ActionBar, Fragment and screen rotation

In the post Tab Layout in Android with ActionBar and Fragment as dnoray wrote in his comment, there is a problem: when you rotate the screen (ctrl + F11 in the emulator) there is an overlap of the two fragments as seen in the figure.

For a further discussion on this topic you can read this.

There are at least three possible solutions, or some variant of these

• first method
  add a line of code to the file AndroidManifest.xml
  
  XHTML

  android:configChanges=”orientation|screenSize”

  1	android:configChanges=”orientation|screenSize”

  
  in this way the activity is not destroyed and recreated and you can update the activity by overriding the method onConfigurationChanged() but in this case you don’t need.
  For more information see Handling the Configuration Change Yourself
• second method
  in the class TabActionBarActivity replace the line 66
  
  Java

  ft.add(android.R.id.content, mFragment, mTag);

  1	ft.add(android.R.id.content, mFragment, mTag);

  
  with
  
  Java

  ft.replace(android.R.id.content, mFragment, mTag);

  1	ft.replace(android.R.id.content, mFragment, mTag);

  
  As explained here the method replace is basically a remove + add.
• third method
  more difficult but interesting
  1. first, you need to know which fragments has been added to the main activity; then you add the following code to the class TabActionBarActivity:
     
     Java

     List<WeakReference<Fragment>> fragList = new ArrayList<WeakReference<Fragment>>(); @Override public void onAttachFragment(Fragment fragment) { fragList.add(new WeakReference(fragment)); } public ArrayList<Fragment> getActiveFragments() { ArrayList<Fragment> ret = new ArrayList<Fragment>(); for (WeakReference<Fragment> ref : fragList) { Fragment f = ref.get(); if (f != null && f.isVisible()) { ret.add(f); } } return ret; }

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     List<WeakReference<Fragment>> fragList = new ArrayList<WeakReference<Fragment>>();       @Override     public void onAttachFragment(Fragment fragment) { fragList.add(new WeakReference(fragment));     }       public ArrayList<Fragment> getActiveFragments() { ArrayList<Fragment> ret = new ArrayList<Fragment>(); for (WeakReference<Fragment> ref : fragList) {     Fragment f = ref.get();     if (f != null && f.isVisible()) { ret.add(f);     } } return ret;     }

     
     this code is taken from Is there a way to get references for all currently active fragments in an Activity?
  2. edit the method onTabSelected of the inner class TabListener
     
     Java

     public void onTabSelected(Tab tab, FragmentTransaction ft) { Iterator<WeakReference<Fragment>> it = fragList.iterator(); while (it.hasNext()) { Fragment f = it.next().get(); if (f.getTag().equals(mTag)) { if (f instanceof Tab1Fragment) { mFragment = (Tab1Fragment) f; } else if (f instanceof Tab2Fragment) { mFragment = (Tab2Fragment) f; } else { mFragment = f; } } else { ft.detach(f); } } // 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); } }

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     public void onTabSelected(Tab tab, FragmentTransaction ft) {       Iterator<WeakReference<Fragment>> it = fragList.iterator();     while (it.hasNext()) { Fragment f = it.next().get(); if (f.getTag().equals(mTag)) {     if (f instanceof Tab1Fragment) { mFragment = (Tab1Fragment) f;     } else if (f instanceof Tab2Fragment) { mFragment = (Tab2Fragment) f;     } else { mFragment = f;     } } else {     ft.detach(f); }     }       // 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);       } }