Develop Reference

Fragment Transaction show() does not show fragment on second time

I have a fragment inside of a fragment. This setup works fine until you rotate the device. After you rotate the device the inner fragment does not show anymore.
I am calling the .show() method and I have a couple of log statements to display what's going on, and the fragment just doesn't show up after rotation.
Any idea on what I'm doing wrong?
Here's my code. The issue can be found in the private method displayTab():
public static class MyTabsListener<T extends Fragment> implements ActionBar.TabListener
{
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
private final Bundle mArgs;
private Fragment mFragment;
private FragmentManager fm;
private Fragment fragmentJobListDetails;
private Fragment fragmentTrends;
public MyTabsListener(Activity activity, String tag, Class<T> clz, FragmentManager fragmentManager)
{
this(activity, tag, clz, null,fragmentManager);
}
public MyTabsListener(Activity activity, String tag, Class<T> clz, Bundle args, FragmentManager fragmentManager)
{
mActivity = activity;
mTag = tag;
mClass = clz;
mArgs = args;
fm = fragmentManager;
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn't shown.
mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
if (mFragment != null && !mFragment.isDetached())
{
FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
ft.hide(mFragment);
ft.commit();
}
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft)
{
displayTab(tab, ft);
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft)
{
if (mFragment != null)
{
ft.hide(mFragment);
//ft.remove(mFragment);
}
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft)
{
displayTab(tab, ft);
}
private void displayTab(Tab tab, FragmentTransaction ft)
{
fragmentJobListDetails = mActivity.getFragmentManager().findFragmentByTag("jobDetails");
fragmentTrends = mActivity.getFragmentManager().findFragmentByTag("trends");
if (fragmentJobListDetails != null && !fragmentJobListDetails.isDetached())
{
ft.hide(fragmentJobListDetails);
}
if (mFragment == null)
{
mFragment = Fragment.instantiate(mActivity, mClass.getName(), mArgs);
ft.add(android.R.id.content, mFragment, mTag);
}
else
{
if (mFragment == fragmentTrends)
{
System.out.println("fragments are equal");
System.out.println("equal. Fragment added? = " + mFragment.isAdded());
System.out.println("equal. Fragment detached? = " + mFragment.isDetached());
System.out.println("equal. Fragment visible? = " + mFragment.isVisible());
ft.show(fragmentTrends);
System.out.println("equal. Fragment added? = " + mFragment.isAdded());
System.out.println("equal. Fragment detached? = " + mFragment.isDetached());
System.out.println("equal. Fragment visible? = " + mFragment.isVisible());
}
ft.show(mFragment);
}
}
}// end MyTabsListener
And here's the output of my logs, after rotation:
11-25 09:17:24.895: I/System.out(14605): mFragment = TrendsPagerHolder{427a94a8 #1 id=0x1020002 trends}
11-25 09:17:24.895: I/System.out(14605): fragments are equal
11-25 09:17:24.895: I/System.out(14605): equal. Fragment added? = true
11-25 09:17:24.895: I/System.out(14605): equal. Fragment detached? = false
11-25 09:17:24.895: I/System.out(14605): equal. Fragment visible? = false
11-25 09:17:24.895: I/System.out(14605): equal. Fragment added? = true
11-25 09:17:24.895: I/System.out(14605): equal. Fragment detached? = false
11-25 09:17:24.895: I/System.out(14605): equal. Fragment visible? = false
Thanks!

I'm not sure what is wrong with the entire operation, but I use the following lines and it always works:
MyDialogFragment dialogFragment = new MyDialogFragment(data);
dialogFragment.show(getFragmentManager(), key);
Note that MyDialogFragment has two constructors one excepts the data the other is default (empty)
using the saveState and restoreState allow you to save the dialog state.
I hope this will work for you as well.

You need to override the default execution of configuration changes. You can do this by using the configChanges attribute of the activity tag in AndroidManifest. Read more about it here.

