Merge pull request #739 from Kellermorph/info-box-pdf

Export component info as invisible PDF text annotations
2026-08-22 00:04:14 +02:00 · 2026-08-20 23:31:09 +02:00
parent 5f83679756 4572fca31f
commit 265ec12351
5 changed files with 369 additions and 14 deletions
@@ -238,6 +238,15 @@ void convertUriToGoTo(const QString &pdfPath)

 			QByteArray uriVal = data.mid(uriStart, closeParen - uriStart);

+			// Skip component-info annotations — handled by
+			// convertComponentInfoAnnotations() in a separate pass.
+			if (uriVal.startsWith("componentinfo://")
+				|| uriVal.startsWith("http://componentinfo.local/")) {
+				out.append(data.mid(found, closeParen + 1 - found));
+				pos = closeParen + 1;
+				continue;
+			}
+
 			// Extract page number: look for #page=N or bare page=N
 			int pageNum = -1;
 			int hashPos = uriVal.lastIndexOf("#page=");
@@ -379,4 +388,269 @@ void convertUriToGoTo(const QString &pdfPath)
 	out.close();
 }

+void convertComponentInfoAnnotations(const QString &pdfPath,
+									const QList<ComponentInfo> &annotations)
+{
+	if (annotations.isEmpty()) return;
+
+	QFile f(pdfPath);
+	if (!f.open(QIODevice::ReadOnly)) return;
+	QByteArray data = f.readAll();
+	f.close();
+
+	const QByteArray markerPrefix("http://componentinfo.local/");
+	if (!data.contains(markerPrefix)) return;
+
+	int xrefStart = data.lastIndexOf("\nxref\n");
+	if (xrefStart == -1) xrefStart = data.lastIndexOf("\nxref ");
+	if (xrefStart == -1) return;
+	++xrefStart;
+	QByteArray body = data.left(xrefStart);
+
+	// Pre-scan body for highest object number
+	int maxObjNum = 0;
+	{
+		const QByteArray objMarker(" 0 obj");
+		int p = 0;
+		while ((p = body.indexOf(objMarker, p)) != -1) {
+			int numStart = p - 1;
+			while (numStart > 0 && body[numStart - 1] != '\n' && body[numStart - 1] != '\r')
+				--numStart;
+			QByteArray numStr = body.mid(numStart, p - numStart).trimmed();
+			bool ok = false;
+			int num = numStr.toInt(&ok);
+			if (ok && num > maxObjNum)
+				maxObjNum = num;
+			++p;
+		}
+	}
+	// Empty Form XObject used as invisible appearance for all annotations.
+	// All annotations reference this single object.
+	int emptyXObjNum = maxObjNum + 1;
+
+	QByteArray out;
+	out.reserve(data.size());
+
+	int pos = 0;
+	bool anyConverted = false;
+
+	while (pos < body.size()) {
+		// Find next indexed marker: http://componentinfo.local/<N>
+		int markerPos = body.indexOf(markerPrefix, pos);
+		if (markerPos == -1) {
+			out.append(body.mid(pos));
+			break;
+		}
+
+		// Extract index from marker URL
+		int idxStart = markerPos + markerPrefix.size();
+		int idxEnd = idxStart;
+		while (idxEnd < body.size() && body[idxEnd] >= '0' && body[idxEnd] <= '9')
+			++idxEnd;
+		if (idxEnd == idxStart) {
+			// No index — skip malformed marker
+			out.append(body.mid(pos, markerPos + markerPrefix.size() - pos));
+			pos = markerPos + markerPrefix.size();
+			continue;
+		}
+		int annotIndex = body.mid(idxStart, idxEnd - idxStart).toInt();
+
+		int uriOpen = body.lastIndexOf("/URI (", markerPos);
+		int closeParen = (uriOpen != -1) ? body.indexOf(')', markerPos) : -1;
+		if (uriOpen == -1 || closeParen == -1 || uriOpen < pos) {
+			out.append(body.mid(pos, idxEnd - pos));
+			pos = idxEnd;
+			continue;
+		}
+
+		// Find /S /URI before /URI (
+		int sUriPos = body.lastIndexOf("/S /URI", uriOpen);
+
+		// Find the /A << that opens the action dict containing /S /URI.
