CanonicalHelper.java

package org.eclipse.uml2.diagram.common.async;

import org.eclipse.gmf.runtime.notation.CanonicalStyle;
import org.eclipse.gmf.runtime.notation.Diagram;
import org.eclipse.gmf.runtime.notation.NotationPackage;
import org.eclipse.gmf.runtime.notation.View;
import org.eclipse.uml2.diagram.common.notation.u2tnotation.U2TDiagramCanonicalStyle;
import org.eclipse.uml2.diagram.common.notation.u2tnotation.U2TNotationFactory;

public class CanonicalHelper implements ICanonicalHelper {

	private CanonicalStyle getStyle(View view) {
		return (CanonicalStyle) view.getStyle(NotationPackage.eINSTANCE.getCanonicalStyle());
	}

	public boolean shouldSyncNodes(View view) {
		CanonicalStyle style = getStyle(view);
		if (style == null) {
			//in GMF this means "synchronized by default"
			return true;
		}
		if (style instanceof U2TDiagramCanonicalStyle) {
			U2TDiagramCanonicalStyle styleImpl = (U2TDiagramCanonicalStyle) style;
			return styleImpl.isCanonical() && styleImpl.isSyncNodes();
		}
		return style.isCanonical();
	}

	public boolean isAutoSynchronized(View view) {
		return shouldSyncNodes(view);
	}

	public void setAutoSynchronized(View target, boolean isAutoSync) {
		CanonicalStyle style = ensureHasCanonicalStyle(target);
		if (target instanceof Diagram && style instanceof U2TDiagramCanonicalStyle) {
			U2TDiagramCanonicalStyle styleImpl = (U2TDiagramCanonicalStyle) style;
			styleImpl.setCanonical(true);
			styleImpl.setSyncLinks(true); // sic!  
			styleImpl.setSyncNodes(isAutoSync);
		} else {
			style.setCanonical(isAutoSync);
		}
	}

	public boolean shouldSyncLinks(View view) {
		CanonicalStyle style = getStyle(view);
		if (style == null) {
			//again, in GMF it means "synchronized by default"
			return true;
		}
		if (style instanceof U2TDiagramCanonicalStyle) {
			U2TDiagramCanonicalStyle styleImpl = (U2TDiagramCanonicalStyle) style;
			return styleImpl.isCanonical() && styleImpl.isSyncLinks();
		}
		return style.isCanonical();
	}

	@SuppressWarnings("unchecked")
	public CanonicalStyle ensureHasCanonicalStyle(View target) {
		CanonicalStyle result = (CanonicalStyle) target.getStyle(NotationPackage.eINSTANCE.getCanonicalStyle());
		if (result != null) {
			return result;
		}
		if (target instanceof Diagram) {
			U2TDiagramCanonicalStyle u2tStyle = U2TNotationFactory.eINSTANCE.createU2TDiagramCanonicalStyle();
			target.getStyles().add(u2tStyle);
			result = u2tStyle;
		} else {
			result = (CanonicalStyle) target.createStyle(NotationPackage.eINSTANCE.getCanonicalStyle());
		}
		return result;
	}

}