Fix share select dropdown not opening when viewer is open

Signed-off-by: Christopher Ng <chrng8@gmail.com>

apps/files_sharing/src/components/SharingInput.vue

@@ -34,6 +34,7 @@
 			:user-select="true"
 			:options="options"
 			v-model="value"
+			@open="handleOpen"
 			@search="asyncFind"
 			@option:selected="addShare">
 			<template #no-options="{ search }">
@@ -46,6 +47,7 @@
 <script>
 import { generateOcsUrl } from '@nextcloud/router'
 import { getCurrentUser } from '@nextcloud/auth'
+import { emit } from '@nextcloud/event-bus'
 import axios from '@nextcloud/axios'
 import debounce from 'debounce'
 import NcSelect from '@nextcloud/vue/dist/Components/NcSelect.js'
@@ -153,6 +155,11 @@ export default {
 	},
 
 	methods: {
+		handleOpen() {
+			// Fix dropdown not opening when viewer is open, see https://github.com/nextcloud/viewer/pull/1319
+			emit('viewer:trapElements:changed', this.$refs.select.$el)
+		},
+
 		async asyncFind(query) {
 			// save current query to check if we display
 			// recommendations or search results