getlegendgraphicrequest.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org.  All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.vfny.geoserver.wms.requests;

import java.util.Map;

import org.geotools.feature.FeatureType;
import org.geotools.styling.Rule;
import org.geotools.styling.Style;
import org.vfny.geoserver.wms.servlets.WMService;


/**
 * Holds the parsed parameters for a GetLegendGraphic WMS request.
 *
 * <p>
 * The GET parameters of the GetLegendGraphic operation are defined as follows
 * (from SLD 1.0 spec, ch.12):<br>
 * <pre>
 * <table>
 *  <tr><td><b>Parameter</b></td><td><b>Required</b></td><td><b>Description</b></td></tr>
 *  <tr><td>VERSION </td><td>Required </td><td>Version as required by OGC interfaces.</td></tr>
 *  <tr><td>REQUEST </td><td>Required </td><td>Value must be  GetLegendRequest . </td></tr>
 *  <tr><td>LAYER </td><td>Required </td><td>Layer for which to produce legend graphic. </td></tr>
 *  <tr><td>STYLE </td><td>Optional </td><td>Style of layer for which to produce legend graphic. If not present, the default style is selected. The style may be any valid style available for a layer, including non-SLD internally-defined styles.</td></tr>
 *  <tr><td>FEATURETYPE </td><td>Optional </td><td>Feature type for which to produce the legend graphic. This is not needed if the layer has only a single feature type. </td></tr>
 *  <tr><td>RULE </td><td>Optional </td><td>Rule of style to produce legend graphic for, if applicable. In the case that a style has multiple rules but no specific rule is selected, then the map server is obligated to produce a graphic that is representative of all of the rules of the style.</td></tr>
 *  <tr><td>SCALE </td><td>Optional </td><td>In the case that a RULE is not specified for a style, this parameter may assist the server in selecting a more appropriate representative graphic by eliminating internal rules that are outof- scope. This value is a standardized scale denominator, defined in Section 10.2</td></tr>
 *  <tr><td>SLD </td><td>Optional </td><td>This parameter specifies a reference to an external SLD document. It works in the same way as the SLD= parameter of the WMS GetMap operation. </td></tr>
 *  <tr><td>SLD_BODY </td><td>Optional </td><td>This parameter allows an SLD document to be included directly in an HTTP-GET request. It works in the same way as the SLD_BODY= parameter of the WMS GetMap operation.</td></tr>
 *  <tr><td>FORMAT </td><td>Required </td><td>This gives the MIME type of the file format in which to return the legend graphic. Allowed values are the same as for the FORMAT= parameter of the WMS GetMap request. </td></tr>
 *  <tr><td>WIDTH </td><td>Optional </td><td>This gives a hint for the width of the returned graphic in pixels. Vector-graphics can use this value as a hint for the level of detail to include. </td></tr>
 *  <tr><td>HEIGHT </td><td>Optional </td><td>This gives a hint for the height of the returned graphic in pixels. </td></tr>
 *  <tr><td>EXCEPTIONS </td><td>Optional </td><td>This gives the MIME type of the format in which to return exceptions. Allowed values are the same as for the EXCEPTIONS= parameter of the WMS GetMap request.</td></tr>
 *  <tr><td>TRANSPARENT </td><td>Optional </td><td><code>true</code> if the legend image background should be transparent. Defaults to <code>false</code>.</td></tr>
 *  </table>
 *  </pre>
 * </p>
 *
 * <p>
 * The GetLegendGraphic operation itself is optional for an SLD-enabled WMS. It
 * provides a general mechanism for acquiring legend symbols, beyond the
 * LegendURL reference of WMS Capabilities. Servers supporting the
 * GetLegendGraphic call might code LegendURL references as GetLegendGraphic
 * for interface consistency. Vendorspecific parameters may be added to
 * GetLegendGraphic requests and all of the usual OGC-interface options and
 * rules apply. No XML-POST method for GetLegendGraphic is presently defined.
 * </p>
 *
 * @author Gabriel Roldan, Axios Engineering
 * @version $Id: GetLegendGraphicRequest.java 7728 2007-11-09 01:53:31Z groldan $
 */
public class GetLegendGraphicRequest extends WMSRequest {
    /** DOCUMENT ME! */
    public static final String SLD_VERSION = "1.0.0";

    /**
     * default legend graphic width, in pixels, to apply if no WIDTH parameter
     * was passed
     */
    public static final int DEFAULT_WIDTH = 20;

    /**
     * default legend graphic height, in pixels, to apply if no WIDTH parameter
     * was passed
     */
    public static final int DEFAULT_HEIGHT = 20;

    /**
     * The default image format in which to produce a legend graphic. Not
     * really used when performing user requests, since FORMAT is a mandatory
     * parameter, but by now serves as a default for expressing LegendURL
     * layer attribute in GetCapabilities.
     */
    public static final String DEFAULT_FORMAT = "image/png";

