/*******************************************************************************
 * Copyright (c) 2014, 2020 Dirk Fauth and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *    Dirk Fauth <dirk.fauth@googlemail.com> - initial API and implementation
 *******************************************************************************/
package org.eclipse.nebula.widgets.nattable.examples._800_Integration;

import java.text.NumberFormat;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.nebula.widgets.nattable.NatTable;
import org.eclipse.nebula.widgets.nattable.command.VisualRefreshCommand;
import org.eclipse.nebula.widgets.nattable.config.AbstractRegistryConfiguration;
import org.eclipse.nebula.widgets.nattable.config.CellConfigAttributes;
import org.eclipse.nebula.widgets.nattable.config.ConfigRegistry;
import org.eclipse.nebula.widgets.nattable.config.DefaultNatTableStyleConfiguration;
import org.eclipse.nebula.widgets.nattable.config.IConfigRegistry;
import org.eclipse.nebula.widgets.nattable.config.IConfiguration;
import org.eclipse.nebula.widgets.nattable.data.ExtendedReflectiveColumnPropertyAccessor;
import org.eclipse.nebula.widgets.nattable.data.IColumnPropertyAccessor;
import org.eclipse.nebula.widgets.nattable.data.IDataProvider;
import org.eclipse.nebula.widgets.nattable.data.ListDataProvider;
import org.eclipse.nebula.widgets.nattable.data.convert.DefaultDoubleDisplayConverter;
import org.eclipse.nebula.widgets.nattable.dataset.person.ExtendedPersonWithAddress;
import org.eclipse.nebula.widgets.nattable.dataset.person.PersonService;
import org.eclipse.nebula.widgets.nattable.examples.AbstractNatExample;
import org.eclipse.nebula.widgets.nattable.examples.runner.StandaloneNatExampleRunner;
import org.eclipse.nebula.widgets.nattable.export.ExportConfigAttributes;
import org.eclipse.nebula.widgets.nattable.export.action.ExportAction;
import org.eclipse.nebula.widgets.nattable.export.command.ExportCommandHandler;
import org.eclipse.nebula.widgets.nattable.export.excel.DefaultExportFormatter;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.GlazedListsEventLayer;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.GlazedListsSortModel;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.DarkGroupByThemeExtension;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.DefaultGroupByThemeExtension;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByConfigAttributes;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByConfigLabelModifier;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByDataLayer;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByHeaderLayer;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByHeaderMenuConfiguration;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.GroupByModel;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.ModernGroupByThemeExtension;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.summary.IGroupBySummaryProvider;
import org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy.summary.SummationGroupBySummaryProvider;
import org.eclipse.nebula.widgets.nattable.extension.poi.HSSFExcelExporter;
import org.eclipse.nebula.widgets.nattable.extension.poi.PoiExcelExporter;
import org.eclipse.nebula.widgets.nattable.grid.data.DefaultColumnHeaderDataProvider;
import org.eclipse.nebula.widgets.nattable.grid.data.DefaultCornerDataProvider;
import org.eclipse.nebula.widgets.nattable.grid.data.DefaultSummaryRowHeaderDataProvider;
import org.eclipse.nebula.widgets.nattable.grid.layer.ColumnHeaderLayer;
