I have a main activity which contains the action bar with 3 menu buttons in it.
I then have a fragment within this main activity which has a list.
I would like to be able to refresh the list in the fragment from the main activity, when one of the menu buttons is clicked, or preferably just removed all the rows from the list.
Any help is appreciated.
Thanks.
public class Favourite extends SherlockFragmentActivity {
ActionBar actionBar;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.favourite);
actionBar = getSupportActionBar();
actionBar.setDisplayShowTitleEnabled(false);
BitmapDrawable bg = (BitmapDrawable)getResources().getDrawable(R.drawable.actionbar_bg);
bg.setTileModeX(TileMode.REPEAT);
getSupportActionBar().setBackgroundDrawable(bg);
getSupportActionBar().setIcon(R.drawable.favourite_title);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.Tab tabAll = actionBar.newTab();
ActionBar.Tab tabfavs = actionBar.newTab();
ActionBar.Tab tabhist = actionBar.newTab();
tabAll.setText("all");
tabfavs.setText("favs");
tabhist.setText("hist");
tabAll.setTabListener(new MyTabListener());
tabfavs.setTabListener(new MyTabListener());
tabhist.setTabListener(new MyTabListener());
actionBar.addTab(tabAll);
actionBar.addTab(tabfavs);
actionBar.addTab(tabhist);
try{
}
catch(Exception e)
{
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getSupportMenuInflater();
inflater.inflate(R.menu.actionbar_itemlist_favourite, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case R.id.history:
break;
case R.id.favourite:
Intent favAct = new Intent(this, Favourite.class);
startActivity(favAct);
break;
case R.id.delete:
///I WANT TO BE ABLE TO REFRESH FRAGMENTLIST FROM HERE
}
return true;
}
}
class MyTabListener implements ActionBar.TabListener {
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if(tab.getPosition()==0)
{
FavouriteAllWords frag = new FavouriteAllWords();
ft.replace(android.R.id.content, frag);
}
else if(tab.getPosition()==1)
{
FavouriteFavWords frag = new FavouriteFavWords();
ft.replace(android.R.id.content, frag);
}
else if(tab.getPosition()==2)
{
FavouriteHistWords frag = new FavouriteHistWords();
ft.replace(android.R.id.content, frag);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
}
////////////////////MY LIST FRAGMENT CLASS
public class FavouriteAllWords extends ListFragment {
ArrayAdapter<String> adapter;
List<String> stringOfFavWords;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup group, Bundle saved)
{
adapter = new ArrayAdapter<String>(
inflater.getContext(), R.layout.row, stringOfFavWords);
setListAdapter(adapter);
return super.onCreateView(inflater, group, saved);
}
#Override
public void onActivityCreated (Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
}
}
You can easily achieve this using 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;
}
}
Just make your update/refresh method public and call it from your Activity.
OR
Use LocalBroadcastManager or EventBus to send event from your Activity, and by subscribing to this event in a Fragment - react to it and call refresh/update method.
Your activity can call methods in the fragment by acquiring a reference to the Fragment.
(1) Provide a tag when you add your fragment.
transaction.add(R.id.fragment_container, myFragment, "myfragmentTag");
(2) In your hosting activity you can find the fragment and have access to it's methods.
FragmentManager fm = getSupportFragmentManager();
myFragment f = (myFragment) fm.findFragmentByTag("myfragmentTag");
f.refreshAdapter()
(3) refreshAdapter() could now call adapter.notifyDataSetChanged().
This is one of the recommended ways to communicate up to a fragment.
The interface implementation is mainly for communicating back to the activity.
