pdf: add writeString for pdf elements for writing element content

This adds a writeString virtual method to PDFElement and
subclasses and implemnts them for each element. This is used to
write the PDF object hierarchy back to a string buffer.

Change-Id: I484c9cebd8ab9149029b925a47e68b6a4fdf9be1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/105492
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
(cherry picked from commit fbf14b4e48c7677d5acf9a0ab91a3dc8d4ffc6fd)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/105778
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Andras Timar <andras.timar@collabora.com>

1 files changed, 25 insertions, 3 deletions

diff --git a/vcl/source/filter/ipdf/pdfdocument.cxx b/vcl/source/filter/ipdf/pdfdocument.cxx
index cf3a0ea430b0..f83d1614364e 100644
--- a/vcl/source/filter/ipdf/pdfdocument.cxx
+++ b/vcl/source/filter/ipdf/pdfdocument.cxx
@@ -49,6 +49,7 @@ class PDFCommentElement : public PDFElement
 public:
     explicit PDFCommentElement(PDFDocument& rDoc);
     bool Read(SvStream& rStream) override;
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 class PDFReferenceElement;
@@ -63,6 +64,8 @@ public:
     PDFEndDictionaryElement();
     bool Read(SvStream& rStream) override;
     sal_uInt64 GetLocation() const;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 /// End of a stream: 'endstream' keyword.
@@ -70,6 +73,8 @@ class PDFEndStreamElement : public PDFElement
 {
 public:
     bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 /// End of an object: 'endobj' keyword.
@@ -77,6 +82,8 @@ class PDFEndObjectElement : public PDFElement
 {
 public:
     bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 /// End of an array: ']'.
@@ -89,14 +96,27 @@ public:
     PDFEndArrayElement();
     bool Read(SvStream& rStream) override;
     sal_uInt64 GetOffset() const;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 /// Boolean object: a 'true' or a 'false'.
 class PDFBooleanElement : public PDFElement
 {
+    bool m_aValue;
+
 public:
-    explicit PDFBooleanElement(bool bValue);
+    explicit PDFBooleanElement(bool bValue)
+        : m_aValue(bValue)
+    {
+    }
+
     bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& rBuffer) override
+    {
+        rBuffer.append(m_aValue ? "true" : "false");
+    }
 };
 
 /// Null object: the 'null' singleton.
@@ -104,6 +124,8 @@ class PDFNullElement : public PDFElement
 {
 public:
     bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& rBuffer) override { rBuffer.append("null"); }
 };
 
 /// The trailer singleton is at the end of the doc.
@@ -119,6 +141,8 @@ public:
     bool Read(SvStream& rStream) override;
     PDFElement* Lookup(const OString& rDictionaryKey);
     sal_uInt64 GetLocation() const;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
 };
 
 XRefEntry::XRefEntry() = default;
@@ -2212,8 +2236,6 @@ sal_uInt64 PDFNumberElement::GetLocation() const { return m_nOffset; }
 
 sal_uInt64 PDFNumberElement::GetLength() const { return m_nLength; }
 
-PDFBooleanElement::PDFBooleanElement(bool /*bValue*/) {}
-
 bool PDFBooleanElement::Read(SvStream& /*rStream*/) { return true; }
 
 bool PDFNullElement::Read(SvStream& /*rStream*/) { return true; }