Hiding/Showing SherlockFragments in ActionBar.TabListener Class, content is empty

I have an app built using TabBarSherlock and the Support library to add ActionBar support to pre 3.0 devices. I can't remember what tutorial I followed to create the Tabs and the Listener but I have the following code.
Firstly creating the Tabs (Inside a SherlockFragmentActivity):
ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
/*--------Setup News Tab--------*/
Tab tab1 = actionBar.newTab()
.setText("News")
.setTabListener(new TabListener<TabFragment>(
this, "tab1", TabFragment.class));
Bundle newsBundle = new Bundle();
newsBundle.putInt("news_id", newsID);
tab1.setTag(newsBundle);
actionBar.addTab(tab1);
/*------------------------------*/
// This is repeated 3 more times to total 4 Tabs.
Then I have a classCalled TabListener which is used in each of these Tabs to detect when they have been selected.
public class TabListener<T extends Fragment> implements ActionBar.TabListener{
private TabFragment mFragment;
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
public TabListener(Activity activity, String tag, Class<T> clz) {
mActivity = activity;
mTag = tag;
mClass = clz;
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialised
if (mFragment == null) {
Log.v("FRAGMENT", "FRAGMENT NEEDS TO BE CREATED");
mFragment = (TabFragment) Fragment.instantiate(mActivity, mClass.getName(), (Bundle)tab.getTag());
ft.add(android.R.id.content, mFragment, mTag);
} else {
Log.v("FRAGMENT", "FRAGMENT ALREADY CREATED");
ft.show(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
ft.hide(mFragment);
}
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
With the class TabFragment containing a ViewPager for each Tab. My issue is that when selecting a Tab other than the first one the content inside the Fragment does not show. From the logs in place when the Fragment is initialised I can tell the views are being created just not being shown, it's just a blank area showing the background.

Instead of using show() and hide(), use attach() and detach(). Using show/hide does not remove the view hierarchy from the screen, simply hides it, so there might be issues related to that.

You are not detaching fragment rather you are just hiding it. so you should detach it so that other fragment should be attached in your onTabUnSelected.
FragmentManager will automatically restore whatever fragment (and history) was currently displayed upon a configuration change. Call findFragmentByTag to see if an instance of the target fragment already exists before creating and attaching a new instance.
Example:
public void onTabSelected(Tab tab, FragmentTransaction ft) {
SherlockFragment preInitializedFragment = (SherlockFragment) mActivity.getSupportFragmentManager().findFragmentByTag(mTag);
// Check if the fragment is already initialized
if (mFragment == null && preInitializedFragment == null) {
// If not, instantiate and add it to the activity
mFragment = (SherlockFragment) SherlockFragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else if (mFragment != null) {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
} else if (preInitializedFragment != null) {
ft.attach(preInitializedFragment);
mFragment = preInitializedFragment;
}
}
and you onTabUnSelected should be like this
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}

Content is empty on tab bar then write below code
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(actionBar.NAVIGATION_MODE_STANDARD);

Replacing Fragment in tab, changes all tabs

EDIT
I edited the previous question, wich i solved. Thanks a lot for the replies.
I have a gui with 3 tabs (News, Strategy and History), in one of them (News) i load an ExpandableListView and when the user clicks in one of the items from the list, it loads another fragment containg details from the selected item. I managed to replace the fragment in that tab with another fragment, using this code:
CategoryTab categories = new CategoryTab();//Fragment 2
FragmentManager manager = activity.getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(this.getId(), categories, "News");
//transaction.replace(android.R.id.content, categories, "News");
transaction.addToBackStack(null);
transaction.commit();
When the seconds fragment loads in the News tab, all the other tabs shows that fragment. I'm using this listener to manage tab navigation
public static class TabListener<T extends Fragment> implements ActionBar.TabListener {
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
private final Bundle mArgs;
private Fragment mFragment;
public TabListener(Activity activity, String tag, Class<T> clz) {
this(activity, tag, clz, null);
}
public TabListener(Activity activity, String tag, Class<T> clz, Bundle args) {
mActivity = activity;
mTag = tag;
mClass = clz;
mArgs = args;
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn't shown.
mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
if (mFragment != null && !mFragment.isDetached()) {
FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
ft.detach(mFragment);
ft.commit();
}
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (mFragment == null) {
mFragment = Fragment.instantiate(mActivity, mClass.getName(), mArgs);
ft.add(android.R.id.content, mFragment, mTag);
} else {
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(mActivity, "Reselected!", Toast.LENGTH_SHORT).show();
}
}
My question is ¿why all the tabs shows the same fragment when the replacement is done? and ¿how can i simulate a back button with the icon provided in the action bar, to load again fragment 1 in News Tab?
Any help will be appreciated
PD: Sorry for my english

Make sure you call getActivity() in or after onActivityCreated, as before then it will return null.
The Fragment will be attached to a null activity until onActivityCreated... that is, if you call getActivity() in onCreate or onCreateView, it will return null because the Activity hasn't been created yet. So make sure you have all of your calls to getActivity() in or after onActivityCreated

