Android how to know when your tab has gained focus, - android

I have a tab view in my activity,
Currently I am doing a UI update in my fragments onCreateView but I don't think this is the correct place.
Is there a method I can overload which will be called when my tab gains view? So that when my user clicks on or scrolls to my tab, I can then poll my server and update my view.
Some simplified code:
#SuppressLint("NewApi")
public class Rhino68PanelActivity extends FragmentActivity implements ActionBar.TabListener {
static String TAG = "Rhino68PanelActivty";
/**
* 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_rhino68_panel);
// 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
protected void onDestroy() {
super.onDestroy();
Network.cancelRequests(Rhino68PanelActivity.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.rhino68_panel, 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.
Fragment fragment = null;
switch (position) {
case 0: {
fragment = new OneSectionFragment();
}
break;
case 1: {
fragment = new TwoSectionFragment();
}
break;
case 2: {
fragment = new ThreeSectionFragment();
}
break;
default: {
fragment = new OneSectionFragment();
}
}
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 "1";
case 1:
"2";
case 2:
"3";
}
return null;
}
}
public static class oneSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}
public static class twoSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}

Problem 1: know which tab has focus
Solution: setOnPageChangeListener on your ViewPager. With the received index, you know which tab is active.
Problem 2: how to execute a method from the active page (fragment)
Solution:
create a public method in your viewpager adapter: onNewTabSelected(int index)
create your tab fragment accessible in your adapter (private MyTabFragment tabFragment;)
with the index, you know which Fragment you should use
create a public method in your Fragment
execute this method in the new created method inside your adapter

You can update your view in each SectionFragment by using:
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) { }
else { }
}
#see: How to determine when Fragment becomes visible in ViewPager

Related

Detect when fragment becomes visible through tab click

I am trying to detect when a fragment becomes visible on a swipe view, in order to update its content when it does become visible. I am doing it like this.
public class MyFragment extends Fragment {
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) { }
else { }
}
}
The thing is when I go to the page be swipping through it works great but when I select the page in the tab it crashes "Attempt to invoke virtual method".
Please help me, thanks
I have a main activity, and then an activity for each fragment.
Main:
public class Principal extends ActionBarActivity 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_principal);
// 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 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.menu_principal, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
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) {
Fragment fragment = new Fragment();
switch (position) {
case 0:
return fragment = new Config();
case 1:
return fragment = new Saidas();
case 2:
return fragment = new Entradas();
case 3:
return fragment = new Enviar();
case 4:
return fragment = new Historico();
case 5:
return fragment = new Status();
default:
break;
}
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 6;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_config).toUpperCase(l);
case 1:
return getString(R.string.title_saidas).toUpperCase(l);
case 2:
return getString(R.string.title_entradas).toUpperCase(l);
case 3:
return getString(R.string.title_enviar).toUpperCase(l);
case 4:
return getString(R.string.title_historico).toUpperCase(l);
case 5:
return getString(R.string.title_status).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_principal, container, false);
return rootView;
}
}
}
and then the fragments are:
public class Entradas extends android.support.v4.app.Fragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_entradas, container, false);
}
#Override
public void setMenuVisibility(final boolean visible) {
super.setMenuVisibility(visible);
if (visible) {
run code here....
}
}
There are 2 ways in which you can do this:
From the fragment you can call isVisible();
Return true if the fragment is currently visible to the user. This
means it: (1) has been added, (2) has its view attached to the window,
and (3) is not hidden.
From the parent activity you can do the following:
public boolean checkIsFragVisible() {
Fragment yourFragment = getSupportFragmentManager().findFragmentById(FRAG_HOLDER_ID);
return yourFragment != null && yourFragment.isVisible();
}

How do I add text and other things in tabs 2 and three?

