Files
openlayers/examples/icon-negative.js
2018-01-10 09:36:28 -07:00

75 lines
2.3 KiB
JavaScript

import Feature from '../src/ol/Feature.js';
import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import Point from '../src/ol/geom/Point.js';
import _ol_interaction_Select_ from '../src/ol/interaction/Select.js';
import TileLayer from '../src/ol/layer/Tile.js';
import VectorLayer from '../src/ol/layer/Vector.js';
import _ol_source_Stamen_ from '../src/ol/source/Stamen.js';
import VectorSource from '../src/ol/source/Vector.js';
import _ol_style_Icon_ from '../src/ol/style/Icon.js';
import _ol_style_Style_ from '../src/ol/style/Style.js';
function createStyle(src, img) {
return new _ol_style_Style_({
image: new _ol_style_Icon_(/** @type {olx.style.IconOptions} */ ({
anchor: [0.5, 0.96],
crossOrigin: 'anonymous',
src: src,
img: img,
imgSize: img ? [img.width, img.height] : undefined
}))
});
}
var iconFeature = new Feature(new Point([0, 0]));
iconFeature.set('style', createStyle('data/icon.png', undefined));
var map = new Map({
layers: [
new TileLayer({
source: new _ol_source_Stamen_({layer: 'watercolor'})
}),
new VectorLayer({
style: function(feature) {
return feature.get('style');
},
source: new VectorSource({features: [iconFeature]})
})
],
target: document.getElementById('map'),
view: new View({
center: [0, 0],
zoom: 3
})
});
var selectStyle = {};
var select = new _ol_interaction_Select_({
style: function(feature) {
var image = feature.get('style').getImage().getImage();
if (!selectStyle[image.src]) {
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
canvas.width = image.width;
canvas.height = image.height;
context.drawImage(image, 0, 0, image.width, image.height);
var imageData = context.getImageData(0, 0, canvas.width, canvas.height);
var data = imageData.data;
for (var i = 0, ii = data.length; i < ii; i = i + (i % 4 == 2 ? 2 : 1)) {
data[i] = 255 - data[i];
}
context.putImageData(imageData, 0, 0);
selectStyle[image.src] = createStyle(undefined, canvas);
}
return selectStyle[image.src];
}
});
map.addInteraction(select);
map.on('pointermove', function(evt) {
map.getTargetElement().style.cursor =
map.hasFeatureAtPixel(evt.pixel) ? 'pointer' : '';
});