I have a problem with comuunicating between fragments that are chnged dynamicaly, i mannaged to use the interface system to cimmunicate if the fragments are all viewble but when i am viewing them sepretly i can't use a their actions since they dont have a tag yet, any thoughts?
main activty
public class MainActivity extends FragmentActivity implements OnClickListener, Communicator {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (isSingleFragment()) {
Button btn_color = (Button) findViewById(R.id.button_color);
Button btn_text = (Button) findViewById(R.id.button_text);
Button btn_list = (Button) findViewById(R.id.button_list);
btn_color.setOnClickListener(this);
btn_list.setOnClickListener(this);
btn_text.setOnClickListener(this);
singleFragActions();
} else {
doubleFragActions();
}
// some more stuff happens
#Override
public void apply(String data) {
Log.d("data", data+"");
FragmentManager fm = getSupportFragmentManager();
Frag_list frag_list = (Frag_list) fm.findFragmentByTag("list");
//i cannot use id because the fragment in
//MainActivity are in a layout and are enterd dynamicaly
frag_list.addItem(data);
}
three fragments here, when on small screen, on is shown and three button on the top change them arrounf, if on tablet, all three are displyed, this is the interface
public interface Communicator {
public void apply(String data);
}
frag_text (first fragment)
public class Frag_text extends Fragment implements OnClickListener{
Communicator comm;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// stuff
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
comm = (Communicator) getActivity();
}
#Override
public void onClick(View v) {
EditText input = (EditText) getView().findViewById(R.id.frag_text_edit);
TextView output = (TextView) getView().findViewById(R.id.frag_text_show);
String text_get = input.getText().toString();
output.setText("hello "+text_get+" how are you today?");
comm.apply(text_get);
}
}
frag_list (other fragment)
public class Frag_list extends Fragment{
ArrayList<String> list;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frag_list, container, false);
list = new ArrayList<String>();
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, list);
ListView lv = (ListView) view.findViewById(R.id.list_frag);
lv.setAdapter(adapter);
return view;
}
public void addItem(String data){
list.add(data);
}
}
how to i access the other fragment if it doesnt have a tag yet?
If you happen to know what fragment you will be calling then FragmentActivity could act as a mediator in this case, as it is a mere "host". You already have this Communicator interface. Have it communicate to a given fragment:
public interface Communicator {
public void apply(String data, String tag);
}
And the override:
#Override
public void apply(String data, String tag) {
FragmentManager fm = getSupportFragmentManager();
Frag_list frag_list = (Frag_list) fm.findFragmentByTag(tag);
//Fallback plan in case the fragment has not been created.
if(frag_list == null) {
frag_list = new Frag_list();
//Include the fragment for future reference.
//This fragment has no view
fm.beginTransaction().add(frag_list, tag);
}
frag_list.addItem(data);
}
And modify the fragment to always have the list available:
public class Frag_list extends Fragment{
ArrayList<String> list = new ArrayList<String>();
//...
public void addItem(String data){
//Add check to avoid problems
if(list != null) {
list.add(data);
}
}
}
Related
Need help with android app (java)
My app starts with SplashActivity. During it I`m getting json via retrofit request and after successfull response I fill my DB
SplashActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
ISplashInteractor splashInteractor = new SplashInteractor();
moviePresenter = new MoviePresenter(this, splashInteractor);
moviePresenter.initDB();
}
after DB successfully loaded automatically starts MovieListActivity
public class MovieListActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_movie_list);
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
Fragment allMoviesFragment = new AllMoviesFragment();
String tag = "MovieList";
transaction.replace(R.id.main_container, allMoviesFragment, tag);
transaction.commit();
}
}
and at once list of movies loads inside inner fragment AllMoviesFragment(inside recyclerView). till this point everything is ok.
now I set onRecyclerViewItemClickListener - it must open another fragment inside MovieListActivity but instead of this - my app restarts from begining and I observe loading of SpalshActivity again(I put progressbar during request) and again my RecyclerView...
my RecyclerViewAdapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
private List<MovieDetails> movieList;
private OnRecyclerViewItemClickListener onRecyclerViewItemClickListener;
public RecyclerViewAdapter(List<MovieDetails> movieList) {
this.movieList = movieList;
}
public void setOnRecyclerViewItemClickListener(OnRecyclerViewItemClickListener onRecyclerViewItemClickListener){
this.onRecyclerViewItemClickListener = onRecyclerViewItemClickListener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.simple_selectable_list_item, parent, false);
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
MovieDetails movieDetails = (movieList.get(position));
holder.name.setText(movieDetails.getTitle());
holder.year.setText(String.valueOf(movieDetails.getReleaseYear()));
}
#Override
public int getItemCount() {
if (movieList == null)
return 0;
return movieList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
TextView name;
TextView year;
public ViewHolder(View itemView) {
super(itemView);
name = itemView.findViewById(R.id.movie_name);
year = itemView.findViewById(R.id.release_year);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(onRecyclerViewItemClickListener != null){
int position = getAdapterPosition();
if(position != RecyclerView.NO_POSITION){
onRecyclerViewItemClickListener.onRecyclerViewItemClick(position);
}
}
}
});
}
}
public interface OnRecyclerViewItemClickListener {
void onRecyclerViewItemClick(int position);
}
}
my AllMoviesFragment
public class AllMoviesFragment extends Fragment implements RecyclerViewAdapter.OnRecyclerViewItemClickListener {
private static final String CURR_MOVIE = "Current Movie";
private static final String TAG = "MSApp";
List<MovieDetails> movieList;
RecyclerView recyclerView;
public AllMoviesFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
movieList = App.getAppInstance().getDatabaseInstance().getMovieDao().getAllMovies();
movieList.sort(new Comparator<MovieDetails>() {
#Override
public int compare(MovieDetails o1, MovieDetails o2) {
return o2.getReleaseYear() - o1.getReleaseYear();
}
});
View resultView = inflater.inflate(R.layout.fragment_all_movies, container, false);
recyclerView = resultView.findViewById(R.id.recycler_view);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
RecyclerViewAdapter adapter = new RecyclerViewAdapter(movieList);
adapter.setOnRecyclerViewItemClickListener(AllMoviesFragment.this);
recyclerView.setAdapter(adapter);
return resultView;
}
#Override
public void onRecyclerViewItemClick(int position) {
MovieDetails choosenMovie = movieList.get(position);
FragmentManager fragmentManager = getFragmentManager();
Fragment movieDetailsFragment = new MovieDetailsFragment();
Bundle args = new Bundle();
args.putParcelable(CURR_MOVIE, choosenMovie);
movieDetailsFragment.setArguments(args);
String tag = "MovieDetails";
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, movieDetailsFragment, tag);
transaction.addToBackStack(tag);
transaction.commit();
}
}
sorry for long post. I dont know how to cut it
I use App class for db access if it is important
#AkakiKapanadze
you was almost right
I didnot see the error message because it disappeared less 1 second
and class MovieDetailsFragment
after I remove binder of ButterKnife all work... I dont know WHY - I always use Butterknife inside Fragments
I will be very grateful for the analysis of these lines of code, because I do not understand the relationship between them. Especially if I
I will change tags to 2 different tags, nothing changes in the application. In addition, if the condition if is removed, there are also no changes. In the comments I have a brief translation, I am still unable to understand these three lines.
Fragment fr = manager.findFragmentByTag("AddCity");
What role does this condition fulfill?
if (fr != null) {// if ???
manager.beginTransaction().remove(fr).commit();
}
And:
fr2.show(manager, "AddCity");
This is the whole code snippet
/*
I create a variable manager, and then I get a FragmentManager and assign it to the variable manager,
thanks to the variable manager, I can run actions on fragments
*/
FragmentManager manager = getSupportFragmentManager();
Fragment fr = manager.findFragmentByTag("AddCity");//I created fr variable and ???
