topolis integration

Example on how to use topolis with OpenLayers.

Example showing the integration of topolis with OpenLayers, enabling creating and editing topological geometry. Standard interaction draws edges, snapping to existing edges. Delete an edge by drawing a new edge crossing the one to delete.

<!DOCTYPE html>
<html>
  <head>
    <title>topolis integration</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v4.5.0/css/ol.css" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
    <script src="https://openlayers.org/en/v4.5.0/build/ol.js"></script>
    <script src="https://cdn.rawgit.com/bjornharrtell/topolis/releases/0.1.1/topolis.min.js"></script>
    <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.js"></script>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.css">
  </head>
  <body>
    <div id="map" class="map"></div>
    <script>
      // this example uses topolis and toastr for which we don't have an externs file.

      var raster = new ol.layer.Tile({
        source: new ol.source.OSM()
      });

      var nodes = new ol.source.Vector({wrapX: false});
      var nodesLayer = new ol.layer.Vector({
        source: nodes,
        style: function(f) {
          var style = new ol.style.Style({
            image: new ol.style.Circle({
              radius: 8,
              fill: new ol.style.Fill({color: 'rgba(255, 0, 0, 0.2)'}),
              stroke: new ol.style.Stroke({color: 'red', width: 1})
            }),
            text: new ol.style.Text({
              text: f.get('node').id.toString(),
              fill: new ol.style.Fill({color: 'red'}),
              stroke: new ol.style.Stroke({
                color: 'white',
                width: 3
              })
            })
          });
          return [style];
        }
      });

      var edges = new ol.source.Vector({wrapX: false});
      var edgesLayer = new ol.layer.Vector({
        source: edges,
        style: function(f) {
          var style = new ol.style.Style({
            stroke: new ol.style.Stroke({
              color: 'blue',
              width: 1
            }),
            text: new ol.style.Text({
              text: f.get('edge').id.toString(),
              fill: new ol.style.Fill({color: 'blue'}),
              stroke: new ol.style.Stroke({
                color: 'white',
                width: 2
              })
            })
          });
          return [style];
        }
      });

      var faces = new ol.source.Vector({wrapX: false});
      var facesLayer = new ol.layer.Vector({
        source: faces,
        style: function(f) {
          var style = new ol.style.Style({
            stroke: new ol.style.Stroke({
              color: 'black',
              width: 1
            }),
            fill: new ol.style.Fill({
              color: 'rgba(0, 255, 0, 0.2)'
            }),
            text: new ol.style.Text({
              font: 'bold 12px sans-serif',
              text: f.get('face').id.toString(),
              fill: new ol.style.Fill({color: 'green'}),
              stroke: new ol.style.Stroke({
                color: 'white',
                width: 2
              })
            })
          });
          return [style];
        }
      });

      var map = new ol.Map({
        layers: [raster, facesLayer, edgesLayer, nodesLayer],
        target: 'map',
        view: new ol.View({
          center: [-11000000, 4600000],
          zoom: 16
        })
      });

      var topo = topolis.createTopology();

      topo.on('addnode', nodeToFeature);
      topo.on('removenode', function(e) {
        removeElementFeature(nodes, e);
      });
      topo.on('addedge', edgeToFeature);
      topo.on('modedge', function(e) {
        var feature = edges.getFeatureById(e.id);
        feature.setGeometry(new ol.geom.LineString(e.coordinates));
      });
      topo.on('removeedge', function(e) {
        removeElementFeature(edges, e);
      });
      topo.on('addface', faceToFeature);
      topo.on('removeface', function(e) {
        removeElementFeature(faces, e);
      });

      function removeElementFeature(source, element) {
        var feature = source.getFeatureById(element.id);
        source.removeFeature(feature);
      }

      function nodeToFeature(node) {
        var feature = new ol.Feature({
          geometry: new ol.geom.Point(node.coordinate),
          node: node
        });
        feature.setId(node.id);
        nodes.addFeature(feature);
      }

      function edgeToFeature(edge) {
        var feature = new ol.Feature({
          geometry: new ol.geom.LineString(edge.coordinates),
          edge: edge
        });
        feature.setId(edge.id);
        edges.addFeature(feature);
      }

      function faceToFeature(face) {
        var coordinates = topo.getFaceGeometry(face);
        var feature = new ol.Feature({
          geometry: new ol.geom.Polygon(coordinates),
          face: face
        });
        feature.setId(face.id);
        faces.addFeature(feature);
      }

      function createNode(topo, coord) {
        var node;
        var existingEdge = topo.getEdgeByPoint(coord, 5)[0];
        if (existingEdge) {
          node = topo.modEdgeSplit(existingEdge, coord);
        } else {
          node = topo.addIsoNode(coord);
        }
        return node;
      }

      function onDrawend(e) {
        var edgeGeom = e.feature.getGeometry().getCoordinates();
        var startCoord = edgeGeom[0];
        var endCoord = edgeGeom[edgeGeom.length - 1];
        var start, end;
        try {
          start = topo.getNodeByPoint(startCoord);
          end = topo.getNodeByPoint(endCoord);
          var edgesAtStart = topo.getEdgeByPoint(startCoord, 5);
          var edgesAtEnd = topo.getEdgeByPoint(endCoord, 5);
          var crossing = topo.getEdgesByLine(edgeGeom);
          if (crossing.length === 1 && !start && !end && edgesAtStart.length === 0 && edgesAtEnd.length === 0) {
            topo.remEdgeNewFace(crossing[0]);
            start = crossing[0].start;
            if (start.face) {
              topo.removeIsoNode(start);
            }
            end = crossing[0].end;
            if (end.face) {
              topo.removeIsoNode(end);
            }
            return;
          }
          if (!start) {
            start = createNode(topo, startCoord);
            edgeGeom[0] = start.coordinate;
          }
          if (!end) {
            end = createNode(topo, endCoord);
            edgeGeom[edgeGeom.length - 1] = end.coordinate;
          }
          topo.addEdgeNewFaces(start, end, edgeGeom);
        } catch (e) {
          toastr.warning(e.toString());
        }
      }

      var draw = new ol.interaction.Draw({
        type: 'LineString'
      });
      draw.on('drawend', onDrawend);
      map.addInteraction(draw);
      var snap = new ol.interaction.Snap({
        source: edges
      });
      map.addInteraction(snap);
      map.addControl(new ol.control.MousePosition());
    </script>
  </body>
</html>