Save the Tab state during orientation change

Question

I have 2 tabs , for example Tab1 & Tab2 which is displayed on the screen. Let the tabs be displayed on the PORTRAIT orientation.

Tab1 displays Activity1 & Ta

Answer 1

That's not the best way. You should use onRetainNonConfigurationInstance() and getLastNonConfigurationInstance() to retain the state between config changes. Those methods are specifically for saving state during config changes.

public Object onRetainNonConfigurationInstance() {
    return mTabHost.getCurrentTab();
}

public void onCreate() {
   ...
   Integer lastTab = (Integer) getLastNonConfigurationInstance();
   if(lastTab != null) {
      mTabHost.setCurrentTab(lastTab);
   }
   ...
}

Answer 2

That's not the way it should be done... instead use the:

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("tabState", getSelectedTab());
}

Then, on the onCreate method:

public void onCreate(Bundle state){
     // do the normal onCreate stuff here... then:
     if( state != null ){
         setCurrentTab(state.getInt("tabState"));
     }
}

The Robby's solution will work too and involves using the onRetainNonConfigurationInstance method. I actually like and prefer that method over onSaveInstanceState since it allows you save a complex object that represents the state of the app, not only parceables inside a Bundle.

So when to use one of the other? It depends on the data you need to save/restore the state of the app. For simple things like saving the tab state, it's almost the same.