True! But the original example also wrong using Canvas: using SVG can not select a markers if it is below a square, with Canvas you can, as if there were no rectangle!
Xavier m1k3ry4n wrote > > When I render a layer as a Canvas it no longer respects the layer index. > > In my case, the Canvas layer is made up of polygons and a separate layer > above it is made up of points. Any points within polygons cannot be > selected -- only the surrounding polygon gets selected. > > I do not have this problem if the polygon layer is rendered as something > other than a Canvas. > > This problem is caused by the order of the layers in the array sent to > OpenLayers.Control.SelectFeature. The workaround is ordering the layers > array so that the Canvas layer comes after layers that are above it in > the layer index. > > In other words, even though I add layers to the map like this: > map.addLayers([canvas_layer, point_layer]) > > I have to add layers to the control like this: > map.addControl(new OpenLayers.Control.SelectFeature([point_layer, > canvas_layer])) > > To reproduce this problem do the following. > > 1. Go to: > http://openlayers.org/dev/examples/select-feature-multilayer.html?renderer=Canvas > > 2. Swap the order of vectors1, vectors2 in lines 62 & 65 so they look > like this: > > (line 62) map.addLayers([wmsLayer, vectors2, vectors1]); > ... > (line 65) selectControl = new OpenLayers.Control.SelectFeature( > [vectors2, vectors1], > > Changing addLayers puts the markers above the squares. Changing > SelectFeature disallows markers within squares to be selected, even > though they are above the squares. You will only see this problem if you > render the layers as Canvases (i.e. include "?renderer=Canvas" in the > url). > > Considering that layer order in SelectFeature has no effect on layers > not rendered as Canvases, this is either a bug or requires some > documentation for SelectFeature. > > This was also an issue in OL 2.11, but 2.12 improved the situation. In > 2.11 if you turned off the Canvas layer it persisted even though you > could not see the layer! If you panned the map, it would finally go away > and you could click the layers below. > > -Mike > > > Reference: > OpenLayers.Control.SelectFeature > http://dev.openlayers.org/docs/files/OpenLayers/Control/SelectFeature-js.html#OpenLayers.Control.SelectFeature.OpenLayers.Control.SelectFeature > > OpenLayers Select Feature on Multiple Layers Example > http://openlayers.org/dev/examples/select-feature-multilayer.html?renderer=Canvas > > > > _______________________________________________ > Dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/openlayers-dev > -- View this message in context: http://osgeo-org.1560.n6.nabble.com/Canvas-SelectFeature-Bug-OL-2-11-2-12-tp4985790p4987449.html Sent from the OpenLayers Dev mailing list archive at Nabble.com. _______________________________________________ Dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/openlayers-dev
