linkomgraphiclist.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/link/LinkOMGraphicList.java,v $
// $RCSfile: LinkOMGraphicList.java,v $
// $Revision: 1.5.2.1 $
// $Date: 2004/10/14 18:27:08 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.link;

import com.bbn.openmap.omGraphics.*;
import com.bbn.openmap.util.Debug;
import com.bbn.openmap.proj.Projection;

import java.awt.Graphics;
import java.util.HashMap;
import java.util.ListIterator;

/**
 * This class extends the OMGraphicList by allowing searches on the
 * AppObject contained by the OMGraphics on the list. The AppObject is
 * where the LinkGraphics store the graphic ID as defined by the
 * server. It also returns indexes from searches instead of the
 * graphic. This allows for deletions, replacements and graphic
 * location movement from within the list.
 */
public class LinkOMGraphicList extends OMGraphicList implements
        LinkPropertiesConstants {

    private HashMap hash = new HashMap(541); // Why 541? Hmm, don't
                                             // know.
    protected Projection currentProjection = null;

    /**
     * Construct an OMGraphicList.
     */
    public LinkOMGraphicList() {
        super(10);
    };

    /**
     * Construct an OMGraphicList with an initial capacity.
     * 
     * @param initialCapacity the initial capacity of the list
     */
    public LinkOMGraphicList(int initialCapacity) {
        super(initialCapacity);
    };

    public void setProjection(Projection proj) {
        currentProjection = proj;
    }

    public Projection getProjection() {
        return currentProjection;
    }

    /**
     * Check whether the list needs to be regenerated, considering the
     * projection that the OMGraphics were projected with when the
     * list was read. The projection equality projection is lazy, just
     * checks objects.
     */
    public boolean getNeedToRegenerate(Projection proj) {
        return super.getNeedToRegenerate() || currentProjection != proj;
    }

    /**
     * Add an OMGraphic to the GraphicList. The OMGraphic must not be
     * null.
     * 
     * @param g the non-null OMGraphic to add
     * @exception IllegalArgumentException if OMGraphic is null
     */
    public synchronized void _add(OMGeometry g) {
        super._add(g);
        String id = ((LinkProperties) g.getAppObject()).getProperty(LPC_GRAPHICID);
        if (Debug.debugging("linkdetail")) {
            Debug.output("LinkOMGraphicList: Adding graphic, id(" + id + ")");
        }
        if (id != null) {
            hash.put(id.intern(), g);
        }
    }

    /**
     * Remove the graphic at a location in the list.
     * 
     * @param location the OMGraphic object to remove.
     * @return true if graphic was on the list, false if otherwise.
     */
    protected synchronized Object _remove(int location) {
        Object ret = super._remove(location);
        if (ret != null) {
            String id = ((LinkProperties) ((OMGeometry) ret).getAppObject()).getProperty(LPC_GRAPHICID);
            if (id != null) {
                hash.remove(id.intern());
                if (Debug.debugging("link")) {
                    Debug.output("LinkOMGraphicList: Removing graphic " + id);
                }
            }
        }

        return ret;
    }

    /**
     * Remove the graphic. If this list is not vague, it will also ask
     * sub-OMGraphicLists to remove it if the geometry isn't found on
     * this OMGraphicList.
     * 
     * @param geometry the OMGeometry object to remove.
     * @return true if geometry was on the list, false if otherwise.
     */
    protected synchronized boolean _remove(OMGeometry geometry) {
        boolean ret = super._remove(geometry);
        if (ret != false) {
            String id = ((LinkProperties) geometry.getAppObject()).getProperty(LPC_GRAPHICID);
            hash.remove(id.intern());
            if (Debug.debugging("link")) {
                Debug.output("LinkOMGraphicList: Removing graphic " + id);
            }
        }
        return ret;
    }

    /**
     * Set the graphic at the specified location. The OMGraphic must
     * not be null, the AppObject in the OMGraphic must be null or a
     * LinkProperties object. This method is extended from
     * OMGraphicList so the link id is added to the hashtable for
     * faster searching.
     * 
     * @param graphic OMGraphic
     * @param index index of the OMGraphic to return
     * @exception ArrayIndexOutOfBoundsException if index is
     *            out-of-bounds
     */
    public synchronized void setOMGraphicAt(OMGraphic graphic, int index) {
        LinkProperties linkp = null;

        try {
            linkp = (LinkProperties) graphic.getAppObject();

            String id = null;
            if (linkp != null) {
                id = linkp.getProperty(LPC_GRAPHICID);
                if (Debug.debugging("link")) {
                    Debug.output("LinkOMGraphicList.setOMGraphicAt(): Updating graphic "
                            + id + " at " + index);
                }
                if (id != null) {
                    hash.put(id.intern(), graphic);
                }
            }

        } catch (ClassCastException cce) {
            Debug.error("LinkOMGraphicList.setOMGraphicAt(): Updated graphic doesn't have id");
        }

        super.setOMGraphicAt(graphic, index);
    }

    /**
     * Get the graphic with the graphic ID.
     * 
     * @param gid graphic ID of the wanted graphic.
     * @return OMGraphic or null if not found
     */
    public OMGraphic getOMGraphicWithId(String gid) {
        return (OMGraphic) hash.get(gid.intern());
    }

    /**
     * Get the graphic with the graphic ID. Traverse mode doesn't
     * matter.
     * 
     * @param gid graphic ID of the wanted graphic.
     * @return OMGraphic index or Link.UNKNOWN if not found
     */
    public int getOMGraphicIndexWithId(String gid) {
        OMGraphic graphic = getOMGraphicWithId(gid);
        if (graphic != null) {
            return super._indexOf(graphic);
        } else {
            return Link.UNKNOWN;
        }
    }

    /**
     * Remove all elements from the graphic list.
     */
    public synchronized void clear() {
        super.clear();
        hash.clear();
    }

    /**
     * Renders all the objects in the list a graphics context. This is
     * the same as <code>paint()</code> for AWT components. The
     * graphics are rendered in the order of traverseMode. Any
     * graphics where <code>isVisible()</code> returns false are not
     * rendered.
     * 
     * @param gr the AWT Graphics context
     */
    public synchronized void render(Graphics gr) {
        OMGraphic graphic;
        ListIterator iterator;

        if (traverseMode == FIRST_ADDED_ON_TOP) {
            iterator = graphics.listIterator(graphics.size());
            while (iterator.hasPrevious()) {
                graphic = (OMGraphic) iterator.previous();
                if (graphic.isVisible()) {
                    Object obj = graphic.getAppObject();
                    if (Debug.debugging("linkdetail")
                            && obj instanceof LinkProperties) {
                        String id = ((LinkProperties) obj).getProperty(LPC_GRAPHICID);
                        Debug.output("LinkOMGraphicList: Rendering graphic "
                                + id);
                    }
                    graphic.render(gr);
                }
            }

        } else {
            iterator = graphics.listIterator();

            while (iterator.hasNext()) {
                graphic = (OMGraphic) iterator.next();
                if (graphic.isVisible()) {
                    Object obj = graphic.getAppObject();
                    if (Debug.debugging("linkdetail")
                            && obj instanceof LinkProperties) {
                        String id = ((LinkProperties) obj).getProperty(LPC_GRAPHICID);
                        Debug.output("LinkOMGraphicList: Rendering graphic "
                                + id);
                    }
                    graphic.render(gr);
                }
            }
        }
    }
}