implementing optional content radiobutton groups

src/core/catalog.js

@@ -486,17 +486,17 @@ class Catalog {
         return shadow(this, "optionalContentConfig", null);
       }
       const groups = [];
-      const groupRefs = new RefSet();
+      const groupRefCache = new RefSetCache();
       // Ensure all the optional content groups are valid.
       for (const groupRef of groupsData) {
-        if (!(groupRef instanceof Ref) || groupRefs.has(groupRef)) {
+        if (!(groupRef instanceof Ref) || groupRefCache.has(groupRef)) {
           continue;
         }
-        groupRefs.put(groupRef);
-
-        groups.push(this.#readOptionalContentGroup(groupRef));
+        const group = this.#readOptionalContentGroup(groupRef);
+        groups.push(group);
+        groupRefCache.put(groupRef, group);
       }
-      config = this.#readOptionalContentConfig(defaultConfig, groupRefs);
+      config = this.#readOptionalContentConfig(defaultConfig, groupRefCache);
       config.groups = groups;
     } catch (ex) {
       if (ex instanceof MissingDataException) {
@@ -517,6 +517,7 @@ class Catalog {
         print: null,
         view: null,
       },
+      rbGroups: [],
     };
 
     const name = group.get("Name");
@@ -565,15 +566,15 @@ class Catalog {
     return obj;
   }
 
-  #readOptionalContentConfig(config, contentGroupRefs) {
+  #readOptionalContentConfig(config, groupRefCache) {
     function parseOnOff(refs) {
       const onParsed = [];
       if (Array.isArray(refs)) {
         for (const value of refs) {
           if (!(value instanceof Ref)) {
             continue;
           }
-          if (contentGroupRefs.has(value)) {
+          if (groupRefCache.has(value)) {
             onParsed.push(value.toString());
           }
         }
@@ -588,7 +589,7 @@ class Catalog {
       const order = [];
 
       for (const value of refs) {
-        if (value instanceof Ref && contentGroupRefs.has(value)) {
+        if (value instanceof Ref && groupRefCache.has(value)) {
           parsedOrderRefs.put(value); // Handle "hidden" groups, see below.
 
           order.push(value.toString());
@@ -605,11 +606,11 @@ class Catalog {
         return order;
       }
       const hiddenGroups = [];
-      for (const groupRef of contentGroupRefs) {
-        if (parsedOrderRefs.has(groupRef)) {
+      for (const item of groupRefCache.items()) {
+        if (parsedOrderRefs.has(item[0])) {
           continue;
         }
-        hiddenGroups.push(groupRef.toString());
+        hiddenGroups.push(item[0].toString());
       }
       if (hiddenGroups.length) {
         order.push({ name: null, order: hiddenGroups });
@@ -642,6 +643,32 @@ class Catalog {
       parsedOrderRefs = new RefSet(),
       MAX_NESTED_LEVELS = 10;
 
+    // Parse RBGroups entry.
+    (rbGroups => {
+      if (!Array.isArray(rbGroups)) {
+        return null;
+      }
+
+      for (const value of rbGroups) {
+        const rbGroup = xref.fetchIfRef(value);
+        if (!Array.isArray(rbGroup) || !rbGroup.length) {
+          continue;
+        }
+
+        const parsedRbGroup = new Set();
+
+        for (const ref of rbGroup) {
+          if (ref instanceof Ref && groupRefCache.has(ref)) {
+            parsedRbGroup.add(ref.toString());
+            // Keep a record of which RB groups the current OCG belongs to.
+            groupRefCache.get(ref).rbGroups.push(parsedRbGroup);
+          }
+        }
+      }
+
+      return null;
+    })(config.get("RBGroups"));
+
     return {
       name:
         typeof config.get("Name") === "string"

src/display/optional_content_config.js

@@ -33,13 +33,14 @@ class OptionalContentGroup {
 
   #visible = true;
 
-  constructor(renderingIntent, { name, intent, usage }) {
+  constructor(renderingIntent, { name, intent, usage, rbGroups }) {
     this.#isDisplay = !!(renderingIntent & RenderingIntentFlag.DISPLAY);
     this.#isPrint = !!(renderingIntent & RenderingIntentFlag.PRINT);
 
     this.name = name;
     this.intent = intent;
     this.usage = usage;
+    this.rbGroups = rbGroups;
   }
 
   /**
@@ -229,12 +230,26 @@ class OptionalContentConfig {
     return true;
   }
 
-  setVisibility(id, visible = true) {
+  setVisibility(id, visible = true, preserveRB = true) {
     const group = this.#groups.get(id);
     if (!group) {
       warn(`Optional content group not found: ${id}`);
       return;
     }
+
+    // If my visibility is about to be set to `true' and if I belong to one or
+    // more radiobutton groups, hide all other OCGs in these radiobutton groups,
+    // provided that radiobutton state relationships are to be preserved.
+    if (visible && preserveRB && group.rbGroups.length) {
+      for (const rbGrp of group.rbGroups) {
+        for (const otherId of rbGrp) {
+          if (otherId !== id) {
+            this.#groups.get(otherId)._setVisible(INTERNAL, false, true);
+          }
+        }
+      }
+    }
+
     group._setVisible(INTERNAL, !!visible, /* userSet = */ true);
 
     this.#cachedGetHash = null;
@@ -258,13 +273,13 @@ class OptionalContentConfig {
       }
       switch (operator) {
         case "ON":
-          group._setVisible(INTERNAL, true);
+          this.setVisibility(elem, true, preserveRB);
           break;
         case "OFF":
-          group._setVisible(INTERNAL, false);
+          this.setVisibility(elem, false, preserveRB);
           break;
         case "Toggle":
-          group._setVisible(INTERNAL, !group.visible);
+          this.setVisibility(elem, !group.visible, preserveRB);
           break;
       }
     }