feats.load(gridListables, 1);
}
#Override
public void onFail(ApiService.ApiResponse response) {
}
});
apiService.getAlbums(artistID, new ApiService.OnAlbumsReceived() {
#Override
public void onSuccess(List<Album> albums) {
ArtistFragment.this.albums=albums;
List<Projective> projectives = new ArrayList<>();
projectives.addAll(albums);
rc_albums.setAdapter(new AlbumAdapter(getContext(), projectives));
rc_albums.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, true));
}
#Override
public void onFail(ApiService.ApiResponse response) {
Toast.makeText(getContext(), "Loading albums failed.", Toast.LENGTH_SHORT).show();
}
});
}else {
Log.i(TAG, "onCreateView: Fragment already initialized, restoring from existing artist");
setArtistToViews(artist,view);
gv_new.load(new ArrayList<>(newSongs),1);
gv_best.load(new ArrayList<>(bestSongs),1);
gv_singles.load(new ArrayList<>(singleSongs),1);
gv_feats.load(new ArrayList<>(feats),1);
rc_albums.setAdapter(new AlbumAdapter(getContext(), new ArrayList<>(albums)));
rc_albums.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, true));
}
return view;
}
I think the problem is the Keys that you use for your Bundles. All your instances of the custom view use the same SavedInstanceKey.SUPERSTATE.name().
You could try to have the Fragment pass a different key to each of the custom views (BEST, NEW...). This way, each of your GridView has its own unique key to use in the saveInstanceState and restoreInstanceState methods.
Related
current I'm facing a problem which I cannot solve, I have a controller, a fragment, and an Activity, the problem is, I need the application context inside the controller, so I created an instance of the controller from the Fragment, and passed the appContext as an argument in its constructor, but an exception is thrown which is class cast exception in function getReligions() inside my controller at the line where I have a call back, any ideas how to solve this?
Here is my code
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
controller = new Controller(getActivity().getApplicationContext());
imageUploadHandler = new ImageHandler(getApplicationContext());
rootView = inflater.inflate(R.layout.setup_edit_profile, container, false);
}
public void getReligions() {
if (religions != null) {
religionSpinner();
return;
}
controller.getReligions();
}
In the controller class
public void getReligions(){
JSONObject params = new JSONObject();
RequestQueue queue = Volley.newRequestQueue(context);
String url = "https://www.doyousonder.com/api/1.0.0/religion";
queue.add(new JsonObjectRequest(com.android.volley.Request.Method.GET, url, params,
new Response.Listener<JSONObject>() {
public void onResponse(JSONObject response) {
((GeneralCallBack)context).VolleyResponse(response,"Religions");
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
}) {
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Authorization", orientation_adj.getContext().getResources().getString(R.string.bearer));
return params;
}
});
}
myLogCat:
java.lang.ClassCastException:
com.eseed.sonder.utils.orientation_adj cannot be cast to
com.eseed.sonder.utils.GeneralCallBack
at com.eseed.sonder.utils.Controller$61.onResponse(Controller.java:904)
at com.eseed.sonder.utils.Controller$61.onResponse(Controller.java:902)
at com.android.volley.toolbox.JsonRequest.deliverResponse(JsonRequest.java:65)
at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:234)
at android.app.ActivityThread.main(ActivityThread.java:5526)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Here're my callbacks
#Override
public void VolleyResponse(String data) {
}
#Override
public void VolleyResponse(JSONObject response) {
}
#Override
public void VolleyResponse(JSONObject response, String data) {
Gson gson = new Gson();
if(data.equals("Religions")){
try {