import org.eclipse.nebula.widgets.nattable.grid.layer.CornerLayer;
import org.eclipse.nebula.widgets.nattable.grid.layer.DefaultColumnHeaderDataLayer;
import org.eclipse.nebula.widgets.nattable.grid.layer.DefaultRowHeaderDataLayer;
import org.eclipse.nebula.widgets.nattable.grid.layer.GridLayer;
import org.eclipse.nebula.widgets.nattable.grid.layer.RowHeaderLayer;
import org.eclipse.nebula.widgets.nattable.hideshow.ColumnHideShowLayer;
import org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform;
import org.eclipse.nebula.widgets.nattable.layer.CompositeLayer;
import org.eclipse.nebula.widgets.nattable.layer.DataLayer;
import org.eclipse.nebula.widgets.nattable.layer.ILayer;
import org.eclipse.nebula.widgets.nattable.layer.LabelStack;
import org.eclipse.nebula.widgets.nattable.layer.cell.AbstractOverrider;
import org.eclipse.nebula.widgets.nattable.layer.cell.ColumnLabelAccumulator;
import org.eclipse.nebula.widgets.nattable.painter.NatTableBorderOverlayPainter;
import org.eclipse.nebula.widgets.nattable.painter.cell.CheckBoxPainter;
import org.eclipse.nebula.widgets.nattable.painter.layer.GridLineCellLayerPainter;
import org.eclipse.nebula.widgets.nattable.persistence.command.DisplayPersistenceDialogCommandHandler;
import org.eclipse.nebula.widgets.nattable.reorder.ColumnReorderLayer;
import org.eclipse.nebula.widgets.nattable.selection.SelectionLayer;
import org.eclipse.nebula.widgets.nattable.sort.SortHeaderLayer;
import org.eclipse.nebula.widgets.nattable.sort.config.SingleClickSortConfiguration;
import org.eclipse.nebula.widgets.nattable.style.CellStyleAttributes;
import org.eclipse.nebula.widgets.nattable.style.DisplayMode;
import org.eclipse.nebula.widgets.nattable.style.HorizontalAlignmentEnum;
import org.eclipse.nebula.widgets.nattable.style.IStyle;
import org.eclipse.nebula.widgets.nattable.style.Style;
import org.eclipse.nebula.widgets.nattable.style.theme.DarkNatTableThemeConfiguration;
import org.eclipse.nebula.widgets.nattable.style.theme.DefaultNatTableThemeConfiguration;
import org.eclipse.nebula.widgets.nattable.style.theme.ModernNatTableThemeConfiguration;
import org.eclipse.nebula.widgets.nattable.style.theme.ThemeConfiguration;
import org.eclipse.nebula.widgets.nattable.summaryrow.FixedSummaryRowLayer;
import org.eclipse.nebula.widgets.nattable.summaryrow.ISummaryProvider;
import org.eclipse.nebula.widgets.nattable.summaryrow.SummaryDisplayConverter;
import org.eclipse.nebula.widgets.nattable.summaryrow.SummaryRowConfigAttributes;
import org.eclipse.nebula.widgets.nattable.summaryrow.SummaryRowLayer;
import org.eclipse.nebula.widgets.nattable.summaryrow.SummationSummaryProvider;
import org.eclipse.nebula.widgets.nattable.tree.TreeLayer;
import org.eclipse.nebula.widgets.nattable.tree.command.TreeCollapseAllCommand;
import org.eclipse.nebula.widgets.nattable.tree.command.TreeExpandAllCommand;
import org.eclipse.nebula.widgets.nattable.tree.config.TreeLayerExpandCollapseKeyBindings;
import org.eclipse.nebula.widgets.nattable.ui.binding.UiBindingRegistry;
import org.eclipse.nebula.widgets.nattable.ui.matcher.KeyEventMatcher;
import org.eclipse.nebula.widgets.nattable.ui.menu.AbstractHeaderMenuConfiguration;
import org.eclipse.nebula.widgets.nattable.ui.menu.PopupMenuBuilder;
import org.eclipse.nebula.widgets.nattable.viewport.ViewportLayer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.GlazedLists;
import ca.odell.glazedlists.SortedList;
import ca.odell.glazedlists.TransformedList;

