I have an Activity with three tabs and three Fragments. First Fragment shows the list of song titles and the second tab displays the selected song. The details of the songs is coming from a database.
I am implementing SearchView feature so that whatever search text user enters, only those songs should be displayed in the index.
This is exactly like the way phone book work in our devices.
I'm not able to understand how to refresh the first Fragment when the search query changes.
I'm basically looking for the method that I can call to refresh the first Fragment.
Got my answer here Android refresh a fragment list from its parent activity as suggested by #Prem. Works perfectly fine for me.
Its is achievable by making an interface
MainActivity.java
public class MainActivity extends Activity {
public FragmentRefreshListener getFragmentRefreshListener() {
return fragmentRefreshListener;
}
public void setFragmentRefreshListener(FragmentRefreshListener fragmentRefreshListener) {
this.fragmentRefreshListener = fragmentRefreshListener;
}
private FragmentRefreshListener fragmentRefreshListener;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b = (Button)findViewById(R.id.btnRefreshFragment);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(getFragmentRefreshListener()!=null){
getFragmentRefreshListener().onRefresh();
}
}
});
}
public interface FragmentRefreshListener{
void onRefresh();
}}
MyFragment.java
public class MyFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = null; // some view
/// Your Code
((MainActivity)getActivity()).setFragmentRefreshListener(new MainActivity.FragmentRefreshListener() {
#Override
public void onRefresh() {
// Refresh Your Fragment
}
});
return v;
}}
Below is the one way, you can easily do it. You just have to save the fragment instance. That's all.
private class ViewPagerAdapter extends FragmentStatePagerAdapter {
private SparseArray<Fragment> array = new SparseArray<>();
ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
array.setValueAt(position, myFragment);
return myFragment;
}
#Override
public int getCount() {
return 3;
}
public SparseArray<Fragment> getFragmentArray() {
return array;
}
}
Then from your activity, you can get all viewpager fragment easily from adapter instance.
MyFragment fragment = (MyFragment) adapter.getFragmentArray().get(0); // get first fragment and casting it to your origin fragment
Then create a method on that fragment. Call like below:
fragment.myFragmentMethod(String myData){}
Have a nice day!
Related
So basically, i have an activity called (Profile Activity) and two fragments connected to it (Profile view and profile edit fragment). Since im completely new with android studio, java language and fragments, im trying to place both fragments into activity but in a way that only profile view fragment is shown. Edit profile fragment needs to be hidden. Im using next part of the code:
getSupportFragmentManager().beginTransaction().add(R.id.profile_fragment, profileViewFragment).commit();
getSupportFragmentManager().beginTransaction().add(R.id.profile_fragment, profileEditFragment).commit();
I already tried something with "hide" and "show", but with no success. I have imported "android.support.v4.app.FragmentManager;" Thank you.
EDIT:
Profile activity after implementing new code:
public class ProfileActivity extends AppCompatActivity implements ProfileViewFragment.ProfileViewListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
//ovo ispod je za proslijedivanje iz activita u fragment
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profile);
ProfileViewFragment profileViewFragment = new ProfileViewFragment();
ProfileEditFragment profileEditFragment=new ProfileEditFragment();
profileViewFragment.setArguments(getIntent().getExtras());
profileEditFragment.setArguments(getIntent().getExtras());
//getSupportFragmentManager().beginTransaction().add(R.id.profile_fragment, profileEditFragment).commit();
getSupportFragmentManager().beginTransaction().add(R.id.profile_fragment, profileViewFragment).commit();
//getSupportFragmentManager().beginTransaction().replace(R.id.profile_fragment, profileViewFragment).commit();
//FragmentManager fm=getSupportFragmentManager();
//fm.beginTransaction().setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out).show(new ProfileViewFragment()).commit();
//fm.beginTransaction().setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out).show(new ProfileEditFragment()).commit();
//-----------------------------------
}
#Override
public void onOpenProfileEditor() {
ProfileEditFragment profileEditFragment=new ProfileEditFragment();
profileEditFragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction().replace(R.id.profile_fragment, profileEditFragment).commit();
}
#Override
public void onAttachFragment(Fragment fragment) {
if (fragment instanceof ProfileViewFragment) {
ProfileViewFragment profileFragment = (ProfileViewFragment) fragment;
profileFragment.setListener(this::onOpenProfileEditor);
}
}
}
Profile view fragment with new code:
public class ProfileViewFragment extends Fragment {
private Unbinder unbinder;
//novi kod sa stacka
private ProfileViewListener listener;
//-------------
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
FragmentProfileViewBinding viewBinding=DataBindingUtil.inflate(inflater, R.layout.fragment_profile_view, container, false);
View view=viewBinding.getRoot();
unbinder = ButterKnife.bind(this, view);
UserModel user = (UserModel) getArguments().get(ModelEnum.UserModel.name());
//viewBinding povezuje fragment i xml (proslijeduje user)
viewBinding.setUser(user);
//viewBinding.setUserGender(user);
return view;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
// #OnClick(R.id.btn_change_settings)
// public void changeSettings(){
//getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.profile_fragment, new ProfileEditFragment()).commit();
// }
#Override
public void onDestroyView() {
super.onDestroyView();
unbinder.unbind();
}
//ISPOD JE NOVI KOD SA STACK OVERFLOWA
public interface ProfileViewListener{
void onProfileEditor();
}
public void setListener(ProfileViewListener listener) {
this.listener = listener;
}
#OnClick(R.id.btn_change_settings)
public void onEdit(View view){
if(listener!=null){
onOpenProfileEditor();
}
}
}
Instead of
getSupportFragmentManager().beginTransaction().add(R.id.profile_fragment, profileEditFragment).commit();
It must be
getSupportFragmentManager().beginTransaction().replace(R.id.profile_fragment, profileEditFragment).commit();
This will replace your fragment, instead of adding it.
Please, also note that you must call "add" for the first time and use "replace" afterwards.
You may find more about fragments here: https://developer.android.com/training/basics/fragments/fragment-ui
EDIT
For the new issue you have outlined, the solution is to "report" you activity that an event had happened, so it can take action. Here is how to do that.
First, we need an interface (you can add it inside you Profile fragment) and to link the activity to our fragment, if it implements that interface.
public class ProfileViewFragment extends Fragment {
...
...
private ProfileViewListener listener;
...
...
#OnClick(R.id.btn_change_settings)
public onEdit(View view) {
// If there is anyone listening, report that we need to open editor
if (listener != null) {
listener .onOpenProfileEditor();
}
}
public void setListener(ProfileViewListener listener) {
this.listener = listener;
}
// The interface
public interface ProfileViewListener {
void onOpenProfileEditor();
}
}
And in the class, we need to implement the interface and subscribe as a listener.
public class ProfileActivity extends AppCompatActivity implements ProfileViewFragment.ProfileViewListener {
...
...
#Override
public void onOpenProfileEditor() {
ProfileEditFragment profileEditFragment=new ProfileEditFragment();
profileEditFragment.setArguments(getIntent().getExtras());
getSupportFragmentManager()
.beginTransaction
.replace(R.id.profile_fragment, profileEditFragment)
.commit();
}
#Override
public void onAttachFragment(Fragment fragment) {
if (fragment instanceof ProfileViewFragment) {
ProfileViewFragment profileFragment = (ProfileViewFragment) fragment;
profileFragment.setListener(this);
}
}
}
You may find more detail on Activity-Fragment communication here - https://developer.android.com/training/basics/fragments/communicating
I'm creating application which has FragmentPagerAdapter with two pages.
The class for FragmentPagerAdapter looks like this
public static class AppSectionsPagerAdapter extends FragmentPagerAdapter {
public AppSectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
Fragment fragment;
switch (i) {
case 0: fragment = new CurrentRateFragment(); break;
case 1: fragment = new HistoryFragment(); break;
default: fragment = new CurrentRateFragment(); break;
}
return fragment;
}
#Override
public int getCount() {
return 2;
}
}
I want that some changes on first page (for example change Spinner selected item) caused changes on second page.
As I've read about Fragment communication (https://developer.android.com/training/basics/fragments/communicating.html) and understand that fragments can communicate only through Activity.