I'm using Android Studios tabbed activity template with ActionBar Tabs, I have a slight problem. I want to be able to add different texts into the different tabs however I get the same text on all tabs. How would I go by doing this?
I have read through all the comments on the code yet still can't find how the different tabs are linked.
public class ScriptsTabbed extends ActionBarActivity 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;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scripts_tabbed);
// 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 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.menu_scripts_tabbed, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onTabSelected(ActionBar.Tab tab1, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab1.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab2, FragmentTransaction fragmentTransaction) {
mViewPager.setCurrentItem(tab2.getPosition());
}
#Override
public void onTabReselected(ActionBar.Tab tab3, FragmentTransaction fragmentTransaction) {
mViewPager.setCurrentItem(tab3.getPosition());
}
/**
* 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_scripts_tabbed, container, false);
return rootView;
}
}
}
Thank you!
Refer this how I update the content based of selected tab
// In this case, the fragment displays simple text based on the page
public class PageFragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static PageFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
// Inflate the fragment layout we defined above for this fragment
// Set the associated text for the title
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
TextView tvTitle = (TextView) view.findViewById(R.id.tvTitle);
tvTitle.setText("Fragment #" + mPage);
return view;
} }

ViewPager only displaying last fragment

I'm setting up a Tabbed ViewPager layout based on the wizard in Android Studio.
I've created two fragments to use in the ViewPager, as well as the included placeholder.
Only the last fragment is shown, whichever tab its on.
MainActivity.java:
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener, TunerFragment.OnFragmentInteractionListener, SettingsFragment.OnFragmentInteractionListener {
/**
* 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;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
// 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);
mViewPager.setCurrentItem(1);
// 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.menu_main, 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();
//noinspection SimplifiableIfStatement
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.
Log.v("tab selected", tab.getPosition() + ":" + tab.toString() +" - "+fragmentTransaction.toString());
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onFragmentInteraction(Uri uri) {
Log.v("onFragmentInteraction",uri.toString());
}
#Override
public void onFragmentInteraction(String id) {
Log.v("onFragmentInteraction",id);
}
/**
* 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).
Fragment fragment = new Fragment();
Log.v("MainActivity","position:"+ position);
switch (position) {
case 0:
fragment = new TunerFragment();
case 1:
fragment = PlaceholderFragment.newInstance(position + 1);
case 2:
fragment = new SettingsFragment();
default:
break;
}
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_tuner).toUpperCase(l);
case 1:
return getString(R.string.title_scale).toUpperCase(l);
case 2:
return getString(R.string.title_settings).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_main, container, false);
return rootView;
}
}
}
You missed the breaks inside the switch block which caused the fragment to always be SettingsFragment:
#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).
Fragment fragment = new Fragment();
Log.v("MainActivity","position:"+ position);
switch (position) {
case 0:
fragment = new TunerFragment();
// should insert break;
case 1:
fragment = PlaceholderFragment.newInstance(position + 1);
// should insert break;
case 2:
fragment = new SettingsFragment();
default:
break;
}
return fragment;
}
Get rid of mViewPager.setCurrentItem(1);. This is setting the current item to 1. This should be done in the adapter.

Android tab-menu switching pages without create new fragments

i have got a problem with my tab-menu.
my menu hast got 3 pages, when the app start it shows the first page, but when i switch to the third and go back to the first, then the first page is created new. i know this in cause of a timer who is set to 00:00 after going to the third page
now my problem is how can i fix this?
i have tried to check whether the object is null and when not then create a new else use the existing but it doenst work.
the complete code:
public class MyActivity extends ActionBarActivity implements ActionBar.TabListener {
private points points;
private teams teams;
private statistics statistics;
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
private String tabs[]= {"Punkte", "Mannschaft", "Statistik"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
// 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 each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < tabs.length; 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(tabs[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.my, 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) {
switch(position){
case 0: if(points == null) return new points();
else return points;
case 1: if(teams == null) return new teams();
else return teams;
case 2: if(statistics == null) return new statistics();
else return statistics;
}
return null;
}
#Override
public int getCount() {
// Show 3 total pages.
return tabs.length;
}
#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_my, container, false);
return rootView;
}
}
}
what i tried:
#Override
public Fragment getItem(int position) {
switch(position){
case 0: if(points == null) return new points();
else return points;
case 1: if(teams == null) return new teams();
else return teams;
case 2: if(statistics == null) return new statistics();
else return statistics;
}
return null;
}
thank you for your help =)
assuming you are using the view pager for loading fragments,use
viewPager.setOffscreenPageLimit(2);

