ltk/org.eclipse.statet.ltk.ui/src/org/eclipse/statet/ltk/ui/sourceediting/OutlineContentProvider.java

/*=============================================================================#
 # Copyright (c) 2014, 2021 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.ltk.ui.sourceediting;

import java.util.List;

import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.Viewer;

import org.eclipse.statet.jcommons.lang.NonNull;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ltk.core.SourceModelStamp;
import org.eclipse.statet.ltk.model.core.element.LtkModelElementFilter;
import org.eclipse.statet.ltk.model.core.element.SourceStructElement;
import org.eclipse.statet.ltk.model.core.element.SourceUnitModelInfo;


@NonNullByDefault
public class OutlineContentProvider implements ITreeContentProvider {
	
	
	private static final @NonNull SourceStructElement<?, ?>[] NO_CHILDREN= new @NonNull SourceStructElement[0];
	
	
	public interface OutlineContent {
		
		@Nullable SourceUnitModelInfo getModelInfo(Object inputElement);
		
		@Nullable LtkModelElementFilter<? super SourceStructElement<?, ?>> getContentFilter();
		
	}
	
	
	private final OutlineContent content;
	
	
	public OutlineContentProvider(final OutlineContent content) {
		this.content= content;
	}
	
	
	protected final OutlineContent getContent() {
		return this.content;
	}
	
	public @Nullable SourceModelStamp getStamp(final Object inputElement) {
		final SourceUnitModelInfo modelInfo= getContent().getModelInfo(inputElement);
		return (modelInfo != null) ? modelInfo.getStamp() : null;
	}
	
	@Override
	public void inputChanged(final Viewer viewer, final @Nullable Object oldInput, final @Nullable Object newInput) {
	}
	
	@Override
	public void dispose() {
	}
	
	
	protected SourceStructElement[] getElements(final @Nullable SourceUnitModelInfo modelInfo) {
		if (modelInfo != null) {
			final List<? extends SourceStructElement<?, ?>> children= modelInfo.getSourceElement()
					.getSourceChildren(getContent().getContentFilter());
			return children.toArray(new @NonNull SourceStructElement[children.size()]);
		}
		return NO_CHILDREN;
	}
	
	protected @Nullable SourceStructElement getParent(final SourceStructElement<?, ?> element) {
		return element.getSourceParent();
	}
	
	protected boolean hasChildren(final @Nullable SourceStructElement<?, ?> element) {
		return (element != null
				&& element.hasSourceChildren(getContent().getContentFilter()) );
	}
	
	protected SourceStructElement[] getChildren(final @Nullable SourceStructElement<?, ?> element) {
		if (element != null) {
			final List<? extends SourceStructElement> children= element
					.getSourceChildren(getContent().getContentFilter());
			return children.toArray(new @NonNull SourceStructElement[children.size()]);
		}
		return NO_CHILDREN;
	}
	
	
	@Override
	public @NonNull Object[] getElements(final Object inputElement) {
		return getElements(getContent().getModelInfo(inputElement));
	}
	
	@Override
	public @Nullable Object getParent(final Object element) {
		return getParent((SourceStructElement<?, ?>)element);
	}
	
	@Override
	public boolean hasChildren(final Object element) {
		return hasChildren((SourceStructElement<?, ?>)element);
	}
	
	@Override
	public @NonNull Object[] getChildren(final Object element) {
		return getChildren((SourceStructElement<?, ?>)element);
	}
	
}