addPageContents

git-svn-id: svn+q:///qpdf/trunk@995 71b93d88-0707-0410-a8cf-f5a4172ac649

ChangeLog

@@ -1,3 +1,10 @@
+2010-08-05  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add new methods to QPDFObjectHandle: replaceStreamData and
+	newStream.  These methods allow users of the qpdf library to add
+	new streams and to replace data of existing streams.  Examples are
+	provided.
+
 2010-06-06  Jay Berkenbilt  <ejb@ql.org>
 
 	* Fix memory leak for QPDF objects whose underlying PDF objects

TODO

@@ -7,20 +7,19 @@ Next
    in August, 2009.  He seems to like to send encrypted mail (key
    01FCC336).  Tell him about newStream and replaceStreamData.
 
+ * Tell stronghorse@tom.com about QPDFObjectHandle::addPageContents.
+   See message from stronghorse@tom.com ("Suggestion for qpdf") from
+   2010-06-09 and my response.
+
 2.2
 ===
 
- * Add helper routines for manipulating page content streams.
-   Operations should include ability to convert page contents from a
-   stream to an array of streams and to append or prepend to the page
-   contents.  See message from stronghorse@tom.com ("Suggestion for
-   qpdf") from 2010-06-09 and my response.  Consider providing an
-   example program that adds the line he suggests.
-
  * Create an example that does some kind of manipulation on every
    image.  Use QPDF::getAllPages and QPDFObjectHandle::getPageImages
    along with new stream data and dictionary manipulation.
 
+ * Add example program for addPageContents using suggestion from
+   stronghorse@tom.com's message above.
 
 General
 =======

include/qpdf/QPDFObjectHandle.hh

@@ -288,14 +288,22 @@ class QPDFObjectHandle
     QPDF_DLL
     std::map<std::string, QPDFObjectHandle> getPageImages();
 
-    // Throws an exception if this is not a Page object.  Returns a
+    // Returns a vector of stream objects representing the content
-    // vector of stream objects representing the content streams for
+    // streams for the given page.  This routine allows the caller to
-    // the given page.  This routine allows the caller to not care
+    // not care whether there are one or more than one content streams
-    // whether there are one or more than one content streams for a
+    // for a page.  Throws an exception if this is not a Page object.
-    // page.
     QPDF_DLL
     std::vector<QPDFObjectHandle> getPageContents();
 
+    // Add the given object as a new content stream for this page.  If
+    // parameter 'first' is true, add to the beginning.  Otherwise,
+    // add to the end.  This routine automatically converts the page
+    // contents to an array if it is a scalar, allowing the caller not
+    // to care what the initial structure is.  Throws an exception if
+    // this is not a Page object.
+    QPDF_DLL
+    void addPageContents(QPDFObjectHandle contents, bool first);
+
     // Initializers for objects.  This Factory class gives the QPDF
     // class specific permission to call factory methods without
     // making it a friend of the whole QPDFObjectHandle class.

libqpdf/QPDFObjectHandle.cc

@@ -472,6 +472,35 @@ QPDFObjectHandle::getPageContents()
     return result;
 }
 
+void
+QPDFObjectHandle::addPageContents(QPDFObjectHandle new_contents, bool first)
+{
+    assertPageObject();
+    new_contents.assertType("Stream", new_contents.isStream());
+
+    std::vector<QPDFObjectHandle> orig_contents = getPageContents();
+
+    std::vector<QPDFObjectHandle> content_streams;
+    if (first)
+    {
+	QTC::TC("qpdf", "QPDFObjectHandle prepend page contents");
+	content_streams.push_back(new_contents);
+    }
+    for (std::vector<QPDFObjectHandle>::iterator iter = orig_contents.begin();
+	 iter != orig_contents.end(); ++iter)
+    {
+	QTC::TC("qpdf", "QPDFObjectHandle append page contents");
+	content_streams.push_back(*iter);
+    }
+    if (! first)
+    {
+	content_streams.push_back(new_contents);
+    }
+
+    QPDFObjectHandle contents = QPDFObjectHandle::newArray(content_streams);
+    this->replaceKey("/Contents", contents);
+}
+
 std::string
 QPDFObjectHandle::unparse()
 {

qpdf/qpdf.testcov

@@ -181,3 +181,5 @@ QPDF_Stream provider length mismatch 0
 QPDFObjectHandle newStream 0
 QPDFObjectHandle newStream with data 0
 QPDF_Stream pipe no stream data 0
+QPDFObjectHandle prepend page contents 0
+QPDFObjectHandle append page contents 0

qpdf/qtest/qpdf.test

@@ -76,26 +76,8 @@ flush_tiff_cache();
 
 show_ntests();
 # ----------
-$td->notify("--- Miscellaneous Tests ---");
+$td->notify("--- Stream Replacement Tests ---");
-$n_tests += 28;
+$n_tests += 8;
-
-$td->runtest("qpdf version",
-	     {$td->COMMAND => "qpdf --version"},
-	     {$td->REGEXP => "qpdf version \\S+\n.*", $td->EXIT_STATUS => 0},
-	     $td->NORMALIZE_NEWLINES);
-$td->runtest("C API: qpdf version",
-	     {$td->COMMAND => "qpdf-ctest --version"},
-	     {$td->REGEXP => "qpdf-ctest version \\S+\n",
-	      $td->EXIT_STATUS => 0},
-	     $td->NORMALIZE_NEWLINES);
-
-foreach (my $i = 1; $i <= 3; ++$i)
-{
-    $td->runtest("misc tests",
-		 {$td->COMMAND => "test_driver 5 misc-$i.pdf"},
-		 {$td->FILE => "misc-$i.out", $td->EXIT_STATUS => 0},
-		 $td->NORMALIZE_NEWLINES);
-}
 