Biraj Zalavadia's answer is 100% right, you will call nay fragment methods from using interface....
this interface methods is running without error...
use this in MainActivity above oncreate
private FragmentRefreshListener fragmentRefreshListener;
public FragmentRefreshListener getFragmentRefreshListener() {
return fragmentRefreshListener;
}
public void setFragmentRefreshListener(
FragmentRefreshListener fragmentRefreshListener) {
this.fragmentRefreshListener = fragmentRefreshListener;
}
inside of Activity
private void refreshcall(String result2) {
// TODO Auto-generated method stub
if (getFragmentRefreshListener() != null) {
getFragmentRefreshListener().onRefresh(result2);
}
}
and put this in needed Fragment
private FragmentRefreshListener fragmentRefreshListener;
public FragmentRefreshListener getFragmentRefreshListener() {
return fragmentRefreshListener;
}
public void setFragmentRefreshListener(
FragmentRefreshListener fragmentRefreshListener) {
this.fragmentRefreshListener = fragmentRefreshListener;
}
Communicating with Other Fragments
http://developer.android.com/training/basics/fragments/communicating.html
This can also be used to communicate between an Activity and a Fragment.
When you click on ActionBar any Button then call interface to refresh the ListFragment. Because in java interface is used for inter-communication.
In Kotlin
Get the list of Support Fragment from the activity and check Instance and then call fragment function
val fragments = supportFragmentManager.fragments
for (fragment in fragments) {
if (fragment is HomeCategoriesFragment) {
fragment.updateAdapter() // Define function in Fragment
}
}
Related
I am using tabs to switch between different lists in my app. When a user touches an item in a list, the following is the code to show and hide the detail. I am wondering how to add a back-button that goes back to the correct list it came from. I am replacing fragments so I don't know if the standard back button works in my case?
public class MainActivity extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListener,
TabLayout.OnTabSelectedListener,
CustomerFragment.CustomerListListener,
CustomerDetailListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ActionBar actionBar = getSupportActionBar();
actionBar.setHomeButtonEnabled(true);
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setDisplayShowHomeEnabled(true);
}
public void onShowCustomerDetail(Customer customer){
HostFragment hostFragment = (HostFragment) customPagerAdapter.getItem(viewPager.getCurrentItem());
CustomerDetailFragment fragment = CustomerDetailFragment.newInstance(customer);
hostFragment.replaceFragment(fragment, true);
}
public void onCloseCustomerDetail() {
HostFragment hostFragment = (HostFragment) customPagerAdapter.getItem(viewPager.getCurrentItem());
CustomerFragment fragment = new CustomerFragment();
hostFragment.replaceFragment(fragment, true);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// just for testing. will do switch case here
onBackPressed();
}
#Override
public void onBackPressed() {
if (getFragmentManager().getBackStackEntryCount() > 0) {
getFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
}
}
CustomPagerAdapter:
public class CustomPagerAdapter extends FragmentStatePagerAdapter {
private final List<String> tabTitles = new ArrayList<String>() {{
add("Messages");
add("Customers");
add("Jobs");
add("Maps");
}};
private List<Fragment> tabs = new ArrayList<>();
public CustomPagerAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
initializeTabs();
}
private void initializeTabs() {
tabs.add(HostFragment.newInstance(new MessageFragment()));
tabs.add(HostFragment.newInstance(new CustomerFragment()));
tabs.add(HostFragment.newInstance(new JobFragment()));
tabs.add(HostFragment.newInstance(new MapFragment()));
}
#Override
public Fragment getItem(int position) {
return tabs.get(position);
}
#Override
public int getCount() {
return tabs.size();
}
#Override
public CharSequence getPageTitle(int position) {
return tabTitles.get(position);
}
}
HostFragment:
public class HostFragment extends BackStackFragment {
private Fragment fragment;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragment_host, container, false);
if (fragment != null) {
replaceFragment(fragment, false);
}
return view;
}
public void replaceFragment(Fragment fragment, boolean addToBackstack) {
if (addToBackstack) {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).addToBackStack(null).commit();
} else {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).commit();
}
}
public static HostFragment newInstance(Fragment fragment) {
HostFragment hostFragment = new HostFragment();
hostFragment.fragment = fragment;
return hostFragment;
}
}
Because of the way I set up my fragments inside tabs using Child Fragment Manager, I had to do this in my onBackPressed to make it work:
#Override
public void onBackPressed() {
HostFragment hostFragment = (HostFragment) customPagerAdapter.getItem(viewPager.getCurrentItem());
FragmentManager fm = hostFragment.getChildFragmentManager();
if (fm.getBackStackEntryCount() > 0) {
fm.popBackStack();
} else {
super.onBackPressed();
}
}
First of all you need to add fragments in backstack while using it
see below code for creating a fragment and adding inside it to backstack
public final static String TAG_FRAGMENT = "HostFragment"; // used inside every fragment
final HostFragment fragment = new HostFragment();
final FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment, fragment, TAG_FRAGMENT);
transaction.addToBackStack(TAG_FRAGMENT);
transaction.commit();
After that inside activity onBackPressed() you need to pop fragment every backpressed that you want.
