InstanceValueLabelProvider.java

/*
 * Copyright (c) 2012 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     HUMBOLDT EU Integrated Project #030962
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.ui.views.data.internal.explore;

import java.util.Collection;

import org.eclipse.jface.viewers.CellLabelProvider;
import org.eclipse.jface.viewers.StyledCellLabelProvider;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.PlatformUI;

import eu.esdihumboldt.hale.common.core.report.Message;
import eu.esdihumboldt.hale.common.instance.extension.validation.report.InstanceValidationMessage;
import eu.esdihumboldt.hale.common.instance.extension.validation.report.InstanceValidationReport;
import eu.esdihumboldt.hale.common.instance.model.Group;
import eu.esdihumboldt.hale.common.instance.model.Instance;
import eu.esdihumboldt.hale.common.instancevalidator.InstanceValidator;
import eu.esdihumboldt.hale.common.schema.model.ChildDefinition;
import eu.esdihumboldt.hale.common.schema.model.Definition;
import eu.esdihumboldt.hale.common.schema.model.TypeDefinition;
import eu.esdihumboldt.hale.ui.HaleUI;
import eu.esdihumboldt.util.Pair;

/**
 * Label provider for instances values in a tree based on a
 * {@link InstanceContentProvider}.
 * 
 * @author Simon Templer
 */
public class InstanceValueLabelProvider extends StyledCellLabelProvider {

	private static final int MAX_STRING_LENGTH = 200;

	private final InstanceValidator validator = InstanceValidator
			.createDefaultValidator(HaleUI.getServiceProvider());

	/**
	 * @see CellLabelProvider#update(ViewerCell)
	 */
	@Override
	public void update(ViewerCell cell) {
		TreePath treePath = cell.getViewerRow().getTreePath();
		Object element = treePath.getLastSegment();
		Definition<?> definition = null;

		Object value = ((Pair<?, ?>) element).getSecond();
		if (((Pair<?, ?>) element).getFirst() instanceof Definition)
			definition = (Definition<?>) ((Pair<?, ?>) element).getFirst();

		InstanceValidationReport report = null;
		if (definition instanceof ChildDefinition<?>) {
			report = validator.validate(value,
					(ChildDefinition<?>) ((Pair<?, ?>) element).getFirst());
		}
		else if (definition instanceof TypeDefinition) {
			report = validator.validate((Instance) value);
		}

		boolean hasValue = false;
		if (value instanceof Instance) {
			hasValue = ((Instance) value).getValue() != null;
		}

		StyledString styledString;
		if (value == null) {
			styledString = new StyledString("no value", StyledString.DECORATIONS_STYLER);
		}
		else if (value instanceof Group && !hasValue) {
			styledString = new StyledString("+", StyledString.QUALIFIER_STYLER);
		}
		else {
			if (value instanceof Instance) {
				value = ((Instance) value).getValue();
			}
			// TODO some kind of conversion?
			String stringValue = value.toString();
			/*
			 * Values that are very large, e.g. string representations of very
			 * complex geometries lead to
			 * StyledCellLabelProvider.updateTextLayout taking a very long time,
			 * rendering the application unresponsive when the data views are
			 * displayed. As such, we reduce the string to a maximum size.
			 */
			if (stringValue.length() > MAX_STRING_LENGTH) {
				stringValue = stringValue.substring(0, MAX_STRING_LENGTH) + "...";
			}

			styledString = new StyledString(stringValue, null);
		}

		cell.setText(styledString.toString());
		cell.setStyleRanges(styledString.getStyleRanges());

		if (report != null && !report.getWarnings().isEmpty()) {
			cell.setImage(PlatformUI.getWorkbench().getSharedImages()
					.getImage(ISharedImages.IMG_OBJS_WARN_TSK));
		}

		super.update(cell);
	}

	/**
	 * @see org.eclipse.jface.viewers.CellLabelProvider#getToolTipText(java.lang.Object)
	 */
	@Override
	public String getToolTipText(Object element) {
		InstanceValidationReport report;

		Object value = ((Pair<?, ?>) element).getSecond();
		Definition<?> definition = null;
		if (((Pair<?, ?>) element).getFirst() instanceof Definition)
			definition = (Definition<?>) ((Pair<?, ?>) element).getFirst();

		if (definition instanceof ChildDefinition<?>) {
			report = validator.validate(value,
					(ChildDefinition<?>) ((Pair<?, ?>) element).getFirst());
		}
		else if (definition instanceof TypeDefinition) {
			report = validator.validate((Instance) value);
		}
		else {
			return null;
		}

		Collection<InstanceValidationMessage> warnings = report.getWarnings();

		if (warnings.isEmpty())
			return null;

		StringBuilder toolTip = new StringBuilder();
		for (Message m : warnings) {
			toolTip.append(m.getFormattedMessage()).append('\n');
		}

		return toolTip.substring(0, toolTip.length() - 1);
	}
}