ltk/org.eclipse.statet.ltk.core/src/org/eclipse/statet/ecommons/text/PartitionerDocumentSetupParticipant.java

/*=============================================================================#
 # Copyright (c) 2008, 2020 Stephan Wahlbrink and others.
 # 
 # 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, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.text;

import org.eclipse.core.filebuffers.IDocumentSetupParticipant;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IDocumentExtension3;
import org.eclipse.jface.text.IDocumentPartitioner;
import org.eclipse.jface.text.IDocumentPartitionerExtension3;
import org.eclipse.jface.text.ISynchronizable;


/**
 * Base implementation of {@link IDocumentSetupParticipant} configuring the document for a
 * {@link IDocumentPartitioner document partitioner}.
 */
public abstract class PartitionerDocumentSetupParticipant implements IDocumentSetupParticipant {
	
	
	public PartitionerDocumentSetupParticipant() {
	}
	
	
	@Override
	public void setup(final IDocument document) {
		if (document instanceof IDocumentExtension3) {
			final Object synch= getLockObject(document);
			synchronized (synch) {
				doSetup(document);
			}
		}
		else {
			throw new UnsupportedOperationException("IDocumentExtension3 required."); //$NON-NLS-1$
		}
	}
	
	private Object getLockObject(final IDocument document) {
		Object synch;
		if (document instanceof ISynchronizable) {
			synchronized (document) {
				synch= ((ISynchronizable) document).getLockObject();
				if (synch == null) {
					synch= new Object();
					((ISynchronizable) document).setLockObject(synch);
				}
			}
		}
		else {
			synch= new Object();
		}
		return synch;
	}
	
	protected void doSetup(final IDocument document) {
		final IDocumentExtension3 extension3= (IDocumentExtension3) document;
		if (extension3.getDocumentPartitioner(getPartitioningId()) == null) {
			// Setup the document scanner
			final IDocumentPartitioner partitioner= createDocumentPartitioner();
			if (partitioner instanceof IDocumentPartitionerExtension3) {
				((IDocumentPartitionerExtension3) partitioner).connect(document, true);
			}
			else {
				partitioner.connect(document);
			}
			extension3.setDocumentPartitioner(getPartitioningId(), partitioner);
		}
	}
	
	public abstract String getPartitioningId();
	
	protected abstract IDocumentPartitioner createDocumentPartitioner();
	
}