Tab content stays visible after changing tab after orientation change

I'm using ActionBarSherlock to implement an ActionBar with tabs in my application.
When I start the app, and switch from tab to tab, everything is fine. However, when I change from portrait to landscape mode, the content of the tab that was last active stays visible. Changing to another tab results in the drawing of the new content on top of the old content (see image).
My main class:
public class TreinVerkeer extends SherlockFragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setupTabs(savedInstanceState);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getSupportMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
private void setupTabs(Bundle savedInstanceState) {
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Tab tab = actionBar.newTab().setText("STATIONS").setTabListener(new TabListener<StationsFragment>(this, "stations", StationsFragment.class));
actionBar.addTab(tab);
tab = actionBar.newTab().setText("ROUTE").setTabListener(new TabListener<RouteFragment>(this, "route", RouteFragment.class));
actionBar.addTab(tab);
tab = actionBar.newTab().setText("DELAYS").setTabListener(new TabListener<DelaysFragment>(this, "delays", DelaysFragment.class));
actionBar.addTab(tab);
if (savedInstanceState != null) {
actionBar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("tab", getSupportActionBar().getSelectedNavigationIndex());
}
}
The TabListener (from "Adding Navigations Tabs" on the Android developer site with some minor changes):
public class TabListener<T extends SherlockFragment> implements com.actionbarsherlock.app.ActionBar.TabListener {
private SherlockFragment mFragment;
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
/**
* Constructor used each time a new tab is created.
*
* #param activity
* The host Activity, used to instantiate the fragment
* #param tag
* The identifier tag for the fragment
* #param clz
* The fragment's Class, used to instantiate the fragment
*/
public TabListener(Activity activity, String tag, Class<T> clz) {
mActivity = activity;
mTag = tag;
mClass = clz;
}
/* The following are each of the ActionBar.TabListener callbacks */
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = (SherlockFragment) SherlockFragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// User selected the already selected tab. Usually do nothing.
}
}
And StationsFragment (RouteFragment and DelaysFragment are the same, with only different text)
public class StationsFragment extends SherlockFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.stationsfragment, container, false);
}
}
With that the layout file for StationsFragment:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Stations" />
</LinearLayout>
And finally the Manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.myapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".TreinVerkeer"
android:label="#string/app_name"
android:theme="#style/Theme.Sherlock.Light" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
I had the same problem before right away when starting the app (so without even changing the orientation), this was solved by removing setContentView(R.layout.main) in the onCreate of the main class. I can't find a solution for this however. Can anyone help me with this?

FragmentManager will automatically restore whatever fragment (and history) was currently displayed upon a configuration change. Call findFragmentByTag to see if an instance of the target fragment already exists before creating and attaching a new instance.

Thanks to Jake, I've updated the onTabSelected method like this:
public void onTabSelected(Tab tab, FragmentTransaction ft) {
SherlockFragment preInitializedFragment = (SherlockFragment) mActivity.getSupportFragmentManager().findFragmentByTag(mTag);
// Check if the fragment is already initialized
if (mFragment == null && preInitializedFragment == null) {
// If not, instantiate and add it to the activity
mFragment = (SherlockFragment) SherlockFragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else if (mFragment != null) {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
} else if (preInitializedFragment != null) {
ft.attach(preInitializedFragment);
mFragment = preInitializedFragment;
}
}
This answer is for clarification purposes only, credits go to Jake :)

As well as the changes Niek posted, there are a couple of trivial changes you need to make. Mainly just changing Activity to SherlockFragmentActivity.
For the benefit of others, here's my final version which seems to work properly.
public static class TabListener<T extends SherlockFragment> implements ActionBar.TabListener
{
private SherlockFragment mFragment;
private final SherlockFragmentActivity mActivity;
private final String mTag;
private final Class<T> mClass;
/** Constructor used each time a new tab is created.
* #param activity The host Activity, used to instantiate the fragment
* #param tag The identifier tag for the fragment
* #param clz The fragment's Class, used to instantiate the fragment
*/
public TabListener(Activity activity, String tag, Class<T> clz)
{
mActivity = (SherlockFragmentActivity) activity;
mTag = tag;
mClass = clz;
}
public void onTabSelected(Tab tab, FragmentTransaction ft)
{
// Check if the fragment has already been initialised
SherlockFragment preInitializedFragment = (SherlockFragment) mActivity.getSupportFragmentManager().findFragmentByTag(mTag);
if (mFragment != null)
{
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
else if (preInitializedFragment != null)
{
mFragment = preInitializedFragment;
ft.attach(mFragment);
}
else
{
// Not found, so instantiate and add it to the activity
mFragment = (SherlockFragment) SherlockFragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft)
{
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft)
{
// User selected the already selected tab. Usually do nothing.
}
}

