vector.js

用来在地图上做操作GIS,在地图上做标记

/* Copyright (c) 2006-2007 MetaCarta, Inc., published under the BSD license.
 * See http://svn.openlayers.org/trunk/openlayers/release-license.txt 
 * for the full text of the license. */

// TRASH THIS
OpenLayers.State = {
    /** states */
    UNKNOWN: 'Unknown',
    INSERT: 'Insert',
    UPDATE: 'Update',
    DELETE: 'Delete'
}

/**
 * @requires OpenLayers/Feature.js
 * @requires OpenLayers/Util.js
 *
 * Class: OpenLayers.Feature.Vector
 * Vector features use the OpenLayers.Geometry classes as geometry description.
 * They have an 'attributes' property, which is the data object, and a 'style'
 * property, the default values of which are defined in the 
 * <OpenLayers.Feature.Vector.style> objects.
 * 
 * Inherits from:
 *  - <OpenLayers.Feature>
 */
OpenLayers.Feature.Vector = OpenLayers.Class(OpenLayers.Feature, {

    /** 
     * Property: fid 
     * {String} 
     */
    fid: null,
    
    /** 
     * APIProperty: geometry 
     * {<OpenLayers.Geometry>} 
     */
    geometry: null,

    /** 
     * APIProperty: attributes 
     * {Object} This object holds arbitrary properties that describe the
     *     feature.
     */
    attributes: null,

    /** 
     * Property: state 
     * {String} 
     */
    state: null,
    
    /** 
     * APIProperty: style 
     * {Object} 
     */
    style: null,
    
    /** 
     * Constructor: OpenLayers.Feature.Vector
     * Create a vector feature. 
     * 
     * Parameters:
     * geometry - {<OpenLayers.Geometry>} The geometry that this feature
     *     represents.
     * attributes - {Object} An optional object that will be mapped to the
     *     <attributes> property. 
     * style - {Object} An optional style object.
     */
    initialize: function(geometry, attributes, style) {
        OpenLayers.Feature.prototype.initialize.apply(this,
                                                      [null, null, attributes]);
        this.lonlat = null;
        this.geometry = geometry;
        this.state = null;
        this.attributes = {};
        if (attributes) {
            this.attributes = OpenLayers.Util.extend(this.attributes,
                                                     attributes);
        }
        this.style = style ? style : null; 
    },
    
    /** 
     * Method: destroy
     * nullify references to prevent circular references and memory leaks
     */
    destroy: function() {
        if (this.layer) {
            this.layer.removeFeatures(this);
            this.layer = null;
        }
            
        this.geometry = null;
        OpenLayers.Feature.prototype.destroy.apply(this, arguments);
    },
    
    /**
     * Method: clone
     * Create a clone of this vector feature.  Does not set any non-standard
     *     properties.
     *
     * Returns:
     * {<OpenLayers.Feature.Vector>} An exact clone of this vector feature.
     */
    clone: function () {
        return new OpenLayers.Feature.Vector(this.geometry.clone(),
                                             this.attributes,
                                             this.style);
    },

    /**
     * Method: onScreen
     * HACK - we need to rewrite this for non-point geometry
     * 
     * Returns:
     * {Boolean} For now just returns null
     */
    onScreen:function() {
        return null;
    },
    
    /**
     * Method: createMarker
     * HACK - we need to decide if all vector features should be able to
     *     create markers
     * 
     * Returns:
     * {<OpenLayers.Marker>} For now just returns null
     */
    createMarker: function() {
        return null;
    },

    /**
     * Method: destroyMarker
     * HACK - we need to decide if all vector features should be able to
     *     delete markers
     * 
     * If user overrides the createMarker() function, s/he should be able
     *   to also specify an alternative function for destroying it
     */
    destroyMarker: function() {
        // pass
    },

    /**
     * Method: createPopup
     * HACK - we need to decide if all vector features should be able to
     *     create popups
     * 
     * Returns:
     * {<OpenLayers.Popup>} For now just returns null
     */
    createPopup: function() {
        return null;
    },

    /**
     * Method: atPoint
     * Determins whether the feature intersects with the specified location.
     * 
     * Parameters: 
     * lonlat - {<OpenLayers.LonLat>} 
     * toleranceLon - {float} Optional tolerance in Geometric Coords
     * toleranceLat - {float} Optional tolerance in Geographic Coords
     * 
     * Returns:
     * {Boolean} Whether or not the feature is at the specified location
     */
    atPoint: function(lonlat, toleranceLon, toleranceLat) {
        var atPoint = false;
        if(this.geometry) {
            atPoint = this.geometry.atPoint(lonlat, toleranceLon, 
                                                    toleranceLat);
        }
        return atPoint;
    },