Type t = new TypeToken<ReligionData[]>() {}.getType();
religions = gson.fromJson(String.valueOf(response.getJSONObject("data").getJSONArray("list_of_religions")), t);
religion_names = new String[religions.length + 1];
religion_names[0] = "Select";
for (int i = 0; i < religions.length; i++) {
religion_names[i + 1] = (religions[i].religion_name);
}
religionSpinner();
} catch (JSONException e) {
e.printStackTrace();
}
}else if(data.equals("Nationalities")){
try {
Type t = new TypeToken<NationalityData[]>() {
}.getType();
nationalities = gson.fromJson(String.valueOf(response.getJSONObject("data").getJSONArray("list_of_nationalities")), t);
nationality_names = new String[nationalities.length + 1];
nationality_names[0] = "Select";
for (int i = 0; i < nationalities.length; i++) {
nationality_names[i + 1] = (nationalities[i].nationality_name);
}
nationalitySpinner();
loadingIcon.hide();
} catch (JSONException e) {
System.out.println(e.getMessage());
}
}
}
`public class orientation_adj extends Application {
private static Context mContext;
#Override
public void onCreate() {
super.onCreate();
Fabric.with(this, new Crashlytics());
mContext = this;
// register to be informed of activities starting up
registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
#Override
public void onActivityCreated(Activity activity,
Bundle savedInstanceState) {
// new activity created; force its orientation to portrait
activity.setRequestedOrientation(
ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}
#Override
public void onActivityStarted(Activity activity) {
}
#Override
public void onActivityResumed(Activity activity) {
}
#Override
public void onActivityPaused(Activity activity) {
}
#Override
public void onActivityStopped(Activity activity) {
}
#Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
}
#Override
public void onActivityDestroyed(Activity activity) {
}
});
}
public static Context getContext(){
return mContext;
}
}
Your problem is here
class orientation_adj extends Application
And here
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
controller = new Controller(getActivity().getApplicationContext());
Your Application class isn't the context that implemented the interface, I assume the Activity is
In that case, you only need
controller = new Controller(getActivity());
After that, set up some additional log statements and breakpoints to debug the callback code better
In a fragment I am trying to save the scroll state of the RecyclerView list, but somehow it is not saving the state. As it is a fragment, I am overriding the onSaveInstanceState() and onActivityCreated() methods to save the scroll position. Even tried implementing in onViewStateRestored() method. I saw related some posts on saving the scroll state but it ain't working. Kindly let me know where am I failing. Below is my code:
public class RecipeListFragment extends Fragment
implements RecipeListContract.View {
#BindView(R.id.recipe_list_recycler_view)
RecyclerView mRecipeListRecyclerView;
#BindView(R.id.recipe_list_progress_bar)
ProgressBar mRecipeListProgressBar;
#BindInt(R.integer.grid_column_count)
int mGridColumnCount;
#BindString(R.string.recipe_list_sync_completed)
String mRecipeListSyncCompleted;
#BindString(R.string.recipe_list_connection_error)
String mRecipeListConnectionError;
GridLayoutManager gridLayoutManager;
Parcelable savedRecyclerLayoutState;
Unbinder unbinder;
private static final String SAVED_LAYOUT_MANAGER
= "com.learnwithme.buildapps.bakingapp.ui.recipelist.fragment";
private RecipeListContract.Presenter mRecipeListPresenter;
private RecipeListAdapter mRecipeListAdapter;
public RecipeListFragment() { }
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup
container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_recipe_list, container,
false);
unbinder = ButterKnife.bind(this, view);
