Files
openlayers/examples/earthquake-custom-symbol.js
2017-12-14 08:56:12 -07:00

79 lines
2.5 KiB
JavaScript

import _ol_Map_ from '../src/ol/Map.js';
import _ol_View_ from '../src/ol/View.js';
import _ol_format_KML_ from '../src/ol/format/KML.js';
import Polygon from '../src/ol/geom/Polygon.js';
import _ol_layer_Tile_ from '../src/ol/layer/Tile.js';
import _ol_layer_Vector_ from '../src/ol/layer/Vector.js';
import _ol_render_ from '../src/ol/render.js';
import _ol_source_Stamen_ from '../src/ol/source/Stamen.js';
import _ol_source_Vector_ from '../src/ol/source/Vector.js';
import _ol_style_Fill_ from '../src/ol/style/Fill.js';
import _ol_style_Icon_ from '../src/ol/style/Icon.js';
import _ol_style_Stroke_ from '../src/ol/style/Stroke.js';
import _ol_style_Style_ from '../src/ol/style/Style.js';
var symbol = [[0, 0], [4, 2], [6, 0], [10, 5], [6, 3], [4, 5], [0, 0]];
var scale;
var scaleFunction = function(coordinate) {
return [coordinate[0] * scale, coordinate[1] * scale];
};
var styleCache = {};
var styleFunction = function(feature) {
// 2012_Earthquakes_Mag5.kml stores the magnitude of each earthquake in a
// standards-violating <magnitude> tag in each Placemark. We extract it from
// the Placemark's name instead.
var name = feature.get('name');
var magnitude = parseFloat(name.substr(2));
var size = parseInt(10 + 40 * (magnitude - 5), 10);
scale = size / 10;
var style = styleCache[size];
if (!style) {
var canvas =
/** @type {HTMLCanvasElement} */ (document.createElement('canvas'));
var vectorContext = _ol_render_.toContext(
/** @type {CanvasRenderingContext2D} */ (canvas.getContext('2d')),
{size: [size, size], pixelRatio: 1});
vectorContext.setStyle(new _ol_style_Style_({
fill: new _ol_style_Fill_({color: 'rgba(255, 153, 0, 0.4)'}),
stroke: new _ol_style_Stroke_({color: 'rgba(255, 204, 0, 0.2)', width: 2})
}));
vectorContext.drawGeometry(new Polygon([symbol.map(scaleFunction)]));
style = new _ol_style_Style_({
image: new _ol_style_Icon_({
img: canvas,
imgSize: [size, size],
rotation: 1.2
})
});
styleCache[size] = style;
}
return style;
};
var vector = new _ol_layer_Vector_({
source: new _ol_source_Vector_({
url: 'data/kml/2012_Earthquakes_Mag5.kml',
format: new _ol_format_KML_({
extractStyles: false
})
}),
style: styleFunction
});
var raster = new _ol_layer_Tile_({
source: new _ol_source_Stamen_({
layer: 'toner'
})
});
var map = new _ol_Map_({
layers: [raster, vector],
target: 'map',
view: new _ol_View_({
center: [0, 0],
zoom: 2
})
});