[Chameleon] Drawing a Point
kueda at wso.williams.edu
Thu Aug 12 13:13:35 EDT 2004
Thanks for the tip on the Locate widget. Unfortunately, as far as I can
tell, that works by creating a temporary shapefile, adding a point to
the shapefile, and then setting the shapefile as the data source for the
new layer. I want to do something much simpler, which is simply drawing
a point directly to the map with the pointObj's draw() method. I've
done this with MapScript before, basically with this same code.
Does anyone know if there's a better way to get at the ImageObj than
$map->draw() in Chameleon? I feel like that's where my problem might be.
Jason Fournier wrote:
>If you take a look at the Locate widget it contains a significant amount of code related
>to adding a point on the map. If you're able to swim your way through it you may find
>some useful tidbits.
>Perhaps someone else on the list knows offhand?
>If this fails then I'd suggest mailing the MapServer list as there are many PHP/MapScript
>(and generally more MapScript) developers who may have input.
>As for debugging ... what kind of information were you looking for? Are you looking for
>information about Chameleon errors? This can be reported by the ErrorReport widget. Or
>are you interested more in logging the application?
>On Aug 11, Ken-ichi <kueda at wso.williams.edu> wrote:
>>Hi again. To learn about widget development, I'm trying to make a copy
>>of the ZoomIn widget draw a point on the map instead of zooming in. To
>>that end, I've altered the ParseURL method so that the if( $szInputType
>>== "POINT" ) clause looks like this:
>> if ($szInputType == "POINT")
>> $aPixPos = explode(",", $szInputCoords);
>> //draw a point with MapScript
>> $map = $this->moMapNavigator->oSession->oMap;
>> $daLayer = ms_newLayerObj($map);
>> $daLayer->set("type", MS_LAYER_POINT);
>> $daLayer->set("transform", MS_FALSE);
>> $daLayer->set("status", MS_ON);
>> $class = ms_newClassObj($daLayer);
>> $class->set("name", "Temp Class");
>> $style = ms_newStyleObj($class);
>> $style->set("symbolname", "circle");
>> $style->set("size", 10);
>> $my_point = ms_newPointObj();
>> $image = $map->draw();
>> $temp = $my_point->draw( $map, $daLayer, $image, 0,
>>"Temp Point" );
>> if( $temp == MS_SUCCESS ) $daLayer->set("name", $temp);
>>This successfully adds a layer to the legend with the correct styling,
>>but fails to draw the point on the map. Note that the last line does
>>result in setting the name of the new layer to MS_SUCCESS (haven't
>>figured out how to use any of Chameleon's debugging capabilities, if
>>such things exist), so the draw() method thinks it's working.
>>Can anyone tell me what I'm doing wrong? Many thanks.
>>Chameleon mailing list
>>Chameleon at lists.maptools.org
>Chameleon mailing list
>Chameleon at lists.maptools.org
More information about the Chameleon