Fragment1 fr1 = (Fragment1)
manager.findFragmentById(R.id.list); // I created fr1 variable and assigned fragment list to the variable fr1
if (view.equals(b1)) {
if (fr != null) {// if ???
manager.beginTransaction().remove(fr).commit();//Creates a new transaction to change fragments at runtime, removes an existing fragment, plans to commit the transaction.
}
Fragment2 fr2 = new Fragment2();//Created object Fragment2
fr2.show(manager, "AddCity");//Display the dialog box by adding the fragment to the given FragmentManager.
}
EDIT:
This is my MainActivity:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button b1, b2;
static int itemSelected;
static boolean isSelected;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = findViewById(R.id.button1);
b2 = findViewById(R.id.button2);
b1.setOnClickListener(this);
b2.setOnClickListener(this);
}
#Override
public void onClick(View view) {
FragmentManager manager = getSupportFragmentManager();//
Fragment fr = manager.findFragmentByTag("addCity");
Fragment1 fr1 = (Fragment1)
getSupportFragmentManager().findFragmentById(R.id.list);
if (view.equals(b1)) {
if (fr != null) {
manager.beginTransaction().remove(fr).commit();
}
Fragment2 fr2 = new Fragment2();
fr2.show(manager, "");
}
if (view.equals(b2)) {
if (!fr1.cities.isEmpty()) {
if (isSelected) {
fr1.cities.remove(itemSelected);
fr1.adapter.notifyDataSetChanged();
itemSelected = 0;
isSelected = false;
fr1.getListView()
.setSelector(android.R.color.transparent);
} else {
Toast.makeText(this, "Select city to be deleted",
Toast.LENGTH_LONG).show();
}
}
}
}
}
Fragment1:
public class Fragment1 extends ListFragment {
ArrayList<String> cities = new ArrayList<>();
ArrayAdapter<String> adapter;
String name;
public Fragment1() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup viewGroup,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_fragment1,
viewGroup, false);
adapter = new ArrayAdapter<>(getActivity(),
android.R.layout.simple_list_item_1, cities);
setListAdapter(adapter);
return view;
}
public void onListItemClick(ListView listView, View view,
int position, long id) {
MainActivity.itemSelected = position;
MainActivity.isSelected = true;
getListView().setSelector(android.R.color.holo_blue_dark);
}
}
Fragment2:
public class Fragment2 extends DialogFragment {
EditText et;
public Fragment2() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup viewGroup,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_fragment2, viewGroup, false);
}
public void onViewCreated(View view, Bundle savedInstanceState) {
et = view.findViewById(R.id.editText);
Button b = view.findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String country = et.getText().toString();
Fragment1 fr1 = (Fragment1)
getFragmentManager().findFragmentById(R.id.list);
if (!country.equals("")) {
fr1.cities.add(country);
fr1.adapter.notifyDataSetChanged();
}
getActivity().getSupportFragmentManager().beginTransaction()
.remove(Fragment2.this).commit();
}
});
}
}
You are adding another fragment in the same name. Can you try changing the name to something else and try?
Like
fr2.show(manager, "Add District");
so that you can find the difference.
Adding a fragment
Fragment fr2 = new Fragment();
FragmentManager manger = getSupportFragmentManager();
FragmentTransaction ft = manger.beginTransaction();
ft.add(R.id.placeHolder, fr2,tag);
ft.commitAllowingStateLoss();
if(fr2.isAdded()){
fr2.show(manager, "");
}
Before calling show, you have to add the fragment.
I have two fragments MyFragment and MyFragment2 , an interface defined within MyFragment2.
