feat: Added epub preview. Resolves #3375 (#3376)

frontend/src/views/files/Preview.vue

@@ -6,7 +6,7 @@
     @mousemove="toggleNavigation"
     @touchstart="toggleNavigation"
   >
-    <header-bar v-if="isPdf || showNav">
+    <header-bar v-if="isPdf || isEpub || showNav">
       <action icon="close" :label="$t('buttons.close')" @action="close()" />
       <title>{{ name }}</title>
       <action
@@ -57,7 +57,37 @@
     </div>
     <template v-else>
       <div class="preview">
-        <ExtendedImage v-if="fileStore.req?.type == 'image'" :src="raw" />
+        <div v-if="isEpub" class="epub-reader">
+          <vue-reader
+            :location="location"
+            :url="raw"
+            :get-rendition="getRendition"
+            :epubInitOptions="{
+              requestCredentials: true,
+            }"
+            :epubOptions="{
+              allowPopups: true,
+              allowScriptedContent: true,
+            }"
+            @update:location="locationChange"
+          />
+          <div class="size">
+            <button
+              @click="changeSize(Math.max(100, size - 10))"
+              class="reader-button"
+            >
+              <i class="material-icons">remove</i>
+            </button>
+            <button
+              @click="changeSize(Math.min(150, size + 10))"
+              class="reader-button"
+            >
+              <i class="material-icons">add</i>
+            </button>
+            <span>{{ size }}%</span>
+          </div>
+        </div>
+        <ExtendedImage v-else-if="fileStore.req?.type == 'image'" :src="raw" />
         <audio
           v-else-if="fileStore.req?.type == 'audio'"
           ref="player"
@@ -129,20 +159,69 @@
 </template>
 
 <script setup lang="ts">
+import { useStorage } from "@vueuse/core";
 import { useAuthStore } from "@/stores/auth";
 import { useFileStore } from "@/stores/file";
 import { useLayoutStore } from "@/stores/layout";
 
 import { files as api } from "@/api";
+import { createURL } from "@/api/utils";
 import { resizePreview } from "@/utils/constants";
 import url from "@/utils/url";
 import throttle from "lodash/throttle";
 import HeaderBar from "@/components/header/HeaderBar.vue";
 import Action from "@/components/header/Action.vue";
 import ExtendedImage from "@/components/files/ExtendedImage.vue";
+import VideoPlayer from "@/components/files/VideoPlayer.vue";
+import { VueReader } from "vue-reader";
 import { computed, inject, onBeforeUnmount, onMounted, ref, watch } from "vue";
 import { useRoute, useRouter } from "vue-router";
-import VideoPlayer from "@/components/files/VideoPlayer.vue";
+import type { Rendition } from "epubjs";
+import { getTheme } from "@/utils/theme";
+
+const location = useStorage("book-progress", 0, undefined, {
+  serializer: {
+    read: (v) => JSON.parse(v),
+    write: (v) => JSON.stringify(v),
+  },
+});
+const size = useStorage("book-size", 120, undefined, {
+  serializer: {
+    read: (v) => JSON.parse(v),
+    write: (v) => JSON.stringify(v),
+  },
+});
+
+const locationChange = (epubcifi: number) => {
+  location.value = epubcifi;
+};
+let rendition: Rendition | null = null;
+const changeSize = (val: number) => {
+  size.value = val;
+  rendition?.themes.fontSize(`${val}%`);
+};
+
+const getRendition = (_rendition: Rendition) => {
+  rendition = _rendition;
+  switch (getTheme()) {
+    case "dark": {
+      rendition.themes.override("color", "rgba(255, 255, 255, 0.6)");
+      break;
+    }
+    case "light": {
+      rendition.themes.override("color", "rgb(111, 111, 111)");
+      break;
+    }
+  }
+  rendition.themes.registerRules("h2Transparent", {
+    "h1,h2,h3,h4": {
+      "background-color": "transparent !important",
+    },
+  });
+  rendition?.themes.fontSize(`${size.value}%`);
+  rendition.themes.select("h2Transparent");
+  rendition.themes.override("background-color", "transparent", true);
+};
 
 const mediaTypes: ResourceType[] = ["image", "video", "audio", "blob"];
 
@@ -182,10 +261,17 @@ const raw = computed(() => {
     return api.getPreviewURL(fileStore.req, "big");
   }
 
+  if (isEpub.value) {
+    return createURL("api/raw" + fileStore.req?.path, {}, false);
+  }
+
   return downloadUrl.value;
 });
 
 const isPdf = computed(() => fileStore.req?.extension.toLowerCase() == ".pdf");
+const isEpub = computed(
+  () => fileStore.req?.extension.toLowerCase() == ".epub"
+);
 
 const isResizeEnabled = computed(() => resizePreview);