I have a fragment holds a recyclerview and textview so i want to call a method which i declared in the fragment inside the recyclerview adapter because i have a plus button in each recyclerview item so when i click on it the method will being called so the textview which is in the fragment change its value.
Fragment code
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_cart, container, false);
ItemsAddedToCart = view.findViewById(R.id.itemsAddRV);
Total = view.findViewById(R.id.TotalPrice);
fillCart = new FillCart(c,cartList);
ItemsAddedToCart.setAdapter(fillCart);
ItemsAddedToCart.setLayoutManager(new LinearLayoutManager(c));
return view;
}
fragment method
public void updateTotal()
{
Total.setText(fillCart.Total());
}
ADAPTER
adapter method
public String Total()
{
return String.valueOf(price * Qt);
}
plus button
((ViewHodler)holder).plusBut.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
price = Integer.parseInt(((ViewHodler)holder).price.getText().toString());
Qt = Integer.parseInt(((ViewHodler)holder).quantity.getText().toString());
Qt++;`
// FRAGMENT METHOD WILL CALLED HERE
}
});
As Hassan Tareq say:
Use this concept - > https://developer.android.com/training/basics/fragments/communicating
Related
I opened dialog in a fragment and when come back to fragment, my fragment's view is null Object.
when the dialog is displaying which lifecycle method fragment is calling?
public class MyFragment extends Fragment{
TextView textView;
View view;
FloatingActionButton actionButton;
#Override
public View onCreateView(final LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_read, container, false);
textView = view.findViewById(R.id.txtSaved);
actionButton = view.findViewById(R.id.floatingActionButton);
actionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
DialogSearch search = new DialogSearch();
search.show(getActivity().getSupportFragmentManager(),"MyDialog");
}
});
return view;
}
}
The problem is the dialog is being showned in the onCreateView life cycle, that is why is the Fragment view is null. You have to do it inside the onViewCreated method.
#Override
public View onViewCreated(View view, Bundle savedInstanceState) {
//Work here, the view argument in the method is the view inflated in the onCreateView method
});
Make a small change,
public class MyFragment extends Fragment{
TextView textView;
View view;
FloatingActionButton actionButton;
#Override
public View onCreateView(final LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_read, container, false);
textView = view.findViewById(R.id.txtSaved);
actionButton = view.findViewById(R.id.floatingActionButton);
actionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
DialogSearch search = new DialogSearch();
search.show(getActivity().getSupportFragmentManager(),"MyDialog");
}
});
return view; / Add this line -------
}
}
You need to return view
when the dialog is displaying which lifecycle method fragment is calling?
onPause() of fragment gets called.
I created a tabbed app where the main acitvity contains two layouts. The top layout contains the actual tabbar (which is a fragment). Underneth the content layout contains another fragments depending on which tabbar button the user has clicked. In order to stay compatible with older android versions I use android.support.v4.app.Fragment.
So, in the tabbar menu I added two buttons and each button triggers another fragment in the content. This is what the code looks like:
public class TabbarMenuFragment extends Fragment implements View.OnClickListener {
LiveFragment liveFragment;
OddsFragment oddsFragment;
FragmentTransaction fragmentTransaction;
Button liveButton;
Button oddsButton;
public TabbarMenuFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
liveFragment = new LiveFragment();
oddsFragment = new OddsFragment();
fragmentTransaction = getFragmentManager().beginTransaction().add(R.id.content_view, oddsFragment);
fragmentTransaction.commit();
View rootView = (View) inflater.inflate(R.layout.tabbar_menu, container, false);
liveButton = (Button) rootView.findViewById(R.id.liveButton);
liveButton.setOnClickListener(this);
oddsButton = (Button) rootView.findViewById(R.id.oddsButton);
oddsButton.setOnClickListener(this);
return rootView;
}
public void updateUIInTabs() {
liveFragment.updateUI();
}
#Override
public void onClick(View v) {
if(v == liveButton) {
fragmentTransaction = getFragmentManager().beginTransaction().replace(R.id.content_view, liveFragment);
fragmentTransaction.commit();
}
if(v == oddsButton) {
fragmentTransaction = getFragmentManager().beginTransaction().replace(R.id.content_view, oddsFragment);
fragmentTransaction.commit();
}
updateUIInTabs();
}
}
The important thing is that the liveFragment is a Fragment that contains a ListView:
public class LiveFragment extends Fragment {
LiveMainAdapter adapter;
ListView list;
LayoutInflater inflater;
View rootView;
public LiveFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
this.inflater = inflater;
rootView = (View) inflater.inflate(R.layout.live_fragment, container, false);
adapter = new LiveMainAdapter(inflater);
list = (ListView) rootView.findViewById(R.id.live_fragment_ListView);
list.setAdapter(adapter);
list.setDivider(null);
list.setDividerHeight(0);
return rootView;
}
public void updateUI() {
if(list != null) {
list.invalidate();
adapter.createRowObjects();
adapter.notifyDataSetChanged();
}
}
}
The oddsFragment is so far just a dummy with a TextView:
public class OddsFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = (View) inflater.inflate(R.layout.odds_fragment, container, false);
return rootView;
}
}
Now there are two settings which are important:
First:
As described above: I start the app and the oddsFragment is initally shown. Now, when I click on the liveFragment button the liveFragment's ListView is not updated.
