viewer: migrate to vue 3, general refactoring and cleanup

Non-exhaustive list of fixes and improvements done at the same time:

- html default background to grey (avoids white flash during init)
- unified links behavior
- added more theme variables
- removed the flex-expand transition (it wasn't working) and replaced it
  with a slide
- fixed LdLoading not centered on the content
- title on removable tags
- fixed an issue with encoded URI from vue-router
- unified Item resource URLs
- removed the iframe for PlainTextViewer (it wasn't working properly)
  and replaced it with a pre
- fixed clear and search buttons tabindex
- fixed the information panel bumping up during the fade animation of
  tag's dropdown
- fixed some focus outlines not appearing correctly
- moved CSS variables to the :root context
- Code cleaning

GitHub: closes #217
GitHub: closes #300
GitHub: closes #297
GitHub: closes #105
GitHub: closes #267
GitHub: closes #275
GitHub: closes #228
GitHub: closes #215
GitHub: closes #112

1 files changed, 99 insertions, 0 deletions

diff --git a/viewer/src/views/ItemThumbnail.vue b/viewer/src/views/ItemThumbnail.vue
new file mode 100644
index 0000000..1c9e206
--- /dev/null
+++ b/viewer/src/views/ItemThumbnail.vue
@@ -0,0 +1,99 @@
+<!-- ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2019-2022  Guillaume FOUET
+--
+-- 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="{ [$style.preload]: loading }">
+    <!-- Can't use img loading="lazy" yet because @loadstart doesn't work on Chromium -->
+    <!-- Also it loads the picture before scroll init (too early) -->
+    <VLazyImage
+      v-if="thumbnailResourceUrl"
+      :src="thumbnailResourceUrl"
+      :style="pictureStyle"
+      :title="item.title"
+      @intersect="loading = true"
+      @load="loading = false"
+    />
+    <div
+      v-else
+      class="flex-column flex-center"
+      :class="$style.thumbnailOther"
+    >
+      <div>
+        <fa-icon
+          :icon="icon"
+          size="4x"
+        />
+      </div>
+      {{ item.title }}
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { Item } from '@/@types/gallery';
+import { useNavigation } from '@/services/navigation';
+import { useItemResource } from '@/services/ui/ldItemResourceUrl';
+import VLazyImage from 'v-lazy-image';
+import { computed, PropType, ref } from 'vue';
+
+const props = defineProps({
+  item: { type: Object as PropType<Item>, required: true },
+});
+
+const navigation = useNavigation();
+
+const loading = ref(false);
+
+const { thumbnailResourceUrl } = useItemResource(props.item);
+
+const pictureStyle = computed(() => {
+  const resolution = props.item.thumbnail?.resolution ?? { width: 1, height: 1 };
+  return { width: `${resolution.width}px`, height: `${resolution.height}px` };
+});
+
+const icon = computed(() => navigation.getIcon(props.item));
+</script>
+
+<style lang="scss" module>
+@import "~@/assets/scss/theme";
+
+.thumbnailOther {
+  width: $thumbnail-other-size;
+  height: $thumbnail-other-size;
+  padding-top: $body-line-height * 1em;
+  text-align: center;
+  word-break: break-word;
+  overflow: hidden;
+  > div {
+    min-height: $body-line-height * 3em;
+  }
+}
+
+.preload {
+  animation: preloadAnimation 1s infinite ease-in-out alternate;
+}
+@keyframes preloadAnimation {
+  from {
+    background-color: $content-bgcolor;
+  }
+  to {
+    background-color: $skeleton-color;
+  }
+}
+</style>