/*******************************************************************************
* Copyright (c) 2014 Dirk Fauth and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Dirk Fauth <dirk.fauth@googlemail.com> - initial API and implementation
******************************************************************************/
package org.eclipse.nebula.widgets.nattable.extension.glazedlists.groupBy;
import java.util.Comparator;
import org.eclipse.nebula.widgets.nattable.layer.IUniqueIndexLayer;
import org.eclipse.nebula.widgets.nattable.sort.ISortModel;
/**
* {@link Comparator} interface specialization for a comparator that can be used
* to sort the tree structure in a groupBy composition.
*
* @param <T>
* The type of the base objects carried in the TreeList
*/
public interface IGroupByComparator<T> extends Comparator<Object> {
/**
* @return The {@link ISortModel} that is used to retrieve the column value
* comparators and the sort direction in case a groupBy value is
* sorted which will directly affect the tree structure build. Can
* be <code>null</code> which leads to a static tree structure that
* only allows sorting for leafs within groups.
*/
ISortModel getSortModel();
/**
* @param sortModel
* The {@link ISortModel} that is used to retrieve the column
* value comparators and the sort direction in case a groupBy
* value is sorted which will directly affect the tree structure
* build. Can be <code>null</code> which leads to a static tree
* structure that only allows sorting for leafs within groups.
*/
void setSortModel(ISortModel sortModel);
/**
* @param treeLayer
* The {@link IUniqueIndexLayer} that should be used to retrieve
* config labels for a column. Needed to be able to determine if
* the column which is used for sorting is the tree column. Can
* be <code>null</code> which avoids specialized handling of tree
* / non tree columns.
*/
void setTreeLayer(IUniqueIndexLayer treeLayer);
/**
* @param dataLayer
* The {@link GroupByDataLayer} that should be used to retrieve
* groupBy summary values for sorting the tree structure. Can be
* <code>null</code> to avoid retrieving and inspecting summary
* values on sorting.
*/
void setDataLayer(GroupByDataLayer<T> dataLayer);
/**
* For performance reasons the {@link IGroupByComparator} might cache
* several information e.g. retrieved via {@link GroupByDataLayer}. This
* method is intended to clear those cached informations to avoid memory
* leaks or sorting based on old information.
*/
void clearCache();
}