Adding a filter strategy for limiting features that are included in a layer's collection. The strategy takes a filter and caches features that don't pass the filter. Call setFilter on the strategy to update the cache and collection on the layer. r=ahocevar (closes #2790)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@10655 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
2010-08-20 22:41:01 +00:00
parent 28558c171c
commit 25fac24436
6 changed files with 406 additions and 0 deletions
@@ -0,0 +1,89 @@
+var map, filter, filterStrategy;
+
+var startDate = new Date(1272736800000); // lower bound of when values
+var endDate = new Date(1272737100000); // upper value of when values
+var step = 8; // sencods to advance each interval
+var interval = 0.125; // seconds between each step in the animation
+
+function init() {
+
+    // add behavior to elements
+    document.getElementById("start").onclick = startAnimation;
+    document.getElementById("stop").onclick = stopAnimation;
+    var spanEl = document.getElementById("span");
+
+    var mercator = new OpenLayers.Projection("EPSG:900913");
+    var geographic = new OpenLayers.Projection("EPSG:4326");
+    map = new OpenLayers.Map("map");
+    
+    var osm = new OpenLayers.Layer.OSM();
+    
+    filter = new OpenLayers.Filter.Comparison({
+        type: OpenLayers.Filter.Comparison.BETWEEN,
+        property: "when",
+        lowerBoundary: startDate,
+        upperBoundary: new Date(startDate.getTime() + (parseInt(spanEl.value, 10) * 1000))
+    });
+
+    filterStrategy = new OpenLayers.Strategy.Filter({filter: filter});
+
+    var flights = new OpenLayers.Layer.Vector("Aircraft Locations", {
+        projection: geographic,
+        strategies: [new OpenLayers.Strategy.Fixed(), filterStrategy],
+        protocol: new OpenLayers.Protocol.HTTP({
+            url: "kml-track.kml",
+            format: new OpenLayers.Format.KML({
+                extractTracks: true
+                //,extractStyles: true // use style from KML instead of styleMap below
+            })
+        }),
+        styleMap: new OpenLayers.StyleMap({
+            "default": new OpenLayers.Style({
+                graphicName: "circle",
+                pointRadius: 3,
+                fillOpacity: 0.25,
+                fillColor: "#ffcc66",
+                strokeColor: "#ff9933",
+                strokeWidth: 1
+            })
+        }),
+        renderers: ["Canvas", "SVG", "VML"]
+    });
+    
+    map.addLayers([osm, flights]);
+    map.setCenter(new OpenLayers.LonLat(-93.2735, 44.8349).transform(geographic, mercator), 8);
+    
+};
+
+var animationTimer;
+var currentDate;
+function startAnimation() {
+    if (animationTimer) {
+        stopAnimation(true);
+    }
+    if (!currentDate) {
+        currentDate = startDate;
+    }
+    var spanEl = document.getElementById("span");
+    var next = function() {
+        var span = parseInt(spanEl.value, 10);
+        if (currentDate < endDate) {
+            filter.lowerBoundary = currentDate;
+            filter.upperBoundary = new Date(currentDate.getTime() + (span * 1000));
+            filterStrategy.setFilter(filter);
+            currentDate = new Date(currentDate.getTime() + (step * 1000))
+        } else {
+            stopAnimation(true);
+        }
+    }
+    animationTimer = window.setInterval(next, interval * 1000);
+}
+
+function stopAnimation(reset) {
+    window.clearInterval(animationTimer);
+    animationTimer = null;
+    if (reset === true) {
+        currentDate = null;
+    }
+}
+