ltk/org.eclipse.statet.ltk.ui/src/org/eclipse/statet/ltk/ui/util/ExtModelLabelProvider.java

/*=============================================================================#
 # Copyright (c) 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.util;

import java.util.IdentityHashMap;

import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.StyledCellLabelProvider;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.swt.graphics.Image;

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

import org.eclipse.statet.ltk.model.core.LtkModels;
import org.eclipse.statet.ltk.model.core.element.EmbeddingForeignElement;
import org.eclipse.statet.ltk.model.core.element.LtkModelElement;
import org.eclipse.statet.ltk.ui.ElementLabelProvider;


@NonNullByDefault
public class ExtModelLabelProvider extends StyledCellLabelProvider
		implements ILabelProvider, ElementLabelProvider, Disposable {
	
	
	protected static final ElementLabelProvider NO_PROVIDER= new ElementLabelProvider() {
	};
	
	
	private final IdentityHashMap<String, ElementLabelProvider> providers= new IdentityHashMap<>(4);
	
	private @Nullable String modelTypeId;
	
	
	public ExtModelLabelProvider(final String modelTypeId) {
		this.modelTypeId= modelTypeId;
	}
	
	public ExtModelLabelProvider() {
	}
	
	
	@Override
	public void dispose() {
		for (final var provider : this.providers.values()) {
			if (provider instanceof Disposable) {
				((Disposable)provider).dispose();
			}
		}
		this.providers.clear();
		
		super.dispose();
	}
	
	
	protected @Nullable ElementLabelProvider getElementLabelProvider(final @Nullable String modelId) {
		if (modelId == null) {
			return null;
		}
		var provider= this.providers.get(modelId);
		if (provider == null) {
			provider= LtkModels.getModelAdapter(modelId, ElementLabelProvider.class);
			if (provider == null) {
				provider= NO_PROVIDER;
			}
			this.providers.put(modelId, provider);
		}
		return (provider != NO_PROVIDER) ? provider : null;
	}
	
	protected void addProvider(final String modelId, final ElementLabelProvider provider) {
		this.providers.put(modelId, provider);
	}
	
	
	@Override
	public @Nullable Image getImage(final @Nullable Object element) {
		if (element instanceof LtkModelElement) {
			return getImage((LtkModelElement<?>)element);
		}
		return null;
	}
	
	@Override
	public @Nullable String getText(final @Nullable Object element) {
		if (element instanceof LtkModelElement) {
			return getText((LtkModelElement<?>)element);
		}
		return null;
	}
	
	
	@Override
	public @Nullable Image getImage(final LtkModelElement<?> element) {
		final boolean embedding= ((element.getElementType() & LtkModelElement.MASK_C1) == LtkModelElement.C1_EMBEDDED);
		Image image= null;
		ElementLabelProvider provider;
		if (image == null && embedding && this.modelTypeId != element.getModelTypeId()
				&& (provider= getElementLabelProvider(this.modelTypeId)) != null) {
			image= provider.getImage(element);
		}
		if (image == null
				&& (provider= getElementLabelProvider(element.getModelTypeId())) != null) {
			image= provider.getImage(element);
		}
		if (image == null && embedding) {
			final var embeddedElement= ((EmbeddingForeignElement<?, ?>)element).getForeignElement();
			if (embeddedElement != null
					&& (provider= getElementLabelProvider(embeddedElement.getModelTypeId())) != null) {
				image= provider.getImage(embeddedElement);
			}
		}
		return image;
	}
	
	@Override
	public String getText(final LtkModelElement<?> element) {
		final boolean embedding= ((element.getElementType() & LtkModelElement.MASK_C1) == LtkModelElement.C1_EMBEDDED);
		String text= null;
		ElementLabelProvider provider;
		if (text == null && embedding && this.modelTypeId != element.getModelTypeId()
				&& (provider= getElementLabelProvider(this.modelTypeId)) != null) {
			text= provider.getText(element);
		}
		if (text == null
				&& (provider= getElementLabelProvider(element.getModelTypeId())) != null) {
			text= provider.getText(element);
		}
		if (text == null && embedding) {
			final var embeddedElement= ((EmbeddingForeignElement<?, ?>)element).getForeignElement();
			if (embeddedElement != null
					&& (provider= getElementLabelProvider(embeddedElement.getModelTypeId())) != null) {
				text= provider.getText(embeddedElement);
			}
		}
		if (text == null) {
			text= element.getElementName().getDisplayName();
		}
		return text;
	}
	
	@Override
	public StyledString getStyledText(final LtkModelElement<?> element) {
		final boolean embedding= ((element.getElementType() & LtkModelElement.MASK_C1) == LtkModelElement.C1_EMBEDDED);
		StyledString text= null;
		ElementLabelProvider provider;
		if (text == null && embedding && this.modelTypeId != element.getModelTypeId()
				&& (provider= getElementLabelProvider(this.modelTypeId)) != null) {
			text= provider.getStyledText(element);
		}
		if (text == null
				&& (provider= getElementLabelProvider(element.getModelTypeId())) != null) {
			text= provider.getStyledText(element);
		}
		if (text == null && embedding) {
			final var embeddedElement= ((EmbeddingForeignElement<?, ?>)element).getForeignElement();
			if (embeddedElement != null
					&& (provider= getElementLabelProvider(embeddedElement.getModelTypeId())) != null) {
				text= provider.getStyledText(embeddedElement);
			}
		}
		if (text == null) {
			text= new StyledString(element.getElementName().getDisplayName());
		}
		return text;
	}
	
	
	@Override
	public void update(final ViewerCell cell) {
		final Object cellElement= cell.getElement();
		if (cellElement instanceof LtkModelElement) {
			final var element= (LtkModelElement<?>)cellElement;
			cell.setImage(getImage(element));
			final StyledString styledText= getStyledText(element);
			cell.setText(styledText.getString());
			cell.setStyleRanges(styledText.getStyleRanges());
		}
		else {
			cell.setImage(null);
			cell.setText(cellElement.toString());
			cell.setStyleRanges(null);
		}
		super.update(cell);
	}
	
}