/// <summary>
        /// Initializes the entire widget and lays out the class.
        /// </summary>
        /// <param name="selectorTreeStore">The selector tree store.</param>
        private void InitializeWidget(TreeStore selectorTreeStore)
        {
            // Set up the configurator area.
            configuratorArea = new ConfiguratorsSelectorEditorComposite(
                selectorTreeStore);

            VBox.PackStart(configuratorArea, true, true, 0);

            // Depending on the mood determines the buttons we'll have.
            Response += OnResponse;

            if (configuratorArea.ApplyMode == ApplyMode.Explicit)
            {
                // For explict apply, add in the apply, cancel, and ok buttons.
                AddButton("Apply", ResponseType.Apply);
                AddButton("Cancel", ResponseType.Cancel);
                AddButton("Ok", ResponseType.Ok);
            }
            else
            {
                // For instant apply, just have a close button.
                AddButton("Close", ResponseType.Close);
            }

            // Set up spacing.
            BorderWidth = 6;
            VBox.Spacing = 12;
            ActionArea.Spacing = 12;
            ActionArea.BorderWidth = 6;
        }
        /// <summary>
        /// Initializes the entire widget and lays out the class.
        /// </summary>
        /// <param name="selectorTreeStore">The selector tree store.</param>
        /// <param name="showCloseButton">if set to <c>true</c> [show close button].</param>
        private void InitializeWidget(
			TreeStore selectorTreeStore,
			bool showCloseButton)
        {
            // Start by doing the VBox stuff to arrange the top levels, a
            // separator bar, and the button bar below.
            var verticalLayout = new VBox();

            // Set up the configurator area.
            configuratorArea = new ConfiguratorsSelectorEditorComposite(
                selectorTreeStore);

            verticalLayout.PackStart(configuratorArea, true, true, 0);

            // Create the button bar on the bottom.
            Widget buttonBar = CreateButtonBar(showCloseButton);

            if (buttonBar != null)
            {
                // Create the vertical separator. The 12 pixel spacing comes from
                // the Gnome HIG.
                verticalLayout.PackStart(new HSeparator(), false, false, 12);

                // Add the buttons to the list.
                verticalLayout.PackStart(buttonBar, false, false, 0);
            }

            // Add the vertical layout to the bin.
            PackStart(verticalLayout);
        }