/**
 * Simple example showing how to add the group by feature to the layer
 * composition of a grid in conjunction with showing summary values of
 * groupings.
 */
public class _811_GroupBySummaryFixedSummaryRowExample extends AbstractNatExample {

    private static final String ROW_HEADER_SUMMARY_ROW = "rowHeaderSummaryRowLabel";

    private IGroupBySummaryProvider<ExtendedPersonWithAddress> sumMoneyGroupBySummaryProvider;
    private IGroupBySummaryProvider<ExtendedPersonWithAddress> avgMoneyGroupBySummaryProvider;

    private ISummaryProvider sumMoneySummaryProvider;
    private ISummaryProvider avgMoneySummaryProvider;

    private boolean useMoneySum = true;

    private int currentTheme = 1;

    public static void main(String[] args) throws Exception {
        StandaloneNatExampleRunner.run(800, 600, new _811_GroupBySummaryFixedSummaryRowExample());
    }

    @Override
    public String getDescription() {
        return "This example shows the usage of the group by feature in conjunction with summary values of the groupings "
                + "and a fixed summary row at the bottom.";
    }

    @Override
    public Control createExampleControl(Composite parent) {
        Composite container = new Composite(parent, SWT.NONE);
        container.setLayout(new GridLayout());

        // create a new ConfigRegistry which will be needed for GlazedLists
        // handling
        final ConfigRegistry configRegistry = new ConfigRegistry();

        // property names of the ExtendedPersonWithAddress class
        String[] propertyNames = { "firstName", "lastName", "age", "money",
                "married", "gender", "birthday" };

        // mapping from property to label, needed for column header labels
        Map<String, String> propertyToLabelMap = new HashMap<>();
        propertyToLabelMap.put("firstName", "Firstname");
        propertyToLabelMap.put("lastName", "Lastname");
        propertyToLabelMap.put("age", "Age");
        propertyToLabelMap.put("money", "Money");
        propertyToLabelMap.put("married", "Married");
        propertyToLabelMap.put("gender", "Gender");
        propertyToLabelMap.put("birthday", "Birthday");

        final IColumnPropertyAccessor<ExtendedPersonWithAddress> columnPropertyAccessor =
                new ExtendedReflectiveColumnPropertyAccessor<>(propertyNames);

        // to enable the group by summary feature, the GroupByDataLayer needs to
        // know the ConfigRegistry
        List<ExtendedPersonWithAddress> persons = PersonService.getExtendedPersonsWithAddress(10);
        final BodyLayerStack<ExtendedPersonWithAddress> bodyLayerStack =
                new BodyLayerStack<>(persons, columnPropertyAccessor, configRegistry);

        bodyLayerStack.getBodyDataLayer().setConfigLabelAccumulator(new ColumnLabelAccumulator());

        // build the column header layer
        IDataProvider columnHeaderDataProvider =
                new DefaultColumnHeaderDataProvider(propertyNames, propertyToLabelMap);
        DataLayer columnHeaderDataLayer =
                new DefaultColumnHeaderDataLayer(columnHeaderDataProvider);
        ILayer columnHeaderLayer =
                new ColumnHeaderLayer(columnHeaderDataLayer, bodyLayerStack, bodyLayerStack.getSelectionLayer());

        // add sorting
        SortHeaderLayer<ExtendedPersonWithAddress> sortHeaderLayer =
                new SortHeaderLayer<>(
                        columnHeaderLayer,
                        new GlazedListsSortModel<>(
                                bodyLayerStack.getSortedList(), columnPropertyAccessor,
                                configRegistry, columnHeaderDataLayer),
                        false);

        // connect sortModel to GroupByDataLayer to support sorting by group by
        // summary values
        bodyLayerStack.getBodyDataLayer().initializeTreeComparator(
                sortHeaderLayer.getSortModel(),
                bodyLayerStack.getTreeLayer(),
                true);

        // build the row header layer
        // Adding the specialized DefaultSummaryRowHeaderDataProvider to
        // indicate the summary row in the row header
        IDataProvider rowHeaderDataProvider =
                new DefaultSummaryRowHeaderDataProvider(bodyLayerStack.getBodyDataProvider(), "\u2211");
        final DataLayer rowHeaderDataLayer =
                new DefaultRowHeaderDataLayer(rowHeaderDataProvider);
        ILayer rowHeaderLayer =
                new RowHeaderLayer(rowHeaderDataLayer, bodyLayerStack, bodyLayerStack.getSelectionLayer());

        // build the corner layer
        IDataProvider cornerDataProvider =
                new DefaultCornerDataProvider(columnHeaderDataProvider, rowHeaderDataProvider);
        DataLayer cornerDataLayer =
                new DataLayer(cornerDataProvider);
        ILayer cornerLayer =
                new CornerLayer(cornerDataLayer, rowHeaderLayer, sortHeaderLayer);

        // build the grid layer
        GridLayer gridLayer =
                new GridLayer(bodyLayerStack, sortHeaderLayer, rowHeaderLayer, cornerLayer, false);