mRecipeListAdapter = new RecipeListAdapter(
getContext(),
new ArrayList<>(0),
recipeId -> mRecipeListPresenter.loadRecipeDetails(recipeId)
);
mRecipeListAdapter.setHasStableIds(true);
gridLayoutManager = new GridLayoutManager(getContext(),
mGridColumnCount);
mRecipeListRecyclerView.setLayoutManager(gridLayoutManager);
mRecipeListRecyclerView.setHasFixedSize(true);
mRecipeListRecyclerView.setAdapter(mRecipeListAdapter);
return view;
}
#Override
public void onPause() {
super.onPause();
mRecipeListPresenter.unsubscribe();
}
#Override
public void onResume() {
super.onResume();
mRecipeListPresenter.subscribe();
}
#Override
public void onSaveInstanceState() { }
#Override
public void onSaveInstanceState(Bundle bundle) {
super.onSaveInstanceState(bundle);
if(bundle != null) {
bundle.putParcelable(SAVED_LAYOUT_MANAGER,
mRecipeListRecyclerView
.getLayoutManager()
.onSaveInstanceState());
Timber.d("instance state=>",
mRecipeListRecyclerView.getLayoutManager().onSaveInstanceState());
}
}
#Override
public void onViewStateRestored(#Nullable Bundle bundle) {
super.onViewStateRestored(bundle);
if(bundle != null) {
savedRecyclerLayoutState =
bundle.getParcelable(SAVED_LAYOUT_MANAGER);
Timber.d("onViewStateRestored savedRecyclerLayoutState=>",
savedRecyclerLayoutState);
mRecipeListRecyclerView
.getLayoutManager()
.onRestoreInstanceState(savedRecyclerLayoutState);
}
}
#Override
public void onActivityCreated(#Nullable Bundle bundle) {
super.onActivityCreated(bundle);
if(bundle != null) {
savedRecyclerLayoutState =
bundle.getParcelable(SAVED_LAYOUT_MANAGER);
Timber.d("onViewStateRestored savedRecyclerLayoutState=>",
savedRecyclerLayoutState);
mRecipeListRecyclerView
.getLayoutManager()
.onRestoreInstanceState(savedRecyclerLayoutState);
}
}
#Override
public void onDestroyView() {
super.onDestroyView();
unbinder.unbind();
}
public static RecipeListFragment newInstance() {
return new RecipeListFragment();
}
#Override
public void setPresenter(RecipeListContract.Presenter recipeListPresenter) {
this.mRecipeListPresenter = recipeListPresenter;
}
#Override
public void showRecipeList(List<Recipe> recipeList) {
mRecipeListAdapter.refreshRecipes(recipeList);
}
#Override
public void loadProgressBar(boolean show) {
setViewVisibility(mRecipeListRecyclerView, !show);
setViewVisibility(mRecipeListProgressBar, show);
}
#Override
public void displayCompletedMessage() {
Toast.makeText(getContext(), mRecipeListSyncCompleted,
Toast.LENGTH_SHORT).show();
}
#Override
public void displayErrorMessage() {
Toast.makeText(getContext(), mRecipeListConnectionError,
Toast.LENGTH_SHORT).show();
}
#Override
public void displayRecipeDetails(int recipeId) {
startActivity(RecipeDetailsActivity.prepareIntent(getContext(),
recipeId));
}
private void setViewVisibility(View view, boolean visible) {
if (visible) {
view.setVisibility(View.VISIBLE);
} else {
view.setVisibility(View.INVISIBLE);
}
}
}
I have resolved the issue myself. The problem was to save the scroll position of the device in onSaveInstanceState() and restoring the same in onViewRestored() method.
private Parcelable mRecipeListParcelable;
private int mScrollPosition = -1;
#Override
public void onSaveInstanceState(Bundle bundle) {
super.onSaveInstanceState(bundle);
int scrollPosition = ((GridLayoutManager)
mRecipeListRecyclerView.getLayoutManager())
.findFirstCompletelyVisibleItemPosition();
mRecipeListParcelable = gridLayoutManager.onSaveInstanceState();
bundle.putParcelable(KEY_LAYOUT, mRecipeListParcelable);
bundle.putInt(POSITION, scrollPosition);
}
#Override
public void onViewStateRestored(#Nullable Bundle bundle) {
super.onViewStateRestored(bundle);
if(bundle != null) {
mRecipeListParcelable = bundle.getParcelable(KEY_LAYOUT);
mScrollPosition = bundle.getInt(POSITION);
}
}
Also, in the loadProgress() method I had to set the scrollToPosition() with the scroll position saved.
