class StatisticsTopComponent extends TopComponent implements ChangeListener {

    //Model
    private transient StatisticsModelUIImpl model;
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton settingsButton;
    private javax.swing.JPanel statisticsPanel;
    private javax.swing.JToolBar toolbar;
    // End of variables declaration//GEN-END:variables

    public StatisticsTopComponent() {
        initComponents();
        initDesign();
        setName(NbBundle.getMessage(StatisticsTopComponent.class, "CTL_StatisticsTopComponent"));

        putClientProperty(TopComponent.PROP_MAXIMIZATION_DISABLED, Boolean.TRUE);

        //Workspace events
        final StatisticsControllerUI sc = Lookup.getDefault().lookup(StatisticsControllerUI.class);
        ProjectController pc = Lookup.getDefault().lookup(ProjectController.class);
        pc.addWorkspaceListener(new WorkspaceListener() {

            @Override
            public void initialize(Workspace workspace) {
            }

            @Override
            public void select(Workspace workspace) {<FILL_FUNCTION_BODY>}

            @Override
            public void unselect(Workspace workspace) {
            }

            @Override
            public void close(Workspace workspace) {
            }

            @Override
            public void disable() {
                refreshModel(null);
            }
        });

        if (pc.getCurrentWorkspace() != null) {
            StatisticsModelUIImpl model = pc.getCurrentWorkspace().getLookup().lookup(StatisticsModelUIImpl.class);
            if (model == null) {
                model = new StatisticsModelUIImpl(pc.getCurrentWorkspace());
                pc.getCurrentWorkspace().add(model);
            }
            refreshModel(model);
        } else {
            refreshModel(null);
        }

        //Settings
        settingsButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                AvailableStatisticsChooser chooser = new AvailableStatisticsChooser();
                chooser.setup(model, ((StatisticsPanel) statisticsPanel).getCategories());
                DialogDescriptor dd = new DialogDescriptor(chooser,
                    NbBundle.getMessage(StatisticsTopComponent.class, "AvailableStatisticsChooser.title"));
                if (DialogDisplayer.getDefault().notify(dd).equals(NotifyDescriptor.OK_OPTION)) {
                    chooser.unsetup();
                }
            }
        });
    }

    private void refreshModel(StatisticsModelUIImpl model) {
        if (model != null && model != this.model) {
            if (this.model != null) {
                this.model.removeChangeListener(this);
            }
            model.addChangeListener(this);
        }
        this.model = model;
        Lookup.getDefault().lookup(StatisticsControllerUIImpl.class).setup(model);
        refreshEnable(model != null);
        ((StatisticsPanel) statisticsPanel).refreshModel(model);
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        refreshModel(model);
    }

    private void refreshEnable(boolean enable) {
        statisticsPanel.setEnabled(enable);
        toolbar.setEnabled(enable);
        settingsButton.setEnabled(enable);
    }

    private void initDesign() {
        Border b = (Border) UIManager.get("Nb.Editor.Toolbar.border"); //NOI18N
        toolbar.setBorder(b);
        if (UIUtils.isAquaLookAndFeel()) {
            toolbar.setBackground(UIManager.getColor("NbExplorerView.background"));
        }
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {
        java.awt.GridBagConstraints gridBagConstraints;

        toolbar = new javax.swing.JToolBar();
        settingsButton = new javax.swing.JButton();
        statisticsPanel = new StatisticsPanel();

        setLayout(new java.awt.GridBagLayout());

        toolbar.setFloatable(false);
        toolbar.setRollover(true);

        org.openide.awt.Mnemonics.setLocalizedText(settingsButton, org.openide.util.NbBundle
            .getMessage(StatisticsTopComponent.class, "StatisticsTopComponent.settingsButton.text")); // NOI18N
        settingsButton.setFocusable(false);
        settingsButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        settingsButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM);
        toolbar.add(settingsButton);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.NORTH;
        gridBagConstraints.weightx = 1.0;
        add(toolbar, gridBagConstraints);
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        add(statisticsPanel, gridBagConstraints);
    }// </editor-fold>//GEN-END:initComponents

    void writeProperties(java.util.Properties p) {
        // better to version settings since initial version as advocated at
        // http://wiki.apidesign.org/wiki/PropertyFiles
        p.setProperty("version", "1.0");
        // TODO store your settings
    }

    void readProperties(java.util.Properties p) {
        String version = p.getProperty("version");
        // TODO read your settings according to their version
    }
}

                StatisticsModelUIImpl model = workspace.getLookup().lookup(StatisticsModelUIImpl.class);
                if (model == null) {
                    model = new StatisticsModelUIImpl(workspace);
                    workspace.add(model);
                }
                refreshModel(model);
            
<no_super_class>