pdf-server: fix Reset bug; show cleared baseline fields w/ revert

Reset-all bug: clearUserFormStorage skipped any field whose name was
in pdfBaselineFormValues — but if the user had EDITED a baseline field,
the edit sits in storage under that name. Skipping it left the widget
showing the stale edit while the panel showed the restored baseline.
Fix: remove ALL storage overrides on reset — every field reverts to the
PDF's /V, which IS baseline. Removed the now-dead helper.

Panel: cleared baseline fields now stay visible instead of vanishing.
State is derived per-field by comparing formFieldValues to
pdfBaselineFormValues (no new data structures — both maps already
exist, the comparison was just never rendered):

- unchanged: current === baseline → solid swatch, trash clears
- modified:  baseline exists, current differs → solid swatch, revert
- cleared:   baseline exists, current empty/absent → outlined cross
             swatch, struck-out label/value, revert restores
- added:     no baseline → solid swatch, trash removes

Panel iterates union(formFieldValues, pdfBaselineFormValues) so cleared
items don't disappear. sidebarItemCount uses the same union so the
toolbar button stays visible as long as there are baseline items OR
edits. Per-item revert: formFieldValues.set(name, baseline) +
storage.remove(id) → widget reverts to /V.

Author: ochafik

examples/pdf-server/src/mcp-app.css

@@ -1046,6 +1046,23 @@ body {
   border: 1px solid rgba(0, 0, 0, 0.15);
 }
 
+/* Swatch for baseline items the user cleared — outlined with a cross
+   instead of solid fill, so the panel still shows "this existed in the
+   file and you removed it" rather than vanishing. */
+.annotation-card-swatch-cleared {
+  background: transparent;
+  border-color: #4a90d9;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.annotation-card-cleared .annotation-card-type,
+.annotation-card-cleared .annotation-card-preview {
+  opacity: 0.55;
+  text-decoration: line-through;
+}
+
 .annotation-card-type {
   font-size: 0.7rem;
   color: var(--text200);

examples/pdf-server/src/mcp-app.ts

@@ -2194,9 +2194,36 @@ function toggleAnnotationPanel(): void {
   setAnnotationPanelOpen(annotationPanelUserPref);
 }
 
-/** Total count of annotations + filled form fields for the sidebar badge. */
+/**
+ * Derived state of a form field relative to the PDF baseline.
+ * Not stored — computed on demand by comparing formFieldValues to
+ * pdfBaselineFormValues.
+ */
+type FieldState =
+  | "unchanged" // current === baseline (came from the PDF, untouched)
+  | "modified" //  baseline exists but current differs
+  | "cleared" //   baseline exists but current is absent/empty
+  | "added"; //    no baseline — user-filled or fill_form
+
+function fieldState(name: string): FieldState {
+  const cur = formFieldValues.get(name);
+  const base = pdfBaselineFormValues.get(name);
+  if (base === undefined) return "added";
+  if (cur === undefined || cur === "" || cur === false) return "cleared";
+  return cur === base ? "unchanged" : "modified";
+}
+
+/** All field names that should appear in the panel: current ∪ baseline.
+ *  Cleared baseline fields remain visible (crossed out) so they can be
+ *  reverted individually. */
+function panelFieldNames(): Set<string> {
+  return new Set([...formFieldValues.keys(), ...pdfBaselineFormValues.keys()]);
+}
+
+/** Total count of annotations + form fields for the sidebar badge.
+ *  Uses the union so cleared baseline items still contribute. */
 function sidebarItemCount(): number {
-  return annotationMap.size + formFieldValues.size;
+  return annotationMap.size + panelFieldNames().size;
 }
 
 function updateAnnotationsBadge(): void {
@@ -2327,12 +2354,19 @@ function renderAnnotationPanel(): void {
     byPage.get(page)!.push(tracked);
   }
 
