Develop Reference

Understanding getItem() in FrameStatePagerAdapter

I'm trying to implement sliding tabs in my app following online tutorials. Particularly this one.
What I want to achieve is:
A MainActivity with Sliding Tabs based on a single Fragment. Each tab showing different data. For this I'm trying to get the current position of the tab selected in my fragment but I don't seem to get the correct value. I'm aware of the function that getItem() is called a number of times and sometimes isn't called at all.
So how do I get the current position of the tab selected in fragment? The tutorial I linked passes the position value with the return statement of getItem() but that doesn't seem to be working quite well as I'm getting different value in log and setText.
getItem()
#Override
public Fragment getItem(int position) {
return PageFragment.newInstance(position + 1);
}
PageFragment:
public static PageFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
Position value difference:

I've run into a similar issue and I decided to just completely change the "default" PagerAdapter so that I wouldn't have to mess around with the position myself:
/**
* TabsPagerAdapter.
*
* #author Niels
* #version 1.0
* #since 11-9-2015
*/
public class TabsPagerAdapter extends FragmentPagerAdapter {
/**
* Contains all the fragments.
*/
private List<Fragment> fragments = new ArrayList<>();
/**
* Contains all the tab titles.
*/
private List<String> tabTitles = new ArrayList<>();
/**
* Creates a new PagerAdapter instance.
*
* #param fragmentManager The FragmentManager.
*/
public TabsPagerAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
}
#Override
public int getCount() {
return fragments.size();
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public CharSequence getPageTitle(int position) {
return tabTitles.get(position);
}
/**
* Adds the fragment to the list, also adds the fragment's tab title.
*
* #param fragment New instance of the Fragment to be associated with this tab.
* #param tabTitle A String containing the tab title for this Fragment.
*/
public void addFragment(Fragment fragment, String tabTitle) {
fragments.add(fragment);
tabTitles.add(tabTitle);
}
}
You can use this as such:
#Override
public void onCreate() {
adapter = new TabsPagerAdapter(getSupportFragmentManager()); //TabsPagerAdapter = whatever you named the PagerAdapter
addFragments();
viewpager.setAdapter(adapter); //viewpager = ViewPager view instance
strip.setViewPager(viewpager); //strip = PagerSlidingTabStrip view instance
}
/**
* Adds fragments to the adapter.
*/
private void addFragments() {
adapter.addFragment(new Fragment1(), "Fragment1");
adapter.addFragment(new Fragment2(), "Fragment2");
adapter.addFragment(new Fragment3(), "Fragment3");
adapter.addFragment(new Fragment4(), "Fragment4");
}

