Develop Reference

How to add back button on action bar with more tabs

know anyone how can I add one back button on my action bar? I want to add the back button befor INFO tab. I've try some method but no one of them don't work for me. Well let's start with started.
In this image in left part it's what I need to do as actionbar and in the right part it's how looks my project right now.
I've try to put that code for add the back button but it don't works:
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setHomeButtonEnabled(true);
Here it's my Activity:
public class TrailActivity extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
Intent intent;
Trail trail;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
intent = getIntent();
setContentView(R.layout.trail_fracment_main);
trail = intent.getParcelableExtra("trail");
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setHomeButtonEnabled(true);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
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) {
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) {
if (position == 0) {
InfoFragments infoFragments = new InfoFragments();
infoFragments.setTrail(trail);
Fragment fragment = infoFragments;
return fragment;
} else if (position == 1) {
return new MapFragments();
} else {
return new WondersFragments();
}
}
#Override
public int getCount() {
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;
}
}
Some one told me to try to implement OnBackStackChangedListener and after that he want to put in my code and that:
#Override
public void onCreate(Bundle savedInstanceState) {
//Listen for changes in the back stack
getSupportFragmentManager().addOnBackStackChangedListener(this);
//Handle when activity is recreated like on orientation Change
shouldDisplayHomeUp();
}
#Override
public void onBackStackChanged() {
shouldDisplayHomeUp();
}
public void shouldDisplayHomeUp(){
//Enable Up button only if there are entries in the back stack
boolean canback = getSupportFragmentManager().getBackStackEntryCount()>0;
getSupportActionBar().setDisplayHomeAsUpEnabled(canback);
}
#Override
public boolean onSupportNavigateUp() {
//This method is called when the up button is pressed. Just the pop back stack.
getSupportFragmentManager().popBackStack();
return true;
}
Also I've try to add and that override method, but again... nothing happen :(
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// app icon in action bar clicked; goto parent activity.
this.finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
I've try and that... but again... I've don't obtain any result :(.
So please guys, if anyone know how can I solve that problem, please show me.. I really need to do that and how much fast is possible.

How to add back button on action bar with more fragments

know anyone how can I add one back button one my action bar?Here it's my acplication and I want to add it before INFO button.
I've try to add that code for action bar but it don't works:
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setHomeButtonEnabled(true);
Here it's my activity:
public class TrailActivity extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
Intent intent;
Trail trail;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
intent = getIntent();
setContentView(R.layout.trail_fracment_main);
trail = intent.getParcelableExtra("trail");
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setHomeButtonEnabled(true);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
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, tell the ViewPager to switch to the corresponding page.
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) {
if (position == 0) {
InfoFragments infoFragments = new InfoFragments();
infoFragments.setTrail(trail);
Fragment fragment = infoFragments;
return fragment;
} else if (position == 1) {
return new MapFragments();
} else {
return new WondersFragments();
}
}
#Override
public int getCount() {
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;
}
}
}
EDITED:
In the left part it's how should be looks my action bar with back button and in the right part it's the actually my application right now. So.. How can I make it to looks like the aplication from left part?
If anyone know please show me how I can do it.
Thx :D

Implement OnBackStackChangedListener and add this code to your Fragment Activity.
#Override
public void onCreate(Bundle savedInstanceState) {
//Listen for changes in the back stack
getSupportFragmentManager().addOnBackStackChangedListener(this);
//Handle when activity is recreated like on orientation Change
shouldDisplayHomeUp();
}
#Override
public void onBackStackChanged() {
shouldDisplayHomeUp();
}
public void shouldDisplayHomeUp(){
//Enable Up button only if there are entries in the back stack
boolean canback = getSupportFragmentManager().getBackStackEntryCount()>0;
getSupportActionBar().setDisplayHomeAsUpEnabled(canback);
}
#Override
public boolean onSupportNavigateUp() {
//This method is called when the up button is pressed. Just the pop back stack.
getSupportFragmentManager().popBackStack();
return true;
}
If you are looking for Back Arrow beside the ActionBar tabs.Using Sherlock you can do it.Try this
https://stackoverflow.com/a/12703960/2365507

How i operation on Back Button in fragment. ask for back button of hardware of phone

i want to operation on back button in main fragment class. i am use swipe tab with help of fragment. so in as par activity class i know function of back button. but this is not help of me. this is my code. i already done on action bar home function. so i want to do same as back button
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Metals","Forex" };
static int i = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
i=0;
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
// actionBar.setHomeButtonEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case android.R.id.home:
Log.d("back", "backkk");
i = 1;
Toast.makeText(getApplicationContext(), "back"+i,100).show();
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}

i think you want to perform an opration when back key is pressed in Fragment
So Create a public method in fragment
and from Fragment activity class , override onBackkeypressed call that method
example
#Override
public void onBackPressed() {
DetailFragment fragment = (DetailFragment) getFragmentManager()
.findFragmentById(R.id.listfragment);
fragment.doSomthing()
}

Null Pointer Exception near actionBar.setHomeButtonEnabled(false), during implementation of View Pager TabView

