detecting a click on action bar back button -(OnOptionsItemSelected not calling when click on action bar back button)

Put this on onCreateOptionsMenu method:

MenuItemCompat.setOnActionExpandListener(menu.findItem(R.id.action_search), new MenuItemCompat.OnActionExpandListener() {
    @Override
    public boolean onMenuItemActionExpand(MenuItem item) {

        return true;
    }

    @Override
    public boolean onMenuItemActionCollapse(MenuItem item) {

        //DO SOMETHING WHEN THE SEARCHVIEW IS CLOSING

        return true;
    }
});

You should add meta data your manifest.xml for which activity you want it

Like

<activity
        android:name=".Example"
        android:label="@string/Example"
        android:theme="Theme.AppCompat.Light">
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value=".MainActivity" />
    </activity>

and your code should be like this in Example

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 .......
         getActionBar().setDisplayHomeAsUpEnabled(true);

......
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        // Respond to the action bar's Up/Home button
        case android.R.id.home:
            NavUtils.navigateUpFromSameTask(this);
            return true;
    }
    return super.onOptionsItemSelected(item);
}