wicket-leaflet.js

/** @license
 *
 *  Copyright (C) 2012 K. Arthur Endsley (kaendsle@mtu.edu)
 *  Michigan Tech Research Institute (MTRI)
 *  3600 Green Court, Suite 100, Ann Arbor, MI, 48105
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * @augments Wkt.Wkt
 * A framework-dependent flag, set for each Wkt.Wkt() instance, that indicates
 * whether or not a closed polygon geometry should be interpreted as a rectangle.
 */
(function ( root, factory ) {
    if ( typeof exports === 'object' ) {
        // CommonJS
        module.exports = factory( require('./wicket') );
    } else if ( typeof define === 'function' && define.amd ) {
        // AMD. Register as an anonymous module.
        define( ['wicket'], factory);
    } else {
        // Browser globals
        factory(root.Wkt );
    }
}
(this, function(Wkt) {
    Wkt.Wkt.prototype.isRectangle = false;

    /**
     * @augments Wkt.Wkt
     * Truncates an Array of coordinates by the closing coordinate when it is
     * equal to the first coordinate given--this is only to be used for closed
     * geometries in order to provide merely an "implied" closure to Leaflet.
     * @param   coords  {Array}     An Array of x,y coordinates (objects)
     * @return          {Array}
     */
    Wkt.Wkt.prototype.trunc = function (coords) {
        var i, verts = [];

        for (i = 0; i < coords.length; i += 1) {
            if (Wkt.isArray(coords[i])) {
                verts.push(this.trunc(coords[i]));

            } else {

                // Add the first coord, but skip the last if it is identical
                if (i === 0 || !this.sameCoords(coords[0], coords[i])) {
                    verts.push(coords[i]);
                }
            }
        }

        return verts;
    };

    /**
     * @augments Wkt.Wkt
     * An object of framework-dependent construction methods used to generate
     * objects belonging to the various geometry classes of the framework.
     */
    Wkt.Wkt.prototype.construct = {
        /**
         * Creates the framework's equivalent point geometry object.
         * @param   config      {Object}    An optional properties hash the object should use
         * @param   component   {Object}    An optional component to build from
         * @return              {L.marker}
         */
        point: function (config, component) {
            var coord = component || this.components;
            if (coord instanceof Array) {
                coord = coord[0];
            }

            return L.marker(this.coordsToLatLng(coord), config);
        },

        /**
         * Creates the framework's equivalent multipoint geometry object.
         * @param   config  {Object}    An optional properties hash the object should use
         * @return          {L.featureGroup}
         */
        multipoint: function (config) {
            var i,
                layers = [],
                coords = this.components;

            for (i = 0; i < coords.length; i += 1) {
                layers.push(this.construct.point.call(this, config, coords[i]));
            }

            return L.featureGroup(layers, config);
        },

        /**
         * Creates the framework's equivalent linestring geometry object.
         * @param   config      {Object}    An optional properties hash the object should use
         * @param   component   {Object}    An optional component to build from
         * @return              {L.polyline}
         */
        linestring: function (config, component) {
            var coords = component || this.components,
                latlngs = this.coordsToLatLngs(coords, 0, this.coordsToLatLng);

            return L.polyline(latlngs, config);
        },

        /**
         * Creates the framework's equivalent multilinestring geometry object.
         * @param   config  {Object}    An optional properties hash the object should use
         * @return          {L.multiPolyline}
         */
        multilinestring: function (config) {
            var coords = this.components,
                latlngs = this.coordsToLatLngs(coords, 1, this.coordsToLatLng);

            if (L.multiPolyline) {
                return L.multiPolyline(latlngs, config);
            }
            else {
                return L.polyline(latlngs, config);
            }
        },

        /**
         * Creates the framework's equivalent polygon geometry object.
         * @param   config      {Object}    An optional properties hash the object should use
         * @return              {L.multiPolygon}
         */
        polygon: function (config) {
            // Truncate the coordinates to remove the closing coordinate
            var coords = this.trunc(this.components),
                latlngs = this.coordsToLatLngs(coords, 1, this.coordsToLatLng);
            return L.polygon(latlngs, config);
        },