 $td->runtest("replace stream data",
 	     {$td->COMMAND => "test_driver 7 qstream.pdf"},
@@ -118,6 +100,36 @@ $td->runtest("new streams",
 $td->runtest("new stream",
 	     {$td->FILE => "a.pdf"},
 	     {$td->FILE => "new-streams.pdf"});
+$td->runtest("add page contents",
+	     {$td->COMMAND => "test_driver 10 minimal.pdf"},
+	     {$td->STRING => "test 10 done\n", $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
+$td->runtest("new stream",
+	     {$td->FILE => "a.pdf"},
+	     {$td->FILE => "add-contents.pdf"});
+
+show_ntests();
+# ----------
+$td->notify("--- Miscellaneous Tests ---");
+$n_tests += 22;
+
+$td->runtest("qpdf version",
+	     {$td->COMMAND => "qpdf --version"},
+	     {$td->REGEXP => "qpdf version \\S+\n.*", $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
+$td->runtest("C API: qpdf version",
+	     {$td->COMMAND => "qpdf-ctest --version"},
+	     {$td->REGEXP => "qpdf-ctest version \\S+\n",
+	      $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
+
+foreach (my $i = 1; $i <= 3; ++$i)
+{
+    $td->runtest("misc tests",
+		 {$td->COMMAND => "test_driver 5 misc-$i.pdf"},
+		 {$td->FILE => "misc-$i.out", $td->EXIT_STATUS => 0},
+		 $td->NORMALIZE_NEWLINES);
+}
 
 # Make sure we ignore decode parameters that we don't understand
 $td->runtest("unknown decode parameters",

qpdf/qtest/qpdf/add-contents.pdf

@@ -0,0 +1,54 @@
+%PDF-1.3
+%¿÷¢þ
+1 0 obj
+<< /Pages 2 0 R /Type /Catalog >>
+endobj
+2 0 obj
+<< /Count 1 /Kids [ 3 0 R ] /Type /Pages >>
+endobj
+3 0 obj
+<< /Contents [ 4 0 R 5 0 R 6 0 R ] /MediaBox [ 0 0 612 792 ] /Parent 2 0 R /Resources << /Font << /F1 7 0 R >> /ProcSet 8 0 R >> /Type /Page >>
+endobj
+4 0 obj
+<< /Length 37 >>
+stream
+BT /F1 12 Tf 72 620 Td (Baked) Tj ET
+endstream
+endobj
+5 0 obj
+<< /Length 44 >>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+6 0 obj
+<< /Length 38 >>
+stream
+BT /F1 18 Tf 72 520 Td (Mashed) Tj ET
+endstream
+endobj
+7 0 obj
+<< /BaseFont /Helvetica /Encoding /WinAnsiEncoding /Name /F1 /Subtype /Type1 /Type /Font >>
+endobj
+8 0 obj
+[ /PDF /Text ]
+endobj
+xref
+0 9
+0000000000 65535 f 
+0000000015 00000 n 
+0000000064 00000 n 
+0000000123 00000 n 
+0000000282 00000 n 
+0000000368 00000 n 
+0000000461 00000 n 
+0000000548 00000 n 
+0000000655 00000 n 
+trailer << /Root 1 0 R /Size 9 /ID [<31415926535897932384626433832795><31415926535897932384626433832795>] >>
+startxref
+685
+%%EOF

qpdf/test_driver.cc

@@ -427,6 +427,24 @@ void runtest(int n, char const* filename)
 	w.setStreamDataMode(qpdf_s_preserve);
 	w.write();
     }
+    else if (n == 10)
+    {
+	PointerHolder<Buffer> b1 = new Buffer(37);
+	unsigned char* bp = b1.getPointer()->getBuffer();
+	memcpy(bp, (char*)"BT /F1 12 Tf 72 620 Td (Baked) Tj ET\n", 37);
+	PointerHolder<Buffer> b2 = new Buffer(38);
+	bp = b2.getPointer()->getBuffer();
+	memcpy(bp, (char*)"BT /F1 18 Tf 72 520 Td (Mashed) Tj ET\n", 38);
+
+	std::vector<QPDFObjectHandle> pages = pdf.getAllPages();
+	pages[0].addPageContents(QPDFObjectHandle::newStream(&pdf, b1), true);
+	pages[0].addPageContents(QPDFObjectHandle::newStream(&pdf, b2), false);
+
+	QPDFWriter w(pdf, "a.pdf");
+	w.setStaticID(true);
+	w.setStreamDataMode(qpdf_s_preserve);
+	w.write();
+    }
     else
     {
 	throw std::runtime_error(std::string("invalid test ") +