--- a/labs/openlayers/lib/OpenLayers/Layer/Text.js +++ b/labs/openlayers/lib/OpenLayers/Layer/Text.js @@ -1,1 +1,265 @@ - +/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for + * full list of contributors). Published under the Clear BSD license. + * See http://svn.openlayers.org/trunk/openlayers/license.txt for the + * full text of the license. */ + + +/** + * @requires OpenLayers/Layer/Markers.js + * @requires OpenLayers/Format/Text.js + * @requires OpenLayers/Request/XMLHttpRequest.js + */ + +/** + * Class: OpenLayers.Layer.Text + * This layer creates markers given data in a text file. The <location> + * property of the layer (specified as a property of the options argument + * in the <OpenLayers.Layer.Text> constructor) points to a tab delimited + * file with data used to create markers. + * + * The first row of the data file should be a header line with the column names + * of the data. Each column should be delimited by a tab space. The + * possible columns are: + * - *point* lat,lon of the point where a marker is to be placed + * - *lat* Latitude of the point where a marker is to be placed + * - *lon* Longitude of the point where a marker is to be placed + * - *icon* or *image* URL of marker icon to use. + * - *iconSize* Size of Icon to use. + * - *iconOffset* Where the top-left corner of the icon is to be placed + * relative to the latitude and longitude of the point. + * - *title* The text of the 'title' is placed inside an 'h2' marker + * inside a popup, which opens when the marker is clicked. + * - *description* The text of the 'description' is placed below the h2 + * in the popup. this can be plain text or HTML. + * + * Example text file: + * (code) + * lat lon title description iconSize iconOffset icon + * 10 20 title description 21,25 -10,-25 http://www.openlayers.org/dev/img/marker.png + * (end) + * + * Inherits from: + * - <OpenLayers.Layer.Markers> + */ +OpenLayers.Layer.Text = OpenLayers.Class(OpenLayers.Layer.Markers, { + + /** + * APIProperty: location + * {String} URL of text file. Must be specified in the "options" argument + * of the constructor. Can not be changed once passed in. + */ + location:null, + + /** + * Property: features + * {Array(<OpenLayers.Feature>)} + */ + features: null, + + /** + * APIProperty: formatOptions + * {Object} Hash of options which should be passed to the format when it is + * created. Must be passed in the constructor. + */ + formatOptions: null, + + /** + * Property: selectedFeature + * {<OpenLayers.Feature>} + */ + selectedFeature: null, + + /** + * Constructor: OpenLayers.Layer.Text + * Create a text layer. + * + * Parameters: + * name - {String} + * options - {Object} Object with properties to be set on the layer. + * Must include <location> property. + */ + initialize: function(name, options) { + OpenLayers.Layer.Markers.prototype.initialize.apply(this, arguments); + this.features = new Array(); + }, + + /** + * APIMethod: destroy + */ + destroy: function() { + // Warning: Layer.Markers.destroy() must be called prior to calling + // clearFeatures() here, otherwise we leak memory. Indeed, if + // Layer.Markers.destroy() is called after clearFeatures(), it won't be + // able to remove the marker image elements from the layer's div since + // the markers will have been destroyed by clearFeatures(). + OpenLayers.Layer.Markers.prototype.destroy.apply(this, arguments); + this.clearFeatures(); + this.features = null; + }, + + /** + * Method: loadText + * Start the load of the Text data. Don't do this when we first add the layer, + * since we may not be visible at any point, and it would therefore be a waste. + */ + loadText: function() { + if (!this.loaded) { + if (this.location != null) { + + var onFail = function(e) { + this.events.triggerEvent("loadend"); + }; + + this.events.triggerEvent("loadstart"); + OpenLayers.Request.GET({ + url: this.location, + success: this.parseData, + failure: onFail, + scope: this + }); + this.loaded = true; + } + } + }, + + /** + * Method: moveTo + * If layer is visible and Text has not been loaded, load Text. + * + * Parameters: + * bounds - {Object} + * zoomChanged - {Object} + * minor - {Object} + */ + moveTo:function(bounds, zoomChanged, minor) { + OpenLayers.Layer.Markers.prototype.moveTo.apply(this, arguments); + if(this.visibility && !this.loaded){ + this.loadText(); + } + }, + + /** + * Method: parseData + * + * Parameters: + * ajaxRequest - {<OpenLayers.Request.XMLHttpRequest>} + */ + parseData: function(ajaxRequest) { + var text = ajaxRequest.responseText; + + var options = {}; + + OpenLayers.Util.extend(options, this.formatOptions); + + if (this.map && !this.projection.equals(this.map.getProjectionObject())) { + options.externalProjection = this.projection; + options.internalProjection = this.map.getProjectionObject(); + } + + var parser = new OpenLayers.Format.Text(options); + var features = parser.read(text); + for (var i=0, len=features.length; i<len; i++) { + var data = {}; + var feature = features[i]; + var location; + var iconSize, iconOffset; + + location = new OpenLayers.LonLat(feature.geometry.x, + feature.geometry.y); + + if (feature.style.graphicWidth + && feature.style.graphicHeight) { + iconSize = new OpenLayers.Size( + feature.style.graphicWidth, + feature.style.graphicHeight); + } + + // FIXME: At the moment, we only use this if we have an + // externalGraphic, because icon has no setOffset API Method. + /** + * FIXME FIRST!! + * The Text format does all sorts of parseFloating + * The result of a parseFloat for a bogus string is NaN. That + * means the three possible values here are undefined, NaN, or a + * number. The previous check was an identity check for null. This + * means it was failing for all undefined or NaN. A slightly better + * check is for undefined. An even better check is to see if the + * value is a number (see #1441). + */ + if (feature.style.graphicXOffset !== undefined + && feature.style.graphicYOffset !== undefined) { + iconOffset = new OpenLayers.Pixel( + feature.style.graphicXOffset, + feature.style.graphicYOffset); + } + + if (feature.style.externalGraphic != null) { + data.icon = new OpenLayers.Icon(feature.style.externalGraphic, + iconSize, + iconOffset); + } else { + data.icon = OpenLayers.Marker.defaultIcon(); + + //allows for the case where the image url is not + // specified but the size is. use a default icon + // but change the size + if (iconSize != null) { + data.icon.setSize(iconSize); + } + } + + if ((feature.attributes.title != null) + && (feature.attributes.description != null)) { + data['popupContentHTML'] = + '<h2>'+feature.attributes.title+'</h2>' + + '<p>'+feature.attributes.description+'</p>'; + } + + data['overflow'] = feature.attributes.overflow || "auto"; + + var markerFeature = new OpenLayers.Feature(this, location, data); + this.features.push(markerFeature); + var marker = markerFeature.createMarker(); + if ((feature.attributes.title != null) + && (feature.attributes.description != null)) { + marker.events.register('click', markerFeature, this.markerClick); + } + this.addMarker(marker); + } + this.events.triggerEvent("loadend"); + }, + + /** + * Property: markerClick + * + * Parameters: + * evt - {Event} + */ + markerClick: function(evt) { + var sameMarkerClicked = (this == this.layer.selectedFeature); + this.layer.selectedFeature = (!sameMarkerClicked) ? this : null; + for(var i=0, len=this.layer.map.popups.length; i<len; i++) { + this.layer.map.removePopup(this.layer.map.popups[i]); + } + if (!sameMarkerClicked) { + this.layer.map.addPopup(this.createPopup()); + } + OpenLayers.Event.stop(evt); + }, + + /** + * Method: clearFeatures + */ + clearFeatures: function() { + if (this.features != null) { + while(this.features.length > 0) { + var feature = this.features[0]; + OpenLayers.Util.removeItem(this.features, feature); + feature.destroy(); + } + } + }, + + CLASS_NAME: "OpenLayers.Layer.Text" +}); +