Bug 219635 [CellEditors] CheckboxEditor flips state when tabbed into
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CheckboxCellEditor.java
/**
     * The checkbox value.
     */
    
    boolean value = false;
    /**
     * Default CheckboxCellEditor style
     */
    private static final int defaultStyle = SWT.NONE;
    /**
     * Creates a new checkbox cell editor with no control
     * @since 2.1
     */
    public CheckboxCellEditor() {
        setStyle(defaultStyle);
    }
    /**
     * Creates a new checkbox cell editor parented under the given control.
     * The cell editor value is a boolean value, which is initially <code>false</code>. 
     * Initially, the cell editor has no cell validator.
     *
     * @param parent the parent control
     */
    public CheckboxCellEditor(Composite parent) {
        this(parent, defaultStyle);