bundles/javafx/org.eclipse.emf.ecp.view.model.fx/src/org/eclipse/emf/ecp/view/model/internal/fx/RendererFX.java

/*******************************************************************************
 * Copyright (c) 2011-2015 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:
 * Lucas Koehler - initial API and implementation
 ******************************************************************************/
package org.eclipse.emf.ecp.view.model.internal.fx;

import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;

import org.eclipse.emf.ecp.view.model.common.AbstractRenderer;
import org.eclipse.emf.ecp.view.spi.context.ViewModelContext;
import org.eclipse.emf.ecp.view.spi.model.VElement;
import org.eclipse.emf.ecp.view.spi.renderer.NoPropertyDescriptorFoundExeption;
import org.eclipse.emf.ecp.view.spi.renderer.NoRendererFoundException;
import org.eclipse.emfforms.spi.common.report.ReportService;

import javafx.scene.Node;

public abstract class RendererFX<VELEMENT extends VElement> extends AbstractRenderer<VELEMENT> {

	private final Map<GridCellFX, Node> nodes;

	/**
	 * Default constructor.
	 *
	 * @param vElement the {@link VElement} to be rendered
	 * @param viewContext the {@link ViewModelContext} to use
	 * @param reportService The {@link ReportService} to use
	 */
	public RendererFX(VELEMENT vElement, ViewModelContext viewContext, ReportService reportService) {
		super(vElement, viewContext, reportService);
		nodes = new LinkedHashMap<GridCellFX, Node>();
	}

	/**
	 * Returns the GridDescriptionFX for this Renderer.
	 *
	 * @return the number of controls per row
	 */
	// TODO: When additional renderers are introduced, this method needs a GridDescriptionFX parameter.
	public abstract GridDescriptionFX getGridDescription();

	/**
	 * Renders the passed {@link GridCellFX} of the {@link VElement} of this renderer.
	 *
	 * @param cell the {@link GridCellFX} of the control to render
	 * @return the rendered {@link Node}
	 * @throws NoRendererFoundException this is thrown when a renderer cannot be found
	 * @throws NoPropertyDescriptorFoundExeption this is thrown when no property descriptor can be found
	 */
	public Node render(final GridCellFX cell)
		throws NoRendererFoundException, NoPropertyDescriptorFoundExeption {

		Node node = nodes.get(cell);
		if (node != null) {
			return node;
		}

		node = renderNode(cell);
		if (node == null) {
			// something went wrong, log
			return null;
		}
		nodes.put(cell, node);

		// TODO: do we need some kind of dispose listener like in SWT?

		return node;
	}

	/**
	 * Renders the passed {@link GridCellFX} of the {@link VElement} of this renderer.
	 *
	 * @param cell the {@link GridCellFX} of the control to render
	 * @return the rendered {@link Node}
	 * @throws NoRendererFoundException this is thrown when a renderer cannot be found
	 * @throws NoPropertyDescriptorFoundExeption this is thrown when no property descriptor can be found
	 */
	protected abstract Node renderNode(GridCellFX cell)
		throws NoRendererFoundException, NoPropertyDescriptorFoundExeption;

	/**
	 * Returns a copy of the {@link GridCellFX} to {@link Node} map.
	 *
	 * @return a copy of the nodes map
	 */
	protected final Map<GridCellFX, Node> getNodes() {
		if (nodes == null) {
			return Collections.emptyMap();
		}
		return new LinkedHashMap<GridCellFX, Node>(nodes);
	}
}