bundles/org.eclipse.emf.ecp.view.core.swt/src/org/eclipse/emf/ecp/view/spi/core/swt/SimpleControlJFaceViewerSWTRenderer.java

/*******************************************************************************
 * Copyright (c) 2011-2013 EclipseSource Muenchen GmbH and others.
 *
 * 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:
 * Edagr Mueller - initial API and implementation
 * Eugen Neufeld - Refactoring
 ******************************************************************************/
package org.eclipse.emf.ecp.view.spi.core.swt;

import org.eclipse.core.databinding.Binding;
import org.eclipse.emf.ecp.view.spi.context.ViewModelContext;
import org.eclipse.emf.ecp.view.spi.model.VControl;
import org.eclipse.emf.ecp.view.template.model.VTViewTemplateProvider;
import org.eclipse.emfforms.spi.common.report.ReportService;
import org.eclipse.emfforms.spi.core.services.databinding.DatabindingFailedException;
import org.eclipse.emfforms.spi.core.services.databinding.EMFFormsDatabinding;
import org.eclipse.emfforms.spi.core.services.label.EMFFormsLabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * Renderer for {@link org.eclipse.swt.widgets.Control Controls} which uses a {@link Viewer}.
 *
 * @author Eugen Neufeld
 *
 */
public abstract class SimpleControlJFaceViewerSWTRenderer extends SimpleControlSWTRenderer {

	private Binding[] bindings;
	private Viewer viewer;

	/**
	 * Default constructor.
	 *
	 * @param vElement the view model element to be rendered
	 * @param viewContext the view context
	 * @param reportService The {@link ReportService}
	 * @param emfFormsDatabinding The {@link EMFFormsDatabinding}
	 * @param emfFormsLabelProvider The {@link EMFFormsLabelProvider}
	 * @param vtViewTemplateProvider The {@link VTViewTemplateProvider}
	 * @since 1.6
	 */
	public SimpleControlJFaceViewerSWTRenderer(VControl vElement, ViewModelContext viewContext,
		ReportService reportService,
		EMFFormsDatabinding emfFormsDatabinding, EMFFormsLabelProvider emfFormsLabelProvider,
		VTViewTemplateProvider vtViewTemplateProvider) {
		super(vElement, viewContext, reportService, emfFormsDatabinding, emfFormsLabelProvider, vtViewTemplateProvider);
	}

	/**
	 * Creates the control itself.
	 *
	 * @param parent the {@link Composite} to render onto
	 * @return the rendered control
	 * @throws DatabindingFailedException if the creation of the control fails due to failed databinding
	 */
	@Override
	protected final Control createControl(Composite parent) throws DatabindingFailedException {
		viewer = createJFaceViewer(parent);
		bindings = createBindings(viewer);

		viewer.getControl().addDisposeListener(new DisposeListener() {

			@Override
			public void widgetDisposed(DisposeEvent e) {
				disposeBindings();
			}
		});
		return viewer.getControl();
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.emf.ecp.view.spi.core.swt.AbstractControlSWTRenderer#rootDomainModelChanged()
	 */
	@Override
	protected void rootDomainModelChanged() throws DatabindingFailedException {
		super.rootDomainModelChanged();
		disposeBindings();
		bindings = createBindings(viewer);
	}

	/**
	 * Disposes all bindings of this renderer.
	 */
	private void disposeBindings() {
		if (bindings != null) {
			for (final Binding binding : bindings) {
				binding.dispose();
			}
		}
	}

	/**
	 * Create the {@link Binding Bindings} for this controls.
	 *
	 * @param viewer the {@link Viewer} to create the binding for
	 * @return all the bindings created by this renderer
	 * @throws DatabindingFailedException if the creation of the bindings failed
	 * @since 1.6
	 */
	protected abstract Binding[] createBindings(Viewer viewer) throws DatabindingFailedException;

	/**
	 * Creates the {@link Viewer}.
	 *
	 * @param parent the {@link Composite} to use as a parent
	 * @return the created {@link Viewer}
	 * @throws DatabindingFailedException if the databinding fails
	 * @since 1.6
	 */
	protected abstract Viewer createJFaceViewer(Composite parent) throws DatabindingFailedException;

}