Changed ordering example to show the effect of zIndexing without

yOrdering.


git-svn-id: http://svn.openlayers.org/trunk/openlayers@9307 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

examples/ordering.html

@@ -110,13 +110,15 @@
             var layer = new OpenLayers.Layer.Vector(
                 "Drawing Order",
                 {
-                    // Note there's no z-index set, and yOrdering is left
+                    // The zIndex is taken from the zIndex attribute of the features
-                    // to its default.
                     styleMap: new OpenLayers.StyleMap({
+                        graphicZIndex: "${zIndex}",
                         externalGraphic: "../img/marker-green.png",
                         pointRadius: 10
                     }),
-                    isBaseLayer: true
+                    isBaseLayer: true,
+                    // enable the indexer by setting zIndexing to true
+                    rendererOptions: {zIndexing: true}
                 }
             );
             
@@ -140,12 +142,17 @@
                 var leftLonLat = map.getLonLatFromViewPortPx(left);
                 orderingFeatures.push(
                     new OpenLayers.Feature.Vector(
-                        new OpenLayers.Geometry.Point(leftLonLat.lon, bottomLonLat.lat)
+                        new OpenLayers.Geometry.Point(leftLonLat.lon, bottomLonLat.lat),
+                        // Set the zIndex attribute of all features to 0.
+                        // This attribute will be assigned to the graphicZIndex symbolizer property by the layer's styleMap
+                        {zIndex: 0}
                     )
                 );
                 bottom.y -= POINT_DISTANCE / 2; // Divide by 2 for better visual.
                 left.x += POINT_DISTANCE / 2;
             }
+            // only the first feature gets a zIndex attribute of 1
+            orderingFeatures[0].attributes.zIndex = 1;
           
             layer.addFeatures(orderingFeatures);
         }
@@ -177,13 +184,13 @@
                     <div class="docs">
                         In this map, the gold features all have the same z-index, and the red features have alternating z-indeces. The gold features' z-index is greater than the red features' z-indeces, which is why gold features look to be drawn on top of the red features. Since each gold feature has the same z-index, gold features succomb to y-ordering: this is where features that seem closest to the viewer (lower lattitude) show up above those that seem farther away (higher lattitude).
                         <br><br>
-                        All vector layers have z-indexing enabled by default, but are not enabled with y-ordering. You can enable y-ordering by passing the parameter <i>yOrdering: true</i> in the vector layer's options hash. For all configurations, if features have the same z-index -- and if y-ordering is enabled: the same lattitude -- those features will succomb to drawing order, where the last feature to be drawn will appear above the rest.
+                        You can enable y-ordering by passing the parameter <i>yOrdering: true</i> in the vector layer's options hash. For all configurations (with yOrdering or zIndexing set to true), if features have the same z-index -- and if y-ordering is enabled: the same latitude -- those features will succomb to drawing order, where the last feature to be drawn will appear above the rest.
                     </div>
                 </td>
             </tr>
         </table>
         <br>
-        <h3>Drawing Order (no Z-Indexes set, and Y-Ordering disabled)</h3>
+        <h3>Z-Index and Drawing Order (Z-Indexes set, and Y-Ordering disabled)</h3>
         <table>
             <tr>
                 <td>
@@ -191,9 +198,9 @@
                 </td>
                 <td>
                     <div class="docs">
-                        In this map, features are not given z-indexes, and the layer's <i>yOrdering</i> parameter is set to the default (false). This configuration makes features succomb to drawing order instead of z-index order or y-order.
+                        In this map, <i>zIndexing</i> is set to true. All features are given the same z-index (0), except for the first feature which has a z-index of 1. The layer's <i>yOrdering</i> parameter is set to the default (false). This configuration makes features succomb to z-index and drawing order (for the features with the same z-index), instead of y-order.
                         <br><br>
-                        The features in this map were drawn from left to right and bottom to top, diagonally, to show that y-ordering is not enabled.
+                        The features in this map were drawn from left to right and bottom to top, diagonally, to show that y-ordering is not enabled. Only the lower-left corner feature is drawn on top of the others, because it has a higher z-index (1 instead of 0).
                     </div>
                 </td>
             </tr>