Add blurhash support

src/components/attachment/attachment.js

@@ -18,6 +18,7 @@ import {
   faPencilAlt,
   faAlignRight
 } from '@fortawesome/free-solid-svg-icons'
+import Blurhash from '../blurhash/Blurhash.vue'
 
 library.add(
   faFile,
@@ -63,7 +64,8 @@ const Attachment = {
   components: {
     Flash,
     StillImage,
-    VideoAttachment
+    VideoAttachment,
+    Blurhash
   },
   computed: {
     classNames () {
@@ -84,6 +86,9 @@ const Attachment = {
     useContainFit () {
       return this.$store.getters.mergedConfig.useContainFit
     },
+    useBlurhash () {
+      return this.$store.getters.mergedConfig.useBlurhash
+    },
     placeholderName () {
       if (this.attachment.description === '' || !this.attachment.description) {
         return this.type.toUpperCase()

src/components/attachment/attachment.vue

@@ -64,7 +64,15 @@
         :title="attachment.description"
         @click.prevent.stop="toggleHidden"
       >
+        <Blurhash
+          v-if="useBlurhash"
+          :height="512"
+          :width="1024"
+          :hash="attachment.blurhash"
+          :punch="1"
+        />
         <img
+          v-else
           :key="nsfwImage"
           class="nsfw"
           :src="nsfwImage"

src/components/blurhash/Blurhash.vue

@@ -0,0 +1,66 @@
+<template>
+  <canvas
+    ref="canvas"
+    class="blurhash"
+  />
+</template>
+
+<script>
+import { decode } from "blurhash";
+
+export default {
+  name: 'Blurhash',
+  props: {
+    hash: {
+      type: String,
+      required: true,
+    },
+    width: {
+      type: Number,
+      required: true,
+    },
+    height: {
+      type: Number,
+      required: true,
+    },
+    punch: {
+      type: Number,
+      default: null,
+    },
+  },
+  data() {
+    return {
+      canvas: null,
+      ctx: null,
+    };
+  },
+  mounted() {
+    this.canvas = this.$refs.canvas;
+    this.ctx = this.canvas.getContext('2d');
+    this.canvas.width = 1024;
+    this.canvas.height = 512;
+    this.draw();
+  },
+  methods: {
+    draw() {
+      const pixels = decode(this.hash, this.width, this.height, this.punch);
+      const imageData = this.ctx.createImageData(this.width, this.height);
+      imageData.data.set(pixels);
+      this.ctx.putImageData(imageData, 0, 0);
+      fetch("/static/blurhash-overlay.png")
+        .then((response) => response.blob())
+        .then((blob) => {
+          const img = new Image();
+          img.src = URL.createObjectURL(blob);
+          img.onload = () => {
+            this.ctx.drawImage(img, 0, 0, this.width, this.height);
+          };
+        });
+    },
+  }
+}
+</script>
+
+<style scoped>
+
+</style>

src/components/settings_modal/tabs/general_tab.vue

@@ -407,6 +407,15 @@
               {{ $t('settings.preload_images') }}
             </BooleanSetting>
           </li>
+          <li>
+            <BooleanSetting
+              path="useBlurhash"
+              expert="1"
+              :disabled="!hideNsfw"
+            >
+              {{ $t('settings.use_blurhash') }}
+            </BooleanSetting>
+          </li>
           <li>
             <BooleanSetting
               path="useOneClickNsfw"

src/i18n/en.json

@@ -939,6 +939,7 @@
             "title": "Version"
         },
         "virtual_scrolling": "Optimize timeline rendering",
+        "use_blurhash": "Use blurhashes for NSFW thumbnails",
         "word_filter": "Word filter",
         "wordfilter": "Wordfilter"
     },

src/modules/config.js

@@ -117,7 +117,8 @@ export const defaultState = {
   maxDepthInThread: undefined, // instance default
   translationLanguage: undefined, // instance default,
   supportedTranslationLanguages: {}, // instance default
-  userProfileDefaultTab: 'statuses'
+  userProfileDefaultTab: 'statuses',
+  useBlurhash: true,
 }
 
 // caching the instance default properties

src/services/entity_normalizer/entity_normalizer.service.js

@@ -234,13 +234,14 @@ export const parseAttachment = (data) => {
   if (masto) {
     // Not exactly same...
     output.mimetype = data.pleroma ? data.pleroma.mime_type : data.type
-    output.meta = data.meta // not present in BE yet
+    output.meta = data.meta
     output.id = data.id
   } else {
     output.mimetype = data.mimetype
     // output.meta = ??? missing
   }
 
+  output.blurhash = data.blurhash
   output.url = data.url
   output.large_thumb_url = data.preview_url
   output.description = data.description