Extracting Safety Countour Line from an ENC set

KennSebesta

I'd love a simple worked example of how to extract the Safety Countour Line from a set of ENCs. It doesn't have to be any particular ENC, just enough breadcrumbs to let get me started so I can expand from there.

A post over in Java SDK land, hints at how to get at the data, but doesn't go all the way to providing a worked example.

P.S. FWIW, it would be great to get the Safety Countour Line directly as requested in the above link. Obviously, the system knows where it is because it draws it dynamically from the data. I understand that there is a limitation, although I don't quite understand why the limitation allows drawing the data but not providing the polyline directly.

JamesBallard1

Hi @KennSebesta ,

I have some code that I was able to add to that existing sample code that should help. This is added within the MapView declaration.

MapView {
        id: mapView
        anchors.fill: parent

        // identify layers on mouse click
        onMouseClicked: {
            // for every EncLayer, clear all selection on every mouse click
            map.operationalLayers.forEach(function(layer) {
               if (layer.layerType === Enums.LayerTypeEncLayer)
                   layer.clearSelection();
            });

            const screenX = mouse.x;
            const screenY = mouse.y;
            const tolerance = 12;
            const returnPopups = false;
            const maxResults = 3;
            mapView.identifyLayersWithMaxResults(screenX, screenY, tolerance, returnPopups, maxResults);
        }

        // handle the identify results
        onIdentifyLayersStatusChanged: {
            if (identifyLayersStatus !== Enums.TaskStatusCompleted)
                return;

            console.log("identified on", identifyLayersResults.length, "layers");

            // for the result of every layer in the map...
            for (let i = 0; i < identifyLayersResults.length; i++) {
                const identifyLayerResult = identifyLayersResults[i];
                let layerContent = identifyLayerResult.layerContent;
                let encFeatures = identifyLayerResult.geoElements;

                // for all geoelements of that layer's results...
                for (let j = 0; j < encFeatures.length; ++j) {
                    let encFeature = encFeatures[j];
                    layerContent.selectFeature(encFeature);
                    console.log("found EncFeature", encFeature.description, encFeature.acronym,
                                JSON.stringify(encFeature.attributes.attributesJson));
                }
            }
        }

 

With that code you can identify the EncFeatures to locate the Safety Contour Line feature(s), and get their geometry. As mentioned in the other post, there is no way to query for features and search for only the Contour features, but you can identify them and get their geometry. In the sample code you can adjust the max number of features identified on each mouse click.

Let us know if this is helpful.

Enc_Identify.mp4