paginationhandler.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 org.apache.commons.lang.StringUtils;
import org.extremecomponents.base.BaseModel;
import org.extremecomponents.table.core.ParameterRegistry;

/**
 * Keep track of the page information
 * 
 * @author Jeff Johnston
 */
public class PaginationHandler {
    //toolbar statics
    public final static String FIRST = "First";
    public final static String LAST = "Last";
    public final static String PREV = "Prev";
    public final static String NEXT = "Next";
    public final static String PAGE = "Page";

    //image statics
    public final static String LAST_PAGE = "lastPage";
    public final static String LAST_PAGE_DISABLED = "lastPageDisabled";
    public final static String FIRST_PAGE = "firstPage";
    public final static String FIRST_PAGE_DISABLED = "firstPageDisabled";
    public final static String PREV_PAGE = "prevPage";
    public final static String PREV_PAGE_DISABLED = "prevPageDisabled";
    public final static String NEXT_PAGE = "nextPage";
    public final static String NEXT_PAGE_DISABLED = "nextPageDisabled";
    private BaseModel model;
    
    public PaginationHandler(BaseModel model) {
        this.model = model;
    }

    public boolean isFirstPageEnabled(int page) {
        if (page == 1) {
            return false;
        }

        return true;
    }

    public boolean isPrevPageEnabled(int page) {
        if (page - 1 < 1) {
            return false;
        }

        return true;
    }

    public boolean isNextPageEnabled(int page, int totalPages) {
        if (page + 1 > totalPages) {
            return false;
        }

        return true;
    }

    public boolean isLastPageEnabled(int page, int totalPages) {
        if (page == totalPages || totalPages == 0) {
            return false;
        }

        return true;
    }

    public int getPage() {
        String pagination = model.getRegistry().getParameter(ParameterRegistry.PAGE); 
        
        int page = 1;

        if (!StringUtils.isEmpty(pagination)) {
            page = Integer.parseInt(pagination);
        }
        
        return page;
    }

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

        if (rowsDisplayed == 0) {
            rowsDisplayed = model.getTableHandler().getTotalRows();
        }

        int totalRows = model.getTableHandler().getTotalRows();

        int totalPages = 1;

        if (rowsDisplayed != 0) {
            totalPages = totalRows / rowsDisplayed;
        }

        if ((rowsDisplayed != 0) && ((totalRows % rowsDisplayed) > 0))
        {
            totalPages++;
        }

        return totalPages;
    }
}