-  // Group form fields by page
-  const fieldsByPage = new Map<number, [string, string | boolean][]>();
-  for (const [name, value] of formFieldValues) {
+  // Group form fields by page — iterate the UNION so cleared baseline
+  // fields remain visible (crossed out) with a per-item revert button.
+  const fieldsByPage = new Map<number, string[]>();
+  for (const name of panelFieldNames()) {
     const page = fieldNameToPage.get(name) ?? 1;
     if (!fieldsByPage.has(page)) fieldsByPage.set(page, []);
-    fieldsByPage.get(page)!.push([name, value]);
+    fieldsByPage.get(page)!.push(name);
+  }
+  // Sort fields by their intrinsic document order within each page
+  for (const names of fieldsByPage.values()) {
+    names.sort(
+      (a, b) => (fieldNameToOrder.get(a) ?? 0) - (fieldNameToOrder.get(b) ?? 0),
+    );
   }
 
   // Collect all pages that have annotations or form fields
@@ -2369,8 +2403,8 @@ function renderAnnotationPanel(): void {
       pageNum === currentPage,
       (body) => {
         // Form fields first
-        for (const [name, value] of fields) {
-          body.appendChild(createFormFieldCard(name, value));
+        for (const name of fields) {
+          body.appendChild(createFormFieldCard(name));
         }
         // Then annotations
         for (const tracked of annotations) {
@@ -2541,54 +2575,85 @@ function createAnnotationCard(tracked: TrackedAnnotation): HTMLElement {
   return card;
 }
 
-function createFormFieldCard(
-  name: string,
-  value: string | boolean,
-): HTMLElement {
+const TRASH_SVG = `<svg width="12" height="12" viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round"><path d="M2 3h8M4.5 3V2a.5.5 0 0 1 .5-.5h2a.5.5 0 0 1 .5.5v1M5 5.5v3M7 5.5v3M3 3l.5 7a1 1 0 0 0 1 1h3a1 1 0 0 0 1-1L9 3"/></svg>`;
+const REVERT_SVG = `<svg width="12" height="12" viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"><path d="M2 6a4 4 0 1 1 1.2 2.85"/><path d="M2 9V6h3"/></svg>`;
+
+/** Revert one field to its PDF-stored baseline value. */
+function revertFieldToBaseline(name: string): void {
+  const base = pdfBaselineFormValues.get(name);
+  if (base === undefined) return;
+  formFieldValues.set(name, base);
+  // Remove our storage override → widget falls back to PDF's /V = baseline
+  if (pdfDocument) {
+    const ids = fieldNameToIds.get(name);
+    if (ids) for (const id of ids) pdfDocument.annotationStorage.remove(id);
+  }
+}
+
+function createFormFieldCard(name: string): HTMLElement {
+  const state = fieldState(name);
+  const value = formFieldValues.get(name);
+  const baseValue = pdfBaselineFormValues.get(name);
+
   const card = document.createElement("div");
   card.className = "annotation-card";
+  if (state === "cleared") card.classList.add("annotation-card-cleared");
 
   const row = document.createElement("div");
   row.className = "annotation-card-row";
 
-  // Color swatch (blue for form fields)
+  // Swatch: solid blue normally; crossed-out for cleared baseline fields
   const swatch = document.createElement("div");
   swatch.className = "annotation-card-swatch";
-  swatch.style.background = "#4a90d9";
+  if (state === "cleared") {
+    swatch.classList.add("annotation-card-swatch-cleared");
+    swatch.innerHTML = `<svg width="10" height="10" viewBox="0 0 10 10" stroke="#4a90d9" stroke-width="1.5" stroke-linecap="round"><path d="M2 2l6 6M8 2L2 8"/></svg>`;
+  } else {
+    swatch.style.background = "#4a90d9";
+  }
+  // Subtle modified marker
+  if (state === "modified") swatch.title = "Modified from file";
   row.appendChild(swatch);
 
   // Field label
-  const label = getFormFieldLabel(name);
   const nameEl = document.createElement("span");
   nameEl.className = "annotation-card-type";
-  nameEl.textContent = label;
+  nameEl.textContent = getFormFieldLabel(name);
   row.appendChild(nameEl);
 