Click on item in ActionBar with tabs in Android 4

I am using an ActionBar with three Tabs. I also have a item in the ActionBar. I want to react on a click on these item different depending on the selected tab. How can I do this?
Code from my activity:
public class CreateProjectManually extends FragmentActivity implements ActionBar.TabListener {
private static ArrayList<String> buildingList;
private static ArrayList<String> roomList;
private static ArrayList<String> deviceList;
/**
* 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
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_project_manually);
// 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 action bar.
final ActionBar actionBar = getActionBar();
// set the app icon as an action to go home
actionBar.setDisplayHomeAsUpEnabled(true);
//enable tabs in actionbar
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// 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
// listener for when this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
/**
* Actionbar
* */
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_save:
//TODO Speichern implementieren
Toast.makeText(getBaseContext(), "Speichern",Toast.LENGTH_LONG).show();
break;
case R.id.menu_add:
//TODO Eintrag hinzufügen implementieren
if(getItem()==0){
}
break;
case android.R.id.home:
// app icon in action bar clicked; go home
Intent intent = new Intent(this, CreateProject.class);
intent.putExtra("Uniqid","From_CreateProjectManually_Activity");
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
return true;
default:
break;
}
return true;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_create_project_manually, menu);
return true;
}
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#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 onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to one of the primary
* sections of the app.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
Fragment building_fragment = new BuildingFragment();
Fragment room_fragment = new RoomFragment();
Fragment device_fragment = new DeviceFragment();
Bundle args = new Bundle();
switch(i){
case 0:
args.putInt(BuildingFragment.ARG_SECTION_NUMBER, i);
building_fragment.setArguments(args);
return building_fragment;
case 1:
args.putInt(RoomFragment.ARG_SECTION_NUMBER, i);
room_fragment.setArguments(args);
return room_fragment;
case 2:
args.putInt(DeviceFragment.ARG_SECTION_NUMBER, i);
device_fragment.setArguments(args);
return device_fragment;
default: return null;
}
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0: return getString(R.string.building).toUpperCase();
case 1: return getString(R.string.room).toUpperCase();
case 2: return getString(R.string.devices).toUpperCase();
}
return null;
}
}
/**
* A fragment representing building structure
*/
public static class BuildingFragment extends Fragment {
public BuildingFragment() {
}
public static final String ARG_SECTION_NUMBER = "section_number";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.listviews, container, false);
ListView listView = (ListView) view.findViewById(R.id.listviewfragment);
buildingList = new ArrayList<String>();
ListAdapter listenAdapter = new ArrayAdapter(getActivity(),
android.R.layout.simple_list_item_1, buildingList);
// Assign adapter to ListView
listView.setAdapter(listenAdapter);
return view;
}
}
/**
* A fragment representing room structure
*/
public static class RoomFragment extends Fragment {
public RoomFragment() {
}
public static final String ARG_SECTION_NUMBER = "section_number";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.listviews, container, false);
ListView listView = (ListView) view.findViewById(R.id.listviewfragment);
roomList = new ArrayList<String>();
ListAdapter listenAdapter = new ArrayAdapter(getActivity(),
android.R.layout.simple_list_item_1, roomList);
// Assign adapter to ListView
listView.setAdapter(listenAdapter);
return view;
}
}
/**
* A fragment representing device structure
*/
public static class DeviceFragment extends Fragment {
public DeviceFragment() {
}
public static final String ARG_SECTION_NUMBER = "section_number";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.listviews, container, false);
ListView listView = (ListView) view.findViewById(R.id.listviewfragment);
deviceList = new ArrayList<String>();
ListAdapter listenAdapter = new ArrayAdapter(getActivity(),
android.R.layout.simple_list_item_1, deviceList);
// Assign adapter to ListView
listView.setAdapter(listenAdapter);
return view;
}
}
}
I guess you had the answer all along:
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

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