        /**
         * Creates the framework's equivalent multipolygon geometry object.
         * @param   config  {Object}    An optional properties hash the object should use
         * @return          {L.multiPolygon}
         */
        multipolygon: function (config) {
            // Truncate the coordinates to remove the closing coordinate
            var coords = this.trunc(this.components),
                latlngs = this.coordsToLatLngs(coords, 2, this.coordsToLatLng);

            if (L.multiPolygon) {
                return L.multiPolygon(latlngs, config);
            }
            else {
                return L.polygon(latlngs, config);
            }
        },

        /**
         * Creates the framework's equivalent collection of geometry objects.
         * @param   config  {Object}    An optional properties hash the object should use
         * @return          {L.featureGroup}
         */
        geometrycollection: function (config) {
            var comps, i, layers;

            comps = this.trunc(this.components);
            layers = [];
            for (i = 0; i < this.components.length; i += 1) {
                layers.push(this.construct[comps[i].type].call(this, comps[i]));
            }

            return L.featureGroup(layers, config);
        }
    };

    L.Util.extend(Wkt.Wkt.prototype, {
        coordsToLatLngs: L.GeoJSON.coordsToLatLngs,
        // TODO Why doesn't the coordsToLatLng function in L.GeoJSON already suffice?
        coordsToLatLng: function (coords, reverse) {
            var lat = reverse ? coords.x : coords.y,
                lng = reverse ? coords.y : coords.x;

            return L.latLng(lat, lng, true);
        }
    });

    /**
     * @augments Wkt.Wkt
     * A framework-dependent deconstruction method used to generate internal
     * geometric representations from instances of framework geometry. This method
     * uses object detection to attempt to classify members of framework geometry
     * classes into the standard WKT types.
     * @param   obj {Object}    An instance of one of the framework's geometry classes
     * @return      {Object}    A hash of the 'type' and 'components' thus derived
     */
    Wkt.Wkt.prototype.deconstruct = function (obj) {
        var attr, coordsFromLatLngs, features, i, verts, rings, tmp, boundary;

        /**
         * Accepts an Array (arr) of LatLngs from which it extracts each one as a
         *  vertex; calls itself recursively to deal with nested Arrays.
         */
        coordsFromLatLngs = function (arr) {
            var i, coords;

            coords = [];
            for (i = 0; i < arr.length; i += 1) {
                if (Wkt.isArray(arr[i])) {
                    coords.push(coordsFromLatLngs(arr[i]));

                } else {
                    coords.push({
                        x: arr[i].lng,
                        y: arr[i].lat
                    });
                }
            }

            return coords;
        };

        // L.Marker ////////////////////////////////////////////////////////////////
        if (obj.constructor === L.Marker || obj.constructor === L.marker) {
            return {
                type: 'point',
                components: [{
                    x: obj.getLatLng().lng,
                    y: obj.getLatLng().lat
                }]
            };
        }

        // L.Rectangle /////////////////////////////////////////////////////////////
        if (obj.constructor === L.Rectangle || obj.constructor === L.rectangle) {
            tmp = obj.getBounds(); // L.LatLngBounds instance
            return {
                type: 'polygon',
                isRectangle: true,
                components: [
                    [
                        { // NW corner
                            x: tmp.getSouthWest().lng,
                            y: tmp.getNorthEast().lat
                        },
                        { // NE corner
                            x: tmp.getNorthEast().lng,
                            y: tmp.getNorthEast().lat
                        },
                        { // SE corner
                            x: tmp.getNorthEast().lng,
                            y: tmp.getSouthWest().lat
                        },
                        { // SW corner
                            x: tmp.getSouthWest().lng,
                            y: tmp.getSouthWest().lat
                        },
                        { // NW corner (again, for closure)
                            x: tmp.getSouthWest().lng,
                            y: tmp.getNorthEast().lat
                        }
                    ]
                ]
            };