+		// Qt always writes: /A <<\n/S /URI\n/URI (...)\n>>\n>>
+		int aDictOpen = (sUriPos != -1)
+			? body.lastIndexOf("/A <<", sUriPos)
+			: -1;
+
+		// If /A << is not found, leave this annotation untouched
+		if (aDictOpen == -1 || aDictOpen < pos) {
+			out.append(body.mid(pos, closeParen + 1 - pos));
+			pos = closeParen + 1;
+			continue;
+		}
+
+		// Validate index
+		if (annotIndex < 0 || annotIndex >= annotations.size()) {
+			// Index out of range — keep original annotation intact
+			out.append(body.mid(pos, closeParen + 1 - pos));
+			pos = closeParen + 1;
+			continue;
+		}
+
+		// Copy annotation dict header up to /A <<
+		out.append(body.mid(pos, aDictOpen - pos));
+
+		QByteArray contents = annotations[annotIndex].contents.toUtf8();
+
+		// Replace /Subtype /Link with /Subtype /Text, bounded to the enclosing
+		// PDF object.  Anchoring to " 0 obj" prevents hitting /Subtype /Link
+		// from a cross-ref annotation that sits between the previous marker
+		// and the current annotation on the same page.
+		int objStart = body.lastIndexOf(" 0 obj", aDictOpen);
+		int subTypeInBody = (objStart != -1)
+			? body.indexOf("/Subtype /Link", objStart) : -1;
+		int subTypePos = (subTypeInBody != -1 && subTypeInBody < aDictOpen)
+			? out.size() - (aDictOpen - subTypeInBody) : -1;
+		if (subTypePos != -1)
+			// Acrobat draws its own sticky-note icon for /Subtype /Text
+			// whatever /AP says (verified on Reader 5.0). /Square with no
+			// /C and no /IC draws nothing anywhere, and is still a markup
+			// annotation, so the /Contents popup is unaffected.
+			out.replace(subTypePos, 14, "/Subtype /Square");
+
+		// Encode as UTF-16BE hex with BOM for proper Unicode support (Umlauten etc.).
+		// PDF spec: hex strings starting with FE FF are interpreted as UTF-16BE.
+		QByteArray utf16be;
+		utf16be.append('\xfe');
+		utf16be.append('\xff');
+		{
+			for (int i = 0; i < contents.size(); ) {
+				ushort cp = 0;
+				uchar c = static_cast<uchar>(contents.at(i));
+				if (c < 0x80) {
+					cp = c;
+					++i;
+				} else if ((c & 0xE0) == 0xC0 && i + 1 < contents.size()) {
+					cp = ((c & 0x1F) << 6)
+					   | (static_cast<uchar>(contents.at(i + 1)) & 0x3F);
+					i += 2;
+				} else if ((c & 0xF0) == 0xE0 && i + 2 < contents.size()) {
+					cp = ((c & 0x0F) << 12)
+					   | ((static_cast<uchar>(contents.at(i + 1)) & 0x3F) << 6)
+					   | (static_cast<uchar>(contents.at(i + 2)) & 0x3F);
+					i += 3;
+				} else {
+					cp = 0xFFFD; // replacement character
+					++i;
+				}
+				utf16be.append(static_cast<char>((cp >> 8) & 0xFF));
+				utf16be.append(static_cast<char>(cp & 0xFF));
+			}
+		}
+
+		out += "/Contents <";
+		out += utf16be.toHex();
+		out += ">\n/AP << /N " + QByteArray::number(emptyXObjNum) + " 0 R >>\n";
+
+		// Skip the entire /A << ... >> action dict.