#Override
public void loadProgressBar(boolean show) {
setViewVisibility(mRecipeListRecyclerView, !show);
setViewVisibility(mRecipeListProgressBar, show);
mRecipeListRecyclerView.scrollToPosition(mScrollPosition);
}
Also, one more thing to remember is that no need to restore anything in onResume() method as the presenter callbacks would get called and the view is reset anyway.
I've found several questions about this, none of which help me. Each question relates to other functions and views I don't implement in my fragments, and the issue is not that I need to swap my method getting the FragmentManager to getChildFragmentManager() anywhere in my fragments, because I don't need to get a FragmentManager there.
I'm guessing that my issue stems from the fragments and not the FragmentTabHost in the main activity, but I am not really sure. At all. All I know is that when you page between tabs, the adapter content disappears, but not the fragment itself. All views are still functional, so the functionality of each fragment remains intact.
This issue popped up only after I added a tab change listener for when to initialize the adapter for my chat fragment.
Note that the content of the tabs is fine when they are first initialized, but when you return to the tab the content in the adapters empty. This means that the tab that is not initialized yet when the FragmentTabHost is created, the hidden tabs haven't been initialized yet, so they will still work the first time you page over to them.
Through debugging, I can see that this issue occurs when the transition happens, and all adapters will remain empty for the duration of the usage session. I put this snippit of code before the initial checks in my tabHost.setOnTabChangedListener call:
//Before paging back to an initialized tab for the first time, the adapters of the initialized tab is populated.
Log.d("test", "pre");
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
//At this point, the adapter is empty.
Log.d("test", "post");
}
}, 50);
The two fragments are as follows:
public class GroupTasksFragment extends Fragment {
public ArrayAdapter<String> adapter;
private Context context;
public ListView taskListView;
public GroupTasksFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_group_tasks, container, false);
taskListView = (ListView) rootView.findViewById(R.id.tasksList);
adapter = new ArrayAdapter<>(context, android.R.layout.simple_list_item_1, new ArrayList<String>());
taskListView.setAdapter(adapter);
return rootView;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
this.context = context;
}
#Override
public void onDetach() {
super.onDetach();
}
}
public class GroupChatFragment extends Fragment{
public ArrayAdapter<String> adapter;
private Context context;
public ListView chatListView;
public GroupChatFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_group_chat, container, false);
chatListView = (ListView) rootView.findViewById(R.id.chatList);
adapter = new ArrayAdapter<>(context, android.R.layout.simple_list_item_1, new ArrayList<String>());
chatListView.setAdapter(adapter);
return rootView;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
this.context = context;
}
#Override
public void onDetach() {
super.onDetach();
}
}
The main activity with the FragmentTabHost (I have excluded methods that just take input and send content to PubNub):
public class GroupContentActivity extends AppCompatActivity {
private GroupChatFragment chatFrag;
private GroupTasksFragment taskFrag;
private FragmentTabHost tabHost;
private PubNub connection;
private String groupName;
private String nickName;
private boolean chatFragInitialized = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_group_content);
tabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
tabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent);
tabHost.addTab(tabHost.newTabSpec("tasks").setIndicator("Tasks"),
GroupTasksFragment.class, null);
tabHost.addTab(tabHost.newTabSpec("chat")
.setIndicator("Chat"), GroupChatFragment.class, null);
groupName = getIntent().getStringExtra("groupName");
nickName = getIntent().getStringExtra("nickName");
PNConfiguration config = new PNConfiguration();
config.setPublishKey(Constants.publishKey);
config.setSubscribeKey(Constants.subscribeKey);
connection = new PubNub(config);
tabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener() {
#Override
public void onTabChanged(String tabId) {
if (!chatFragInitialized && tabId.equals("chat")) {