FragmentListView with Actionbar Tabs and Pager

I am attempting to get a list fragment working within the template generated by android studio for tabs and swiping between them.
The symptoms are that the fragment gets executed once at the start of the activity but never again if the tab is changed.
It never shows up contents (whether start of activity or otherwise).
The boilerplate code is as so:
package com.responseapp.android.activity;
import java.util.Locale;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v13.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.responseapp.android.R;
public class TestActivity extends Activity implements ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {#link android.support.v13.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test2);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
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(getFragmentManager());
// 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 each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.test, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#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) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.newInstance(position + 1);
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_test2, container, false);
return rootView;
}
}
}
I have done the following to little success:
package com.responseapp.android.ui;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import com.activeandroid.ActiveAndroid;
import com.responseapp.android.R;
import com.responseapp.android.model.Trip;
import com.responseapp.android.ui.authorisation.LoginActivity;
import com.responseapp.android.ui.trips.CreateTripActivity;
import java.util.Locale;
import uk.co.senab.actionbarpulltorefresh.library.ActionBarPullToRefresh;
import uk.co.senab.actionbarpulltorefresh.library.PullToRefreshLayout;
public class HomeActivity extends Activity implements ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
private static final String STATE_SELECTED_NAVIGATION_ITEM = "selected_navigation_item";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
ActiveAndroid.initialize(this);
SharedPreferences sharedPref = getSharedPreferences("com.responseapp.app.SHARED", 0);
boolean loggedIn = sharedPref.getBoolean("LOGGED_IN", false);
if (!loggedIn) {
Intent intent = new Intent(this, LoginActivity.class);
startActivity(intent);
finish();
}
// Set up the action bar.
final ActionBar actionBar = getActionBar();
if (actionBar != null) {
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
}
// Create the adapter that will return a fragment for each of the
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
getActionBar().setTitle("Response");
// 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) {
if (actionBar != null) {
actionBar.setSelectedNavigationItem(position);
}
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.home, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_logout) {
SharedPreferences sharedPref = getSharedPreferences("com.responseapp.app.SHARED", 0);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putBoolean("LOGGED_IN", false);
editor.commit();
Intent intent = new Intent(this, LoginActivity.class);
startActivity(intent);
finish();
return true;
}
if (id == R.id.action_new_trip) {
Intent intent = new Intent(this, CreateTripActivity.class);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Called when a tab enters the selected state.
*
* #param tab The tab that was selected
* #param ft A {#link android.app.FragmentTransaction} for queuing fragment operations to execute
* during a tab switch. The previous tab's unselect and this tab's select will be
* executed in a single transaction. This FragmentTransaction does not support
*/
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
System.out.println("FRAGMENT TAPPED!");
}
/**
* Called when a tab exits the selected state.
*
* #param tab The tab that was unselected
* #param ft A {#link android.app.FragmentTransaction} for queuing fragment operations to execute
* during a tab switch. This tab's unselect and the newly selected tab's select
* will be executed in a single transaction. This FragmentTransaction does not
*/
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
}
/**
* Called when a tab that is already selected is chosen again by the user.
* Some applications may use this action to return to the top level of a category.
*
* #param tab The tab that was reselected.
* #param ft A {#link android.app.FragmentTransaction} for queuing fragment operations to execute
* once this method returns. This FragmentTransaction does not support
*/
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
String type = position == 0 ? "all" : "managed";
System.out.println("GOT THIS FAR");
return TripListFragment.newInstance(type);
}
#Override
public int getCount() {
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.all_trips_title).toUpperCase(l);
case 1:
return getString(R.string.managed_trips_title).toUpperCase(l);
}
return null;
}
}
/**
* A trip list fragment containing a simple view.
*/
public static class TripListFragment extends Fragment implements AdapterView.OnItemClickListener {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_TYPE = "all";
/**
* The fragment's ListView/GridView.
*/
private AbsListView mListView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
private PullToRefreshLayout mPullToRefreshLayout;
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static TripListFragment newInstance(String sectionType) {
TripListFragment fragment = new TripListFragment();
Bundle args = new Bundle();
args.putString(ARG_SECTION_TYPE, sectionType);
fragment.setArguments(args);
return fragment;
}
public TripListFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
System.out.println("BEING CALLED");
if(ARG_SECTION_TYPE == "all") {
mAdapter = new ArrayAdapter<Trip.TripItem>(getActivity(),
android.R.layout.two_line_list_item, android.R.id.text1, Trip.getAllAsItems(0));
} else {
mAdapter = new ArrayAdapter<Trip.TripItem>(getActivity(),
android.R.layout.two_line_list_item, android.R.id.text1, Trip.getManagedAsItems(0));
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_triplist, container, false);
mPullToRefreshLayout = new PullToRefreshLayout(container.getContext());
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
mListView.setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
System.out.println("VIEW:"+view.toString());
return view;
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Trip.TripItem trip = (Trip.TripItem) parent.getItemAtPosition(position);
HomeActivity.onFragmentInteraction(1, trip.id);
}
}
private static void onFragmentInteraction(int i, int id) {
}
}
The difference being the fragment class embedded in the main class.
In the boilerplate:
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_test2, container, false);
return rootView;
}
}
In my code:
/**
* A trip list fragment containing a simple view.
*/
public static class TripListFragment extends Fragment implements AdapterView.OnItemClickListener {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_TYPE = "all";
/**
* The fragment's ListView/GridView.
*/
private AbsListView mListView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
private PullToRefreshLayout mPullToRefreshLayout;
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static TripListFragment newInstance(String sectionType) {
TripListFragment fragment = new TripListFragment();
Bundle args = new Bundle();
args.putString(ARG_SECTION_TYPE, sectionType);
fragment.setArguments(args);
return fragment;
}
public TripListFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
System.out.println("BEING CALLED");
if(ARG_SECTION_TYPE == "all") {
mAdapter = new ArrayAdapter<Trip.TripItem>(getActivity(),
android.R.layout.two_line_list_item, android.R.id.text1, Trip.getAllAsItems(0));
} else {
mAdapter = new ArrayAdapter<Trip.TripItem>(getActivity(),
android.R.layout.two_line_list_item, android.R.id.text1, Trip.getManagedAsItems(0));
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_triplist, container, false);
mPullToRefreshLayout = new PullToRefreshLayout(container.getContext());
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
mListView.setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
System.out.println("VIEW:"+view.toString());
return view;
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Trip.TripItem trip = (Trip.TripItem) parent.getItemAtPosition(position);
HomeActivity.onFragmentInteraction(1, trip.id);
}
}
Any help would be greatly appreciated.

Application won't start

For some reason, the project that I've just begun, seems to get on my nerves. I obviously don't know why, my application won't run. Here's my MainActivity's code:
package com.example.testarearg;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends FragmentActivity {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
}
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/ private String mText; // display this text in your fragment
public static Fragment getInstance(String text) {
Fragment f = new Fragment();
Bundle args = new Bundle();
args.putString("text", text);
f.setArguments(args);
return f;
}
public void onCreate(Bundle state) {
super.onCreate(state);
setmText(getArguments().getString("text"));
// rest of your code
}
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy, container, false);
TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
public String getmText() {
return mText;
}
public void setmText(String mText) {
this.mText = mText;
}
}
}
And here's a screenshot of my logcat's log. http://s23.postimg.org/imxwv32ez/5555.jpg

You have a NullPointerException at this line :
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
because mSectionsPagerAdapter is never initialized in your code