Clicking again on the button for oddsFragment the oddsFragment is properly shown. Clicking back to liveFragment I get nothing - no ListView is shown.
The second setting:
Is exactly the same as the first, but instead I set the liveFragment as the intial view that is in TabbarMenuFragment I replace:
fragmentTransaction = getFragmentManager().beginTransaction().add(R.id.content_view, oddsFragment);
with
fragmentTransaction = getFragmentManager().beginTransaction().add(R.id.content_view, liveFragment);
Then the ListView is properly shown and the data in the list view is updated and displayed correctly. However, if I click on oddsFragement and then again on liveFragement the ListView has disappeared.
I already tried different things for over two hours now and I'm pretty desperated because I have not clue what might be the reason for this wired behaviour.
Anybody got an idea what is going on here?
Give this a try...
In your LiveFragment add a Handler and a Runnable and update the UI from your Runnable.
Handler handler = new Handler();
Runnable updater = new Runnable()
{
public void run()
{
if(list != null) {
list.invalidate();
adapter.createRowObjects();
adapter.notifyDataSetChanged();
}
}
};
and then change your updateUI() method in LiveFragment
public void updateUI()
{
handler.post(updater);
}
I have a main activity which consists of spinner + 3 fragments (tabs). I want to access spinner value from fragment. So I wrote this code into onActivityCreated inside my fragment:
final Spinner spinner = (Spinner) getView().findViewById(R.id.spinnerOblasti);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
/*TextView[] vystrahy = new TextView[1];
vystrahy[0] = (TextView) getView().findViewById(R.id.txtVystrahy);
(new htmlParser(vystrahy, 0) ).execute(new Integer[]{spinner.getSelectedItemPosition()});*/
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
but when I run my application spinner throws nullpointerexception. Any ideas on how to access it from fragment?
Here is my onCreateView which I believe is causing problem but I dont know how to fix it:
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_tab1, container, false);
return rootView;
}
Thanks in forward
Doesn't work like that, what do you mean for spinner value? If you want to access to the spinner object you have to setup an interface which will be implemented by your activity and then in onActivityCreated you can call the method of that interface to do something. For example:
public class MyClass implements MyInterface {
public interface MyInterface {
void doSomethingWithSpinner();
}
public void doSomethingWithSpinner() {
mySpinner.setVisibility(View.VISIBLE);
}
}
And your onActivityCreated:
if(getActivity() instanceof MyInterface) {
((MyInterface)getActivity()).doSomethingWithSpinner();
}
What I need to achieve
A screen displaying a ListView, which can be replaced by an error screen in case of problems (missing connection, server unavailable and the like).
I need to be able to switch (programmatically) back and forth between these two screens.
Requirements
The main screen must be a Fragment.
This is because my application is composed of several sections, each one accessible from the navigation drawer.
What I have done so far
The main fragment class is named AllQueuesFragment: its XML layout consists of a FrameLayout, which I use in combination with the FragmentManager to switch between ErrorFragment (containing the error message) and QueuesViewFragment (containing the ListView).
public class AllQueuesFragment extends Fragment
{
public AllQueuesFragment()
{
super();
}
#Override
public void onStart()
{
super.onStart();
// Show the right fragment based on connectivity status
checkConnection();
}
public void checkConnection()
{
final NetworkManager netManager = NetworkManager.getInstance(this.getActivity());
if (netManager.isConnected())
showQueues();
else
showNoConnection();
}
public void showNoConnection()
{
ErrorFragment fragNoConnection = new ErrorFragment();
displayFragment(fragNoConnection);
fragNoConnection.setTitle(R.string.text_no_connection);
fragNoConnection.setIcon(R.drawable.thatfeel);
fragNoConnection.setLoaderVisibility(false);
}
public void showQueues()
{
QueuesViewFragment fragQueuesView = new QueuesViewFragment();
displayFragment(fragQueuesView);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the view
View rootView = inflater.inflate(R.layout.fragment_allqueues, container, false);
return rootView;
}
// Displays a new fragment
public void displayFragment(Fragment fragment)
{
if (fragment != null)
{
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
}
}
}
The error screen is the following:
public class ErrorFragment extends Fragment
{
private TextView textTitle;
public ErrorFragment()
{
super();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the view
View rootView = inflater.inflate(R.layout.fragment_error, container, false);
// Get the widgets
textTitle = (TextView)rootView.findViewById( R.id.fragment_error_text );
return rootView;
}
// Set methods
public void setTitle(int id) { textTitle.setText(id); }
}
The problem
The setTitle() method gets called before the layout is ready, and as a result, a NullPointerException is thrown.
