title: Selecting multiple rows on CheckboxTreeViewer without using the 'ctrl' button
body: <p>I have created a <a href="https://github.com/eclipse/eclipse.platform.ui/blob/master/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CheckboxTreeViewer.java" rel="nofollow noreferrer">checkboxtreeviewer</a> using the JFace library. I have created the tree viewer as below</p>
  
  <pre class="lang-java prettyprint-override"><code>Tree tree = new Tree(parent,SWT.CHECK | SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL | SWT.FULL_SELECTION | SWT.MULTI);
  
  CheckboxTreeViewer checkboxTreeViewer = new CheckboxTreeViewer(tree);
  </code></pre>
  
  <p>The SWT.MULTI allows me to select(highlight) multiple rows of the tree using the 'CTRL key.</p>
  
  <p>Is there a way we can select multiple rows without using the ctrl key. One way i know of is using the setSelection() method, which cannot be used since that causes a flickering effect when the user goes from one row to another , the Tree.java would deselect all the existing rows and then highlight the rows that are called in the setSelection method. </p>
  
  <p>I feel the code <a href="https://github.com/eclipse/eclipse.platform.swt/blob/master/bundles/org.eclipse.swt/Eclipse%20SWT/win32/org/eclipse/swt/widgets/Tree.java#L6705-L6710" rel="nofollow noreferrer">here</a> is causing a deselect to all rows and then a select on the row selected by the user.</p>