DistributeHorizontallyHandler.java

/**
 * Copyright (c) 2004-2025 Carnegie Mellon University and others. (see Contributors file).
 * All Rights Reserved.
 *
 * NO WARRANTY. ALL MATERIAL IS FURNISHED ON AN "AS-IS" BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY
 * KIND, EITHER EXPRESSED OR IMPLIED, AS TO ANY MATTER INCLUDING, BUT NOT LIMITED TO, WARRANTY OF FITNESS FOR PURPOSE
 * OR MERCHANTABILITY, EXCLUSIVITY, OR RESULTS OBTAINED FROM USE OF THE MATERIAL. CARNEGIE MELLON UNIVERSITY DOES NOT
 * MAKE ANY WARRANTY OF ANY KIND WITH RESPECT TO FREEDOM FROM PATENT, TRADEMARK, OR COPYRIGHT INFRINGEMENT.
 *
 * 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
 *
 * Created, in part, with funding and support from the United States Government. (see Acknowledgments file).
 *
 * This program includes and/or can make use of certain third party source code, object code, documentation and other
 * files ("Third Party Software"). The Third Party Software that is used by this program is dependent upon your system
 * configuration. By using this program, You agree to comply with any and all relevant Third Party Software terms and
 * conditions contained in any such Third Party Software or separate license file distributed with such Third Party
 * Software. The parties who own the Third Party Software ("Third Party Licensors") are intended third party benefici-
 * aries to this license with respect to the terms applicable to their Third Party Software. Third Party Software li-
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 */
package org.osate.ge.internal.ui.handlers;

import java.util.Comparator;
import java.util.List;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.osate.ge.graphics.Point;
import org.osate.ge.internal.diagram.runtime.AgeDiagram;
import org.osate.ge.internal.diagram.runtime.DiagramElement;
import org.osate.ge.internal.diagram.runtime.layout.DiagramElementLayoutUtil;
import org.osate.ge.internal.ui.util.UiUtil;

/**
 * Handler for the distribute horizontally command
 */
public class DistributeHorizontallyHandler extends AbstractHandler {
	/**
	 * Distributes shapes along the X axis so each shape has an equal distance between them
	 */
	@Override
	public Object execute(final ExecutionEvent event) throws ExecutionException {
		final List<DiagramElement> selectedDiagramElements = AgeHandlerUtil.getSelectedDiagramElements();
		final AgeDiagram diagram = UiUtil.getDiagram(selectedDiagramElements);
		if (diagram == null) {
			throw new RuntimeException("Unable to get diagram");
		}

		diagram.modify("Distribute Horizontally", m -> {
			selectedDiagramElements.sort(XValueComparator);

			// Distribute the shapes horizontally
			final double xDistribution = getXDistribution(selectedDiagramElements);
			for (int i = 1; i < selectedDiagramElements.size() - 1; i++) {
				final DiagramElement de = selectedDiagramElements.get(i);
				final double x = getXValue(selectedDiagramElements.get(i - 1), xDistribution);
				final double y = de.getY();

				DiagramElementLayoutUtil.moveElement(m, de, new Point(x, y));
			}
		});

		return null;
	}

	/**
	 * Calculate the width of all shapes, used for distribution calculations
	 * @param diagramElements the selected shapes
	 * @return the width of the middle shapes
	 */
	private static double getWidthOfShapes(final List<DiagramElement> diagramElements) {
		return diagramElements.stream().mapToDouble(de -> de.getWidth()).sum();
	}

	/**
	 * Calculate the distance between each selected shape after distribution
	 * @param diagramElements the selected shapes
	 * @return the distance between each shape after distribution
	 */
	private static double getXDistribution(final List<DiagramElement> diagramElements) {
		final int lastIndex = diagramElements.size() - 1;
		final double widthOfShapes = getWidthOfShapes(diagramElements);
		final DiagramElement firstElement = diagramElements.get(0);
		final DiagramElement lastElement = diagramElements.get(lastIndex);
		return (lastElement.getX() + lastElement.getWidth() - firstElement.getX() - widthOfShapes) / lastIndex;
	}

	/**
	 * Calculate the X-coordinate value for the shape being evaluated
	 * @param prevElement the element of the shape just before the current element being evaluated
	 * @param xDistribution the X-coordinate distance that needs to be between each shape
	 * @return the X-coordinate value for the shape being evaluated
	 */
	private static double getXValue(final DiagramElement prevElement, final double xDistribution) {
		return prevElement.getX() + prevElement.getWidth() + xDistribution;
	}

	/**
	 * Sort the selected shapes based on X-coordinate value
	 */
	private static final Comparator<DiagramElement> XValueComparator = (de1, de2) -> Double.compare(de1.getX(),
			de2.getX());
}