        FixedSummaryRowLayer summaryRowLayer =
                new FixedSummaryRowLayer(bodyLayerStack.getGlazedListsEventLayer(), gridLayer, configRegistry, false);
        summaryRowLayer.setSummaryRowLabel("\u2211");
        summaryRowLayer.setConfigLabelAccumulator(new AbstractOverrider() {
            @Override
            public void accumulateConfigLabels(LabelStack configLabels, int columnPosition, int rowPosition) {
                if (columnPosition == 0) {
                    // our label is more important regarding styling than the
                    // summary row labels
                    configLabels.addLabelOnTop(ROW_HEADER_SUMMARY_ROW);
                }
            }
        });

        // ensure the body data layer uses a layer painter with correct
        // configured clipping
        bodyLayerStack.getBodyDataLayer().setLayerPainter(new GridLineCellLayerPainter(false, true));

        // set the group by header on top of the grid
        CompositeLayer compositeGridLayer = new CompositeLayer(1, 3);
        final GroupByHeaderLayer groupByHeaderLayer = new GroupByHeaderLayer(
                bodyLayerStack.getGroupByModel(),
                gridLayer,
                columnHeaderDataProvider);
        compositeGridLayer.setChildLayer(
                GroupByHeaderLayer.GROUP_BY_REGION,
                groupByHeaderLayer,
                0, 0);
        compositeGridLayer.setChildLayer("Grid", gridLayer, 0, 1);
        compositeGridLayer.setChildLayer("Summary", summaryRowLayer, 0, 2);

        // add the export configuration to the composite layer
        compositeGridLayer.registerCommandHandler(new ExportCommandHandler(compositeGridLayer));
        compositeGridLayer.addConfiguration(new IConfiguration() {

            @Override
            public void configureUiBindings(UiBindingRegistry uiBindingRegistry) {
                uiBindingRegistry.registerKeyBinding(
                        new KeyEventMatcher(SWT.MOD1, 'e'), new ExportAction());
            }

            @Override
            public void configureRegistry(IConfigRegistry configRegistry) {
                PoiExcelExporter exporter = new HSSFExcelExporter();
                exporter.setApplyBackgroundColor(false);
                configRegistry.registerConfigAttribute(
                        ExportConfigAttributes.EXPORTER,
                        exporter);
                configRegistry.registerConfigAttribute(
                        ExportConfigAttributes.EXPORT_FORMATTER,
                        new DefaultExportFormatter());
                configRegistry.registerConfigAttribute(
                        ExportConfigAttributes.DATE_FORMAT, "m/d/yy h:mm"); //$NON-NLS-1$
            }

            @Override
            public void configureLayer(ILayer layer) {
            }
        });

        // turn the auto configuration off as we want to add our header menu
        // configuration
        final NatTable natTable = new NatTable(container, compositeGridLayer, false);

        // as the autoconfiguration of the NatTable is turned off, we have to
        // add the DefaultNatTableStyleConfiguration and the ConfigRegistry
        // manually
        natTable.setConfigRegistry(configRegistry);
        natTable.addConfiguration(new DefaultNatTableStyleConfiguration());

        // add some additional styling
        natTable.addConfiguration(new AbstractRegistryConfiguration() {

            @Override
            public void configureRegistry(IConfigRegistry configRegistry) {
                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.CELL_PAINTER,
                        new CheckBoxPainter(),
                        DisplayMode.NORMAL,
                        ColumnLabelAccumulator.COLUMN_LABEL_PREFIX + 4);

                IStyle style = new Style();
                style.setAttributeValue(
                        CellStyleAttributes.HORIZONTAL_ALIGNMENT,
                        HorizontalAlignmentEnum.RIGHT);
                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.CELL_STYLE,
                        style,
                        DisplayMode.NORMAL,
                        ColumnLabelAccumulator.COLUMN_LABEL_PREFIX + 2);
                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.CELL_STYLE,
                        style,
                        DisplayMode.NORMAL,
                        ColumnLabelAccumulator.COLUMN_LABEL_PREFIX + 3);

                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.DISPLAY_CONVERTER,
                        new DefaultDoubleDisplayConverter(),
                        DisplayMode.NORMAL,
                        ColumnLabelAccumulator.COLUMN_LABEL_PREFIX + 3);