For this case I've created public interface in my first page class fragment
public interface CurrencyListener {
public void onCurrencyChanged();
}
And implement it in my Activity.
Now I can call void onCurrencyChanged in my Activity from my first page fragment.
But the problem is:
How to recreate second page fragment in my FragmentPagerAdapter?
Fragment creation operation is heavy.
1. If you recreate fragment the all the views will be created and previous Fragment needs to be garbage collected. Therefore there will extra memory.
Therefore rather than recreating the FirstPageFragment just refresh the data based on the callback received on your currencyChanged() method.
In this case, fragment will be created once and data will be updated every time the currencyChanged() method is called.
HistoryFragment Code(Fragment to be refreshed)
public class HistoryFragment extends Fragment implements MyActivity.IUpdateData{
/**
* Other method goes here
*/
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
//
if(getActivity() instanceof /**Your Activity**/){
((/**Your Activity**/)getActivity()).setOnUpdateListener(this);
}
return super.onCreateView(inflater, container, savedInstanceState);
}
#Override
public void updateData(Object object) {
//Refresh Data
}
}
Activity (Which will refresh data)
public class MyActivity extends Activity {
/**
* Other method goes here
*/
private IUpdateData dataUpdateListener;
public void setOnUpdateListener(IUpdateData listener){
dataUpdateListener = listener;
}
public void onCurrencyChanged(){
if(dataUpdateListener!=null){
dataUpdateListener.updateData(/**Update Data**/);
}
}
public interface IUpdateData{
void updateData(Object o);
}
}
I am trying to call the functions frag.updateButtons() etc from within GameScreen (Main Activity) as ten times a second, the game cycles through these things and updates the variables accordingly.
The code is as it currently is. The frag.*** functions work when it is set up as a fragment, but now that I am wanting to use it as viewPager, it keeps having the following error:
java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.support.v4.app.FragmentActivity.findViewById(int)' on a null object reference
I am fairly new to programming and Android code, and clearly don't entirely understand fragments and viewPager etc, so any help here would be very much appreciated.
I have not included the whole code, just the code that I think is relevant to the problem. If you need more code or info, please ask me and I'll get you what you need.
Thank you
public class GameScreen extends FragmentActivity implements GameScreenFragment.FragInterface{
ViewPager mViewPager;
GameScreenFragment frag;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.game_screen);
mViewPager = (ViewPager) findViewById(R.id.bottomFragment);
/** set the adapter for ViewPager */
mViewPager.setAdapter(new SamplePagerAdapter(getSupportFragmentManager()));
startRepeatingTask();
//the code here calls the mainLoop() function 10 times a second
}
}
//for the fragment functions
public void displayCompany(String companyName){}
public void displayCompanyIncome(){}
public void checkTeamImage(){}
public void getCostOfEmployees(){}
public void updateButtons(){}
public void mainLoop(){
//display company name and company income in fragment
frag = (GameScreenFragment) getSupportFragmentManager().findFragmentById(R.id.bottomFragment);
frag.updateButtons();
frag.displayCompanyIncome();
frag.getCostOfEmployees();
frag.displayCompany(Global.companyName[Global.companyNumber]);
//updates the picture for that company
frag.checkTeamImage();
}
public class SamplePagerAdapter extends FragmentPagerAdapter {
public SamplePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public android.support.v4.app.Fragment getItem(int position) {
/** Show a Fragment based on the position of the current screen */
Global.companyNumber = position;
return new GameScreenFragment();
}
#Override
public int getCount() {
// Show 2 total pages.
return 2;
}
}
}
and then in the fragment whose ID in the .xml is bottomFragment
public class GameScreenFragment extends Fragment {
FragInterface fragStuff;
public interface FragInterface {
void displayCompany(String companyName);
void displayCompanyIncome();
void checkTeamImage();
void getCostOfEmployees();
void displayCompanyName();
void updateButtons();
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState){
View view = inflater.inflate(R.layout.game_screen_fragment, container, false);
//other code here
return view;
}
}
I have a ListView in my activity.On clicking on the list item it invokes another activity.In that activity I have implemented ViewPager and fragments.
