lookAndFeel/plugins/org.eclipse.papyrus.uml.diagram.clazz.lf.associationlabellayout/src/org/eclipse/papyrus/uml/diagram/clazz/lf/associationlabellayout/edit/parts/LocatorManager.java

/*****************************************************************************
 * Copyright (c) 2019 CEA LIST.
 *
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *  Xavier Le Pallec (for CEA LIST) xlepallec@lilo.org - Bug 558456
 *
 *****************************************************************************/

package org.eclipse.papyrus.uml.diagram.clazz.lf.associationlabellayout.edit.parts;

import org.eclipse.draw2d.Connection;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.gef.editparts.AbstractConnectionEditPart;
import org.eclipse.gmf.runtime.notation.NotationPackage;
import org.eclipse.papyrus.infra.gmfdiag.common.locator.PapyrusLabelLocator;
import org.eclipse.papyrus.uml.diagram.clazz.lf.associationlabellayout.preferences.Settings;

/**
 * This class is used to centralize and delegate operations about locators of
 * the association end * edit parts. The class aims at:
 * <UL>
 * <LI>Checking if a locator has been created and associated to the edit
 * part</LI>
 * <LI>Initializing the locator</LI>
 * <LI>Checking Papyrus preferences to see whether the locators of this plug-in
 * will be used or not</LI>
 * </UL>
 *
 */
public class LocatorManager {

	private AccessForLocatorManager accessForLocatorManager;
	private boolean activated;

	/**
	 * Each locator manager is associated to an edit part. Here, in order to access
	 * different types of edit parts (with not enough things in common), we have
	 * defined and used an interface {@link AccessForLocatorManager} for this common
	 * access/association.
	 * 
	 * @param editPart edit part that implements our specific interface {@link AccessForLocatorManager}
	 */
	public LocatorManager(AccessForLocatorManager editPart) {
		this.accessForLocatorManager = editPart;
		activated = Settings.getInstance().isActivated();
	}

	/**
	 * This method is called by association end * edit part at the first refreshBounds invocation.
	 * It will invoke the {@link LocatorManager#initializeLocator()} method if there is no locator in the edit part. 
	 */
	protected void connectSpecificLocatorIfActivated() {
		hasActivationStatusChanged();
		if (Settings.getInstance().isActivated()) {
			PapyrusLabelLocator locator = accessForLocatorManager.getLocator();
			if (locator == null) {
				initializeLocator();
			}
		}
	}

	/**
	 * This method just stores the plug-in activation status and/or see whether it has changed or not in order to reset locator (and it will be re-created at the next refreshBounds of the edit part). 
	 */
	protected void hasActivationStatusChanged() {
		if (Settings.getInstance().isActivated() != activated) {
			accessForLocatorManager.setLocator(null);
			activated = Settings.getInstance().isActivated();
		}
	}

	/**
	 * Reuse a part of the implementation of super class for the locator initialization, but with different types of objects for figure and locator. 
	 */
	protected void initializeLocator() {
		int dx = ((Integer) accessForLocatorManager.getStructuralFeatureValue(NotationPackage.eINSTANCE.getLocation_X())).intValue();
		int dy = ((Integer) accessForLocatorManager.getStructuralFeatureValue(NotationPackage.eINSTANCE.getLocation_Y())).intValue();

		Point offset = new Point(dx, dy);

		if (accessForLocatorManager.getParent() instanceof AbstractConnectionEditPart) {

			Connection connectionFigure = AbstractConnectionEditPart.class.cast(accessForLocatorManager.getParent()).getConnectionFigure();

			if (accessForLocatorManager.getLocator() == null) {
				accessForLocatorManager.initializeLocator(connectionFigure, offset);
			}
		}
	}
}