#Override
public void onBackPressed() {
if (getFragmentManager().getBackStackEntryCount() > 0) {
getFragmentManager().popBackStack(); // pop fragment here
} else {
super.onBackPressed(); // after nothing is there default behavior of android works.
}
}
All you need to do is add the fragment to the back stack when you create your fragment. It would look something like this:
CustomerDetailFragment fragment=CustomerDetailFragment.newInstance(customer);
getFragmentManager().beginTransaction()
.addToBackStack("Fragment Tag")
.replace(R.id.yourContainer, fragment, "Fragment Tag")
.commit();
Once you have this, you can just use the home back button to pop the fragments off the stack. If you want to use a custom button to go back, you would have to implement your own popping of the stack, which would call getFragmentManager().popBackStack();
Write a fuction onBackpress()
#Override
public void onBackPressed() {
new AlertDialog.Builder(this)
.setTitle("Exit?")
.setMessage("Do you really want to exit?")
.setNegativeButton("No")
.setPositiveButton("Yes", new OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
YourActivityname.super.onBackPressed();
}
}).create().show();
}
Hello I'm developing an android app using 3 Fragments (Fragment A, B, C) inside viewpager and tabs, the viewpager works fine. The fragment A contains a List View, when the user clicks a item, the app open a Fragment Dialog with information about the item selected. This dialog has a button called "Add to favorites". Now I want to do this when user press button:
close the fragment dialog
show the fragment B inside the view pager
send the information from dialog fragment to fragment B
How can I do this?
This is part of my code:
* MainFragmentActivity * (This works fine)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tube);
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
FragmentA a = new FragmentA();
Bundle args1 = new Bundle();
args1.putInt(FragmentA.ARG_SECTION_NAME , position + 1);
a.setArguments(args1);
return a;
case 1:
FragmentB b= new FragmentB();
Bundle args2 = new Bundle();
args2.putInt(FragmentB.ARG_SECTION_NAME , position + 2);
b.setArguments(args2);
return b;
case 2:
FragmentC c= new FragmentC();
Bundle args3 = new Bundle();
args3.putInt(FragmentC.ARG_SECTION_NAME , position + 3);
c.setArguments(args3);
return c;
default:
return null;
}
}
This is the Fragment Dialog
* FragmentDialogView *
public class FragmentDialogView extends DialogFragment implements OnClickListener {
private static final int REAUTH_ACTIVITY_CODE = 0;
private String videoId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Bundle mArgs = getArguments();
View view = (View) inflater.inflate(R.layout.fragment_dialog_view, container, false);
//Buttons
Button button = (Button) view.findViewById(R.id.button_one);
button.setOnClickListener(this);
buttonDownload.setOnClickListener(this);
return view;
}
#Override
public void onSaveInstanceState(Bundle bundle) {
super.onSaveInstanceState(bundle);
}
#Override
public void onResume() {
super.onResume();
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REAUTH_ACTIVITY_CODE) {
}
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button_one:
//Here it should show the fragment B inside the viewpager
break;
default:
break;
}
}
}
To dismiss the Dialog include the following in your DialogFragment's class
private Dialog dialog;
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
dialog = new Dialog(getActivity());
return dialog;
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button_one:
dismiss();
break;
default:
break;
}
}
And create a interface
Create the following Communicator.java
public interface Communicator {
public void respond(int i);
}
Implement this Communicator in your MainAcitvity
And create a instance of this Communicator in your fragment like this
