/*
 * @(#)PageControl.java 1.00 2004-9-22
 *
 * Copyright 2004 2004 . All rights reserved.
 * PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package beansoft.jsp;

/**
 * PageControl, 分頁控制, 可以判斷總頁數和是否有上下頁.
 *
 * @author beansoft
 * @version 1.00 2004-9-22
 */
public class PageControl {
    /** 每頁顯示記錄數 */
    private int pageCount;
    /** 是否有上一頁 */
    private boolean hasPrevPage;
    /** 記錄總數 */
    private int recordCount;
    /** 是否有下一頁 */
    private boolean hasNextPage;
    /** 最大頁面數 */
    private int maxPage;
    /** 當前頁碼數 */
    private int currentPage;

    /**
     *
     */
    public PageControl() {
    }

    /**
     * 進行分頁計算.
     */
    private void calculate() {
        if (getPageCount() == 0) {
            setPageCount(1);
        }

        maxPage = (int) Math.ceil(1.0 * getRecordCount() / getPageCount()); // 總頁面數
        if (maxPage == 0)
            maxPage = 1;
//        System.out.println("currentPage=" + currentPage);
//        System.out.println("maxPage=" + maxPage);
//        // Fixed logic error at 2004-09-25
        hasNextPage = currentPage < maxPage;
        hasPrevPage = currentPage > 1;
        return;
    }

    /**
     * @return Returns the 最大頁面數.
     */
    public int getMaxPage() {
    	calculate();
        return maxPage;
    }

    /**
     * @param currentPage
     *            The 最大頁面數 to set.
     */
    private void setMaxPage(int maxPage) {
        this.maxPage = maxPage;
    }

    /**
     * 是否有上一頁數據
     */
    public boolean hasPrevPage() {
    	calculate();
        return hasPrevPage;
   }

    /**
     * 是否有下一頁數據
     */
    public boolean hasNextPage() {
    	calculate();
        return hasNextPage;
    }

    // Test
    public static void main(String[] args) {
        PageControl pc = new PageControl();
        pc.setCurrentPage(0);
        pc.setPageCount(5);
        pc.setRecordCount(7);

        System.out.println("當前頁 " + pc.getCurrentPage());
        System.out.println("有上一頁 " + pc.hasPrevPage());
        System.out.println("有下一頁 " + pc.hasNextPage());
        System.out.println("最大頁面數 " + pc.getMaxPage());
    }

    /**
     * @return Returns the 當前頁碼數.
     */
    public int getCurrentPage() {
        return currentPage;
    }

    /**
     * 設置當前頁碼, 從 1 開始.
	 * @param currentPage
     *            The 當前頁碼數 to set.
     */
    public void setCurrentPage(int currentPage) {
        if (currentPage <= 0) {
           currentPage = 1;
		}
        this.currentPage = currentPage;
    }

    /**
     * @return Returns the recordCount.
     */
    public int getRecordCount() {
        return recordCount;
    }

    /**
     * @param recordCount
     *            The recordCount to set.
     */
    public void setRecordCount(int property1) {
        this.recordCount = property1;
    }

    /**
     * @return Returns the 每頁顯示記錄數.
     */
    public int getPageCount() {
        return pageCount;
    }

    /**
     * @param pageCount
     *            The 每頁顯示記錄數 to set.
     */
    public void setPageCount(int pageCount) {
        this.pageCount = pageCount;
    }
}