Getting Null Pointer Exception near actionBar.setHomeButtonEnabled(false), I have also implemented View Pager and Tabs.
I have have not defined #android:style/Theme.Black.NoTitleBar in the manifest file.
When I don't implement TabView and View Pager and pass a normal activity then the app works but when I try to implement TabView and View Pager I getting Null Pointer Exception.
Can anyone point out the mistake which I would have done?
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Merchants", "Personal Payee" };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_screen_tab_layout_bp);
//Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
//Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#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.main, menu); //inflate our menu
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.item_refresh) {
Intent i = new Intent(MainScreenTab.this,ListMerchantType.class);
startActivity(i);
return true;
}
else if (id == R.id.item_save) {
Intent i = new Intent(MainScreenTab.this,ListPayee.class);
startActivity(i);
return true;
}
return super.onOptionsItemSelected(item);
}

ActionBarCompat contains one Activity class which all of your Activity
classes should extend: ActionBarActivity. This class itself extends
from FragmentActivity so you can continue to use Fragments in your
application. There is not a ActionBarCompat Fragment class that you
need to extend, so you should continue using
android.support.v4.Fragment as the base class for your Fragments.
You have the info here:
http://android-developers.blogspot.in/2013/08/actionbarcompat-and-io-2013-app-source.html
That's the reason why you are getting NPE on actionBar element. So you should have it this way:
public class YourActivity extends ActionBarActivity implements TabListener {

listviewselection in a listfragment in a tab

I have the following problem. I have an app with a viewpager and two tabs. The two tabs are two listfragments. Now I want that if the user selects an item in the first tab, that the 5th item is selected in the second tab. (the second tab is the translation of text from the first item). My problem is that when i select an item in the first tab, and now switch to the second tab, there is nothing selected.
When I click something in the first tab I call a function in the Parent activity which calls a function in the second fragment which should select the 5th Item.
This is the code of the Fragment activity:
public class Dailyquran extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
public ArrayList<Tweet> tweets = new ArrayList<Tweet>();
public ArrayList<Tweet> tweets2 = new ArrayList<Tweet>();
//private static ArrayList<String> roomList;
public String a;
public static int laenge_inhalt;
public static int selected;
public static String sure_media;
public static String vers_media;
String koran_filename;
//int tabwahl=0;
int playstatus=0;
MediaPlayer mp = new MediaPlayer();
MenuItem playMenu;
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.activity_dailyquran, menu);
playMenu = menu.findItem(R.id.menu_play);
return true;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("Daily Quran");
setContentView(R.layout.activity_dailyquran);
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 (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));
}
main();
}
/* WEITER UNTEN SIND DIE TABSELECTED FUNKTIONEN !!!!
//#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) {
}
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private FragmentTransaction mCurTransaction = null;
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE; //To make notifyDataSetChanged() do something
}
#Override
public Fragment getItem(int i) {
// Fragment building_fragment = new BuildingFragment();
Fragment room_fragment = new RoomFragment();
Fragment transl_fragment = new TransliterationFragment();
// Fragment device_fragment = new DeviceFragment();
Bundle args = new Bundle();
switch(i){
case 0:
room_fragment.setArguments(args);
return room_fragment;
case 1:
return transl_fragment;
case 2:
// args.putInt(RoomFragment.ARG_SECTION_NUMBER, i);
// room_fragment.setArguments(args);
return room_fragment;
default: return null;
}
}
#Override
public int getCount() {
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0: return "a";
case 1: return "b";
case 2: return "c";
}
return null;
}
#Override
public Object instantiateItem(View container, int position) {
if (mCurTransaction == null) {
mCurTransaction = getSupportFragmentManager().beginTransaction();
}
// TODO Auto-generated method stub
Fragment fragment = getItem(position);
if (fragment!=null){
System.out.println("Fragment Found!");
mCurTransaction.attach(fragment);
}
return fragment;//super.instantiateItem(container, position);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.menu_play:
play();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem switchButton = menu.findItem(R.id.menu_play);
}
public class Tweet {
String content;
String sure;
String vers;
}
public class Tweet2 {
String content;
String sure;
String vers;
}
public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
mViewPager.setCurrentItem(tab.getPosition());
}
public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
//HERE IS THE CODE FOR SELECTING THE SECOND ITEM
public void one_changed()
{
TransliterationFragment fragment_meaning = (TransliterationFragment) getSupportFragmentManager().findFragmentById(R.id.myfragment2);
Toast.makeText(getApplicationContext(),"Change Selection", Toast.LENGTH_SHORT).show();
fragment_meaning.change_selected(); // do what updates are required
}
AND THIS IS THE RELEVANT CODE OF THE SECOND FRAGMENT, I can see the string "Hallo" is in the console, so the function is really called, but i the Item isnt selected.
public void change_selected()
{
System.out.println("Hallo");
ListView list=getListView();
list.setSelection(4);
}

Its working now when i add this code in the function on_changed in the parent activity:
TransliterationFragment fragment_meaning = (TransliterationFragment) getSupportFragmentManager().findFragmentByTag("android:switcher:"+R.id.pager+":1");
fragment_meaning.change_selected(); // do what updates are required