Enhance/PDF viewer (#7369)

* fix(pdf): WIP potential memory leaks
* enhance(pdf): sync page number in highlights metafile
* enhance(pdf): support preview highlight area image in a lightbox
* fix: clojurescript unit tests
* fix(pdf): page number overflow when more digits

src/main/frontend/state.cljs

@@ -296,10 +296,6 @@
 ;;  (re-)fetches get-current-repo needlessly
 ;; TODO: Add consistent validation. Only a few config options validate at get time
 
-(defn get-current-pdf
-  []
-  (:pdf/current @state))
-
 (def default-config
   "Default config for a repo-specific, user config"
   {:feature/enable-search-remove-accents? true
@@ -1967,3 +1963,16 @@ Similar to re-frame subscriptions"
   []
   (when (mobile-util/native-ios?)
     (get-in @state [:mobile/container-urls :iCloudContainerUrl])))
+
+(defn get-current-pdf
+  []
+  (:pdf/current @state))
+
+(defn set-current-pdf!
+  [inflated-file]
+  (let [settle-file! #(set-state! :pdf/current inflated-file)]
+    (if-not (get-current-pdf)
+      (settle-file!)
+      (when (apply not= (map :identity [inflated-file (get-current-pdf)]))
+        (set-state! :pdf/current nil)
+        (js/setTimeout #(settle-file!) 16)))))