SkPDF: fix PDF/A

src/pdf/SkPDFDocument.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPDFCanon.h"
 #include "SkPDFCanvas.h"
 #include "SkPDFDevice.h"
@@ skipping 220 matching lines @@
     fObjectSerializer.serializeObjects(this->getStream());
 }
 
 SkCanvas* SkPDFDocument::onBeginPage(SkScalar width, SkScalar height,
                                      const SkRect& trimBox) {
     SkASSERT(!fCanvas.get());  // endPage() was called before this.
     if (fPages.empty()) {
         // if this is the first page if the document.
         fObjectSerializer.serializeHeader(this->getStream(), fMetadata);
         fDests = sk_make_sp<SkPDFDict>();
+        #ifdef SK_PDF_GENERATE_PDFA
+            SkPDFMetadata::UUID uuid = fMetadata.uuid();
+            // We use the same UUID for Document ID and Instance ID since this
+            // is the first revision of this document (and Skia does not
+            // support revising existing PDF documents).
+            // If we are not in PDF/A mode, don't use a UUID since testing
+            // works best with reproducible outputs.
+            fID.reset(SkPDFMetadata::CreatePdfId(uuid, uuid));
+            fXMP.reset(fMetadata.createXMPObject(uuid, uuid));
+            fObjectSerializer.addObjectRecursively(fXMP);
+            fObjectSerializer.serializeObjects(this->getStream());
+        #endif
     }
     SkISize pageSize = SkISize::Make(
             SkScalarRoundToInt(width), SkScalarRoundToInt(height));
     fPageDevice.reset(
             SkPDFDevice::Create(pageSize, fRasterDpi, this));
     fCanvas = sk_make_sp<SkPDFCanvas>(fPageDevice);
     fCanvas->clipRect(trimBox);
     fCanvas->translate(trimBox.x(), trimBox.y());
     return fCanvas.get();
 }
@@ skipping 39 matching lines @@
 
 bool SkPDFDocument::onClose(SkWStream* stream) {
     SkASSERT(!fCanvas.get());
     if (fPages.empty()) {
         fPages.reset();
         fCanon.reset();
         renew(&fObjectSerializer);
         return false;
     }
     auto docCatalog = sk_make_sp<SkPDFDict>("Catalog");
-    sk_sp<SkPDFObject> id, xmp;
     #ifdef SK_PDF_GENERATE_PDFA
-        SkPDFMetadata::UUID uuid = metadata.uuid();
-        // We use the same UUID for Document ID and Instance ID since this
-        // is the first revision of this document (and Skia does not
-        // support revising existing PDF documents).
-        // If we are not in PDF/A mode, don't use a UUID since testing
-        // works best with reproducible outputs.
-        id.reset(SkPDFMetadata::CreatePdfId(uuid, uuid));
-        xmp.reset(metadata.createXMPObject(uuid, uuid));
-        docCatalog->insertObjRef("Metadata", std::move(xmp));
-
+        SkASSERT(fXMP);
+        docCatalog->insertObjRef("Metadata", fXMP);
         // sRGB is specified by HTML, CSS, and SVG.
         auto outputIntent = sk_make_sp<SkPDFDict>("OutputIntent");
         outputIntent->insertName("S", "GTS_PDFA1");
         outputIntent->insertString("RegistryName", "http://www.color.org");
         outputIntent->insertString("OutputConditionIdentifier",
                                    "sRGB IEC61966-2.1");
         auto intentArray = sk_make_sp<SkPDFArray>();
         intentArray->appendObject(std::move(outputIntent));
         // Don't specify OutputIntents if we are not in PDF/A mode since
         // no one has ever asked for this feature.
         docCatalog->insertObject("OutputIntents", std::move(intentArray));
     #endif
-
     docCatalog->insertObjRef("Pages", generate_page_tree(&fPages));
 
     if (fDests->size() > 0) {
         docCatalog->insertObjRef("Dests", std::move(fDests));
     }
 
     // Build font subsetting info before calling addObjectRecursively().
     for (const auto& entry : fGlyphUsage) {
         sk_sp<SkPDFFont> subsetFont(
                 entry.fFont->getFontSubset(entry.fGlyphSet));
         if (subsetFont) {
             fObjectSerializer.fSubstituteMap.setSubstitute(
                     entry.fFont, subsetFont.get());
         }
     }
 
     fObjectSerializer.addObjectRecursively(docCatalog);
     fObjectSerializer.serializeObjects(this->getStream());
-    fObjectSerializer.serializeFooter(
-            this->getStream(), docCatalog, std::move(id));
-
+    #ifdef SK_PDF_GENERATE_PDFA
+        fObjectSerializer.serializeFooter(this->getStream(), docCatalog, fID);
+    #else
+        fObjectSerializer.serializeFooter(
+                this->getStream(), docCatalog, nullptr);
+    #endif
     SkASSERT(fPages.count() == 0);
     fCanon.reset();
     renew(&fObjectSerializer);
     return true;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkDocument> SkPDFMakeDocument(SkWStream* stream,
                                     void (*proc)(SkWStream*, bool),
@@ skipping 12 matching lines @@
     return SkPDFMakeDocument(stream, nullptr, dpi, jpegEncoder).release();
 }
 
 SkDocument* SkDocument::CreatePDF(const char path[], SkScalar dpi) {
     auto delete_wstream = [](SkWStream* stream, bool) { delete stream; };
     std::unique_ptr<SkFILEWStream> stream(new SkFILEWStream(path));
     return stream->isValid()
         ? SkPDFMakeDocument(stream.release(), delete_wstream, dpi, nullptr).release()
         : nullptr;
 }