portletbeangrid.java

java 写的一个新闻发布系统

package org.jahia.layout;

/**
 * Title:        2D grid of PortletBean object, used to map notably on HTML
 * tables
 * Description:  This object offers 2D layout of portlets, allowing them to
 * be added to the grid, as well as interactively moved.
 * Copyright:    Copyright (c) 2002
 * Company:      Jahia Ltd
 * @author Serge Huber
 * @version 1.0
 * @todo Currently this is not optimized, we go through enumerations a lot,
 * we might want to add a real grid to speed up operations
 */
import java.util.Enumeration;

import org.jahia.utils.JahiaConsole;
import org.jahia.exceptions.JahiaException;

public class PortletBeanGrid extends PortletBeanSet {

    protected int columnCount = 0;
    protected int rowCount = 0;

    public PortletBeanGrid() {
    }

    /**
     * Copy constructor
     * @param sourceSet original set to copy from
     */
    public PortletBeanGrid(PortletBeanSet sourceSet) {
        Enumeration sourceElements = sourceSet.elements();
        while (sourceElements.hasMoreElements()) {
            PortletBean portlet = (PortletBean) sourceElements.nextElement();
            this.add(portlet);
        }
    }

    /**
     * Retrieves the PortletBean at the specified position in the grid.
     * @param rowID the number of the row (0-based)
     * @param columnID the number of the column (0-based)
     * @returns the portlet bean at the specified position, and if there is none,
     * returns null
     */
    public PortletBean getPosPortlet(int rowID, int columnID) {
        Enumeration portletList = this.elements();
        while (portletList.hasMoreElements()) {
            PortletBean curPortlet = (PortletBean) portletList.nextElement();
            if ( (curPortlet.getPortletRow() == rowID) &&
                 (curPortlet.getPortletColumn() == columnID) ) {
                return curPortlet;
            }
        }
        return null; // no portlet at that position ! Might be better to return
        // an exception here !
    }

    /**
     * Retrieves all the portlets on a given row
     * @param rowID the number of the row to retrieve (0-based)
     * @returns a PortletBeanSet object containing a set of the PortletBean objects
     * available on that row. This set might be empty if the row doesn't exist. The
     * result list is sorted according to the column position
     */
    public PortletBeanSet getRowPortlets(int rowID) {
        Enumeration portletList = this.elements();
        PortletBeanSet resultList = new PortletBeanSet();
        while (portletList.hasMoreElements()) {
            PortletBean curPortlet = (PortletBean) portletList.nextElement();
            if (curPortlet.getPortletRow() == rowID) {
                resultList.add(curPortlet);
            }
        }

        // let's sort inside the row by column
        // FIXME : this could be much faster with better sorting algorithms
        PortletBeanSet sortedResultList = new PortletBeanSet();
        for (int i = 0; i < resultList.size(); i++) {
            for (int j = 0; j < resultList.size(); j++) {
                PortletBean curPortlet = (PortletBean) resultList.elementAt(j);
                if (curPortlet.getPortletColumn() == i)
                    sortedResultList.add(curPortlet);
            }
        }
        return sortedResultList;
    }

    /**
     * Retrieves all the portlets on a given column
     * @param columnID the number of the column to retrieve (0-based)
     * @returns a PortletBeanSet object containing a set of the PortletBean objects
     * available on that column. This set might be empty if the column doesn't exist.
     */
    public PortletBeanSet getColumnPortlets(int columnID) {
        Enumeration portletList = this.elements();
        PortletBeanSet resultList = new PortletBeanSet();
        while (portletList.hasMoreElements()) {
            PortletBean curPortlet = (PortletBean) portletList.nextElement();
            if (curPortlet.getPortletColumn() == columnID) {
                resultList.add(curPortlet);
            }
        }

        // let's sort inside the column by row
        // FIXME : this could be much faster with better sorting algorithms
        PortletBeanSet sortedResultList = new PortletBeanSet();
        for (int i = 0; i < resultList.size(); i++) {
            for (int j = 0; j < resultList.size(); j++) {
                PortletBean curPortlet = (PortletBean) resultList.elementAt(j);
                if (curPortlet.getPortletRow() == i)
                    sortedResultList.add(curPortlet);
            }
        }

        return sortedResultList;
    }

    /**
     * Move the portlet up by one row in the grid. If the row is already the top
     * one no movement is down. Otherwise the movement is simply done by swapping
     * positions with the portlet above the one we want to move.
     * @param portletID the identifier of the portlet to move
     * @throws JahiaException if the portlet corresponding to the identifier
     * cannot be found.
     */
    public void movePortletUp(int portletID)
    throws JahiaException {
        PortletBean targetPortlet = findPortlet(portletID);
        if (targetPortlet.getPortletRow() == 0) {
            /** @todo for the moment we just do nothing, but we could also
             *  decide to move everything down and insert a new first row with
             *  our portlet alone on it
             */
        } else {
            PortletBean portletToSwap = getPosPortlet(targetPortlet.getPortletRow() - 1,
                                                      targetPortlet.getPortletColumn());
            if (portletToSwap != null) {
                portletToSwap.setPortletRow(targetPortlet.getPortletRow());
            }
            targetPortlet.setPortletRow(targetPortlet.getPortletRow() - 1);
        }
    }

    /**
     * Moves the portlet down one row, creating a new row if it doesn't exist
     * @param portletID identifier of the portlet to be moved
     * @throws JahiaException if the portlet cannot be found.
     */
    public void movePortletDown(int portletID)
    throws JahiaException {
        PortletBean targetPortlet = findPortlet(portletID);
        if (targetPortlet.getPortletRow() == getRowCount()-1) {
            rowCount++;
        } else {
            PortletBean portletToSwap = getPosPortlet(targetPortlet.getPortletRow() + 1 ,
                                                      targetPortlet.getPortletColumn());
            if (portletToSwap != null) {
                portletToSwap.setPortletRow(targetPortlet.getPortletRow());
            }
        }
        targetPortlet.setPortletRow(targetPortlet.getPortletRow() + 1);
    }

    /**
     * Moves the specified portlet one column to the left. If the portlet is
     * already in the leftmost column, this method does nothing.
     * @param portletID identifier of the portlet to be moved
     * @throws JahiaException if the portlet corresponding to the identifier
     * cannot be found
     */
    public void movePortletLeft(int portletID)
    throws JahiaException {
        PortletBean targetPortlet = findPortlet(portletID);
        int oldRow = targetPortlet.getPortletRow();
        int oldColumn = targetPortlet.getPortletColumn();
        if (targetPortlet.getPortletColumn() == 0) {
            /** @todo for the moment we just do nothing, but we could also
             *  decide to move everything down and insert a new first row with
             *  our portlet alone on it
             */
        } else {
            /* Let's move all the portlets in the current column up one row */
            for (int i = oldRow +1; i <= getRowCount(oldColumn); i++) {
                PortletBean curPortlet = getPosPortlet(i, oldColumn);
                if (curPortlet != null) {
                    curPortlet.setPortletRow(i-1);
                }
            }
            /* Let's move all the portlets in the new column down to insert the portlet */
            for (int i = getRowCount(oldColumn - 1) - 1; i >= oldRow; i--) {
                PortletBean curPortlet = getPosPortlet(i, oldColumn - 1);
                if (curPortlet != null) {
                    curPortlet.setPortletRow(i+1);
                }
            }
            /* Let's check if we are inserting in a column that is smaller than