class AllQueuesFragment
{
....
public void displayFragment(Fragment fragment)
{
if (fragment != null)
{
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
}
}
public void showNoConnection()
{
ErrorFragment fragNoConnection = new ErrorFragment();
displayFragment(fragNoConnection);
// PROBLEM HERE: Before calling setTitle(), I must be sure that ErrorFragment's
// layout is inflated!
fragNoConnection.setTitle(R.string.text_no_connection);
}
....
}
class ErrorFragment
{
....
public void setTitle(String value) { textTitle.setText(value); }
....
}
I can't call setTitle() directly from ErrorFragment::onCreateView(), because I don't know beforehand which message I need to show.
How can I ensure that fragNoConnection has completed its layouting?
Is there a better way to achieve my goal?
Unsatisfying workaround
The only workaround I can think of is to use a buffer to defer the actual call:
class ErrorFragment
{
// This string will hold the title until the layout is inflated
private String titleBuffer;
private TextView textTitle = null;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the view
View rootView = inflater.inflate(R.layout.fragment_error, container, false);
// Get the widgets
textTitle = (TextView)rootView.findViewById( R.id.fragment_error_text );
// Do the actual set
setTitle(titleBuffer);
return rootView;
}
....
public void setTitle(String value)
{
titleBuffer = value;
// If the layout is not inflated, defer the actual set
if (textTitle != null)
textTitle.setText(titleBuffer);
}
....
}
but I don't like this solution very much (the code above is simplified; ErrorFragment has more properties).
Advices?
Thanks in advance
This is exactly the type of thing arguments are supposed to be used for:
public void showNoConnection() {
ErrorFragment fragNoConnection = new ErrorFragment();
Bundle args = new Bundle();
//you can also use putInt here if you'd rather pass a string resource id, along with anything else you can stick into a Bundle
args.putString("title", "some title");
fragNoConnection.setArguments(args);
displayFragment(fragNoConnection);
}
Then in ErrorFragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_error, container, false);
TextView textTitle = (TextView)rootView.findViewById( R.id.fragment_error_text );
//now retrieve the argument...
textTitle.setText(getArguments().getString("title"));
return rootView;
}
The Fragment will even remember it's arguments after an orientation change.
If you feel like being pedantic, you can create a static factory method within ErrorFragment that takes the title as an argument and then creates the Fragment and adds the argument, that way you can achieve proper encapsulation :)
You need to have a callback method in your ErrorFragment and when the view is inflated you then call the method in your callback interface in the onViewCreated and set the title.
