Make PDF title accessible to extractor scripts and filters

This also implements decoding PDF meta data strings properly, the previous
way only worked by accident for non-Unicode content.

autotests/scriptenginedata/iata-bcbp-demo.pdf.json

@@ -23,7 +23,8 @@
                 }
             ],
             "producer": "cairo 1.16.0 (https://cairographics.org)",
-            "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n"
+            "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n",
+            "title": ""
         }
     },
     {
@@ -85,7 +86,8 @@
                 }
             ],
             "producer": "cairo 1.16.0 (https://cairographics.org)",
-            "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n"
+            "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n",
+            "title": ""
         },
         "contextDateTime": "Mon Aug 19 20:23:28 2019 GMT+0200",
         "isNull": false,

src/lib/pdf/pdfdocument.cpp

@@ -19,6 +19,7 @@
 
 #include <DateInfo.h>
 #include <PDFDoc.h>
+#include <PDFDocEncoding.h>
 #include <Stream.h>
 
 #include <cmath>
@@ -296,15 +297,34 @@ QDateTime PdfDocument::modificationTime() const
 #endif
 }
 
-QString PdfDocument::producer() const
+
+QString gooStringToUnicode(const std::unique_ptr<GooString> &s)
 {
-    std::unique_ptr<GooString> s(d->m_popplerDoc->getDocInfoProducer());
     if (!s) {
         return {};
     }
+
+    if (s->hasUnicodeMarker() || s->hasUnicodeMarkerLE()) {
+        return QString::fromUtf16(reinterpret_cast<const ushort*>(s->toStr().c_str()), s->toStr().size() / 2);
+    } else {
+        int len = 0;
+        std::unique_ptr<const char[]> utf16Data(pdfDocEncodingToUTF16(s->toStr(), &len));
+        return QString::fromUtf16(reinterpret_cast<const ushort*>(utf16Data.get()), len / 2);
+    }
+
     return QString::fromUtf8(s->c_str());
 }
 
+QString PdfDocument::title() const
+{
+    return gooStringToUnicode(d->m_popplerDoc->getDocInfoTitle());
+}
+
+QString PdfDocument::producer() const
+{
+    return gooStringToUnicode(d->m_popplerDoc->getDocInfoProducer());
+}
+
 QVariantList PdfDocument::pagesVariant() const
 {
     QVariantList l;

src/lib/pdf/pdfdocument.h

@@ -92,6 +92,7 @@ class KITINERARY_EXPORT PdfDocument : public QObject
     Q_PROPERTY(QVariantList pages READ pagesVariant CONSTANT)
     Q_PROPERTY(QDateTime creationTime READ creationTime CONSTANT)
     Q_PROPERTY(QDateTime modificationTime READ modificationTime CONSTANT)
+    Q_PROPERTY(QString title READ title CONSTANT)
     Q_PROPERTY(QString producer READ producer CONSTANT)
 
 public:
@@ -115,6 +116,8 @@ public:
     /** Modification time as specified in the PDF file. */
     QDateTime modificationTime() const;
 
+    /** The document title. */
+    QString title() const;
     /** The document producer. */
     QString producer() const;