-  // Field value preview
+  // Value preview: show current, or struck-out baseline when cleared
+  const shown = state === "cleared" ? baseValue : value;
   const displayValue =
-    typeof value === "boolean" ? (value ? "checked" : "unchecked") : value;
+    typeof shown === "boolean" ? (shown ? "checked" : "unchecked") : shown;
   if (displayValue) {
     const valueEl = document.createElement("span");
     valueEl.className = "annotation-card-preview";
     valueEl.textContent = displayValue;
     row.appendChild(valueEl);
   }
 
-  // Delete button
-  const deleteBtn = document.createElement("button");
-  deleteBtn.className = "annotation-card-delete";
-  deleteBtn.title = "Clear field";
-  deleteBtn.innerHTML = `<svg width="12" height="12" viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round"><path d="M2 3h8M4.5 3V2a.5.5 0 0 1 .5-.5h2a.5.5 0 0 1 .5.5v1M5 5.5v3M7 5.5v3M3 3l.5 7a1 1 0 0 0 1 1h3a1 1 0 0 0 1-1L9 3"/></svg>`;
-  deleteBtn.addEventListener("click", (e) => {
+  // Action button: revert for modified/cleared baseline fields, trash otherwise
+  const isRevertable = state === "modified" || state === "cleared";
+  const actionBtn = document.createElement("button");
+  actionBtn.className = "annotation-card-delete";
+  actionBtn.title = isRevertable
+    ? "Revert to value stored in file"
+    : "Clear field";
+  actionBtn.innerHTML = isRevertable ? REVERT_SVG : TRASH_SVG;
+  actionBtn.addEventListener("click", (e) => {
     e.stopPropagation();
-    formFieldValues.delete(name);
-    clearFieldInStorage(name);
+    if (isRevertable) {
+      revertFieldToBaseline(name);
+    } else {
+      formFieldValues.delete(name);
+      clearFieldInStorage(name);
+    }
     updateAnnotationsBadge();
     renderAnnotationPanel();
     renderPage();
     persistAnnotations();
   });
-  row.appendChild(deleteBtn);
+  row.appendChild(actionBtn);
 
   // Click handler: navigate to page and focus form input
   card.addEventListener("click", () => {
@@ -2853,28 +2918,31 @@ function clearFieldInStorage(name: string): void {
   for (const id of ids) storage.setValue(id, { value: clearValue });
 }
 
-/** Remove all user-sourced entries from annotationStorage, leaving the
- *  PDF's own stored values intact. */
-function clearUserFormStorage(): void {
-  if (!pdfDocument) return;
-  for (const [name] of formFieldValues) {
-    if (pdfBaselineFormValues.has(name)) continue; // PDF-native — leave alone
-    const ids = fieldNameToIds.get(name);
-    if (ids) for (const id of ids) pdfDocument.annotationStorage.remove(id);
-  }
-}
-
 /**
  * Revert to what's in the PDF file: restore baseline annotations, restore
  * baseline form values, discard all user edits. Result: diff is empty, clean.
+ *
+ * Form fields: remove ALL storage overrides — every field reverts to the
+ * PDF's /V (which IS baseline). We can't skip baseline-named fields: if the
+ * user edited one, our override is in storage under that name, and skipping
+ * it leaves the widget showing the stale edit.
  */
 function resetToBaseline(): void {
   clearAnnotationMap();
   for (const def of pdfBaselineAnnotations) {
     annotationMap.set(def.id, { def: { ...def }, elements: [] });
   }
 
-  clearUserFormStorage();
+  if (pdfDocument) {
+    const storage = pdfDocument.annotationStorage;
+    for (const name of new Set([
+      ...formFieldValues.keys(),
+      ...pdfBaselineFormValues.keys(),
+    ])) {
+      const ids = fieldNameToIds.get(name);
+      if (ids) for (const id of ids) storage.remove(id);
+    }
+  }
   formFieldValues.clear();
   for (const [name, value] of pdfBaselineFormValues) {
     formFieldValues.set(name, value);