UBERF-8180 Text file preview (#6633)

Signed-off-by: Alexander Onnikov <Alexander.Onnikov@xored.com>

packages/presentation/src/components/FilePreview.svelte

@@ -14,7 +14,14 @@
 -->
 <script lang="ts">
   import { type Blob, type Ref } from '@hcengineering/core'
-  import { Button, Component, Label, resizeObserver, deviceOptionsStore as deviceInfo } from '@hcengineering/ui'
+  import {
+    Button,
+    Component,
+    Label,
+    resizeObserver,
+    deviceOptionsStore as deviceInfo,
+    Loading
+  } from '@hcengineering/ui'
 
   import presentation from '../plugin'
 
@@ -34,9 +41,11 @@
   let minHeight: number | undefined
   $: parentHeight = ($deviceInfo.docHeight * 80) / 100
 
+  let loading = true
   let previewType: FilePreviewExtension | undefined = undefined
   $: void getPreviewType(contentType, $previewTypes).then((res) => {
     previewType = res
+    loading = false
   })
 
   const updateHeight = (
@@ -91,6 +100,8 @@
       </div>
     {:else if previewType !== undefined}
       <Component is={previewType.component} props={{ value: file, name, contentType, metadata, ...props, fit }} />
+    {:else if loading}
+      <Loading />
     {:else}
       <div class="flex-col items-center flex-gap-3">
         <Label label={presentation.string.ContentTypeNotSupported} />