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feat(bookmark): improve PDF bookmark extraction logic

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enhance named destinations handling to support full name-tree traversal
add fallback page index resolution for better compatibility
fix parent-child relationship handling for zero-page bookmarks
This commit is contained in:
abdullahalam123
2025-11-07 09:31:57 +05:30
parent ad49adb744
commit e64215a022
2 changed files with 91 additions and 33 deletions
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122
src/js/logic/bookmark-pdf.ts
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@@ -1540,6 +1540,7 @@ extractExistingBtn.addEventListener('click', async () => {
}
});
async function extractExistingBookmarks(doc) {
try {
const outlines = doc.catalog.lookup(PDFName.of('Outlines'));
@@ -1557,21 +1558,53 @@ async function extractExistingBookmarks(doc) {
return obj;
}
// Build named destinations map
// Build named destinations map (support full name-tree with Kids and Catalog-level Dests)
const namedDests = new Map();
try {
function addNamePair(nameObj, destObj) {
try {
const key = nameObj.decodeText ? nameObj.decodeText() : String(nameObj);
namedDests.set(key, resolveRef(destObj));
} catch (_) {
// ignore malformed entry
}
}
function traverseNamesNode(node) {
if (!node) return;
node = resolveRef(node);
if (!node) return;
const namesArray = node.lookup ? node.lookup(PDFName.of('Names')) : null;
if (namesArray && namesArray.array) {
for (let i = 0; i < namesArray.array.length; i += 2) {
const n = namesArray.array[i];
const d = namesArray.array[i + 1];
addNamePair(n, d);
}
}
const kidsArray = node.lookup ? node.lookup(PDFName.of('Kids')) : null;
if (kidsArray && kidsArray.array) {
for (const kid of kidsArray.array) traverseNamesNode(kid);
}
}
// Names tree under Catalog/Names/Dests
const names = doc.catalog.lookup(PDFName.of('Names'));
if (names) {
const dests = names.lookup(PDFName.of('Dests'));
if (dests) {
const namesArray = dests.lookup(PDFName.of('Names'));
if (namesArray && namesArray.array) {
for (let i = 0; i < namesArray.array.length; i += 2) {
const name = namesArray.array[i];
const dest = namesArray.array[i + 1];
namedDests.set(name.decodeText(), resolveRef(dest));
}
}
const destsTree = names.lookup(PDFName.of('Dests'));
if (destsTree) traverseNamesNode(destsTree);
}
// Some PDFs store Dests directly under the Catalog's Dests as a dictionary
const catalogDests = doc.catalog.lookup(PDFName.of('Dests'));
if (catalogDests && catalogDests.dict) {
const entries = catalogDests.dict.entries();
for (const [key, value] of entries) {
// keys are PDFName; convert to string
const keyStr = key.decodeText ? key.decodeText() : key.toString();
namedDests.set(keyStr, resolveRef(value));
}
}
} catch (e) {
@@ -1580,34 +1613,40 @@ async function extractExistingBookmarks(doc) {
function findPageIndex(pageRef) {
if (!pageRef) return 0;
try {
const resolved = resolveRef(pageRef);
// Try to match by object number
if (pageRef.numberValue !== undefined) {
const numericIndex = pageRef.numberValue | 0;
if (numericIndex >= 0 && numericIndex < pages.length) return numericIndex;
}
if (pageRef.objectNumber !== undefined) {
const idx = pages.findIndex(p => p.ref.objectNumber === pageRef.objectNumber);
if (idx !== -1) return idx;
const idxByObjNum = pages.findIndex(
(p) => p.ref.objectNumber === pageRef.objectNumber
);
if (idxByObjNum !== -1) return idxByObjNum;
}
// Try to match by reference string
if (pageRef.toString) {
const idx = pages.findIndex(p => p.ref.toString() === pageRef.toString());
if (idx !== -1) return idx;
const target = pageRef.toString();
const idxByString = pages.findIndex((p) => p.ref.toString() === target);
if (idxByString !== -1) return idxByString;
}
// Try to match by page dictionary
if (resolved && resolved.get) {
const idx = pages.findIndex(p => {
const pageDict = doc.context.lookup(p.ref);
return pageDict === resolved;
});
if (idx !== -1) return idx;
for (let i = 0; i < pages.length; i++) {
const pageDict = doc.context.lookup(pages[i].ref);
if (pageDict === resolved) return i;
}
}
} catch (e) {
console.error('Error finding page:', e);
}
// Fallback: keep current behavior but log for diagnostics
console.warn('Falling back to page 0 for destination');
return 0;
}
@@ -1627,8 +1666,19 @@ async function extractExistingBookmarks(doc) {
// Handle named destinations
if (dest && !dest.array) {
const name = dest.decodeText ? dest.decodeText() : dest.toString();
dest = namedDests.get(name);
try {
const name = dest.decodeText ? dest.decodeText() : dest.toString();
if (namedDests.has(name)) {
dest = namedDests.get(name);
} else if (dest.lookup) {
// Some named destinations resolve to a dictionary with 'D' entry
const maybeDict = resolveRef(dest);
const dictD = maybeDict && maybeDict.lookup ? maybeDict.lookup(PDFName.of('D')) : null;
if (dictD) dest = resolveRef(dictD);
}
} catch (_) {
// leave dest as-is if it can't be decoded
}
}
return resolveRef(dest);
@@ -1707,6 +1757,17 @@ async function extractExistingBookmarks(doc) {
child = resolveRef(child.lookup(PDFName.of('Next')));
}
if (pageIndex === 0 && bookmark.children.length > 0) {
const firstChild = bookmark.children[0];
if (firstChild) {
bookmark.page = firstChild.page;
bookmark.destX = firstChild.destX;
bookmark.destY = firstChild.destY;
bookmark.zoom = firstChild.zoom;
}
}
return bookmark;
}
@@ -1741,11 +1802,8 @@ downloadBtn.addEventListener('click', async () => {
itemDict.set(PDFName.of('Title'), PDFString.of(node.title));
itemDict.set(PDFName.of('Parent'), parentRef);
// const pageIndex = Math.max(0, Math.min(node.page - 2, pages.length - 1));
const pageIndex =
node.destX !== null && node.destY !== null
? Math.max(0, Math.min(node.page - 2, pages.length - 1))
: Math.max(0, Math.min(node.page - 1, pages.length - 1));
// Always map bookmark page to zero-based index consistently
const pageIndex = Math.max(0, Math.min(node.page - 1, pages.length - 1));
const pageRef = pages[pageIndex].ref;
// Handle custom destination with zoom and position