        }

        // L.Polyline //////////////////////////////////////////////////////////////
        if (obj.constructor === L.Polyline || obj.constructor === L.polyline) {
            verts = [];
            tmp = obj.getLatLngs();

            if (!tmp[0].equals(tmp[tmp.length - 1])) {

                for (i = 0; i < tmp.length; i += 1) {
                    verts.push({
                        x: tmp[i].lng,
                        y: tmp[i].lat
                    });
                }

                return {
                    type: 'linestring',
                    components: verts
                };

            }
        }

        // L.Polygon ///////////////////////////////////////////////////////////////

        if (obj.constructor === L.Polygon || obj.constructor === L.polygon) {
            rings = [];
            verts = [];
            boundary = obj.getLatLngs()[0];

            // First, we deal with the boundary points
            for (i = 0; i < boundary.length; i += 1) {
                verts.push({ // Add the first coordinate again for closure
                    x: boundary[i].lng,
                    y: boundary[i].lat
                });
            }

            verts.push({ // Add the first coordinate again for closure
                x: boundary[0].lng,
                y: boundary[0].lat
            });

            rings.push(verts);

            // Now, any holes
            if (obj._holes && obj._holes.length > 0) {
                // Reworked to support holes properly
                verts = coordsFromLatLngs(obj._holes);
                for (i=0; i < verts.length;i++) {
                    verts[i].push(verts[i][0]); // Copy the beginning coords again for closure
                    rings.push(verts[i]);
                }
            }

            return {
                type: 'polygon',
                components: rings
            };

        }

        // L.MultiPolyline /////////////////////////////////////////////////////////
        // L.MultiPolygon //////////////////////////////////////////////////////////
        // L.LayerGroup ////////////////////////////////////////////////////////////
        // L.FeatureGroup //////////////////////////////////////////////////////////
        if (obj.constructor === L.MultiPolyline || obj.constructor === L.MultiPolygon
                || obj.constructor === L.LayerGroup || obj.constructor === L.FeatureGroup) {

            features = [];
            tmp = obj._layers;

            for (attr in tmp) {
                if (tmp.hasOwnProperty(attr)) {
                    if (tmp[attr].getLatLngs || tmp[attr].getLatLng) {
                        // Recursively deconstruct each layer
                        features.push(this.deconstruct(tmp[attr]));
                    }
                }
            }

            return {

                type: (function () {
                    switch (obj.constructor) {
                    case L.MultiPolyline:
                        return 'multilinestring';
                    case L.MultiPolygon:
                        return 'multipolygon';
                    case L.FeatureGroup:
                        return (function () {
                            var i, mpgon, mpline, mpoint;

                            // Assume that all layers are of one type (any one type)
                            mpgon = true;
                            mpline = true;
                            mpoint = true;

                            for (i in obj._layers) {
                                if (obj._layers.hasOwnProperty(i)) {
                                    if (obj._layers[i].constructor !== L.Marker) {
                                        mpoint = false;
                                    }
                                    if (obj._layers[i].constructor !== L.Polyline) {
                                        mpline = false;
                                    }
                                    if (obj._layers[i].constructor !== L.Polygon) {
                                        mpgon = false;
                                    }
                                }
                            }

                            if (mpoint) {
                                return 'multipoint';
                            }
                            if (mpline) {
                                return 'multilinestring';
                            }
                            if (mpgon) {
                                return 'multipolygon';
                            }
                            return 'geometrycollection';

                        }());
                    default:
                        return 'geometrycollection';
                    }
                }()),

                components: (function () {
                    // Pluck the components from each Wkt
                    var i, comps;

                    comps = [];
                    for (i = 0; i < features.length; i += 1) {
                        if (features[i].components) {
                            comps.push(features[i].components);
                        }
                    }

                    return comps;
                }())

            };

        }

        // L.Circle ////////////////////////////////////////////////////////////////
        if (obj.constructor === L.Circle || obj.constructor === L.circle) {
            console.log('Deconstruction of L.Circle objects is not yet supported');

        } else {
            console.log('The passed object does not have any recognizable properties.');
        }

    };

    return Wkt;
}));