renderinghintsrenderpolicy.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/policy/RenderingHintsRenderPolicy.java,v $
// $RCSfile: RenderingHintsRenderPolicy.java,v $
// $Revision: 1.2.2.2 $
// $Date: 2005/10/26 15:47:15 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.policy;

import java.awt.RenderingHints;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.util.Iterator;
import java.util.Properties;
import java.util.Vector;

import com.bbn.openmap.layer.OMGraphicHandlerLayer;
import com.bbn.openmap.util.Debug;
import com.bbn.openmap.util.PropUtils;

/**
 * The RenderingHintsRenderPolicy is a StandardRenderPolicy that lets
 * you set RenderingHints on the java.awt.Graphics object before the
 * layer is painted, and then simply paints the current graphic list.
 * No conditions or deviations are considered. This class can be set
 * with properties.
 * <P>
 * The properties have to look like:
 * 
 * <pre>
 * 
 * 
 *  prefix.renderingHints=RENDERINGHINTS_KEY1 RENDERINGHINTS_KEY2
 *  prefix.RENDERINGHINTS_KEY1=RENDERINGHINTS_VALUE1
 *  prefix.RENDERINGHINTS_KEY2=RENDERINGHINTS_VALUE2
 * 
 *  
 * </pre>
 * 
 * For example, for a GraticuleLayer in the properties file with a
 * 'graticule' prefix:
 * 
 * <pre>
 * 
 *  
 *  graticule.renderPolicy=textAliasing
 *  graticule.textAliasing.class=com.bbn.openmap.layer.policy.RenderingHintsRenderPolicy
 *  graticule.textAliasing.renderingHints=KEY_TEXT_ANTIALIASING
 *  graticule.textAliasing.KEY_TEXT_ANTIALIASING=VALUE_TEXT_ANTIALIAS_ON
 *  
 *  
 * </pre>
 * 
 * The HintsMapBeanRepaintPolicy uses a RenderingHintsRenderPolicy
 * with properties that look like these, where 'repaintPolicy' is the
 * prefix for the RenderingHintsRenderPolicy:
 * 
 * <pre>
 * 
 * 
 *  repaintPolicy.class=com.bbn.openmap.HintsMapBeanRepaintPolicy
 *  repaintPolicy.renderingHints=KEY_ANTIALIASING
 *  repaintPolicy.KEY_ANTIALIASING=VALUE_ANTIALIAS_ON
 *  repaintPolicy.KEY_RENDERING=VALUE_RENDER_SPEED
 *  
 *  
 * </pre>
 * 
 * See the java.awt.RenderingHints javadocs for the key-value pairs
 * that can be used.
 *  
 */
public class RenderingHintsRenderPolicy extends StandardRenderPolicy {

    public final static String RenderingHintsProperty = "renderingHints";

    protected RenderingHints renderingHints = null;

    /**
     * The layer needs to be set at some point before use.
     */
    public RenderingHintsRenderPolicy() {
        super();
        setRenderingHints(new RenderingHints(null));
    }

    public RenderingHintsRenderPolicy(OMGraphicHandlerLayer layer) {
        super(layer);
        setRenderingHints(new RenderingHints(null));
    }

    /**
     * Set the RenderingHints Map that should be used on the MapBean.
     * If null, no modifications will be set on the MapBean's Graphics
     * object.
     */
    public void setRenderingHints(RenderingHints rh) {
        renderingHints = rh;
    }

    /**
     * Get the RenderingHints Map that should be used on the MapBean.
     * May be null (default).
     */
    public RenderingHints getRenderingHints() {
        return renderingHints;
    }

    /**
     * If you are going to change the Graphics object in this method,
     * you should make a copy of it first using the Graphics.create()
     * method so the changes won't affect other layers.
     */
    public void paint(Graphics g) {
        g = g.create(); // Make a copy to use just for this layer.
        setRenderingHints(g);
        setCompositeOnGraphics((Graphics2D)g);
        super.paint(g);
    }

    public void setRenderingHints(Graphics g) {
        if (renderingHints != null && g instanceof Graphics2D) {
            ((Graphics2D) g).setRenderingHints(renderingHints);
        }
    }

    public void setProperties(String prefix, Properties props) {
        super.setProperties(prefix, props);
        prefix = PropUtils.getScopedPropertyPrefix(prefix);

        String renderingHintsString = props.getProperty(prefix
                + RenderingHintsProperty);

        if (DEBUG) {
            Debug.output("RHRP: decoding rendering hints: "
                    + renderingHintsString);
        }

        Vector renderingHintsVector = PropUtils.parseSpacedMarkers(renderingHintsString);

        if (renderingHintsVector != null) {
            Iterator it = renderingHintsVector.iterator();
            while (it.hasNext()) {
                String renderingHintKeyString = (String) it.next();
                if (renderingHintKeyString != null) {
                    String renderingHintValueString = props.getProperty(prefix
                            + renderingHintKeyString);

                    if (renderingHintValueString != null) {
                        Object key = null;
                        Object value = null;

                        try {
                            key = RenderingHints.class.getField(renderingHintKeyString)
                                    .get(null);
                            value = RenderingHints.class.getField(renderingHintValueString)
                                    .get(null);
                        } catch (NoSuchFieldException nsfe) {
                        } catch (IllegalAccessException iae) {
                        }

                        if (key != null && value != null) {
                            if (renderingHints == null) {
                                renderingHints = new RenderingHints(null);
                            }
                            renderingHints.put(key, value);
                            if (DEBUG) {
                                Debug.output("RHRP+++ adding "
                                        + renderingHintKeyString + " | "
                                        + renderingHintValueString);
                            }
                        } else {
                            if (DEBUG) {
                                Debug.output("RHRP--- NOT adding "
                                        + renderingHintKeyString + " (" + key
                                        + ") | " + renderingHintValueString
                                        + " (" + value + ")");
                            }
                        }
                    } else if (DEBUG) {
                        Debug.output("RHRP--- NOT adding "
                                + renderingHintKeyString);
                    }
                }
            }
        }
    }

    public Properties getProperties(Properties props) {
        props = super.getProperties(props);
        return props;
    }

    public Properties getPropertyInfo(Properties props) {
        props = super.getPropertyInfo(props);
        return props;
    }

}