public class FragmentDialogView extends DialogFragment implements OnClickListener {
private Communicator com;
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
com = (Communicator) getActivity();
btn.setOnClickListener(this);
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn:
com.respond(1);
break;
}
}
Whenever you click that button it sends the int to the method which is residing inside the MainActivity
which will look like following
#Override
public void respond(int i) {
// Receive a bundle here
// and pass the corresponding information to the FragmentB
// here i'm receving an int and pass it to the FragmentB as a String
FragmentManager fm = getFragmentManager();
FragmentB fragment = (FragmentB) fm.findFragmentByTag("FragmentB");
fragment.fromMainActivity(""+i);
// If the above the one doesn't work keep the instance as Static and then try
viewPager.invalidate();
pagerAdapter.notifyDataSetChanged();
viewPager.setCurrentItem(1, true);
// Inside the setCuttentItem() method 0 first tab
// 1 second tab
// 2 third tab and so on
}
Here I'm receiving an int . You can use a bundle to pass the corresponding information. This will change the viewPager to show the next tab as well
and keep any simple method insdie the FragmentB like the following
public void fromMainActivity(String sample) {
Toast.makeText(getActivity(), sample, duration).show();
}
I hope this would help :) Happy coding
1.Try this : getDialog().dismiss();
2.As I understood correctly, create a method like this in your fragment ,
public static FirstFragment newInstance(String text){
FirstFragment f= new FirstFragment();
return f;
}
Call it in your button onClick() such as FirstFragment.newInstance("Fragment, Instance 1");
3.Create Interface with the method in your DialogFragment can call to pass any data you want back to Fragment that created said DialogFragment. Also set your Fragment as target such as myFragmentDialog.setTargetFragment(this, 0). Then in dialog, get your target fragment object with getTargetFragment() and cast to interface you created. Now you can pass the data using ((MyInterface)getTargetFragment()).methodToPassData(data).
For more info : link
I am trying to attach ActionBar Tabs to respect fragment, But it is not working. I don't no where i am getting wrong.
Here is my FragmentActivity
public class MainActivity extends FragmentActivity implements TabListener {
String cPlusPlusFrag = "CPP", javaFrag = "Java";
CPlusPlusFragment cPlusPlusFragment;
JavaFragment javaFragment;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar mAction = getActionBar();
mAction.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
createTab(mAction, cPlusPlusFrag);
createTab(mAction, javaFrag);
}
public void createTab(ActionBar mActionBar, String tabName) {
Tab tab = mActionBar.newTab();
tab.setText(tabName);
tab.setTabListener(this);
mActionBar.addTab(tab);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(this, tab.getText() + "Re-Selected", Toast.LENGTH_LONG)
.show();
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (cPlusPlusFrag.equals(tab.getText())) {
if (cPlusPlusFragment == null) {
cPlusPlusFragment = new CPlusPlusFragment();
ft.add(android.R.id.content, cPlusPlusFragment);
}
} else if (javaFrag.equals(tab.getText())) {
if (javaFragment == null) {
javaFragment = new JavaFragment();
ft.add(android.R.id.content, javaFragment);
}
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(this, tab.getText() + " Un-Selected", Toast.LENGTH_LONG)
.show();
if (cPlusPlusFrag.equals(tab.getText().toString())) {
ft.detach(cPlusPlusFragment);
} else if (javaFrag.equals(tab.getText().toString())) {
ft.detach(javaFragment);
}
}
}
Java Fragment code.
public class JavaFragment extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View viewToInflate = inflater.inflate(R.layout.java_frag_layout,
container);
return viewToInflate;
};
}
C++ Fragment code.
