viewer/epub: add EPUB item handler

This adds a paginated ePub viewer using epub.js.

5 files changed, 179 insertions, 0 deletions

diff --git a/viewer/src/assets/scss/theme.scss b/viewer/src/assets/scss/theme.scss
index 63febbf..fe70f17 100644
--- a/viewer/src/assets/scss/theme.scss
+++ b/viewer/src/assets/scss/theme.scss
@@ -41,6 +41,8 @@ $dropdown-item-color: $palette-600;
 $dropdown-item-hover-color: $palette-500;
 $panel-top-bgcolor: $palette-800;
 $panel-top-txtcolor: $primary;
+$panel-bottom-bgcolor: $palette-800;
+$panel-bottom-txtcolor: $primary;
 $panel-left-bgcolor: $palette-800;
 $panel-left-txtcolor: $primary;
 $command-buttons-bgcolor: $palette-700;
diff --git a/viewer/src/locales/en.yml b/viewer/src/locales/en.yml
index 86ecd49..280f18b 100644
--- a/viewer/src/locales/en.yml
+++ b/viewer/src/locales/en.yml
@@ -15,6 +15,9 @@ directory:
   no-results: Empty directory
 download:
   download-file-fmt: Download {0}
+epubViewer:
+  previousSection: Previous section
+  nextSection: Next section
 gallery:
   resource-loading-error: Error loading resource
   unknown-resource: Resource not found
diff --git a/viewer/src/views/GalleryNavigation.vue b/viewer/src/views/GalleryNavigation.vue
index 0869aaf..b342c52 100644
--- a/viewer/src/views/GalleryNavigation.vue
+++ b/viewer/src/views/GalleryNavigation.vue
@@ -44,6 +44,7 @@ import { computedEager } from '@vueuse/shared';
 import { computed, watchEffect } from 'vue';
 import { useI18n } from 'vue-i18n';
 import GallerySearch from './GallerySearch.vue';
+import { EpubViewer } from './item_handlers/async';
 import AudioViewer from './item_handlers/AudioViewer.vue';
 import DirectoryViewer from './item_handlers/DirectoryViewer.vue';
 import DownloadViewer from './item_handlers/DownloadViewer.vue';
@@ -67,6 +68,7 @@ const COMPONENT_BY_TYPE: Record<ItemType, unknown> = {
   plaintext: PlainTextViewer,
   markdown: MarkdownViewer,
   pdf: PdfViewer,
+  epub: EpubViewer,
   video: VideoViewer,
   audio: AudioViewer,
   other: DownloadViewer,
diff --git a/viewer/src/views/item_handlers/async/AsyncEpubViewer.vue b/viewer/src/views/item_handlers/async/AsyncEpubViewer.vue
new file mode 100644
index 0000000..712a844
--- /dev/null
+++ b/viewer/src/views/item_handlers/async/AsyncEpubViewer.vue
@@ -0,0 +1,149 @@
+<!--
+-- ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2022  Pacien TRAN-GIRARD
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-->
+
+<template>
+  <div :class="$style.container">
+    <div
+      ref="view"
+      :class="$style.epubView"
+      class="scrollbar"
+    />
+
+    <ul
+      v-if="prevSection || nextSection"
+      :class="$style.navBar"
+    >
+      <li>
+        <a
+          v-if="prevSection"
+          @click.prevent="goToPrevSection"
+        >« {{ prevSectionLabel }}</a>
+      </li>
+
+      <li>
+        {{ currSectionLabel }}
+      </li>
+
+      <li>
+        <a
+          v-if="nextSection"
+          @click.prevent="goToNextSection"
+        >{{ nextSectionLabel }} »</a>
+      </li>
+    </ul>
+  </div>
+</template>
+
+<script setup lang="ts">
+
+import { EPUBItem } from '@/@types/gallery';
+import { useItemResource } from '@/services/ui/ldItemResourceUrl';
+import ePub from 'epubjs';
+import { SpineItem } from 'epubjs/types/section';
+import { PropType, Ref, ref, toRef, computed, watchEffect } from 'vue';
+import { useI18n } from 'vue-i18n';
+const { t } = useI18n();
+
+const props = defineProps({
+  item: { type: Object as PropType<EPUBItem>, required: true },
+});
+
+const { itemResourceUrl } = useItemResource(toRef(props, 'item'));
+const view = ref<HTMLDivElement>();
+
+const book = computed(() => ePub(itemResourceUrl.value));
+
+const rendition = computed(() => {
+  if (!view.value) return;
+  return book.value.renderTo(view.value, {
+    flow: 'scrolled-doc',
+    width: '100%',
+    fullsize: true,
+  });
+});
+
+const currSection = ref<SpineItem>();
+const prevSection = ref<SpineItem>();
+const nextSection = ref<SpineItem>();
+
+// TODO: reflow on side panel open/close event, like when resizing the window
+
+watchEffect(async() => {
+  if (!rendition.value) return;
+  await rendition.value.display();
+  rendition.value.on('rendered', updateNavigation);
+});
+
+function updateNavigation(currentSection: SpineItem) {
+  currSection.value = currentSection;
+  prevSection.value = currentSection.prev();
+  nextSection.value = currentSection.next();
+}
+
+const currSectionLabel = computed(() => getSectionTitle(currSection) ?? '');
+const prevSectionLabel = computed(() =>
+  getSectionTitle(prevSection) ?? t('epubViewer.previousSection'));
+const nextSectionLabel = computed(() =>
+  getSectionTitle(nextSection) ?? t('epubViewer.nextSection'));
+
+function getSectionTitle(section: Ref<SpineItem | undefined>): string | null {
+  if (!section.value?.href) return null;
+  return book.value?.navigation.get(section.value.href).label;
+}
+
+function goToPrevSection() {
+  rendition.value?.prev();
+}
+
+function goToNextSection() {
+  rendition.value?.next();
+}
+</script>
+
+<style lang="scss" module>
+@import "~@/assets/scss/theme";
+
+.container {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+}
+
+.epubView {
+  flex: 1;
+  overflow-x: hidden;
+}
+
+.navBar {
+  display: flex;
+  flex-direction: row;
+  list-style-type: none;
+  margin: 0;
+  padding: .75em;
+
+  background-color: $panel-bottom-bgcolor;
+  color: $panel-bottom-txtcolor;
+
+  > * {
+    flex: 1;
+    text-align: center;
+  }
+}
+</style>
diff --git a/viewer/src/views/item_handlers/async/index.ts b/viewer/src/views/item_handlers/async/index.ts
new file mode 100644
index 0000000..d4ca996
--- /dev/null
+++ b/viewer/src/views/item_handlers/async/index.ts
@@ -0,0 +1,23 @@
+/* ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2022  Pacien TRAN-GIRARD
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,