                // the main styling of the summary row cell in the row header is
                // done via summary row default style, but we need to override
                // the alignment
                style = new Style();
                style.setAttributeValue(
                        CellStyleAttributes.HORIZONTAL_ALIGNMENT,
                        HorizontalAlignmentEnum.CENTER);
                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.CELL_STYLE,
                        style,
                        DisplayMode.NORMAL, ROW_HEADER_SUMMARY_ROW);
                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.CELL_STYLE,
                        style,
                        DisplayMode.SELECT, ROW_HEADER_SUMMARY_ROW);
            }
        });

        // add sorting configuration
        natTable.addConfiguration(new SingleClickSortConfiguration());

        this.sumMoneyGroupBySummaryProvider =
                new SummationGroupBySummaryProvider<>(columnPropertyAccessor);
        this.avgMoneyGroupBySummaryProvider = new AverageMoneyGroupBySummaryProvider();

        // create a new IDataProvider that operates on the basic underlying list
        // this is necessary because the IDataProvider in the body layer stack
        // is operating on the TreeList, and on collapsing a node, the children
        // will be not visible, which has effect on the summary value.
        final IDataProvider summaryDataProvider =
                new ListDataProvider<>(bodyLayerStack.getSortedList(), columnPropertyAccessor);
        this.sumMoneySummaryProvider = new SummationSummaryProvider(summaryDataProvider, false);
        this.avgMoneySummaryProvider = new AverageMoneySummaryProvider(summaryDataProvider);

        // add group by summary configuration
        natTable.addConfiguration(new AbstractRegistryConfiguration() {

            @Override
            public void configureRegistry(IConfigRegistry configRegistry) {
                // GroupBy summary configuration
                configRegistry.registerConfigAttribute(
                        GroupByConfigAttributes.GROUP_BY_SUMMARY_PROVIDER,
                        _811_GroupBySummaryFixedSummaryRowExample.this.sumMoneyGroupBySummaryProvider,
                        DisplayMode.NORMAL,
                        GroupByDataLayer.GROUP_BY_COLUMN_PREFIX + 3);

                configRegistry.registerConfigAttribute(
                        GroupByConfigAttributes.GROUP_BY_SUMMARY_PROVIDER,
                        new AverageAgeGroupBySummaryProvider(),
                        DisplayMode.NORMAL,
                        GroupByDataLayer.GROUP_BY_COLUMN_PREFIX + 2);

                configRegistry.registerConfigAttribute(
                        GroupByConfigAttributes.GROUP_BY_CHILD_COUNT_PATTERN,
                        "[{0}] - ({1})");

                // SummaryRow configuration
                configRegistry.registerConfigAttribute(
                        SummaryRowConfigAttributes.SUMMARY_PROVIDER,
                        _811_GroupBySummaryFixedSummaryRowExample.this.sumMoneySummaryProvider,
                        DisplayMode.NORMAL,
                        SummaryRowLayer.DEFAULT_SUMMARY_COLUMN_CONFIG_LABEL_PREFIX + 3);

                configRegistry.registerConfigAttribute(
                        SummaryRowConfigAttributes.SUMMARY_PROVIDER,
                        new AverageAgeSummaryProvider(summaryDataProvider),
                        DisplayMode.NORMAL,
                        SummaryRowLayer.DEFAULT_SUMMARY_COLUMN_CONFIG_LABEL_PREFIX + 2);

                configRegistry.registerConfigAttribute(
                        CellConfigAttributes.DISPLAY_CONVERTER,
                        new SummaryDisplayConverter(new DefaultDoubleDisplayConverter()),
                        DisplayMode.NORMAL,
                        SummaryRowLayer.DEFAULT_SUMMARY_COLUMN_CONFIG_LABEL_PREFIX + 3);
            }
        });

        // add group by header configuration
        natTable.addConfiguration(new GroupByHeaderMenuConfiguration(natTable, groupByHeaderLayer));

        natTable.addConfiguration(new AbstractHeaderMenuConfiguration(natTable) {

            @Override
            protected PopupMenuBuilder createColumnHeaderMenu(NatTable natTable) {
                return super.createColumnHeaderMenu(natTable)
                        .withHideColumnMenuItem().withShowAllColumnsMenuItem()
                        .withStateManagerMenuItemProvider();
            }

