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//
// Copyright (C) 2006-2016 Talend Inc. - www.talend.com
//
// This source code is available under agreement available at
// %InstallDIR%\features\org.talend.rcp.branding.%PRODUCTNAME%\%PRODUCTNAME%license.txt
//
// You should have received a copy of the agreement
// along with this program; if not, write to Talend SA
// 9 rue Pages 92150 Suresnes, France
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package org.talend.dataprofiler.common.ui.pagination.pageloder;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.nebula.widgets.pagination.IPageLoader;
import org.eclipse.nebula.widgets.pagination.PageableController;
import org.eclipse.nebula.widgets.pagination.collections.PageResult;
import org.talend.cwm.indicator.ColumnFilter;
import org.talend.cwm.indicator.DataValidation;
import org.talend.dataquality.indicators.mapdb.AbstractDB;

/**
 * created by talend on Aug 14, 2014 Detailled comment
 * 
 */
public class MapDBPageLoader<T> implements IPageLoader<PageResult<Object[]>> {

    private AbstractDB<T> db = null;

    private Map<Long, T> indexMap = new HashMap<Long, T>();

    private long itemsSize = 0l;

    private DataValidation dataValidator;

    private ColumnFilter columnFilter;

    public MapDBPageLoader(AbstractDB<T> db, DataValidation validator, long size) {
        this(db, validator, size, null);

    }

    public MapDBPageLoader(AbstractDB<T> db, DataValidation validator, long size, ColumnFilter filter) {
        this.db = db;
        itemsSize = size;
        dataValidator = validator;
        columnFilter = filter;
    }

    public MapDBPageLoader(AbstractDB<T> db) {
        this(db, null, Long.valueOf(db.size()));
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.eclipse.nebula.widgets.pagination.IPageLoader#loadPage(org.eclipse.nebula.widgets.pagination.PageableController
     * )
     */
    @Override
    public PageResult<Object[]> loadPage(PageableController controller) {
        long totalSize = itemsSize;
        long pageSize = controller.getPageSize();
        long pageIndex = controller.getPageOffset();

        long fromIndex = pageIndex;
        long toIndex = pageIndex + pageSize;
        if (toIndex > totalSize) {
            toIndex = totalSize;
        }

        if (dataValidator == null) {
            return MapDBPageListHelper.createPage(db, indexMap, columnFilter, fromIndex, toIndex, totalSize);
        } else {
            return MapDBPageListHelper.createPage(db, indexMap, dataValidator, fromIndex, toIndex, totalSize);
        }
    }

}