Re: [Gwt-openlayers-users] containsPoint method of Polygon class

[Edwin C. <com...@gm...>]

Hi Philipp,

Aha, so I did not understand containsPoint correctly. What we need is
three-valued logic, but there is no basic type for that :). One option
is to return a String and map the values onto that:

true = 'in'
false = 'out'
1 = 'edge'

That way the containsPoint implementation can just return a String.

public static native String containsPoint(JSObject p, JSObject self)/*-{
        var out = self.containsPoint(p);
        if (out === true) {return 'in'} // if out === 1 then if (out)
will also run!
        else if (out===1) {return 'edge'}
        else {return 'out'}
}-*/;

Greetings,
Edwin

On 13 October 2010 14:06, Philipp Verhoeven
<phi...@go...> wrote:
> Hi there,
>
> thanks for that. But there is a problem:
> your suggested code returns true if var is 1. But if var is true it returns
> false...
>
> The containsPoint()-method returns 1, if the point is on an edge.
> It returns true, if the point is inside and it returns false, if the point
> is outside.
>
> With my not existing JS skills the solution was the following:
>
> public static native boolean containsPoint(JSObject p, JSObject self)/*-{
>        var out = self.containsPoint(p);
>        if (out) {return true}
>        else if (out===1) {return true}
>        else {return false}
>     }-*/;
>
> Cheers and thanks,
> Philipp
>
>
> 2010/10/12 Edwin Commandeur <com...@gm...>
>>
>> Hi Phillip,
>>
>> The containsPoint function in OL is a bit silly in that it returns 1
>> for true and false for false :). I would say we return a boolean.
>>
>> Try adding this to Polygon
>>
>> public boolean containsPoint(Point p){
>>    PolygonImpl.containsPoint(p.getJSObject(), this.getJSObject());
>> }
>>
>> and this to PolygonImpl
>>
>> public static native boolean containsPoint(JSObject p, JSObject self)/*-{
>>    var out = self.containsPoint(p);
>>    return (out===1)?true:false;
>> }-*/;
>>
>> Greetings,
>> Edwin Commandeur
>>
>> On 12 October 2010 15:47, Philipp Verhoeven
>> <phi...@go...> wrote:
>> > Greetings,
>> >
>> >
>> > I would like to use the containsPoint method of the Polygon class like
>> > it is
>> > desribed:
>> >
>> > http://dev.openlayers.org/docs/files/OpenLayers/Geometry/Polygon-js.html#OpenLayers.Geometry.Polygon.containsPoint
>> >
>> > The method doesn't seem to be implemented in gwt-openlayers, am I
>> > right?!
>> >
>> > Does anyone know a quick fix to use this method anyway?
>> >
>> >
>> > Thanks and cheers,
>> > Philipp
>> >
>> >
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