tablehandler.java

分页查询控件 分页查询控件

/*
 * Copyright 2004 original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.extremecomponents.table.handler;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.extremecomponents.base.BaseModel;
import org.extremecomponents.table.bean.Table;

/**
 * The first pass over the table just loads up the column properties. The
 * properties will be loaded up and held here.
 * 
 * @author Jeff Johnston
 */
public class TableHandler {
    private static Log logger = LogFactory.getLog(TableHandler.class);
    private BaseModel model;

    private Table table;
    private Object collectionOfBeans;
    private Object currentCollectionBean;

    /**
     * The current page that will be displayed.
     */
    private int page;

    /**
     * The first row that will be displayed.
     */
    private int rowStart;

    /**
     * The last row that will be displayed.
     */
    private int rowEnd;

    /**
     * The totals rows that are in the Collection, not the rows just being
     * displayed.
     */
    private int totalRows;

    public TableHandler(BaseModel model) {
        this.model = model;
    }

    public Table getTable() {
        return table;
    }

    public void addTable(Table table) {
        this.table = table;
    }

    /**
     * @deprecated use the prefixWithCollection() attribute instead
     */
    public String getTableKey() {
        return table.getCollection() + "_";
    }

    /**
     * The unique name for this table.
     */
    public String prefixWithCollection() {
        return table.getCollection() + "_";
    }

    public List getCollectionOfBeans() {
        return (List) collectionOfBeans;
    }

    public void setCollectionOfBeans(Collection collectionOfBeans)
            throws Exception {
        this.collectionOfBeans = collectionOfBeans;

        if (collectionOfBeans == null) {
            String message = "The collection sent into the eXtremeTable is NULL.";
            logger.error(message);
            throw new Exception(message);
        }
    }

    public Object getCurrentCollectionBean() {
        return currentCollectionBean;
    }

    public void setCurrentCollectionBean(Object currentCollectionBean) {
        this.currentCollectionBean = currentCollectionBean;
    }

    public int getPage() {
        return page;
    }

    public int getRowStart() {
        return rowStart;
    }

    public int getRowEnd() {
        return rowEnd;
    }

    public int getTotalRows() {
        return totalRows;
    }

    public void setTotalRows(int totalRows) {
        this.totalRows = totalRows;
    }

    /**
     * Find out where we should start and end to get the relevant section of the
     * table.
     */
    public void setTableSections(int totalRows) {
        if (this.totalRows == 0) {
            this.totalRows = totalRows;
        }

        boolean invokeExport = model.getExportHandler().invokeExport();

        if (invokeExport) {
            page = 1;
            rowStart = 1;
            rowEnd = totalRows;
            return;
        }

        page = model.getPaginationHandler().getPage();

        int rowsDisplayed = Integer.parseInt(model.getTableHandler().getTable().getRowsDisplayed());

        if (rowsDisplayed == 0) {
            rowsDisplayed = totalRows;
            page = 1;
        }

        if (rowStart == 0) {
            rowStart = (page - 1) * rowsDisplayed;
        }

        if (rowEnd == 0) {
            rowEnd = rowStart + rowsDisplayed;
        }

        if (rowEnd > this.totalRows) // make sure do not go over
        {
            rowEnd = this.totalRows;
        }
    }

    /**
     * Grab the relevant section of the table.
     */
    public Collection splitIntoTableSectionRows(Collection rows) {
        boolean invokeExport = model.getExportHandler().invokeExport();

        if (invokeExport) {
            return rows;
        }

        Collection results = null;

        if (getRowStart() >= rows.size()) { // obviously doing something custom
            results = rows;
        } else {
            results = new ArrayList();
            for (int i = getRowStart(); i < getRowEnd(); i++) {
                Object obj = (Object) ((List) rows).get(i);
                results.add(obj);
            }
        }

        return results;
    }

    public boolean showPagination() {
        if (!table.showPagination()) {
            return false;
        }

        return !"0".equals(table.getInitialRowsDisplayed());
    }

    public void destroy() {
        table = null;
        collectionOfBeans = null;
    }
}