title: Set width of SWT Table Column
body: <p>I'm adding column one by one to my swt table. with</p>
  
  <pre><code>int totalwidth=0;
  for(String s:phoneErrs){
      TableColumn tblclmnError = new TableColumn(tablephone, SWT.CENTER);
      tblclmnError.setText(s);
      tblclmnError.pack();
      totalwidth+=tblclmnError.getWidth();
  }
  </code></pre>
  
  <p>and after this I want to add a last column, that should fill the rest of the
  space in table header. Now that I have the total width of the added columns
  already, I should be able to calculate the width of my last column and specify
  it right? but how? I tried </p>
  
  <pre><code>TableColumn tblclmnComment = new TableColumn(tablephone, SWT.CENTER);
  tblclmnComment.setWidth(tablephone.getSize().x-totalwidth);
  tblclmnComment.setText("Comment");
  </code></pre>
  
  <p>but it's not working. the <code>getSize()</code> return <code>0</code>.</p>