+		// After closeParen ')' we have: \n>>  (closes /A dict)  \n>>  (closes annot dict)
+		int actionDictClose = body.indexOf(">>", closeParen + 1);
+		if (actionDictClose != -1) {
+			pos = actionDictClose + 2;  // skip past >> that closes /A dict
+		} else {
+			pos = closeParen + 1;
+		}
+		anyConverted = true;
+	}
+
+	if (!anyConverted) return;
+
+	// Append empty Form XObject (shared by all annotations for invisible appearance)
+	QByteArray emptyXObj;
+	emptyXObj += QByteArray::number(emptyXObjNum) + " 0 obj\n";
+	emptyXObj += "<< /Type /XObject /Subtype /Form /BBox [0 0 0 0] /Length 0 >>\n";
+	emptyXObj += "stream\nendstream\n";
+	emptyXObj += "endobj\n";
+	out += emptyXObj;
+
+	// Rebuild xref table
+	QMap<int, int> offsets;
+	{
+		const QByteArray objMarker(" 0 obj");
+		int p = 0;
+		while ((p = out.indexOf(objMarker, p)) != -1) {
+			int numStart = p - 1;
+			while (numStart > 0 && out[numStart - 1] != '\n' && out[numStart - 1] != '\r')
+				--numStart;
+			QByteArray numStr = out.mid(numStart, p - numStart).trimmed();
+			bool ok = false;
+			int objNum = numStr.toInt(&ok);
+			if (ok && objNum > 0)
+				offsets[objNum] = numStart;
+			++p;
+		}
+	}
+
+	if (offsets.isEmpty()) return;
+
+	int maxObj = offsets.lastKey();
+
+	QByteArray xref;
+	xref += "xref\n";
+	xref += "0 " + QByteArray::number(maxObj + 1) + "\n";
+	xref += "0000000000 65535 f \n";
+	for (int i = 1; i <= maxObj; ++i) {
+		if (offsets.contains(i)) {
+			xref += QByteArray::number(offsets[i]).rightJustified(10, '0')
+				+ " 00000 n \n";
+		} else {
+			xref += "0000000000 65535 f \n";
+		}
+	}
+
+	// Copy trailer and bump /Size to account for the new XObject
+	QByteArray trailer;
+	{
+		int tPos = data.indexOf("trailer", xrefStart);
+		if (tPos != -1) {
+			int tEnd = data.indexOf("%%EOF", tPos);
+			if (tEnd != -1) tEnd += 5;
+			if (tEnd != -1)
+				trailer = data.mid(tPos, tEnd - tPos);
+		}
+	}
+	if (trailer.isEmpty())
+		trailer = "trailer\n<<>>\n%%EOF";
+
+	// Bump /Size: original was maxObjNum+1, now it's emptyXObjNum+1
+	{
+		int sizePos = trailer.indexOf("/Size ");
+		if (sizePos != -1) {
+			int numStart = sizePos + 6;
+			int numEnd = numStart;
+			while (numEnd < trailer.size() && trailer[numEnd] >= '0' && trailer[numEnd] <= '9')
+				++numEnd;
+			if (numEnd > numStart) {
+				trailer.replace(numStart, numEnd - numStart,
+								QByteArray::number(emptyXObjNum + 1));
+			}
+		}
+	}
+
+	// Remove duplicate startxref if present in copied trailer
+	{
+		int stPos = trailer.indexOf("\nstartxref\n");
+		if (stPos != -1)
+			trailer = trailer.left(stPos);
+		// Ensure trailer ends with %%EOF
+		if (!trailer.endsWith("%%EOF\n"))
+			trailer += "\n%%EOF\n";
+	}
+
+	QByteArray result;
+	result.reserve(out.size() + xref.size() + trailer.size() + 64);
+	result += out;
+	int newXrefOffset = out.size();
+	result += xref;
+	result += trailer;
+	result += "\nstartxref\n";
+	result += QByteArray::number(newXrefOffset);
+	result += "\n%%EOF\n";
+
+	QFile outF(pdfPath);
+	if (!outF.open(QIODevice::WriteOnly | QIODevice::Truncate)) return;
+	outF.write(result);
+	outF.close();
+}
+
 } // namespace PdfLinks