[OpenLayers-Users] clickTolerance on selectFeature?

[Phil Scadden]

> I'm mainly dealing with polylines, but if that is the only way, then 
> so be it. How can I perform buffer calculations?
>
Buffering every line in your display to see if selected is very 
intensive. If you are struggling with accurate selection of lines, can I 
suggest an alternative approach? If you use a highlight only hoverselect 
control as well as a select control, then you can move mouse till target 
is highlighted, then click to select.

Code like:
                        HoverSelectControl = new 
OpenLayers.Control.SelectFeature(myLayers,{hover:true, highlightOnly: 
true, renderIntent: "temporary" });
                        SelectControl = new 
OpenLayers.Control.SelectFeature(myLayers,{clickout: true});
                        SelectControl.events.on({
                                 "featurehighlighted": onFeatureSelect,
                                 "featureunhighlighted": onFeatureUnselect
                        });
                        map.addControl(HoverSelectControl);
                        map.addControl(SelectControl);
                        HoverSelectControl.activate();
                        SelectControl.activate();

The order you add controls is important - hover first. I find that this 
feels quite natural.

If  the layers cans handle wfs, you might be better to create a 
wfsprotocol object and do a spatial intersects
query, passing a rectangle around the click point and then processing 
the return.


-- 
Phil Scadden, Senior Scientist GNS Science Ltd 764 Cumberland St, 
Private Bag 1930, Dunedin, New Zealand Ph +64 3 4799663, fax +64 3 477 5232

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