    /** The featuretype of the requested LAYER */
    private FeatureType layer;

    /**
     * The Style object for styling the legend graphic, or layer's default if
     * not provided. This style can be aquired by evaluating the STYLE
     * parameter, which provides one of the  layer's named styles, the SLD
     * parameter, which provides a URL for an external SLD document, or the
     * SLD_BODY parameter, which provides the SLD body in the request body.
     */
    private Style style;

    /**
     * should hold FEATURETYPE parameter value, though not used by now, since
     * GeoServer WMS still does not supports nested layers and layers has only
     * a single feature type. This should change in the future.
     */
    private String featureType;

    /** holds RULE parameter value, or <code>null</code> if not provided */
    private Rule rule;

    /**
     * holds the standarized scale denominator passed as the SCALE parameter
     * value, or <code>-1.0</code> if not provided
     */
    private double scale = -1d;

    /**
     * the mime type of the file format in which to return the legend graphic,
     * as requested by the FORMAT request parameter value.
     */
    private String format;

    /**
     * the width in pixels of the returned graphic, or
     * <code>DEFAULT_WIDTH</code> if not provided
     */
    private int width = DEFAULT_WIDTH;

    /**
     * the height in pixels of the returned graphic, or
     * <code>DEFAULT_HEIGHT</code> if not provided
     */
    private int height = DEFAULT_HEIGHT;

    /** mime type of the format in which to return exceptions information. */
    private String exceptionsFormat = GetMapRequest.SE_XML;
    
    /** holds the geoserver-specific getLegendGraphic options for controlling
     * things like the label font, label font style, label font antialiasing, etc.
     */ 
    private Map legendOptions;

    /**
     * Whether the legend graphic background shall be transparent or not.
     */
    private boolean transparent;

    /**
     * Creates a new GetLegendGraphicRequest object.
     * @param service The service that will handle the request
     */
    public GetLegendGraphicRequest(WMService service) {
        super("GetLegendGraphic", service);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getExceptionsFormat() {
        return exceptionsFormat;
    }

    /**
     * DOCUMENT ME!
     *
     * @param exceptionsFormat DOCUMENT ME!
     */
    public void setExceptionsFormat(String exceptionsFormat) {
        this.exceptionsFormat = exceptionsFormat;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getFeatureType() {
        return featureType;
    }

    /**
     * DOCUMENT ME!
     *
     * @param featureType DOCUMENT ME!
     */
    public void setFeatureType(String featureType) {
        this.featureType = featureType;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getFormat() {
        return format;
    }

    /**
     * DOCUMENT ME!
     *
     * @param format DOCUMENT ME!
     */
    public void setFormat(String format) {
        this.format = format;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public int getHeight() {
        return height;
    }

    /**
     * DOCUMENT ME!
     *
     * @param height DOCUMENT ME!
     */
    public void setHeight(int height) {
        this.height = height;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public FeatureType getLayer() {
        return layer;
    }

    /**
     * DOCUMENT ME!
     *
     * @param layer DOCUMENT ME!
     */
    public void setLayer(FeatureType layer) {
        this.layer = layer;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public Rule getRule() {
        return rule;
    }

    /**
     * DOCUMENT ME!
     *
     * @param rule DOCUMENT ME!
     */
    public void setRule(Rule rule) {
        this.rule = rule;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public double getScale() {
        return scale;
    }

    /**
     * DOCUMENT ME!
     *
     * @param scale DOCUMENT ME!
     */
    public void setScale(double scale) {
        this.scale = scale;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public Style getStyle() {
        return style;
    }

    /**
     * DOCUMENT ME!
     *
     * @param style DOCUMENT ME!
     */
    public void setStyle(Style style) {
        this.style = style;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public int getWidth() {
        return width;
    }

    /**
     * DOCUMENT ME!
     *
     * @param width DOCUMENT ME!
     */
    public void setWidth(int width) {
        this.width = width;
    }
    
    public Map getLegendOptions() {
        return legendOptions;
    }
    
    public void setLegendOptions(Map legendOptions) {
        this.legendOptions = legendOptions;
    }

    /**
     * Sets the value of the background transparency flag depending on the value
     * of the <code>TRANSPARENT</code> request parameter.
     * 
     * @param transparentBackground
     *            whether the legend graphic background shall be transparent or
     *            not
     */
    public void setTransparent(boolean transparentBackground) {
        this.transparent = transparentBackground;
    }

    /**
     * Returns the value of the optional request parameter
     * <code>TRANSPARENT</code>, which might be either the literal
     * <code>true</code> or <code>false</code> and specifies if the
     * background of the legend graphic to return shall be transparent or not.
     * <p>
     * If the <code>TRANSPARENT</code> parameter is not specified, this
     * property defaults to <code>false</code>.
     * </p>
     * 
     * @return whether the legend graphic background shall be transparent or not
     */
    public boolean isTransparent() {
        return transparent;
    }
}