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ol-interaction-dragbox

Allows the user to draw a vector box by clicking and dragging on the map, normally combined with a condition that limits it to when the shift or other key is held down.

Demo

Setup

Plugin usage

This component is part of the Interactions plugin. If not installed globally, you need to import and use the plugin in your main.ts or use the explicit component import (see section below).

Import and use the Interactions plugin
ts
import { createApp } from "vue";
import App from "./App.vue";

import {
  Map,
  Layers,
  Sources,
  Interactions,
} from "vue3-openlayers";

const app = createApp(App);
// ...
app.use(Interactions); 
// ...

Explicit import

If you don't want to install a plugin, you can import the component explicitly. It's available as a child of the named export Interactions.

NOTE

The following documentation refers to the plugin usage. Please make sure to adopt the component names, when you decided to use explicit component imports (e. g. <ol-map> becomes <Map.OlMap> etc.).

Usage

Plugin UsageExplicit Import
<ol-interaction-dragbox><Interactions.OlInteractionDragbox>
vue
<template>
  <form>
    <fieldset>
      <label for="opacity">Layer Opacity</label>
      <input
        type="range"
        id="opacity"
        min="0"
        max="1"
        step="0.1"
        v-model.number="opacity"
      />
      <span class="description">{{ opacity }}</span>
    </fieldset>
  </form>

  <ol-map
    :loadTilesWhileAnimating="true"
    :loadTilesWhileInteracting="true"
    style="height: 400px"
  >
    <ol-view
      ref="view"
      :center="center"
      :zoom="zoom"
      :projection="projection"
      :constrainRotation="16"
    />

    <ol-vector-layer
      background="#1a2b39"
      ref="vectorSourceRef"
      :opacity="opacity"
    >
      <ol-source-vector :url="url" :format="geoJson">
        <ol-style :overrideStyleFunction="styleFn"></ol-style>
      </ol-source-vector>
    </ol-vector-layer>

    <ol-interaction-dragbox
      :condition="shiftKeyOnly"
      @boxstart="log('boxstart', $event)"
      @boxdrag="log('boxdrag', $event)"
      @boxend="log('boxend', $event)"
      @boxcancel="log('boxcancel', $event)"
    ></ol-interaction-dragbox>
  </ol-map>
</template>

<script setup lang="ts">
import type { Feature } from "ol";
import { Fill, Style } from "ol/style";
import { shiftKeyOnly } from "ol/events/condition";
import { ref, inject } from "vue";
import type { DragBoxEvent } from "ol/interaction/DragBox";

const opacity = ref(1);
const center = ref([0, 0]);
const projection = ref("EPSG:4326");
const zoom = ref(0);
const url = ref("https://openlayers.org/data/vector/ecoregions.json");
const format = inject("ol-format");
const geoJson = new format.GeoJSON();

function styleFn(feature: Feature) {
  return new Style({
    fill: new Fill({
      color: feature.get("COLOR_BIO") || "#eeeeee",
    }),
  });
}

function log(eventType: string, event: DragBoxEvent) {
  console.log(eventType, event);
}
</script>

Properties

Props from OpenLayers

Properties are passed-trough from OpenLayers directly. Their types and default values can be checked-out in the official OpenLayers docs. Only some properties deviate caused by reserved keywords from Vue / HTML. This deviating props are described in the section below.

Deviating Properties

None.

Events

You have access to all Events from the underlying interaction. Check out the official OpenLayers docs to see the available events tht will be fired.

html
<ol-interaction-dragbox @error="handleEvent">
  <!-- ... -->
</ol-interaction-dragbox>

Methods

You have access to all Methods from the underlying interaction. Check out the official OpenLayers docs to see the available methods.

To access the source, you can use a ref() as shown below:

vue
<template>
  <!-- ... -->
  <ol-interaction-dragbox ref="dragboxRef" @error="handleEvent" />
  <!-- ... -->
</template>

<script setup lang="ts">
import { ref, onMounted } from "vue";
import type DragBox from "ol/interaction/DragBox";

const dragboxRef = ref<{ dragbox: DragBox } | null>(null);

onMounted(() => {
  const dragbox: DragBox = dragboxRef.value?.dragbox;
  // call your method on `dragbox`
});
</script>