Add ugly buttons for switching class tree logic.

     */

    initComponent: function() {

        var tree = new Docs.view.cls.InheritanceLogic({classes: this.data, showPrivateClasses: true});

        this.root = tree.create();

        this.setLogic(Docs.view.cls.PackageLogic);

        this.buttons = [

            {

                xtype: 'button',

                text: 'By package',

                toggleGroup: 'logic',

                pressed: true,

                allowDepress: false,

                handler: function() {

                    this.setLogic(Docs.view.cls.PackageLogic);

                },

                scope: this

            },

            {

                xtype: 'button',

                text: 'By inheritance',

                toggleGroup: 'logic',

                allowDepress: false,

                handler: function() {

                    this.setLogic(Docs.view.cls.InheritanceLogic);

                },

                scope: this

            }

        ];

        this.callParent();

    },

    setLogic: function(logic) {

        var tree = new logic({classes: this.data, showPrivateClasses: true});

        if (this.root) {

            // remember the current selection

            var selected = this.getSelectionModel().getLastSelected();

            // create new treestructure

            var root = tree.create();

            this.setRootNode(root);

            this.initNodeLinks();

            // expand first child

            this.getRootNode().getChildAt(0).expand();

            // re-establish the previous selection

            selected && this.selectUrl(selected.raw.url);

        }

        else {

            this.root = tree.create();

        }

    }

});