Question

In my Activity I have two Gallery items one ExpandableListView and for the children of the ExpandableListView I am having a GridView. Program runs perfectly. What I need is to handle orientation change. I know, when orientation change, activity will call onDestroy and after that onCreate. Because of that my ExpandableListView will collapsed even though the user has expanded before he has done an orientation change.

I found a great concept for handling rotation changes in StackOverflow. This is the link. I have tried to implement that way but I have failed.

What I need is to take the same interface that user has used before the orientation change even after the orientation change happen. Please guide me.

Update with the Manifest content

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >

    <activity 
        android:name=".activities.HomeActivity"  
        android:configChanges="keyboardHidden|orientation|screenLayout" >       

        <intent-filter>
            <action android:name="android.intent.action.MAIN" ></action>
            <category android:name="android.intent.category.LAUNCHER" ></category>
        </intent-filter>            
    </activity>

    <activity 
        android:name=".activities.WebViewActivity"
        android:configChanges="keyboardHidden|orientation|screenLayout" >          
    </activity>

</application>

Answer 1

Handling rotation could be trivial and depends on what you have to react to when the screen rotates. If you have nothing in particular to do, you can always tell Android itself to manage the rotation, and avoid restarting your activity. This could be achieved by declaring in the AndroidManifest.xml android:configChanges="orientation". If you do so, Android will call onConfigurationChanged, that you can always override. If you want your activity to restart when the screen rotates, you have to save the current state. That is, in your case, it could be the current groups and children currently collapsed and re collapse. You can use onSavedInstanceState()/onRestoreInstanceState() to save and restore the states you need.

Edit: if you are targeting API level 13, you have to add the screenSize option to the android:configChanges in conjunction with the orientation option as stated in the documentation:

The screen orientation has changed — the user has rotated the device.

Note: If your application targets API level 13 or higher (as declared
by the minSdkVersion and targetSdkVersion attributes), then you should
also declare the “screenSize” configuration, because it also changes
when a device switches between portrait and landscape orientations.