Bug 34221 [code manipulation] Comment and uncomment code
The same key ctrl-/ should be used for both comments and uncommenting code. If code isn't commented ctrl-/ will comment. If already commented ctrl-/ will uncomment it. If two levels of comments, uncomment the first, then the second. For example //this is a comment ////this is a second comment hitting ctrl-/ would result in this is a comment //this is a second comment
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ToggleCommentAction.java
* @return <code>true</code> iff all selected lines are single-line commented
	 */
	private boolean isSelectionCommented(ISelection selection) {
		if (!(selection instanceof ITextSelection))
			return false;
			
		ITextSelection ts= (ITextSelection) selection;
		if (ts.getStartLine() < 0 || ts.getEndLine() < 0)
			return false;
		
		IDocument document= getTextEditor().getDocumentProvider().getDocument(getTextEditor().getEditorInput());
		OUTER: for (int i= ts.getStartLine(); i <= ts.getEndLine(); i++) {
			for (int j= 0; j < fCommentPrefixes.length; j++) {
				try {
					if (fCommentPrefixes[j].length() == 0)
						continue;
					String s= document.get(document.getLineOffset(i), document.getLineLength(i));
					int index= s.indexOf(fCommentPrefixes[j]);
					if (index >= 0 && s.substring(0, index).trim().length() == 0)
						continue OUTER;
				} catch (BadLocationException e) {
					
					JavaPlugin.log(e);
				}
			}
			return false;
		}
		return true;
	}
	/**