chatFragInitialized = true;
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
chatFrag = (GroupChatFragment) getSupportFragmentManager().findFragmentByTag("chat");
connection.history()
.channel(groupName)
.count(50)
.async(new PNCallback<PNHistoryResult>() {
#Override
public void onResponse(PNHistoryResult result, PNStatus status) {
for (PNHistoryItemResult item : result.getMessages()) {
final String[] sForm = item.getEntry().getAsString().split(">>>>");
String m = "";
if (sForm.length > 2) {
for (int x = 1; x < sForm.length; x++) {
m += sForm[x];
}
} else {
m = sForm[1];
}
final String mCopy = m;
runOnUiThread(new Runnable() {
#Override
public void run() {
switch (sForm[0]) {
case "groupCreated":
chatFrag.adapter.clear();
break;
case "chat":
chatFrag.adapter.add(mCopy);
}
}
});
}
}
});
}
}, 50);
}
}
});
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
taskFrag = (GroupTasksFragment) getSupportFragmentManager().findFragmentByTag("tasks");
connection.history()
.channel(groupName)
.count(50)
.async(new PNCallback<PNHistoryResult>() {
#Override
public void onResponse(PNHistoryResult result, PNStatus status) {
for (PNHistoryItemResult item : result.getMessages()) {
final String[] sForm = item.getEntry().getAsString().split(">>>>");
String m = "";
if (sForm.length > 2) {
for (int x = 1; x < sForm.length; x++) {
m += sForm[x];
}
} else {
m = sForm[1];
}
final String mCopy = m;
runOnUiThread(new Runnable() {
#Override
public void run() {
switch (sForm[0]) {
case "addTask":
if (taskFrag.adapter.getPosition(mCopy) < 0) {
taskFrag.adapter.add(mCopy);
}
break;
case "deleteTask":
if (taskFrag.adapter.getPosition(mCopy) >= 0) {
taskFrag.adapter.remove(mCopy);
}
break;
case "groupCreated":
taskFrag.adapter.clear();
break;
}
}
});
}
}
});
connection.addListener(new SubscribeCallback() {
#Override
public void status(PubNub pubnub, PNStatus status) {
if (status.getCategory() == PNStatusCategory.PNUnexpectedDisconnectCategory) {
Toast.makeText(getApplicationContext(), "You were disconnected!", Toast.LENGTH_SHORT).show();
} else if (status.getCategory() == PNStatusCategory.PNConnectedCategory) {
if (status.getCategory() == PNStatusCategory.PNConnectedCategory) {
pubnub.publish().channel(groupName).message("chat>>>><ADMIN> User '" + nickName + "' Connected").async(new PNCallback<PNPublishResult>() {
#Override
public void onResponse(PNPublishResult result, PNStatus status) {
}
});
}
} else if (status.getCategory() == PNStatusCategory.PNReconnectedCategory) {
Toast.makeText(getApplicationContext(), "You were reconnected!", Toast.LENGTH_SHORT).show();
}
}
#Override
public void message(PubNub pubnub, PNMessageResult message) {
final String[] sForm = message.getMessage().getAsString().split(">>>>");
String m = "";
if (sForm.length > 2) {
for (int x = 1; x < sForm.length; x++) {
m += sForm[x];
}
} else {
m = sForm[1];
}
final String mCopy = m;
runOnUiThread(new Runnable() {
#Override
public void run() {
switch (sForm[0]) {
case "chat":
if (chatFragInitialized) {
chatFrag.adapter.add(mCopy);
runOnUiThread(new Runnable() {
#Override
public void run() {
chatFrag.chatListView.setSelection(chatFrag.adapter.getCount() - 1);
}
});
}
break;
case "addTask":
taskFrag.adapter.add(mCopy);
connection.publish().channel(groupName).message("chat>>>><ADMIN> Task '" + mCopy + "' added.").async(new PNCallback<PNPublishResult>() {
#Override
public void onResponse(PNPublishResult pnPublishResult, PNStatus pnStatus) {
}
});
break;
case "deleteTask":
taskFrag.adapter.remove(mCopy);
connection.publish().channel(groupName).message("chat>>>><ADMIN> Task '" + mCopy + "' deleted.").async(new PNCallback<PNPublishResult>() {
#Override
public void onResponse(PNPublishResult pnPublishResult, PNStatus pnStatus) {
}
});
break;
}
}
});
}
#Override
public void presence(PubNub pubnub, PNPresenceEventResult presence) {
}
});
connection.subscribe().channels(java.util.Collections.singletonList(groupName)).execute();
}
}, 100);
}
#Override
public void onDestroy(){
super.onDestroy();
connection.publish().channel(groupName).message("chat>>>><ADMIN> User '" + nickName + "' Logged Out.").async(new PNCallback<PNPublishResult>() {
#Override
public void onResponse(PNPublishResult pnPublishResult, PNStatus pnStatus) {
}
});
connection.disconnect();
Toast.makeText(getApplicationContext(), "Logged out", Toast.LENGTH_SHORT).show();
}
//More Methods
}
Also note that the issue is not that I need to store the FragmentManager instance, as that doesn't do anything.