code for MyFragment2:
public class MyFragment2 extends android.support.v4.app.Fragment implements View.OnClickListener {
public interface MyInterface2
{
public void respond(String s);
}
EditText editText;
Button sendData;
MyInterface2 comm;
View v=getView();
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
v = inflater.inflate(R.layout.my_fragment_2,container,false);
return v;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
this.comm = (MyInterface2)getActivity();
editText = (EditText)getActivity().findViewById(R.id.text);
sendData =(Button)getActivity().findViewById(R.id.sendData);
sendData.setOnClickListener(this);
}
#Override
public void onClick(View v) {
try {
String s = editText.getText().toString();
comm.respond(s);
}
catch(Exception e)
{
Toast.makeText(getActivity(),"error:"+e,Toast.LENGTH_LONG).show();
}
}
}
I am trying to send the content of editText from MyFragment2 to the fragment MyFragment by pressing the button (Myfragment2 initially set on the main activity's view using the Java code)
The main activity's code is as follows*(my_layout is the id of layout in which I am putting the fragments)*:
public class MainActivity extends AppCompatActivity implements MyFragment2.MyInterface2 {
//String data;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyFragment2 fragment2= new MyFragment2();
FragmentManager fManager= getSupportFragmentManager();
FragmentTransaction transaction= fManager.beginTransaction();
transaction.add(R.id.my_layout,fragment2,"MyFragment2");
transaction.commit();
}
public void respond(String s)
{
MyFragment fragment = new MyFragment();
FragmentManager fManager =getSupportFragmentManager();
FragmentTransaction transaction = fManager.beginTransaction();
transaction.replace(R.id.my_layout,fragment);
transaction.commit();
fragment.getData(s);
}
}
when I click the sendData button in fragment MyFragment2 , MyFragment2 gets replaced with fragment Myfragment but no data change occurs in the MyFragmnet's textView and an error is also shown which I have catched in a try catch block from fragment MyFragment2(here is the image for that).
code for MyFragment :
public class MyFragment extends android.support.v4.app.Fragment {
TextView textView;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.my_fragment,container,false);
//textView =(TextView)v.findViewById(R.id.getText);
return v;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
textView =(TextView)getActivity().findViewById(R.id.getText);
}
public void getData(String data)
{
textView.setText(data);
}
}
You can easily pass data between fragments using a callback or passing the arguments via a bundle.
Check out this article:
https://developer.android.com/training/basics/fragments/communicating.html
onActivityCreated is no need. Uncomment ur text view initiation statement in onCreateView block.
Ensure you have text view in your respective layout file with same id you have passed
I am trying to communicate between an activity and the fragment that sits on top of it, I want new data (image/text - retrieved from the db) to be passed into the frag every time an onclick occurs (onclick is in the activity). I made a simple interface to test (let me know if this is not suitable for images or if it is too slow or inefficient), and I am trying to have it included in my fragment so when an onclick occurs the fragment changes the image and the text.
Here is the simple interface code:
public interface FragmentCommunicator {
public void passDataToFragment(String someValue);
}
Here is the activity code:
public class RandomActivity extends FragmentActivity implements ActivityCommunicator {
//viewpager adapter
private PageAdapter mAdapter;
private ViewPager viewPager;
//interface through which communication is made to fragment
public FragmentCommunicator fragmentCommunicator;
//Buttons for yes, no, skip
Button btnYesRandom, btnNoRandom, btnSkipRandom;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_random);
//set buttons
btnYesRandom = (Button) findViewById(R.id.btnYesRandom);
// Initializing pager
viewPager = (ViewPager) findViewById(R.id.random_pager);
//calling bundle to attach data to fragment
Bundle bundle = new Bundle();
bundle.putString("edttext", "From Activity");
// set Fragmentclass Arguments
RandomFragment randFrag = new RandomFragment();
randFrag.setArguments(bundle);
//Setting up fragment
FragmentManager fm = getFragmentManager();
mAdapter = new PageAdapter(getSupportFragmentManager(), new UserUpVotesFragment(), randFrag, new UserDownVotesFragment());
viewPager.setAdapter(mAdapter);
// Here you would declare which page to visit on creation
viewPager.setCurrentItem(1);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
public void onPageScrollStateChanged(int state) {}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
public void onPageSelected(int position) {
// Check if this is the page you want.
