Impl #156 - [GroupBy] Improve commands for programmatic groupBy

org.eclipse.nebula.widgets.nattable.core/META-INF/MANIFEST.MF

@@ -90,6 +90,7 @@ Export-Package: org.eclipse.nebula.widgets.nattable;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.group.performance.event;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.group.performance.gui;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.group.performance.painter;version="2.6.0",
+ org.eclipse.nebula.widgets.nattable.groupby;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.hideshow;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.hideshow.command;version="2.6.0",
  org.eclipse.nebula.widgets.nattable.hideshow.event;version="2.6.0",

org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/grid/GridRegion.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2020 Original authors and others.
+ * Copyright (c) 2012, 2025 Original authors and others.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -33,4 +33,8 @@ private GridRegion() {
     public static final String BODY = "BODY"; //$NON-NLS-1$
     public static final String DATAGRID = "DATAGRID"; //$NON-NLS-1$
     public static final String FILTER_ROW = "FILTER_ROW"; //$NON-NLS-1$
+    /**
+     * @since 2.6
+     */
+    public static final String GROUP_BY_REGION = "GROUP_BY_REGION"; //$NON-NLS-1$
 }

org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/groupby/GroupByCommand.java

@@ -0,0 +1,97 @@
+/*******************************************************************************
+ * Copyright (c) 2025 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.groupby;
+
+import org.eclipse.nebula.widgets.nattable.command.ILayerCommand;
+import org.eclipse.nebula.widgets.nattable.layer.ILayer;
+
+/**
+ * Command to trigger a groupBy action.
+ *
+ * @since 2.6
+ */
+public class GroupByCommand implements ILayerCommand {
+
+    public enum GroupByAction {
+        /**
+         * Action to add indexes an existing grouping.
+         */
+        ADD,
+        /**
+         * Action to clear the existing grouping.
+         */
+        CLEAR,
+        /**
+         * Action to remove indexes from an existing grouping.
+         */
+        REMOVE,
+        /**
+         * Action to set indexes as new grouping which overrides the existing
+         * grouping.
+         */
+        SET
+    };
+
+    private final GroupByAction action;
+    private final int[] indexes;
+
+    /**
+     * Performs the specified groupBy action for the given indexes.
+     *
+     * @param action
+     *            The groupBy action to perform
+     *            <ul>
+     *            <li>{@link GroupByAction#ADD} - Add the given indexes to the
+     *            existing grouping.</li>
+     *            <li>{@link GroupByAction#CLEAR} - Clears the existing
+     *            grouping. Given indexes will be ignored.</li>
+     *            <li>{@link GroupByAction#REMOVE} - Removes the given indexes
+     *            from the existing grouping.</li>
+     *            <li>{@link GroupByAction#SET} - Set the given indexes which
+     *            overrides the existing grouping.</li>
+     *            </ul>
+     * @param indexes
+     *            The indexes of the columns/rows that should be grouped.
+     */
+    public GroupByCommand(GroupByAction action, int... indexes) {
+        this.action = action;
+        this.indexes = indexes;
+    }
+
+    /**
+     *
+     * @return The groupBy action to perform.
+     */
+    public GroupByAction getAction() {
+        return this.action;
+    }
+
+    /**
+     *
+     * @return The indexes of the columns/rows that should be grouped.
+     */
+    public int[] getIndexes() {
+        return this.indexes;
+    }
+
+    @Override
+    public GroupByCommand cloneCommand() {
+        return this;
+    }
+
+    @Override
+    public boolean convertToTargetLayer(ILayer targetLayer) {
+        return true;
+    }
+
+}

org.eclipse.nebula.widgets.nattable.examples/src/org/eclipse/nebula/widgets/nattable/examples/_600_GlazedLists/_605_GroupBy/_6053_GroupBySummaryExample.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013, 2021 Dirk Fauth and others.
+ * Copyright (c) 2013, 2025 Dirk Fauth and others.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -52,6 +52,8 @@
 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.groupby.GroupByCommand;
+import org.eclipse.nebula.widgets.nattable.groupby.GroupByCommand.GroupByAction;
 import org.eclipse.nebula.widgets.nattable.hideshow.ColumnHideShowLayer;
 import org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform;
 import org.eclipse.nebula.widgets.nattable.layer.CompositeLayer;
@@ -350,7 +352,7 @@ public void widgetSelected(SelectionEvent e) {
         groupLastFirstButton.addSelectionListener(new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                bodyLayerStack.groupByModel.setGroupByColumnIndexes(1, 0);
+                natTable.doCommand(new GroupByCommand(GroupByAction.SET, 1, 0));
             }
         });
 
@@ -359,7 +361,7 @@ public void widgetSelected(SelectionEvent e) {
         groupFirstLastButton.addSelectionListener(new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                bodyLayerStack.groupByModel.setGroupByColumnIndexes(0, 1);
+                natTable.doCommand(new GroupByCommand(GroupByAction.SET, 0, 1));
             }
         });
 
@@ -368,7 +370,7 @@ public void widgetSelected(SelectionEvent e) {
         groupLastMarriedButton.addSelectionListener(new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                bodyLayerStack.groupByModel.setGroupByColumnIndexes(1, 5);
+                natTable.doCommand(new GroupByCommand(GroupByAction.SET, 1, 5));
             }
         });
 
@@ -377,7 +379,7 @@ public void widgetSelected(SelectionEvent e) {
         clearGroupByButton.addSelectionListener(new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                bodyLayerStack.groupByModel.clearGroupByColumnIndexes();
+                natTable.doCommand(new GroupByCommand(GroupByAction.CLEAR));
             }
         });