android - OnClickListener must override a superclass method

/*
public void scrollTo (int x, int y) 
Since: API Level 1 
Set the scrolled position of your view. This will cause a call to onScrollChanged(int, int, int, int) and the view will be invalidated. 

This version also clamps the scrolling to the bounds of our child.

Parameters
x  the x position to scroll to 
y  the y position to scroll to  
  */

// sroll to top of hscrollViewMain
ScrollView hscrollViewMain = (ScrollView)findViewById(R.id.scrollViewMain);
hscrollViewMain.scrollTo(0, 0); // scroll to application top

// get position of a View
EditText hEdit = (EditText)findViewById(R.id.username_edit);
int nY_Pos = hEdit.getTop(); // getBottom(); X_pos  getLeft(); getRight();
// scroll to top of hEdit
hscrollViewMain.scrollTo(0,nY_Pos); 

<LinearLayout
    xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <ScrollView
        android:id="@*id/scrollViewMain"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical"
            android:paddingTop="5dip"
            android:paddingBottom="13dip"
            android:paddingLeft="20dip"
            android:paddingRight="20dip">
            <TextView
                android:id="@+id/message"
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="5dip" />
            <TextView
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:textStyle="bold"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/login_activity_username_label" />
            <EditText
                android:id="@+id/username_edit"
                android:singleLine="true"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:minWidth="250dip"
                android:scrollHorizontally="true"
                android:capitalize="none"
                android:autoText="false"
                android:inputType="textEmailAddress" />
        </LinearLayout>
    </ScrollView>

</LinearLayout>

import java.util.Hashtable;

public class MainClass {
	public static void main(String[] arg) {
		
		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "three;drei" };

	    Hashtable hashTable = new Hashtable();
	    for(String s: arrayOfString){
	    	String[] array = s.split(";");
	    	String sKey ="", sValue="";
	    	if(array.length > 1){
	    	sKey = array[0]; sValue = array[1];
	    		hashTable.put(sKey, sValue);
	    	}
	    }

       // check if key exists 	    
	   if( hashTable.containsKey("two")){
		System.out.print("two = " + hashTable.get("two"));
	   }
	    
	}
}
/*
two = zwei
 */

public class MainActivity extends ActionBarActivity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		if (savedInstanceState == null) {
			getSupportFragmentManager().beginTransaction()
					.add(R.id.containerMoje, new PlaceholderFragment()).commit();
		}
		
	}


	/**
	 * A placeholder fragment containing a simple view.
	 */
	public static class PlaceholderFragment extends Fragment {
		public PlaceholderFragment() {
		}

		@Override
		public View onCreateView(LayoutInflater inflater, ViewGroup container,
				Bundle savedInstanceState) {
			View rootView = inflater.inflate(R.layout.fragment_main, container,
					false);
			if (container == null) {
		        return null;
		    }


			 TextView mText;
			mText = (TextView)rootView.findViewById(R.id.idText);
			mText.setText("Hello from fragment_main");

			return rootView;
		}
	}
}

<FrameLayout xmlns:android="//schemas.android.com/apk/res/android"
    xmlns:tools="//schemas.android.com/tools"
    android:id="@+id/containerMoje"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="cz.okhelp.autoskola.MainActivity"
    tools:ignore="MergeRootFrame" />

<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android"
    xmlns:tools="//schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="cz.okhelp.autoskola.MainActivity$PlaceholderFragment" >

    <TextView
        android:id="@+id/idText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

public void updateList() {
		Context ctx = getActivity();
		Notes notes = new Notes(ctx);

		String[] from = { Notes.COLUMN_TITLE };
		int[] to = { android.R.id.text1 };
		int layout = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ?
				android.R.layout.simple_list_item_activated_1 : android.R.layout.simple_list_item_1;
		ListAdapter adapter = new SimpleCursorAdapter(ctx,
				layout, notes.getNotes(), from,
				to, 0);

		setListAdapter(adapter);

		notes.close();
	}

/..................
@Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        
        // Set the item as checked to be highlighted when in two-pane layout
        getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        getListView().setItemChecked(position, true);
     
    }