            @Override
            protected PopupMenuBuilder createCornerMenu(NatTable natTable) {
                return super.createCornerMenu(natTable)
                        .withShowAllColumnsMenuItem()
                        .withStateManagerMenuItemProvider();
            }
        });

        // adds the key bindings that allow space bar to be pressed to
        // expand/collapse tree nodes
        natTable.addConfiguration(
                new TreeLayerExpandCollapseKeyBindings(
                        bodyLayerStack.getTreeLayer(),
                        bodyLayerStack.getSelectionLayer()));

        natTable.configure();

        // set the modern theme to visualize the summary better
        final ThemeConfiguration defaultTheme = new DefaultNatTableThemeConfiguration();
        defaultTheme.addThemeExtension(new DefaultGroupByThemeExtension());

        final ThemeConfiguration modernTheme = new ModernNatTableThemeConfiguration();
        modernTheme.addThemeExtension(new ModernGroupByThemeExtension());

        final ThemeConfiguration darkTheme = new DarkNatTableThemeConfiguration();
        darkTheme.addThemeExtension(new DarkGroupByThemeExtension());

        natTable.setTheme(modernTheme);

        // add a border on every side of the table
        natTable.addOverlayPainter(new NatTableBorderOverlayPainter());

        natTable.registerCommandHandler(new DisplayPersistenceDialogCommandHandler(natTable));

        GridDataFactory.fillDefaults().grab(true, true).applyTo(natTable);

        Composite buttonPanel = new Composite(container, SWT.NONE);
        buttonPanel.setLayout(new RowLayout());
        GridDataFactory.fillDefaults().grab(true, false).applyTo(buttonPanel);

        Button toggleHeaderButton = new Button(buttonPanel, SWT.PUSH);
        toggleHeaderButton.setText("Toggle Group By Header");
        toggleHeaderButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                groupByHeaderLayer.setVisible(!groupByHeaderLayer.isVisible());
            }
        });

        Button collapseAllButton = new Button(buttonPanel, SWT.PUSH);
        collapseAllButton.setText("Collapse All");
        collapseAllButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                natTable.doCommand(new TreeCollapseAllCommand());
            }
        });

        Button expandAllButton = new Button(buttonPanel, SWT.PUSH);
        expandAllButton.setText("Expand All");
        expandAllButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                natTable.doCommand(new TreeExpandAllCommand());
            }
        });

        Button toggleMoneySummaryButton = new Button(buttonPanel, SWT.PUSH);
        toggleMoneySummaryButton.setText("Toggle Money Group Summary (SUM/AVG)");
        toggleMoneySummaryButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                // clear the group by summary cache so the new summary
                // calculation gets triggered
                bodyLayerStack.getBodyDataLayer().clearCache();

                _811_GroupBySummaryFixedSummaryRowExample.this.useMoneySum = !_811_GroupBySummaryFixedSummaryRowExample.this.useMoneySum;
                if (_811_GroupBySummaryFixedSummaryRowExample.this.useMoneySum) {
                    configRegistry.registerConfigAttribute(
                            GroupByConfigAttributes.GROUP_BY_SUMMARY_PROVIDER,
                            _811_GroupBySummaryFixedSummaryRowExample.this.sumMoneyGroupBySummaryProvider,
                            DisplayMode.NORMAL,
                            GroupByDataLayer.GROUP_BY_COLUMN_PREFIX + 3);

                    configRegistry.registerConfigAttribute(
                            SummaryRowConfigAttributes.SUMMARY_PROVIDER,
                            _811_GroupBySummaryFixedSummaryRowExample.this.sumMoneySummaryProvider,
                            DisplayMode.NORMAL,
                            SummaryRowLayer.DEFAULT_SUMMARY_COLUMN_CONFIG_LABEL_PREFIX + 3);