public class CPlusPlusFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View viewToInflate = inflater.inflate(R.layout.cplusplus_frag_layout,
container);
return viewToInflate;
}
}
The Problem is in
methods: onTabSelected, onTabUnSelected
and variables: cPlusPlusFragment and javaFrag (You did not Declared/Created them anywhere)
*Solution*
// The following variables are at Class level (data members)
String cPlusPlusFragment = "C++";
String javaFrag = "Java"
// Pass them in the method createTab accordingly
createTab(mActionBar, cPlusPlusFragment);
createTab(mActionBar, javaFrag);
// Modify you onTabSelected and onTabUnselected methods as follows:
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (cPlusPlusFrag.equals(tab.getText().toString)) {
if (cPlusPlusFragment == null) {
cPlusPlusFragment = new CPlusPlusFragment();
// No need to Create custom FragmentTransaction, use
// one that is passed in the argument
ft.add(android.R.id.content, cPlusPlusFragment);
} else {
ft.attach(cPlusPlusFragment);
}
} else if (javaFrag.equals(tab.getText().toString)) {
if (javaFragment == null) {
javaFragment = new JavaFragment();
ft.add(android.R.id.content, javaFragment);
} else {
ft.attach(javaFragment);
}
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(this, tab.getText() + " Un-Selected", Toast.LENGTH_LONG)
.show();
if (cPlusPlusFrag.equals(tab.getText().toString)) {
ft.detach(cPlusPlusFragment);
} else if (javaFrag.equals(tab.getText().toString)) {
ft.detach(javaFragment);
}
}
I am 100 % sure that this will solve your problem :)
I see nothing wrong in you code at first sight apart from the fact that you are not commiting your fragment changes.
EveryTime you call to getFragmentManager().beginTransaction(). you have to call .commit() at the end of the line like this:
getFragmentManager().beginTransaction().replace(R.id.main_layout, javaFragment).commit();
Hope it helps :)
Dears,
I searched for this issue for more than a day but with no luck.
I implement exactly the code posted here:
Adding Navigation Tabs
My code for onTabSelected look like:
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(R.id.alert_fragment_container, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
// prepare adapter for ExpandableListView
Log.i("After Adapter Created", "Passed");
final ExpandableListAdapter expListAdapter = new AlertsAdapter(
mActivity, myAlerts, violations);
Log.i("After Adapter Initialized", "Passed");
((MyCustomFragment)mFragment).violations.setAdapter(expListAdapter);
}
The code is working fine till last line, where I need to set the adapter for public static list initialized in MyCustomFragment in onCreateView, here my code for fragment:
public class MyCustomFragment extends Fragment {
public MyCustomFragment() {
}
public static ExpandableListView violations;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_alerts_poi, container, false);
violations = (ExpandableListView) rootView.findViewById(R.id.POIAlertList);
Log.i("onCreateView POI", "Called");
return rootView;
}
}
It give Null pointer error. With my debugging logs, I notice that this log Log.i("onCreateView POI", "Called"); appears after this Log.i("After Adapter Initialized", "Passed");. This means that I'm trying to set the adapter for a fragment isn't initialized yet.
This is the exact problem I'm face, I need to fed the ExpandableListView with data based on Tab selection in onTabSelected.
What I'm doing wrong? What is the best solution?
Regards,
It seems that you need a ViewPager, I just implemented a navigation tabs few days ago, here is my code, it navigates between 4 fragments:
public class MainActivity extends FragmentActivity implements ActionBar.TabListener{
private ActionBar actionBar;
private ViewPager mViewPager;
private AppSectionsPagerAdapter mAppSectionsPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
actionBar=getActionBar();
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAppSectionsPagerAdapter);
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.icon1).setTabListener(this));
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.icon2).setTabListener(this));
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.icon3).setTabListener(this));
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.icon4).setTabListener(this));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// TODO Auto-generated method stub
getMenuInflater().inflate(R.menu.action_menu, menu);
return true;
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
And here is the adapter:
public class AppSectionsPagerAdapter extends FragmentPagerAdapter {
public AppSectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new Fragment1();
case 1:
return new Fragment2();
case 2:
return new Fragment3();
case 3:
return new Fragment4();
}
return null;
}
#Override
public int getCount() {
return 4;
}
}
Have a look # this Tablayout.onTabselected for latest API updates. ActionBar.TabListener is a old implementation.
