From add45567d8925968c4e9091fce82b29ca9e946f1 Mon Sep 17 00:00:00 2001
From: Ross <xkjq@ymail.com>
Date: Mon, 27 Apr 2026 09:34:07 +0100
Subject: [PATCH] Enhance metadata caching in setLoadedImageIdsAndCacheMeta and
 add forced warm-up for visible stack viewports

---
 dicom-viewer/src/App.tsx | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/dicom-viewer/src/App.tsx b/dicom-viewer/src/App.tsx
index fe576b3..449fac7 100644
--- a/dicom-viewer/src/App.tsx
+++ b/dicom-viewer/src/App.tsx
@@ -856,12 +856,13 @@ function App({ container_id, imageStacks, autoCacheStack, annotationJson, viewer
   }, [availableStacks, generateThumbnail, stackThumbnails]);
 
   // Wrap setLoadedImageIds to also cache DICOM metadata
-  const setLoadedImageIdsAndCacheMeta = async (imageIds: string[]) => {
+  const setLoadedImageIdsAndCacheMeta = async (imageIds: string[], options?: { force?: boolean }) => {
     console.log("Setting loaded imageIds:", imageIds);
     console.log("autoCacheStack:", autoCacheStack);
     const loadPromises: Promise<any>[] = [];
+    const shouldCache = Boolean(autoCacheStack || options?.force);
 
-    if (autoCacheStack) {
+    if (shouldCache) {
       for (const imageId of imageIds) {
         if (imageId.startsWith("wadouri:")) {
           try {
@@ -1171,6 +1172,19 @@ function App({ container_id, imageStacks, autoCacheStack, annotationJson, viewer
     const modifierActive = shiftPressed || (altEnablesReferenceCursors && altPressed);
 
     if (modifierActive) {
+      // Force metadata warm-up for visible stack viewports so nearest-slice lookup
+      // can consider the entire stack (including images not yet viewed/cached).
+      const visibleCount = viewportGrid.rows * viewportGrid.cols;
+      const visibleStackImageIds = viewportImageIds
+        .slice(0, visibleCount)
+        .filter((ids, idx) => viewportModes[idx] === 'stack' && Array.isArray(ids) && ids.length > 0);
+
+      visibleStackImageIds.forEach((ids) => {
+        setLoadedImageIdsAndCacheMeta(ids, { force: true }).catch((err) => {
+          console.warn('Reference cursor metadata warm-up failed:', err);
+        });
+      });
+
       if (!mainToolGroup.hasTool(ReferenceCursors.toolName)) {
         mainToolGroup.addTool(ReferenceCursors.toolName);
       }
@@ -1181,7 +1195,16 @@ function App({ container_id, imageStacks, autoCacheStack, annotationJson, viewer
         mainToolGroup.setToolDisabled(ReferenceCursors.toolName);
       }
     }
-  }, [altPressed, shiftPressed, altEnablesReferenceCursors]);
+  }, [
+    altPressed,
+    shiftPressed,
+    altEnablesReferenceCursors,
+    viewportGrid.rows,
+    viewportGrid.cols,
+    viewportImageIds,
+    viewportModes,
+    setLoadedImageIdsAndCacheMeta,
+  ]);
 
   // Helper to apply all mouse tool bindings (normal or ctrl)
   const applyMouseToolBindings = useCallback(() => {