    /**
     * Method: destroyPopup
     * HACK - we need to decide if all vector features should be able to
     * delete popups
     */
    destroyPopup: function() {
        // pass
    },
    
    /**
     * Method: toState
     * Sets the new state
     *
     * Parameters:
     * state - {String} 
     */
    toState: function(state) {
        if (state == OpenLayers.State.UPDATE) {
            switch (this.state) {
                case OpenLayers.State.UNKNOWN:
                case OpenLayers.State.DELETE:
                    this.state = state;
                    break;
                case OpenLayers.State.UPDATE:
                case OpenLayers.State.INSERT:
                    break;
            }
        } else if (state == OpenLayers.State.INSERT) {
            switch (this.state) {
                case OpenLayers.State.UNKNOWN:
                    break;
                default:
                    this.state = state;
                    break;
            }
        } else if (state == OpenLayers.State.DELETE) {
            switch (this.state) {
                case OpenLayers.State.INSERT:
                    // the feature should be destroyed
                    break;
                case OpenLayers.State.DELETE:
                    break;
                case OpenLayers.State.UNKNOWN:
                case OpenLayers.State.UPDATE:
                    this.state = state;
                    break;
            }
        } else if (state == OpenLayers.State.UNKNOWN) {
            this.state = state;
        }
    },
    
    CLASS_NAME: "OpenLayers.Feature.Vector"
});


/**
 * Constant: OpenLayers.Feature.Vector.style
 * OpenLayers features can have a number of style attributes. The 'default' 
 *     style will typically be used if no other style is specified.
 *
 * Default style properties:
 *
 *  - fillColor: "#ee9900",
 *  - fillOpacity: 0.4, 
 *  - hoverFillColor: "white",
 *  - hoverFillOpacity: 0.8,
 *  - strokeColor: "#ee9900",
 *  - strokeOpacity: 1,
 *  - strokeWidth: 1,
 *  - strokeLinecap: "round",
 *  - hoverStrokeColor: "red",
 *  - hoverStrokeOpacity: 1,
 *  - hoverStrokeWidth: 0.2,
 *  - pointRadius: 6,
 *  - hoverPointRadius: 1,
 *  - hoverPointUnit: "%",
 *  - pointerEvents: "visiblePainted"
 *
 * Other style properties that have no default values:
 *
 *  - externalGraphic,
 *  - graphicWidth,
 *  - graphicHeight,
 *  - graphicOpacity
 *  - graphicXOffset
 *  - graphicYOffset
 */ 
OpenLayers.Feature.Vector.style = {
    'default': {
        fillColor: "#ee9900",
        fillOpacity: 0.4, 
        hoverFillColor: "white",
        hoverFillOpacity: 0.8,
        strokeColor: "#ee9900",
        strokeOpacity: 1,
        strokeWidth: 1,
        strokeLinecap: "round",
        hoverStrokeColor: "red",
        hoverStrokeOpacity: 1,
        hoverStrokeWidth: 0.2,
        pointRadius: 6,
        hoverPointRadius: 1,
        hoverPointUnit: "%",
        pointerEvents: "visiblePainted"
    },
    'select': {
        fillColor: "blue",
        fillOpacity: 0.4, 
        hoverFillColor: "white",
        hoverFillOpacity: 0.8,
        strokeColor: "blue",
        strokeOpacity: 1,
        strokeWidth: 2,
        strokeLinecap: "round",
        hoverStrokeColor: "red",
        hoverStrokeOpacity: 1,
        hoverStrokeWidth: 0.2,
        pointRadius: 6,
        hoverPointRadius: 1,
        hoverPointUnit: "%",
        pointerEvents: "visiblePainted",
        cursor: "pointer"
    },
    'temporary': {
        fillColor: "yellow",
        fillOpacity: 0.2, 
        hoverFillColor: "white",
        hoverFillOpacity: 0.8,
        strokeColor: "yellow",
        strokeOpacity: 1,
        strokeLinecap: "round",
        strokeWidth: 4,
        hoverStrokeColor: "red",
        hoverStrokeOpacity: 1,
        hoverStrokeWidth: 0.2,
        pointRadius: 6,
        hoverPointRadius: 1,
        hoverPointUnit: "%",
        pointerEvents: "visiblePainted"
    }
};