[OpenLayers-Users] SelectFeature unselecting programmatically

[Andreas Hocevar]

Would you mind creating a pull request for this? It is easier to
discuss things like this over code that can be seen in context an
executed.

Thanks,
Andreas.

On Fri, Dec 7, 2012 at 1:24 PM, Slawomir Messner
<slawomir.messner at staff.uni-marburg.de> wrote:
> Hi,
> when you use select/unselect function of SelectFeature control why
> this.handlers.feature.lastFeature is set in select function but not in unset
> in unselect? It's not just the asymmetry which bother me, it is also that it
> would solve an issue in the following scenario:
> We have a RemoveFeature control which can also remove vertices of polygons
> and lines.
> We use a SelectFeature to select a feature. On select it draws edit vertices
> on the edges, like the ModifyFeature control and a Feature handler handles
> the click on the vertices and removes it form layer and the geometry. After
> removing it redraws the feature and all seams well, the feature is correctly
> drawn, the vertex is gone and it's selected but unfortunately clickout
> doesn't work(it works when you select and clickout without deleting vertex).
> After some investigation I found out that lastFeature of the feature handler
> in SelectFeature control is the deleted vertex. So on click outside the
> feature the handler runs handle method where it sets lastFeature to null,
> because it is removed from layer.
>         if(this.lastFeature && !this.lastFeature.layer) {
>             // last feature has been destroyed
>             this.lastFeature = null;
>         }
> so it never gets some lines below:
> } else {
>             if(this.lastFeature && (previouslyIn || click)) {
>                 this.triggerCallback(type, 'out', [this.lastFeature]);
>             }
>         }
> there it should call the clickout callback. So I tried it with unselect and
> than select the feature programmatically after deleting the vertex, to reset
> the select, but this didn't help. The only thing that helps is when I set
> the lastFeature to null before reselect or to set it to the feature without
> . Why not "simple" do something like:
> "this.selectFeature.handlers.feature.lastFeature = this.feature"
> because it looks ugly, uses some attributes which should be private and I
> saw the asymmetry in the code of the SelectFeature and asked myself if it's
> a bug or a feature.
> Is there something why not change the unselect method of SelectFeature to:
>     unselect: function(feature) {
>         var layer = feature.layer;
>         // Store feature style for restoration later
>         this.unhighlight(feature);
>         // if the feature handler isn't involved in the feature
>         // selection (because the feature is selected programatically)
>         // we fake the
>         // feature handler to allow unselecting on clickout
>         if(this.handlers.feature.lastFeature) {
>             this.handlers.feature.lastFeature = null;
>         }
>         OpenLayers.Util.removeItem(layer.selectedFeatures, feature);
>         layer.events.triggerEvent("featureunselected", {feature: feature});
>         this.onUnselect.call(this.scope, feature);
>     },
> It doesn't crash the tests.
> Btw:
> I think there is a documentation error in OL.Handler.Feauture deactivate
> function it should be:
>
> /**
> * Method: deactivate
> * Turn off the handler. Returns false if the handler was not active.
> *
> * Returns:
> * {Boolean}
> */
>
> Keep up the excellent work guys, we look forward to OL3.
> Regards
> Slawomir
>
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-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.