Double fragment rotating Android with ActionBar

I've made a simple Android Activity with an ActionBar to switch between 2 fragments.
It's all ok until I rotate the device. In facts, when I rotate I've got 2 fragment one over the other: the previous active one and the first one.
Why?
If the rotation destroy and recreate my activity, why I obtain 2 fragments?
Sample code:
Activity
package rb.rfrag.namespace;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.os.Bundle;
public class RFragActivity extends Activity {
/** Called when the activity is first created. */
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Notice that setContentView() is not used, because we use the root
// android.R.id.content as the container for each fragment
// setup action bar for tabs
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
//actionBar.setDisplayShowTitleEnabled(false);
Tab tab;
tab = actionBar.newTab()
.setText(R.string.VarsTab)
.setTabListener(new TabListener<VarValues>(
this, "VarValues", VarValues.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText(R.string.SecTab)
.setTabListener(new TabListener<SecFrag>(
this, "SecFrag", SecFrag.class));
actionBar.addTab(tab);
}
}
TabListener
package rb.rfrag.namespace;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.app.ActionBar.Tab;
public class TabListener<T extends Fragment> implements ActionBar.TabListener {
private Fragment mFragment;
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
/** Constructor used each time a new tab is created.
* #param activity The host Activity, used to instantiate the fragment
* #param tag The identifier tag for the fragment
* #param clz The fragment's Class, used to instantiate the fragment
*/
public TabListener(Activity activity, String tag, Class<T> clz) {
mActivity = activity;
mTag = tag;
mClass = clz;
}
/* The following are each of the ActionBar.TabListener callbacks */
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
}

I've resolved using onSaveInstanceState and onRestoreInstanceState in the Activity to maintain the selected tab and modifying onTabSelected as follows.
The last modify avoids that Android rebuild the Fragment it doesn't destoy. However I don't understand why the Activity is destroyed by the rotation event while the current Fragment no. (Have you some idea about this?)
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// previous Fragment management
Fragment prevFragment;
FragmentManager fm = mActivity.getFragmentManager();
prevFragment = fm.findFragmentByTag(mTag);
if (prevFragment != null) {
mFragment = prevFragment;
} // \previous Fragment management
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}

Since I use a android.support.v4.view.ViewPager overriding onTabSelected would not help. But still you hint pointed me in the right direction.
The android.support.v4.app.FragmentManager saves all fragments in the onSaveInstanceState of the android.support.v4.app.FragmentActivity. Ignoring setRetainInstance — Depending on your design this might lead to duplicate fragments.
The simplest solution is to delete the saved fragment in the orCreate of the activity:
#Override
public void onCreate (final android.os.Bundle savedInstanceState)
{
if (savedInstanceState != null)
{
savedInstanceState.remove ("android:support:fragments");
} // if
super.onCreate (savedInstanceState);
…
return;
} // onCreate

The solution does not actually require a whole lot of work, the following steps ensure, that when rotating the screen, the tab selection is maintained. I ran into overlapping Fragments, because upon screen rotation my first tab was selected, not the second one that was selected before rotating the screen and hence the first tab was overlapping the content of the second tab.
This is how your Activity should look (I am using ActionBarSherlock but adjusting it should be very easy):
public class TabHostActivity extends SherlockFragmentActivity {
private static final String SELETED_TAB_INDEX = "tabIndex";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Setup the action bar
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the Tabs you need and add them to the actionBar...
if (savedInstanceState != null) {
// Select the tab that was selected before orientation change
int index = savedInstanceState.getInt(SELETED_TAB_INDEX);
actionBar.setSelectedNavigationItem(index);
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save the index of the currently selected tab
outState.putInt(SELETED_TAB_INDEX, getSupportActionBar().getSelectedTab().getPosition());
}
}
And this is what my ActionBar.TabListener looks like (its a private class in the above Activity):
private class MyTabsListener<T extends Fragment> implements ActionBar.TabListener {
private Fragment fragment;
private final SherlockFragmentActivity host;
private final Class<Fragment> type;
private String tag;
public MyTabsListener(SherlockFragmentActivity parent, String tag, Class type) {
this.host = parent;
this.tag = tag;
this.type = type;
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction transaction) {
/*
* The fragment which has been added to this listener may have been
* replaced (can be the case for lists when drilling down), but if the
* tag has been retained, we should find the actual fragment that was
* showing in this tab before the user switched to another.
*/
Fragment currentlyShowing = host.getSupportFragmentManager().findFragmentByTag(tag);
// Check if the fragment is already initialised
if (currentlyShowing == null) {
// If not, instantiate and add it to the activity
fragment = SherlockFragment.instantiate(host, type.getName());
transaction.add(android.R.id.content, fragment, tag);
} else {
// If it exists, simply attach it in order to show it
transaction.attach(currentlyShowing);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction fragmentTransaction) {
/*
* The fragment which has been added to this listener may have been
* replaced (can be the case for lists when drilling down), but if the
* tag has been retained, we should find the actual fragment that's
* currently active.
*/
Fragment currentlyShowing = host.getSupportFragmentManager().findFragmentByTag(tag);
if (currentlyShowing != null) {
// Detach the fragment, another tab has been selected
fragmentTransaction.detach(currentlyShowing);
} else if (this.fragment != null) {
fragmentTransaction.detach(fragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction fragmentTransaction) {
// This tab is already selected
}
The above implementation also allows replacement of Fragments within a tab, based on their tags. For this purpose when switching fragments within the same tab I use the same Tag name, that was used for the initial framework that's been added to the tab.

