Hi Tim, I tried your "FeatureAgent"...
"featureclick" works fine. "featureover" and "featureout" do not fire. In your modified (sandbox) Vector.js file, I could find "featureclick", but not the other 2 events, listed at line 99. "EVENT_TYPES" Is it possible this could be a reason for the events not firing, or should I be looking at my own code? Thanks! Michael. ps. I add my vote for this to be included as an OpenLayers feature. Ivan Grcic-2 wrote: > > > On Sat, Oct 17, 2009 at 1:46 AM, Tim Schaub <tsch...@opengeo.org> wrote: >> Hey- >> >> We've wrestled for some time with browser events being blocked by >> svg/vml elements. This originally meant that you could only use a >> select feature control with one layer at a time. Andreas contributed a >> nice solution for selecting features on multiple layers for the last >> release. >> >> I got a number of things wrong in the select feature control (layer gets >> selectedFeatures array [ack] and control maintains it [ug], control has >> select method but layer doesn't, you can't easily deal with >> feature/mouse interaction without getting all the select feature control >> behavior, etc.) I've long wanted to just have vector layers trigger >> feature related events. >> >> I put together what seems like a potential solution: >> http://dev.openlayers.org/sandbox/tschaub/select/examples/feature-events.html >> >> This introduces a "FeatureAgent" constructor. If a map has the >> "featureEvents" property set to true, it gets a feature agent that >> manages feature related events (from click and mousemove). This gives >> us featureclick, nofeatureclick, featureover, and featureout event on >> vector layers. >> >> As described in the example, these events are fired for visible vector >> layers. The over/out events are similar to mouseover/mouseout for other >> doc elements - except that all features on all layers are essentially >> treated as if they share the same z-index. This means you get over/out >> for every feature on every layer as you pass over and out. Similarly, >> the featureclick event "drills" through all features on all layers. You >> get the event once for each of multiple overlapping features on a single >> layer or the same on multiple layers. Listeners are triggered for >> features in reverse draw order (top first). Any listener can return >> false to stop remaining listeners from getting called. >> >> The whole thing relies on document.elementFromPoint [1]. This is a >> handy method that accounts for the currently computed style of all >> elements. The trick is to set the display style to none for each target >> and call the method again, until all targets on all layers have been >> accounted for. All this happens in a single browser event listener >> sequence. Since style display is getting set and reset for all targets >> during the same sequence, we don't trigger a reflow with each display >> change. It appears that there also isn't a reflow at the end of the >> listener sequence either (though I need some heavier examples to test >> with). >> >> I've played with the example on Firefox 3.5 and IE 6. Haven't tested >> other browsers yet. >> >> There are a number of ways this could be implemented: >> >> a) As a control. Traditional, but we don't need the dom element or >> events object - and this may be a more awkward way in practice. >> >> b) As it is now. The agent is added/activated if a map property is set. >> Could also be added/activated after map construction. >> >> c) Crammed into Map.js. I'd rather not do this. >> >> d) Other (handler, plugin, more). >> >> Thanks for any feedback. >> Tim >> >> [1] https://developer.mozilla.org/en/DOM/document.elementFromPoint >> >> -- >> Tim Schaub >> OpenGeo - http://opengeo.org >> Expert service straight from the developers. >> _______________________________________________ >> Dev mailing list >> Dev@openlayers.org >> http://openlayers.org/mailman/listinfo/dev >> > > -- View this message in context: http://n2.nabble.com/feature-events-tp3839189p4075103.html Sent from the OpenLayers Dev mailing list archive at Nabble.com. _______________________________________________ Dev mailing list Dev@openlayers.org http://openlayers.org/mailman/listinfo/dev
