[OpenLayers-Dev] Problem with the developpement of a "overlay Strategy"

Eric Lemoine eric.c2c at gmail.com
Mon Oct 27 15:36:55 EDT 2008


Can't you have your strategy listen to featureunselected and fix the
ordering within the feature group including the unselected feature and
all the features that feature intersects? Eric

2008/10/27, Jerome Freyre <jerome.freyre at hispeed.ch>:
>
> Hi everybody,
>
> Currently I am trying to developp a new strategy (based on
> OpenLayers.Strategy.Cluster) that can modify the order of features (bigger
> features go downer and small one go higher) to display features with correct
> "overlay" or "superposition".
>
> To do that, I found that I have to order my features.
>
> Actually, I am loading my features with HTTP protocol (see:
> http://www.nabble.com/Problem-with-Protocol-HTTP-and-vector-layer-tt20088456.html
> ;) ).
>
> My "sort algorithm" seems to work because it is ordering features based on
> the "overlayAttribute".
>
> The problem appears when I select a feature that is "downer". When I
> unselect it, the feature goes "higher" than the smaller one and stays like
> this.
>
> Has somebody got an idea to resolve this problem?
>
> My strategy function :
> ============================================
>         if(this.features.length >= 2) {
>
> 			var tempArray = this.features;
> 			//alert('count = ' + this.features.length);
> 			for (var i=0; i<this.features.length; i++) {	
> 				for(var j=this.features.length-1; j>i;j--) {
> 					//alert('Comparaison de ' +
> this.features[j].attributes[this.overlayAttribute] + ' et ' +
> this.features[j-1].attributes[this.overlayAttribute]);
> 					if (parseInt(this.features[j].attributes[this.overlayAttribute]) >
> parseInt(this.features[j-1].attributes[this.overlayAttribute])) {
> 						var tmp = this.features[j];
> 						this.features[j] = this.features[j-1];
> 						this.features[j-1] = tmp;
> 					}
> 				}
> 			}
> 		}
>
> 		alert('count = ' + this.features.length);
> 		var attr = "";
> 		for(var i=0; i<this.features.length; ++i) {
> 			attr += this.features[i].attributes[this.overlayAttribute] + ' \\ ';
> 		}
>
> 	if(this.features.length > 0) {
>                  this.clustering = true;
>                  // A legitimate feature addition could occur during this
>                  // addFeatures call.  For clustering to behave well,
> features
>                  // should be removed from a layer before requesting a new
> batch.
> 				 this.layer.removeFeatures();
>                  this.layer.addFeatures(this.features);
>                  this.clustering = false;
>              }
> ============================================
>
> --
> View this message in context:
> http://www.nabble.com/Problem-with-the-developpement-of-a-%22overlay-Strategy%22-tp20187399p20187399.html
> Sent from the OpenLayers Dev mailing list archive at Nabble.com.
>
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