Bug 64874 [Themes] [Preferences] Colors and Fonts preference page: Doubleclick should edit
RC1 Double clicking an entry in the 'Colors and Fonts' preference page could open the edit dialog
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/ColorSelector.java
* 
     * @param listener
     *            a property change listener
     * @since 3.0
     */
    public void addListener(IPropertyChangeListener listener) {
        listeners.add(listener);
    }
    /**
     * Compute the size of the image to be displayed.
     * 
     * @param window -
     *            the window used to calculate
     * @return <code>Point</code>
     */
    private Point computeImageSize(Control window) {
        GC gc = new GC(window);
        Font f = JFaceResources.getFontRegistry().get(
                JFaceResources.DEFAULT_FONT);
        gc.setFont(f);
        int height = gc.getFontMetrics().getHeight();
        gc.dispose();
        Point p = new Point(height * 3 - 6, height);
        return p;
    }
    /**
     * Get the button control being wrappered by the selector.
     * 
     * @return <code>Button</code>
     */