Add factory methods for creating empty arrays and dictionaries.

Also updated pdf_from_scratch test driver to use the new factories,
and made some cosmetic improvements and documentation updates for the
emptyPDF() method.

ChangeLog

@@ -1,3 +1,10 @@
+2012-06-22  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add empty QPDFObjectHandle factories for array and dictionary.
+	With PDF-from-scratch capability, it is useful to be able to
+	create empty arrays and dictionaries and add keys to them.
+	Updated pdf_from_scratch.cc to use these interfaces.
+
 2012-06-21  Jay Berkenbilt  <ejb@ql.org>
 
 	* Add QPDF::emptyPDF() to create an empty QPDF object suitable for

TODO

@@ -37,7 +37,10 @@ Next
       space to do the tests, probably enough space for two coipes of
       the file.  The test program should also have an interactive mode
       so we can generate the large file and then look at it with a
-      PDF viewer like Adobe Reader.
+      PDF viewer like Adobe Reader.  The test suite should actually
+      read the file back in and look at all the page and stream
+      contents to make sure the file is really correct.  We need to
+      test normal writing and linearization.
 
  * Consider adding an example that uses the page APIs, or update the
    documentation to refer the user to the test suite.

include/qpdf/QPDFObjectHandle.hh

@@ -106,9 +106,13 @@ class QPDFObjectHandle
     QPDF_DLL
     static QPDFObjectHandle newString(std::string const& str);
     QPDF_DLL
+    static QPDFObjectHandle newArray();
+    QPDF_DLL
     static QPDFObjectHandle newArray(
 	std::vector<QPDFObjectHandle> const& items);
     QPDF_DLL
+    static QPDFObjectHandle newDictionary();
+    QPDF_DLL
     static QPDFObjectHandle newDictionary(
 	std::map<std::string, QPDFObjectHandle> const& items);
 

include/qpdf/QUtil.hh

@@ -14,7 +14,6 @@
 #include <list>
 #include <stdexcept>
 #include <stdio.h>
-#include <sys/stat.h>
 
 namespace QUtil
 {

libqpdf/QPDF.cc

@@ -370,7 +370,7 @@ QPDF::processMemoryFile(char const* description,
 void
 QPDF::emptyPDF()
 {
-    processMemoryFile("empty file", EMPTY_PDF, strlen(EMPTY_PDF));
+    processMemoryFile("empty PDF", EMPTY_PDF, strlen(EMPTY_PDF));
 }
 
 void

libqpdf/QPDFObjectHandle.cc

@@ -615,12 +615,24 @@ QPDFObjectHandle::newString(std::string const& str)
     return QPDFObjectHandle(new QPDF_String(str));
 }
 
+QPDFObjectHandle
+QPDFObjectHandle::newArray()
+{
+    return newArray(std::vector<QPDFObjectHandle>());
+}
+
 QPDFObjectHandle
 QPDFObjectHandle::newArray(std::vector<QPDFObjectHandle> const& items)
 {
     return QPDFObjectHandle(new QPDF_Array(items));
 }
 
+QPDFObjectHandle
+QPDFObjectHandle::newDictionary()
+{
+    return newDictionary(std::map<std::string, QPDFObjectHandle>());
+}
+
 QPDFObjectHandle
 QPDFObjectHandle::newDictionary(
     std::map<std::string, QPDFObjectHandle> const& items)

libqpdf/QUtil.cc

@@ -1,5 +1,8 @@
-#include <qpdf/QUtil.hh>
+// Include qpdf-config.h first so off_t is gauaranteed to have the right size.
 #include <qpdf/qpdf-config.h>
+
+#include <qpdf/QUtil.hh>
+
 #include <stdio.h>
 #include <errno.h>
 #include <ctype.h>

qpdf/pdf_from_scratch.cc

@@ -40,49 +40,40 @@ void runtest(int n)
     {
         // Create a minimal PDF from scratch.
 
-        std::map<std::string, QPDFObjectHandle> keys;
-        std::vector<QPDFObjectHandle> items;
-
-        keys.clear();
-        keys["/Type"] = newName("/Font");
-        keys["/Subtype"] = newName("/Type1");
-        keys["/Name"] = newName("/F1");
-        keys["/BaseFont"] = newName("/Helvetica");
-        keys["/Encoding"] = newName("/WinAnsiEncoding");
         QPDFObjectHandle font = pdf.makeIndirectObject(
-            QPDFObjectHandle::newDictionary(keys));
+            QPDFObjectHandle::newDictionary());
+        font.replaceKey("/Type", newName("/Font"));
+        font.replaceKey("/Subtype", newName("/Type1"));
+        font.replaceKey("/Name", newName("/F1"));
+        font.replaceKey("/BaseFont", newName("/Helvetica"));
+        font.replaceKey("/Encoding", newName("/WinAnsiEncoding"));
 
-        items.clear();
-        items.push_back(newName("/PDF"));
-        items.push_back(newName("/Text"));
         QPDFObjectHandle procset = pdf.makeIndirectObject(
-            QPDFObjectHandle::newArray(items));
+            QPDFObjectHandle::newArray());
+        procset.appendItem(newName("/PDF"));
+        procset.appendItem(newName("/Text"));
 
         QPDFObjectHandle contents = createPageContents(pdf, "First Page");
 
-        items.clear();
-        items.push_back(QPDFObjectHandle::newInteger(0));
-        items.push_back(QPDFObjectHandle::newInteger(0));
-        items.push_back(QPDFObjectHandle::newInteger(612));
-        items.push_back(QPDFObjectHandle::newInteger(792));
-        QPDFObjectHandle mediabox = QPDFObjectHandle::newArray(items);
+        QPDFObjectHandle mediabox = QPDFObjectHandle::newArray();
+        mediabox.appendItem(QPDFObjectHandle::newInteger(0));
+        mediabox.appendItem(QPDFObjectHandle::newInteger(0));
+        mediabox.appendItem(QPDFObjectHandle::newInteger(612));
+        mediabox.appendItem(QPDFObjectHandle::newInteger(792));
 
-        keys.clear();
-        keys["/F1"] = font;
-        QPDFObjectHandle rfont = QPDFObjectHandle::newDictionary(keys);
+        QPDFObjectHandle rfont = QPDFObjectHandle::newDictionary();
+        rfont.replaceKey("/F1", font);
 
-        keys.clear();
-        keys["/ProcSet"] = procset;
-        keys["/Font"] = rfont;
-        QPDFObjectHandle resources = QPDFObjectHandle::newDictionary(keys);
+        QPDFObjectHandle resources = QPDFObjectHandle::newDictionary();
+        resources.replaceKey("/ProcSet", procset);
+        resources.replaceKey("/Font", rfont);
 
-        keys.clear();
-        keys["/Type"] = newName("/Page");
-        keys["/MediaBox"] = mediabox;
-        keys["/Contents"] = contents;
-        keys["/Resources"] = resources;
         QPDFObjectHandle page = pdf.makeIndirectObject(
-            QPDFObjectHandle::newDictionary(keys));
+            QPDFObjectHandle::newDictionary());
+        page.replaceKey("/Type", newName("/Page"));
+        page.replaceKey("/MediaBox", mediabox);
+        page.replaceKey("/Contents", contents);
+        page.replaceKey("/Resources", resources);
 
         pdf.addPage(page, true);