Hi I have a problem with tab+fragment, here frist I have the class which will create the tab:
public class TestSwipeABActivity extends FragmentActivity {
FragmentTransaction transaction;
static ViewPager mViewPager;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Fragment tabOneFragment = new TabOne();
Fragment tabTwoFragment = new TabTwo();
PagerAdapter mPagerAdapter = new PagerAdapter(getSupportFragmentManager());
mPagerAdapter.addFragment(tabOneFragment);
mPagerAdapter.addFragment(tabTwoFragment);
//transaction = getSupportFragmentManager().beginTransaction();
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mPagerAdapter);
mViewPager.setOffscreenPageLimit(2);
mViewPager.setCurrentItem(0);
mViewPager.setOnPageChangeListener(
new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// When swiping between pages, select the
// corresponding tab.
getActionBar().setSelectedNavigationItem(position);
}
});
ActionBar ab = getActionBar();
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Tab tab1 = ab.newTab().setText("Tab One").setTabListener(new TabListener<TabOne>(
this, "tabone", TabOne.class));
Tab tab2 = ab.newTab().setText("Tab Two").setTabListener(new TabListener<TabTwo>(
this, "tabtwo", TabTwo.class));
ab.addTab(tab1);
ab.addTab(tab2);
}
public static class TabListener<T extends Fragment> implements ActionBar.TabListener {
private Fragment mFragment;
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
/** Constructor used each time a new tab is created.
* #param activity The host Activity, used to instantiate the fragment
* #param tag The identifier tag for the fragment
* #param clz The fragment's Class, used to instantiate the fragment
*/
public TabListener(Activity activity, String tag, Class<T> clz) {
mActivity = activity;
mTag = tag;
mClass = clz;
}
/* The following are each of the ActionBar.TabListener callbacks */
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// User selected the already selected tab. Usually do nothing.
}
public void onTabReselected(Tab arg0,
android.app.FragmentTransaction arg1)
{
// TODO Auto-generated method stub
}
public void onTabSelected(Tab arg0, android.app.FragmentTransaction arg1)
{
// TODO Auto-generated method stub
mViewPager.setCurrentItem(arg0.getPosition());
}
public void onTabUnselected(Tab arg0,
android.app.FragmentTransaction arg1)
{
// TODO Auto-generated method stub
}
}
public class PagerAdapter extends FragmentPagerAdapter {
private final ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
public PagerAdapter(FragmentManager manager) {
super(manager);
}
public void addFragment(Fragment fragment) {
mFragments.add(fragment);
notifyDataSetChanged();
}
#Override
public int getCount() {
return mFragments.size();
}
#Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
}
}
And then here is the fragment for each tab, for example the two one:
public class TabTwo extends Fragment
{
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.tabtwo, container, false);
Button Activity1= (Button) view.findViewById(R.id.button1);
Activity1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent intent = new Intent().setClass(this,ABActivity.class);
startActivity(intent);
}
});
return view;
}
}
The error was: The method setClass(Context, Class<?>) in the type Intent is not applicable for the arguments (new View.OnClickListener(){},
Class<ABActivity>)
I try out changing the context to TabTwo.this, tabtwo.getcontext.this, but nothing, eclipse says to change .setclassName but doesnt work.
If you could help... THANKS!!!
Try this
Intent intent = new Intent(getActivity(),ABActivity.class);
startActivity(intent );
HI I just have a solution:
public void onClick(View view) {
Activity activity = getActivity();
Intent intent = new Intent().setClass(activity, ABActivity.class);
startActivity(intent);
}
Explanation: "Another difference is that a Fragment is not a subclass of Context. This means that a Fragment can not be launched as a component inside your app and therefore always has to live inside of an Activity. This also means that whenever you need a Context inside of a Fragment, you need to get access to the parent Activity. You can do this by using the getActivity() method as we have done in the Fragment button's OnClickListener callback. You need to watch out because getActivity() can return null depending on where the Fragment is in the Activity's lifecycle. So, you should also include a check to see if the Activity is null before you use it."
FROM: http://neilgoodman.net/2012/01/29/working-with-fragments-on-android-part-1/