Fix initially hidden large items spanning the whole visible range (extended by 25% to the …

lib/timeline/component/Group.js

@@ -827,7 +827,20 @@ class Group {
       return visibleItems;
     } 
 
-    const interval = (range.end - range.start) / 4;
+    const rangeDuration = range.end - range.start;
+    let interval = rangeDuration / 4;
+
+    for (let i = 0; i < orderedItems.byEnd.length; i++) {
+      const item = orderedItems.byEnd[i];
+
+      const duration = item.data.end - item.data.start;
+      const maxProtruding = duration - rangeDuration;
+
+      if (maxProtruding > interval) {
+        interval = maxProtruding;
+      }
+    }
+
     const lowerBound = range.start - interval;
     const upperBound = range.end + interval;