                } else {
                    configRegistry.registerConfigAttribute(
                            GroupByConfigAttributes.GROUP_BY_SUMMARY_PROVIDER,
                            _811_GroupBySummaryFixedSummaryRowExample.this.avgMoneyGroupBySummaryProvider,
                            DisplayMode.NORMAL,
                            GroupByDataLayer.GROUP_BY_COLUMN_PREFIX + 3);

                    configRegistry.registerConfigAttribute(
                            SummaryRowConfigAttributes.SUMMARY_PROVIDER,
                            _811_GroupBySummaryFixedSummaryRowExample.this.avgMoneySummaryProvider,
                            DisplayMode.NORMAL,
                            SummaryRowLayer.DEFAULT_SUMMARY_COLUMN_CONFIG_LABEL_PREFIX + 3);
                }
                natTable.doCommand(new VisualRefreshCommand());
            }
        });

        Button toggleThemeButton = new Button(buttonPanel, SWT.PUSH);
        toggleThemeButton.setText("Toggle Theme");
        toggleThemeButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                if (_811_GroupBySummaryFixedSummaryRowExample.this.currentTheme == 0) {
                    natTable.setTheme(modernTheme);
                    _811_GroupBySummaryFixedSummaryRowExample.this.currentTheme++;
                } else if (_811_GroupBySummaryFixedSummaryRowExample.this.currentTheme == 1) {
                    natTable.setTheme(darkTheme);
                    _811_GroupBySummaryFixedSummaryRowExample.this.currentTheme++;
                } else if (_811_GroupBySummaryFixedSummaryRowExample.this.currentTheme == 2) {
                    natTable.setTheme(defaultTheme);
                    _811_GroupBySummaryFixedSummaryRowExample.this.currentTheme = 0;
                }
            }
        });

        Button button = new Button(buttonPanel, SWT.PUSH);
        button.setText("Add Row");
        button.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                bodyLayerStack.getSortedList().add(
                        PersonService.createExtendedPersonWithAddress(bodyLayerStack.getSortedList().size()));
            }
        });

        return container;
    }

    /**
     * Always encapsulate the body layer stack in an AbstractLayerTransform to
     * ensure that the index transformations are performed in later commands.
     *
     * @param <T>
     */
    class BodyLayerStack<T> extends AbstractLayerTransform {

        private final SortedList<T> sortedList;

        private final IDataProvider bodyDataProvider;

        private final GroupByDataLayer<T> bodyDataLayer;

        private final GlazedListsEventLayer<T> glazedListsEventLayer;

        private final SelectionLayer selectionLayer;

        private final TreeLayer treeLayer;

        private final GroupByModel groupByModel = new GroupByModel();

        public BodyLayerStack(List<T> values,
                IColumnPropertyAccessor<T> columnPropertyAccessor,
                ConfigRegistry configRegistry) {
            // wrapping of the list to show into GlazedLists
            // see http://publicobject.com/glazedlists/ for further information
            EventList<T> eventList = GlazedLists.eventList(values);
            TransformedList<T, T> rowObjectsGlazedList = GlazedLists.threadSafeList(eventList);

            // use the SortedList constructor with 'null' for the Comparator
            // because the Comparator
            // will be set by configuration
            this.sortedList = new SortedList<>(rowObjectsGlazedList, null);

            // Use the GroupByDataLayer instead of the default DataLayer
            this.bodyDataLayer =
                    new GroupByDataLayer<>(getGroupByModel(), this.sortedList, columnPropertyAccessor, configRegistry);
            // get the IDataProvider that was created by the GroupByDataLayer
            this.bodyDataProvider =
                    this.bodyDataLayer.getDataProvider();

            // layer for event handling of GlazedLists and PropertyChanges
            this.glazedListsEventLayer =
                    new GlazedListsEventLayer<>(this.bodyDataLayer, this.sortedList);

            ColumnReorderLayer columnReorderLayer = new ColumnReorderLayer(this.glazedListsEventLayer);
            ColumnHideShowLayer columnHideShowLayer = new ColumnHideShowLayer(columnReorderLayer);
            this.selectionLayer = new SelectionLayer(columnHideShowLayer);

            // add a tree layer to visualise the grouping
            this.treeLayer = new TreeLayer(this.selectionLayer, this.bodyDataLayer.getTreeRowModel());

