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, 11 insertions, 0 deletions

diff --git a/viewer/src/services/itemGuards.ts b/viewer/src/services/itemGuards.ts
new file mode 100644
index 0000000..114c2d9
--- /dev/null
+++ b/viewer/src/services/itemGuards.ts
@@ -0,0 +1,11 @@
+import { DirectoryItem, DownloadableItem, Item } from '@/@types/gallery';
+import { ItemType } from '@/@types/itemType';
+
+export function isDirectory(item: Item | null): item is DirectoryItem {
+  return item?.properties.type === ItemType.DIRECTORY;
+}
+
+export function isDownloadableItem(item: Item | null): item is DownloadableItem {
+  if (!item?.properties) return false;
+  return 'resource' in item.properties;
+}