Eclipse ADT plugin not recent graphical layout editor

public class TimerActivity extends Activity {
TextView hTextView;
Button hButton, hButtonStop;
private Handler mHandler = new Handler();
private int nCounter = 0;
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        hTextView = (TextView)findViewById(R.id.idTextView);
        hButton = (Button)findViewById(R.id.idButton);
        hButton.setOnClickListener(mButtonStartListener);
        hButtonStop = (Button)findViewById(R.id.idButtonStop);
        hButtonStop.setOnClickListener(mButtonStopListener);
    } // end onCreate

View.OnClickListener mButtonStartListener = new OnClickListener() {
	public void onClick(View v) {
		try {
			mHandler.removeCallbacks(hMyTimeTask);
         //        Parameters
         //        r  The Runnable that will be executed. 
         //        delayMillis  The delay (in milliseconds) until the Runnable will be executed. 
                       mHandler.postDelayed(hMyTimeTask, 1000); // delay 1 second
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
};


private Runnable hMyTimeTask = new Runnable() {
	   public void run() {
		   nCounter++;
	    	   hTextView.setText("Hallo from thread counter: " + nCounter);
	   }
	}; 
/**
 * 
 */
    View.OnClickListener mButtonStopListener = new OnClickListener() {
    	public void onClick(View v) {
    		 mHandler.removeCallbacks(hMyTimeTask);
    		
    	}
    };
}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
	android:id="@+id/idTextView"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<Button android:text="Button" 
android:id="@+id/idButton" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content"></Button>
 
 <Button android:layout_width="wrap_content" 
 android:layout_height="wrap_content" 
 android:id="@+id/idButtonStop" 
 android:text="Stop"></Button> 
    
    
</LinearLayout>

public class MainActivity extends Activity {
Boolean bColorYellow = true;
TextView hTextView;
TableRow hTableRow;
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        hTextView = (TextView)findViewById(R.id.idTextView);
        hTableRow = (TableRow)findViewById(R.id.idTableRow1);


        
        
    } // end onCreate
  
    
    public void myTableRowClickHandler(View view) {
		switch (view.getId()) {
		case R.id.idTableRow1:{
			
			if(bColorYellow){
			hTableRow.setBackgroundColor(Color.GREEN);
			bColorYellow = false;
			}
			else{
			hTableRow.setBackgroundColor(Color.YELLOW);
			bColorYellow = true;
			}
		}
		break;
		}
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >


<TableLayout android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/tableLayout1">
    <TableRow android:id="@+id/idTableRow1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:background="#5655AA"
    android:onClick="@string/myTableRowClick"
    android:focusable="true">
<TextView  
	android:id="@+id/idTextView"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
    
    </TableRow>
</TableLayout>
    
    
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World!</string>
    <string name="app_name">TableRow</string>
    <string name="myTableRowClick">myTableRowClickHandler</string>
</resources>

String s = "Some text for appending

";
 TextView   mTitle = (TextView) findViewById(R.id.title_text);
 mTitle.setText(R.string.app_name); // insert text from strings.xml
 mTitle.append(s); // append string like a variable value
 mTitle.append("My string will appended

"); // append string