I found my issue. It turns out that every time a fragment is paged to in the FragmentTabHost, it's createView method is called again, and only that method, so by setting the adapter in the fragment to empty in that view, which I thought was only at the start, I reset the adapter each time.
I fixed this by keeping the adapter content as an instance variable list object that I add or remove strings to/from when I want to change the adapter. DO NOT ALSO PUT THE STRINGS IN THE ADAPTER, updating the list is enough. The list will directly add it to the adapter.
Also note that if you set the initial content outside of the fragment, it may not show when the tabs are first initialized. Just be careful of your statement ordering and when things are called. Fragment construction is funky business.
Then, I set the adapter to whatever is in the list each time the createView method is called.
I'm making an Reddit app for my android exam and I have a question about inheritence.
I have a Fragment who has a RecyclerView. That recyclerview contains a list of redditposts. My app consists of multiple subreddits (funny, gaming, news, etc..). Every subreddit has his own Fragment. I have some methods that every Fragment has to have. (a showProgressBar, hideProgressBar, populateResult, etc...) I think it would be simple if i just make an Fragment class where all the subreddit Fragments can inheritance from. I could put all the methods in that fragment class because the methods are the same for every subreddit fragment. But my lecturer said that is a bad use of inheritance. So does anybody have a best practice around this problem?
This is the fragment i'm talking about:
package com.example.thomas.redditapp;
public class FunnyFragment extends Fragment {
private OnListFragmentInteractionListener mListener;
#Bind(R.id.funny_recyclerview)
RecyclerView mRecyclerView;
#Bind(R.id.progressBarFetch)
ProgressBar progress;
private RedditHelper helper;
private RedditPostRecyclerViewAdapter mAdapter;
List<RedditPost> redditPosts;
public FunnyFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
helper = null;
helper = new RedditHelper(SubRedditEnum.funny, this);
redditPosts = new ArrayList<>();
startLoad();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_funny_list, container, false);
ButterKnife.bind(this, view);
showProgressBar();
mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
mAdapter = new RedditPostRecyclerViewAdapter(redditPosts, mListener, mRecyclerView);
mAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
#Override
public void onLoadMore() {
redditPosts.add(null);
helper.loadListFromUrl();
}
});
mRecyclerView.setAdapter(mAdapter);
return view;
}
protected void startLoad() {
if (helper != null) {
helper.loadListFromDb();
}
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
if (isTaskRunning()) {
showProgressBar();
} else {
hideProgressBar();
}
super.onActivityCreated(savedInstanceState);
}
public void hideProgressBar() {
progress.setVisibility(View.GONE);
}
public void showProgressBar() {
progress.setVisibility(View.VISIBLE);
progress.setIndeterminate(true);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnListFragmentInteractionListener) {
mListener = (OnListFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnListFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public void populateResult(List<RedditPost> result) {
if(!redditPosts.isEmpty()){
redditPosts.remove(redditPosts.size() - 1);
}
redditPosts.addAll(result);
mAdapter.setLoaded();
mAdapter.notifyDataSetChanged();
}
protected boolean isTaskRunning() {
if (helper == null) {
return false;
} else if (helper.getStatus() == 0) {
return false;
} else {
return true;
}
}
}
I call the hideProgressBar(), showProgressBar() and populateResult() in my helper class.