The problem is NullPointerException. mSectionsPagerAdapter is null. You need to initialize it before using.

mSectionsPagerAdapter.getCount()
Returns null as you never initialized mSectionsPagerAdapter to anything

Tabs and Swipe - editing the getItem to display 3 different fragments

I have been at this for about 3 days looking up various websites for reference, but I am stuck. I am using the swipe and tabs layout which give you the standard dummy section fragment. But I have 3 separate fragments that I want to display different .xml layouts for. This is the section of code that is bothering me:
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
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 each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#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 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) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Fragment fragment2 = new DummySectionFragment2();
Fragment fragment3 = new DummySectionFragment3();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
args.putInt(DummySectionFragment2.ARG_SECTION_NUMBER, position + 2);
args.putInt(DummySectionFragment3.ARG_SECTION_NUMBER, position + 3);
fragment.setArguments(args);
fragment2.setArguments(args);
fragment3.setArguments(args);
return fragment2;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
public static class DummySectionFragment2 extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment2() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView2 = inflater.inflate(R.layout.fragment_2, container, false);
return rootView2;
}
}
public static class DummySectionFragment3 extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number_3";
public DummySectionFragment3() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView3 = inflater.inflate(R.layout.fragment_3, container, false);
return rootView3;
}
}
}
This returns fragment 2. I want to display 3 fragments when each tab is selected. How do I do it? I'm guessing that it's what is returning right?
edit.. ive included the whole java class.. in the hope i can resove this.. How do I use FragmentPagerAdapter to have tabs with different content? ive just tried the following (Second Answer as i didnt understnd what was meant in the first) it didnt work

Use the method this way:
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
switch (position) {
case 0:
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(fragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
case 1:
Fragment fragment2 = new DummySectionFragment2();
Bundle args = new Bundle();
args.putInt(fragment2 .ARG_SECTION_NUMBER, position + 2);
fragment2.setArguments(args);
return fragment2;
case 2:
Fragment fragment3 = new DummySectionFragment3();
Bundle args = new Bundle();
args.putInt(fragment3.ARG_SECTION_NUMBER, position + 3);
fragment3.setArguments(args);
return fragment3;
default:
return null;
}
}

How to add class with listview to a viewpager

I'm very new to Android, so forgive me if this is a terrible question, but I've searched high and low and I've been reading lots of material and can't seem to figure this out. I've created an app in Eclipse using one of the default views (fixed tabs + swipe). I created a second class with a listview and I'm trying to add this class to load in one of the tabs.
EDIT to include full MainActivity.java
package com.sonnyparlin.gracietampa;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
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 each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#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 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) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView;
if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) {
rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Html.fromHtml(getString(R.string.page1text)));
} else if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) {
// I want to add my listview here
} else {
rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
}
return rootView;
}
}
}
My TechniqueActivity.java file:
public class TechniqueActivity extends ListActivity{
public TechniqueActivity() {
// TODO Auto-generated constructor stub
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// storing string resources into Array
String[] technique_list = getResources().getStringArray(R.array.technique_list);
// Binding resources Array to ListAdapter
this.setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, R.id.label, technique_list));
}
}
I would really appreciate it if someone could point me in the right direction so that I can populate the second tab of my application with the listview I've created in TechniqueActivity.java. Or maybe there's a completely different / better way of doing it?

Okay, after more research and playing around, I found the solution, which was basically what Rarw said in the second part of his answer, which was to use a Fragment instead of an Activity. So, I got rid of TechniqueActivity.java and created a TechniqueFragment instead. Then I call it in the getItem().
package com.sonnyparlin.gracietampa;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
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 each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#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 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) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment;
if (position == 0 || position == 2) {
fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
} else {
fragment = new TechniqueFragment();
//setContentView(R.layout.technique_activity);
}
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView;
if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) {
rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Html.fromHtml(getString(R.string.page1text)));
} else {
rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
}
return rootView;
}
}
public static class TechniqueFragment extends Fragment {
public TechniqueFragment() {
// TODO Auto-generated constructor stub
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View rootView;
rootView = inflater.inflate(R.layout.technique_activity,
container, false);
ListView lv1 = (ListView) rootView.findViewById(R.id.ListView01);
String[] technique_list = getResources().getStringArray(R.array.technique_list);
lv1.setAdapter(new ArrayAdapter<String>(lv1.getContext(), R.layout.list_item, technique_list));
return rootView;
}
}
}

It doesn't look like you're actually using any tabs. Check out this tutorial for the basic idea. If you're going to use tabs you need to (1) create the tabs and then (2) set your activity to be loaded by that tab. The code above just looks like you're creating one activity and then inflating that layout. The blog post provides a good overview of a simple 3 tab application which you can adapt to your case.
The other way to do this would be to use a ViewPager which you can read more about here. The ViewPager approach uses Fragment and not Acitivity. Basicly you create a ViewPager and an adapter which you then add instances of your fragments to. As you swipe the ViewPager rotates through the fragments in the order you add them to the adapter.
Those look like the 2 most relevant ways to approach this situation.