Thanks Martin and asclepix for theirs solutions. I have 3 tabs and first tab contains 2 fragments, like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".MainActivity" >
<FrameLayout
android:id="#+id/frActiveTask"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
/>
<FrameLayout
android:id="#+id/frTaskList"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_above="#id/frActiveTask"
/>
</RelativeLayout>
Using onRestoreInstanceState, onSaveInstanceState and savedInstanceState.remove("android:support:fragments"); methods and statement working almost fine except if your active tab is not the first one and rotate and click on first, a clear display appears and only for the second click on the first tab came the right fragment display.
After debugging code I recognized that the first addTab always calls an onTabSelected event in the tab listener, with a fragment add method and then when the setSelectedNavigationItem is called from onRestoreInstanceState a detach is executed on the first tab and an add for other one.
This unecessary add calling is fixed in my solution.
My activity
protected void onCreate(Bundle savedInstanceState) {
boolean firstTabIsNotAdded = false;
if (savedInstanceState != null) {
savedInstanceState.remove("android:support:fragments");
firstTabIsNotAdded = savedInstanceState.getInt(SELETED_TAB_INDEX) != 0;
}
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// codes before adding tabs
actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
tabStartAndStop = actionBar.newTab().setText(getString(R.string.tab_title_start_and_stop))
.setTabListener(
new FragmentTabListener<StartStopFragment>(this,
getString(R.string.tab_title_start_and_stop_id),
StartStopFragment.class,
firstTabIsNotAdded));
tabHistory = actionBar.newTab().setText(getString(R.string.tab_title_history))
.setTabListener(
new FragmentTabListener<HistoryFragment>(this,
getString(R.string.tab_title_history_id),
HistoryFragment.class,
false));
tabRiporting = actionBar.newTab().setText(getString(R.string.tab_title_reporting))
.setTabListener(
new FragmentTabListener<ReportingFragment>(this,
getString(R.string.tab_title_reporting_id),
ReportingFragment.class,
false));
actionBar.addTab(tabStartAndStop);
actionBar.addTab(tabHistory);
actionBar.addTab(tabRiporting);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
if (savedInstanceState != null) {
int index = savedInstanceState.getInt(SELETED_TAB_INDEX);
actionBar.setSelectedNavigationItem(index);
}
super.onRestoreInstanceState(savedInstanceState);
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save the index of the currently selected tab
outState.putInt(SELETED_TAB_INDEX, getSupportActionBar().getSelectedTab().getPosition());
}
And the modified tab listener
public class FragmentTabListener<T extends SherlockFragment> implements com.actionbarsherlock.app.ActionBar.TabListener {
private Fragment mFragment;
private final Activity mFragmentActivity;
private final String mTag;
private final Class<T> mClass;
private boolean doNotAdd;
/** Constructor used each time a new tab is created.
* #param activity The host Activity, used to instantiate the fragment
* #param tag The identifier tag for the fragment
* #param clz The fragment's Class, used to instantiate the fragment
*/
public FragmentTabListener(Activity activity, String tag, Class<T> clz, boolean doNotAdd) {
mFragmentActivity = activity;
mTag = tag;
mClass = clz;
this.doNotAdd = doNotAdd;
}
/* The following are each of the ActionBar.TabListener callbacks */
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
if(doNotAdd){
doNotAdd = false;
}else{
mFragment = Fragment.instantiate(mFragmentActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
}
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// User selected the already selected tab. Usually do nothing.
}
}