            ViewportLayer viewportLayer = new ViewportLayer(this.treeLayer);

            // this will avoid tree specific rendering regarding alignment and
            // indentation in case no grouping is active
            viewportLayer.setConfigLabelAccumulator(new GroupByConfigLabelModifier(getGroupByModel()));

            setUnderlyingLayer(viewportLayer);
        }

        public SelectionLayer getSelectionLayer() {
            return this.selectionLayer;
        }

        public TreeLayer getTreeLayer() {
            return this.treeLayer;
        }

        public SortedList<T> getSortedList() {
            return this.sortedList;
        }

        public IDataProvider getBodyDataProvider() {
            return this.bodyDataProvider;
        }

        public GroupByDataLayer<T> getBodyDataLayer() {
            return this.bodyDataLayer;
        }

        public GlazedListsEventLayer<T> getGlazedListsEventLayer() {
            return this.glazedListsEventLayer;
        }

        public GroupByModel getGroupByModel() {
            return this.groupByModel;
        }
    }

    /**
     * Example implementation for a typed IGroupBySummaryProvider that
     * calculates the average age of ExtendedPersonWithAddress objects in a
     * grouping.
     */
    class AverageAgeGroupBySummaryProvider implements IGroupBySummaryProvider<ExtendedPersonWithAddress> {

        @Override
        public Object summarize(int columnIndex, List<ExtendedPersonWithAddress> children) {
            int summaryValue = 0;
            for (ExtendedPersonWithAddress child : children) {
                summaryValue += child.getAge();
            }
            return summaryValue / (children.size() > 0 ? children.size() : 1);
        }

    }

    /**
     * Example implementation for a typed IGroupBySummaryProvider that
     * calculates the average money of ExtendedPersonWithAddress objects in a
     * grouping.
     */
    class AverageMoneyGroupBySummaryProvider implements IGroupBySummaryProvider<ExtendedPersonWithAddress> {

        @Override
        public Object summarize(int columnIndex, List<ExtendedPersonWithAddress> children) {
            double summaryValue = 0;
            for (ExtendedPersonWithAddress child : children) {
                summaryValue += child.getMoney();
            }

            NumberFormat format = NumberFormat.getInstance();
            format.setMaximumFractionDigits(2);

            return format.format(summaryValue / (children.size() > 0 ? children.size() : 1));
        }

    }

    /**
     * Example implementation for a ISummaryProvider that calculates the average
     * age of ExtendedPersonWithAddress objects.
     */
    class AverageAgeSummaryProvider implements ISummaryProvider {

        private IDataProvider dataProvider;

        public AverageAgeSummaryProvider(IDataProvider dataProvider) {
            this.dataProvider = dataProvider;
        }

        @Override
        public Object summarize(int columnIndex) {
            double total = 0;
            int rowCount = this.dataProvider.getRowCount();
            int valueRows = 0;

            for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
                Object dataValue = this.dataProvider.getDataValue(columnIndex, rowIndex);
                // this check is necessary because of the GroupByObject
                if (dataValue instanceof Number) {
                    total = total + Double.parseDouble(dataValue.toString());
                    valueRows++;
                }
            }
            return "Avg: " + String.format("%.2f", total / (valueRows > 0 ? valueRows : 1));
        }

    }

    /**
     * Example implementation for a ISummaryProvider that calculates the average
     * money of ExtendedPersonWithAddress objects.
     */
    class AverageMoneySummaryProvider implements ISummaryProvider {

        private IDataProvider dataProvider;

        public AverageMoneySummaryProvider(IDataProvider dataProvider) {
            this.dataProvider = dataProvider;
        }

        @Override
        public Object summarize(int columnIndex) {
            double total = 0;
            int rowCount = this.dataProvider.getRowCount();
            int valueRows = 0;

            for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
                Object dataValue = this.dataProvider.getDataValue(columnIndex, rowIndex);
                // this check is necessary because of the GroupByObject
                if (dataValue instanceof Number) {
                    total = total + Double.parseDouble(dataValue.toString());
                    valueRows++;
                }
            }
            return "Avg: " + String.format("%.2f", total / (valueRows > 0 ? valueRows : 1));
        }

    }

}