openlayers/examples/vector-layer.js

Build tools and sources for developing OpenLayers based mapping applications

goog.require('ol.Map');
goog.require('ol.View');
goog.require('ol.format.GeoJSON');
goog.require('ol.layer.Vector');
goog.require('ol.source.Vector');
goog.require('ol.style.Fill');
goog.require('ol.style.Stroke');
goog.require('ol.style.Style');
goog.require('ol.style.Text');


var style = new ol.style.Style({
  fill: new ol.style.Fill({
    color: 'rgba(255, 255, 255, 0.6)'
  }),
  stroke: new ol.style.Stroke({
    color: '#319FD3',
    width: 1
  }),
  text: new ol.style.Text({
    font: '12px Calibri,sans-serif',
    fill: new ol.style.Fill({
      color: '#000'
    }),
    stroke: new ol.style.Stroke({
      color: '#fff',
      width: 3
    })
  })
});

var vectorLayer = new ol.layer.Vector({
  source: new ol.source.Vector({
    url: 'data/geojson/countries.geojson',
    format: new ol.format.GeoJSON()
  }),
  style: function(feature) {
    style.getText().setText(feature.get('name'));
    return style;
  }
});

var map = new ol.Map({
  layers: [vectorLayer],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 1
  })
});

var highlightStyle = new ol.style.Style({
  stroke: new ol.style.Stroke({
    color: '#f00',
    width: 1
  }),
  fill: new ol.style.Fill({
    color: 'rgba(255,0,0,0.1)'
  }),
  text: new ol.style.Text({
    font: '12px Calibri,sans-serif',
    fill: new ol.style.Fill({
      color: '#000'
    }),
    stroke: new ol.style.Stroke({
      color: '#f00',
      width: 3
    })
  })
});

var featureOverlay = new ol.layer.Vector({
  source: new ol.source.Vector(),
  map: map,
  style: function(feature) {
    highlightStyle.getText().setText(feature.get('name'));
    return highlightStyle;
  }
});

var highlight;
var displayFeatureInfo = function(pixel) {

  var feature = map.forEachFeatureAtPixel(pixel, function(feature) {
    return feature;
  });

  var info = document.getElementById('info');
  if (feature) {
    info.innerHTML = feature.getId() + ': ' + feature.get('name');
  } else {
    info.innerHTML = ' ';
  }

  if (feature !== highlight) {
    if (highlight) {
      featureOverlay.getSource().removeFeature(highlight);
    }
    if (feature) {
      featureOverlay.getSource().addFeature(feature);
    }
    highlight = feature;
  }

};

map.on('pointermove', function(evt) {
  if (evt.dragging) {
    return;
  }
  var pixel = map.getEventPixel(evt.originalEvent);
  displayFeatureInfo(pixel);
});

map.on('click', function(evt) {
  displayFeatureInfo(evt.pixel);
});