if(position !=1) {
//swiping to the right
if(position == 0) {
Log.e("Swiping", "SWIPING TO THE Right BUT RESET ERR");
getIntent().removeExtra("edttext");
}
//swiping to the left
if(position == 2) {
Log.e("Swiping", "SWIPING TO THE left BUT RESET ERR");
}
// RandomFragment randomFrag = (RandomFragment) getFragmentManager().findFragmentById(R.id.fra);
viewPager.setCurrentItem(1);
}
}
});
btnYesRandom.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
if(fragmentCommunicator != null)
fragmentCommunicator.passDataToFragment("Hi from FragmentActivity");
}
});
}
Code for Fragment:
public class RandomFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//call data from activity bundle
String strtext = getArguments().getString("edttext");
View rootView = inflater.inflate(R.layout.fragment_random, container, false);
RelativeLayout random_frag_layout = (RelativeLayout) rootView.findViewById(R.id.random_frag_layout);
activityButton = (ImageView) rootView.findViewById(R.id.imagehere);
//setRetainInstance(true);
texthere = (TextView) rootView.findViewById(R.id.texthere);
texthere.setText(strtext);
return rootView;
}
//FragmentCommunicator interface implementation
public void passDataToFragment(String someValue){
activityAssignedValue = someValue;
Log.e("ACTIVITY", activityAssignedValue);
}
}
If you have only one fragment, then you can access it directly and send any data just via method: make your fragment a field and call your passDataToFragment() on it from activity.
To access an activity from fragment, call ((RandomActivity)getActivity()).activityMethod()
What is ActivityCommunicator?
If you wish to go down this route have your RandomActivity class implement the FragmentCommunicator interface, which should either be declared as an inner-public interface in the RandomFragment class say, or publicly (or package local) in its own file.
I've make it more simple and updated it based on the answers in my previous post: Adding Assigned Values in Spinner NullPointerException
I have a MainAcitivty that uses a ViewPager. I have 2 Fragments in my MainActivity (FragA and FragB)
In my FragA I have a spinner. While in FragB, I have a TextView and a Button.
Now what am I trying to do is, when I select "Hello" in my spinner, my int a will have a value of 5. And when I click the Button, 5 will display in the TextView.
Here's my code:
FragA
public class FragA extends Fragment {
Spinner spinner1;
String s1;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fraga, container, false);
spinner1 = (Spinner) view.findViewById(R.id.spinner1);
ArrayAdapter<CharSequence> adapter_a = ArrayAdapter.createFromResource(getActivity(), R.array.spinner1,android.R.layout.simple_spinner_item );
spinner1.setAdapter(adapter_a);
s1 = spinner1.getSelectedItem().toString();
return view;
}
public int getInt() {
int a = 0;
if(s1.equals("Hello")) {
a = 5;
}
return a;
}
}
MainActivity
public class MainActivity extends FragmentActivity {
ViewPager viewPager = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager)findViewById(R.id.pager);
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager.setAdapter(new MyAdapter(fragmentManager));
}
public class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter (FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
Fragment fragment = null;
if (i == 0)
{
fragment = new FragA();
}
if (i == 1)
{
fragment = new FragB();
}
return fragment;
}
#Override
public int getCount() {
return 2;
}
}
public String get() {
FragA FragA = new FragA();
return Integer.toString(FragA.getInt());
}
}
FragB
public class FragB extends Fragment{
TextView textView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragb, container, false);
textView = (TextView) view.findViewById(R.id.textview);
Button button = (Button) view.findViewById(R.id.button);
button.setOnClickListener(Click);
return view;
}
OnClickListener Click = new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(((MainActivity)getActivity()).get());
}
};
}
By the way, I have no problem passing the value of a from FragA to FragB when this is my code:
public int getInt() {
int a = 5;
return a;
}
But, it doesn't involve my spinner and that's not I want to do.
Here is a simple way to communicate between fragments.
In MainActivity, keep static instances of the fragments.
public static FragA fragmentA;
public static FragB fragmentB;
Now if you want to access FragB from FragA, write something similar:
((MainActivity) getActivity()).fragmentB.setSomething();
And Here is a better/proper way to communicate between fragments:
http://developer.android.com/training/basics/fragments/communicating.html