sample:
in ErroFragment
public class ErroFragment extends Fragment
{
static interface ErrorDone{
public void doneInflating();
}
private TextView textTitle;
private ErrorDone ed;
public ErroFragment()
{
super();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the view
View rootView = inflater.inflate(R.layout.fragment_error, container, false);
// Get the widgets
textTitle = (TextView)rootView.findViewById( R.id.fragment_error_text );
return rootView;
}
// Set methods
public void setTitle(int id) { textTitle.setText(id); }
public void setInterFace(ErrorDone er){ this.ed = er; }
}
Then you implement the interface in your AllQueuesFragment
public class AllQueuesFragment extends Fragment implements ErroFragment.ErrorDone
It will generate method doneInflating
and you need to set the interface:
public void showNoConnection()
{
ErrorFragment fragNoConnection = new ErrorFragment();
displayFragment(fragNoConnection);
fragNoConnection.setInterFace(this);
}
And in the generated method(doneInflating) of the AllQueuesFragment you then set the title in there:
public void doneInflating(){
fragNoConnection.setTitle(R.string.text_no_connection);
fragNoConnection.setIcon(R.drawable.thatfeel);
fragNoConnection.setLoaderVisibility(false);
}
If you want to be sure that the FragmentTransaction is commited and effective, you can use the executePendingTransactions method:
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
fragmentManager.executePendingTransactions();
But, the right way to do it is to send the title value to the Fragment when instantiating it. This is the default pattern when you create a Fragment from your IDE (eclipse or Android Studio)
I have seen Link1 for this issue but could understand it right. I have a fragment that loads a list. When i click the list item it opens another activity. But i press back button it loads the list again. I want it to be at the same scroll position where it was before. In above mentioned link it specifies to use flag but i haven't got the point.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dashboard);
android.app.Fragment fragment = new MeFragment();
getFragmentManager().beginTransaction().replace(R.id.layout_FragmentsContainer, fragment).addToBackStack(null).commit();
}
}
public class MeFragment extends Fragment
{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_me, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
meLV = (ListView) getView().findViewById(R.id.lv_Inbox);
loadingListProgress = (ProgressBar) getView().findViewById(R.id.progress_LoadingList);
meList = new ArrayList<Message>();
meAdapter = new MessagesListAdapter(getActivity(), meList);
//addFooter();
meLV.setAdapter(meAdapter);
meLV.setOnItemClickListener(this);
pageCount = 0;
loadmoreProgressDialog = new ProgressDialog(getActivity());
loadmoreProgressDialog.setTitle("Please wait ...");
loadmoreProgressDialog.setMessage("Loading more ...");
loadmoreProgressDialog.setCancelable(true);
loadUserMessages();
meLV.setOnScrollListener(new EndlessScrollListener() {
#Override
public void onLoadMore(int page, int totalItemsCount) {
// TODO Auto-generated method stub
//addFooter();
loadmoreProgressDialog.show();
loadUserMessages();
}
});
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
Utils.showToast_msg(getActivity(), "MessageItemClicked");
ReferralDetailFragment fragment = new ReferralDetailFragment();
getFragmentManager().beginTransaction().replace(R.id.layout_FragmentsContainer, fragment).addToBackStack(null).commit();
}
}
public class ReferralDetailFragment extends Fragment implements OnClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_referraldetail,container, false);
linkToAcknowledge = (TextView) view.findViewById(R.id.lbl_Link_to_Acknowledge);
return view;
}
}
I implemented a simple solution for this in my app, basically when you press back to go to the fragment again, onCreateView() is called. Here in onCreateView() you have done all initialization, so we change
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_me, container, false);
/*
*Whatever you want to do
*
*/
return view;
}
to:
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
if(view==null){
view = inflater.inflate(R.layout.fragment_me, container, false);
/*
*Whatever you want to do
*
*/
}
else{
((ViewGroup)view.getParent()).removeView(view);
}
return view;
}
Here, we move View view outside and make it a class variable. So if it is the first time the fragment is called, it is null and the initialization occurs, otherwise it goes to else black. Else block is required because onCreateView() adds whatever it returns as a child of the view's parent, so since view is already there, we remove it and onCreateView automatically adds it again.
According to our exchange in the comments, I completely deletde my answer and re-write a new one.
I copy/paste the code from one of my apps and removing the useless things and changing the names. Hope there is not too many typing mistakes, at that it is the minimum required to have it working.
When I pop back to FirstFragment from SecondFragment, the scroll position of FirstFragment is the same as when I clicked an item to load the SecondFragment.
Note that I don't extend FragmentActivity. I have an activity which loads the fragments.
Extend/modify to match your needs.
MainActivity :
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
}
}
FirstFragment Class :
public class FirstFragment extends Fragment implements OnItemClickListener {
private ListView mListView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.first_fragment_layout, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mListView = (ListView) getView().findViewById(R.id.listview_first_fragment);
mListView.setAdapter(mAdapter); // depends on your adapter
mListView.setOnItemClickListener(this);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mListView.setItemChecked(position, true);
//in case you need, set the bundle here, for example pass the position
Bundle arguments = new Bundle();
arguments.putInt("position", position);
SecondFragment secondFragment = new SecondFragment();
secondFragment.setArguments(arguments);
getFragmentManager().beginTransaction().replace(R.id.fragment_container, secondFragment).addToBackStack(null).commit();
}
}
SecondFragment Class :
public class SecondFragment extends Fragment {
private Integer mPosition;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.second_fragment_layout, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Bundle arguments = getArguments();
if (arguments == null) {
mPosition= 0;
} else {
mPosition= arguments.getInt("Position");
}
}
}
What you are trying to achieve may be done with help of savedInstanceState. i also had this kind of problem which i resolved by using add() method instead of replace() in transition.
If you can change your method or already not using add() than give it a shot.
and if add() method didn't do the trick then check the implementation of savedInstanceState.
correctly save instance state.
How to save states of fragment views.