When it loads first time onResume() ,onCreate() and onCreateView() method called twice, if I clicks on first list item. (i.e. it loads first and second fragment view)
when I click on the any other List fragment except first then it calls onResume() ,onCreate() and onCreateView() methods three times (i.e. It loads previous and after and click view )
It is absoutely fine but I have google analytics code with which I have to track only current page so where I can put this code to load for only current page
My question is my googleAnalytics code tracs three or two pages at first time even user doesnot gone through those pages how to avoid this ?
My code is as below for fragment
public class MainListActivity extends Activity{
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v(TAG, "onCreate()");
CustomFragmentPagerAdapter adapter = new CustomFragmentPagerAdapter();
viewPager.setAdapter(adapter);
}
}
//code for fragment adapter
public class CustomFragmentPagerAdapter extends FragmentPagerAdapter {
public CustomFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int pos) {
CustomFragment customFragment = new CustomFragment();
arrayList.add(customFragment);
return customFragment;
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return arrayList.size();
}
}
//code for fragment
public class CustomFragment extends Fragment{
public CustomFragment() {
super();
}
#Override
public void onResume() {
super.onResume();
Log.v(TAG, "onCreate -Resume");
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v(TAG, "onCreate");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
Log.v(TAG, "onCreateView");
return myAnyView;
}
}
The problem is that the onResume() method is called for all your fragments, that is including the invisible ones.
Check gorn's answer here:
How to determine when Fragment becomes visible in ViewPager
You have to override
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
// Your logic
}
and do your logic in there.
I'm currently trying to work with fragment, but I'm stuck with an issue I can't solve.
I have one activity, which holds 4 different fragment. From this activity, I launch an ASyncTask which goes to the web and get different data I need, and then will send it to the fragments.
But, when my app gets killed and opened again, or when I change the orientation, my fragments are apparently recreated and my custom FragmentAdapter doesn't hold the good reference to the fragment.
Here is the code of my main activity.
public class MainActivity extends FragmentActivity {
MyPagerAdapter fgsAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//...
FragmentManager fm = super.getSupportFragmentManager();
fgsAdapter = new MyPagerAdapter(fm,this);
ViewPager myPager = (ViewPager) findViewById(R.id.home_pannels_pager);
myPager.setAdapter(fgsAdapter);
myPager.setCurrentItem(0);
}
#Override
protected void onResume() {
super.onResume();
ATaskGetUser task = new ATaskGetUser(callback, (ProgressBar) findViewById(R.id.PB_AsyncTask));
task.execute();
}
//What's called by the ASyncTask onPostExecute()
private void notifyDataChanged() {
fgsAdapter.notifyFragments(user.getItems());
}
private class MyPagerAdapter extends FragmentPagerAdapter {
private List<CardFragment> fragments = new ArrayList<CardFragment>();
private Context c;
public MyPagerAdapter(FragmentManager fm, Context c) {
super(fm);
CardFragment h = new HabitFragment();
CardFragment d = new DailyFragment();
CardFragment t = new ToDoFragment();
CardFragment r = new RewardFragment();
fragments.add(h);
fragments.add(d);
fragments.add(t);
fragments.add(r);
}
public int getCount() {
return fragments.size();
}
#Override
public CardFragment getItem(int position) {
Log.v("MainActivity_fgsmanager", "getItem()");
CardFragment f = (CardFragment) this.fragments.get(position);
return f;
}
public void notifyFragments(List<HabitItem> items) {
for(OnTasksChanged f : fragments) {
f.onChange(items);
}
}
}
}
So, what I want to be able to do, is to be able to call the onChange (an interface implemented by my four fragments), in my notifyDataChanged function. Is this possible, are am I thinking the wrong way?
I got the same problems once with Fragments, I was losing the current fragment after every screen rotation.
I simply solved it by adding one line in the Fragment class (not in the parent FragmentActivity class):
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.rate_fragment, container,false);
setRetainInstance(true);//Added not to lose the fragment instance during screen rotations
(...)
For your case where your app gets killed and opened again, I am not sure it will work though.