bundles/org.eclipse.emf.ecp.ui/src/org/eclipse/emf/ecp/internal/ui/model/StructuredContentProvider.java

/********************************************************************************
 * Copyright (c) 2011 Eike Stepper (Berlin, Germany) 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:
 * Eike Stepper - initial API and implementation
 ********************************************************************************/
package org.eclipse.emf.ecp.internal.ui.model;

import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;

/**
 * @author Eike Stepper
 * @param <INPUT> The type of input (root of the tree)
 */
public abstract class StructuredContentProvider<INPUT> implements IStructuredContentProvider {
	private Viewer viewer;

	private INPUT input;

	public StructuredContentProvider() {
	}

	public Viewer getViewer() {
		return viewer;
	}

	public INPUT getInput() {
		return input;
	}

	/** {@inheritDoc} */
	@Override
	public final void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		this.viewer = viewer;

		if (input != null) {
			disconnectInput(input);
		}

		@SuppressWarnings("unchecked")
		final INPUT tmp = (INPUT) newInput;
		input = tmp;

		if (input != null) {
			connectInput(input);
		}
	}

	public void refreshViewer() {
		final Control control = viewer.getControl();
		if (!control.isDisposed()) {
			final Display display = control.getDisplay();
			if (display.getSyncThread() != Thread.currentThread()) {
				display.asyncExec(new Runnable() {
					@Override
					public void run() {
						if (!control.isDisposed()) {
							viewer.refresh();
						}
					}
				});
			} else {
				viewer.refresh();
			}
		}
	}

	/** {@inheritDoc} */
	@Override
	public void dispose() {
		if (input != null) {
			disconnectInput(input);
		}
	}

	protected void connectInput(INPUT input) {
		// Can be overridden in subclasses
	}

	protected void disconnectInput(INPUT input) {
		// Can be overridden in subclasses
	}
}