There's a long standing mantra in programming that states: "Favor composition over inheritance"
You can read about the details of this statement and a lot of discussion here.
In this case, inheritance is unnecessary because you can simply build 1 Fragment and, on initialization pass it the subreddit, thus avoiding any constraining links between a super and subclass that may not even have any sort of polymorphic relationship.
I have a SignupActivity which will go through several fragments as users go through a signup process. On the last fragment, I'm calling
getActivity().setResult(Activity.RESULT_OK)
since SingupActivity intent was started for result. Some users are crashing at this point, because getActivity() is producing a NPE. I'm not able to figure out what is causing this. Screen rotation is disabled, so there is no reason that I know of for the fragment to detach from the Activity.
Any insight as to what may be causing this, and how I can resolve it?
public class SignupConfirmationFragment extends Fragment {
public static final String TAG = SignupConfirmationFragment.class.getSimpleName();
private User mNewUser;
private myAppClient mmyAppClient;
private Animation rotateAnimation;
private ImageView avatar;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNewUser = ((SignUpActivity) getActivity()).getNewUser();
mmyAppClient = ((SignUpActivity) getActivity()).getmyAppClient();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_signup_confirmation, null);
((TextView) v.findViewById(R.id.username_textView)).setText(((SignUpActivity) getActivity()).getNewUser().getName());
avatar = (ImageView) v.findViewById(R.id.avatar);
if (mNewUser.getAvatarImage() != null) {
avatar.setImageBitmap(mNewUser.getAvatarImage());
}
rotateAnimation = AnimationUtils.loadAnimation(getActivity(), R.anim.progress_rotate);
v.findViewById(R.id.progress_loading).startAnimation(rotateAnimation);
if (mNewUser.getAvatarImage() != null) {
startAvatarUpload();
} else if (mNewUser.getNewsletter()) {
setNewsletterStatus();
} else {
pauseForOneSecond();
}
return v;
}
private void startAvatarUpload() {
mmyAppClient.uploadUserAvatar(mNewUser.getAvatarImage(), new FutureCallback<JsonObject>() {
#Override
public void onCompleted(Exception e, JsonObject result) {
if (mNewUser.getNewsletter()) {
setNewsletterStatus();
} else {
updateFragment();
}
}
},
null,
null);
}
private void setNewsletterStatus() {
mmyAppClient.setNewsletter(mNewUser.getEmail(), mNewUser.getFirstName(), mNewUser.getLastName(), new FutureCallback<String>() {
#Override
public void onCompleted(Exception e, String result) {
//Log.d(TAG, "Result: " + result);
updateFragment();
}
});
}
private void pauseForOneSecond() {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
updateFragment();
}
}, 1000);
}
private void updateFragment() {
rotateAnimation.cancel();
if (isAdded()) {
getActivity().setResult(Activity.RESULT_OK);
AnalyticsManager.logUIEvent("sign up completed");
getActivity().finish();
} else {
AnalyticsManager.logUIEvent("sign up failed");
}
}
}
According to Fragment lifecycle in Android OS, you cannot get the Activity associated with the fragment in the onCreateView, because the Activity with which the Fragment is associated will not be created at that stage.
See the figure below:
Also, refer to this link, http://developer.android.com/guide/components/fragments.html
As you can see the Activity is created in onActivityCreated which is after onCreateView, hence you'll get null if you try to call the Activity in the onCreateView. Try to call it in onActivityCreated or in onStart that should solve your problem.
I hope this helps.