New layer type PointTrack: connects point features to lines. r=crschmidt,elemoine. (closes #1167)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@5733 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
2008-01-14 14:42:29 +00:00
parent cb13a6d053
commit 651b60f8f7
6 changed files with 344 additions and 0 deletions
--- a/lib/OpenLayers/Layer/PointTrack.js
+++ b/lib/OpenLayers/Layer/PointTrack.js
@@ -0,0 +1,99 @@
+/* Copyright (c) 2006-2007 MetaCarta, Inc., 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/Vector.js
+ * 
+ * Class: OpenLayers.Layer.PointTrack
+ * Vector layer to display ordered point features as a line, creating one
+ * LineString feature for each pair of two points.
+ *
+ * Inherits from:
+ *  - <OpenLayers.Layer.Vector> 
+ */
+OpenLayers.Layer.PointTrack = OpenLayers.Class(OpenLayers.Layer.Vector, {
+  
+    /**
+     * APIProperty:
+     * dataFrom  - {<OpenLayers.Layer.PointTrack.dataFrom>} optional. If the
+     *             lines should get the data/attributes from one of the two
+     *             points, creating it, which one should it be?
+     */
+    dataFrom: null,
+    
+    /**
+     * Constructor: OpenLayers.PointTrack
+     * Constructor for a new OpenLayers.PointTrack instance.
+     *
+     * Parameters:
+     * name     - {String} name of the layer
+     * options  - {Object} Optional object with properties to tag onto the
+     *            instance.
+     */    
+    initialize: function(name, options) {
+        OpenLayers.Layer.Vector.prototype.initialize.apply(this, arguments);
+    },
+        
+    /**
+     * APIMethod: addNodes
+     * Adds point features that will be used to create lines from, using point
+     * pairs. The first point of a pair will be the source node, the second
+     * will be the target node.
+     * 
+     * Parameters:
+     * pointFeatures - {Array(<OpenLayers.Feature>)}
+     * 
+     */
+    addNodes: function(pointFeatures) {
+        if (pointFeatures.length < 2) {
+            OpenLayers.Console.error(
+                    "At least two point features have to be added to create" +
+                    "a line from");
+            return;
+        }
+        
+        var lines = new Array(pointFeatures.length-1);
+        
+        var pointFeature, startPoint, endPoint;
+        for(var i = 0; i < pointFeatures.length; i++) {
+            pointFeature = pointFeatures[i];
+            endPoint = pointFeature.geometry;
+            
+            if (!endPoint) {
+              var lonlat = pointFeature.lonlat;
+              endPoint = new OpenLayers.Geometry.Point(lonlat.lon, lonlat.lat);
+            } else if(endPoint.CLASS_NAME != "OpenLayers.Geometry.Point") {
+                OpenLayers.Console.error(
+                        "Only features with point geometries are supported.");
+                return;
+            }
+            
+            if(i > 0) {
+                var attributes = (this.dataFrom != null) ?
+                        (pointFeatures[i+this.dataFrom].data ||
+                                pointFeatures[i+this.dataFrom].attributes) :
+                        null;
+                var line = new OpenLayers.Geometry.LineString([startPoint,
+                        endPoint]);
+                        
+                lines[i-1] = new OpenLayers.Feature.Vector(line, attributes);
+            }
+            
+            startPoint = endPoint;
+        }
+
+        this.addFeatures(lines);
+    },
+    
+    CLASS_NAME: "OpenLayers.Layer.PointTrack"
+});
+
+/**
+ * Constant: OpenLayers.Layer.PointTrack.dataFrom
+ * {Object} with the following keys
+ * - SOURCE_NODE: take data/attributes from the source node of the line
+ * - TARGET_NODE: take data/attributes from the target node of the line
+ */
+OpenLayers.Layer.PointTrack.dataFrom = {'SOURCE_NODE': -1, 'TARGET_NODE': 0};
+