Render start / complete

by Vladimir Vershinin

HTML

<script src="https://unpkg.com/vue@latest/dist/vue.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io/en/v5.3.0/build/ol.js"></script>
<script src="https://unpkg.com/[email protected]/lib/index.umd.js"></script>
<link rel="stylesheet" href="https://unpkg.com/[email protected]/lib/style.css">
<script src="https://unpkg.com/@reactivex/[email protected]/dist/global/rxjs.umd.min.js"></script>
<div id="app">
  <div>Loading: {{ mapLoading }}</div>
  <vl-map ref="map" data-projection="EPSG:4326">
    <vl-view ref="mapView" :zoom.sync="zoom" :center.sync="center"></vl-view>

    <vl-layer-tile>
      <vl-source-osm></vl-source-osm>
    </vl-layer-tile>

    <vl-layer-vector id="countries">
      <vl-source-vector url="https://openlayers.org/en/latest/examples/data/geojson/countries.geojson"></vl-source-vector>
    </vl-layer-vector>
  </vl-map>
</div>

CSS

html,
body,
#app {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

new Vue({
  el: '#app',
  data() {
    return {
      zoom: 5,
      center: [0, 0],
      points: [{
        type: 'Feature',
        id: 'one',
        properties: {},
        geometry: {
          type: 'Point',
          coordinates: [10, 10],
        },
      }],
      mapLoading: true,
    }
  },
  mounted () {
  	rxFromVueEvent(this.$refs.map, 'rendercomplete').pipe(
    	rxjs.operators.debounceTime(500)
    ).subscribe(evt => {
    	this.mapLoading = false
      console.log('rendercomplete')
    })
  
  	rxjs.merge(
    	rxFromVueEvent(this.$refs.mapView, 'update:zoom'),
	    rxFromVueEvent(this.$refs.mapView, 'update:center')
    ).pipe(
    	rxjs.operators.debounceTime(100),
    ).subscribe(evt => {
    	this.mapLoading = true
      console.log('renderstart')
    })
  },
})

function rxFromVueEvent (vm, event) {
	return rxjs.fromEventPattern(
  	function (handler) { vm.$on(event, handler) },
    function (handler) { vm.$off(event, handler) },
  )
}