Convert examples to use new page helper classes

Jay Berkenbilt
1 parent 2e7ee23b
Showing 9 changed files with 60 additions and 31 deletions
ChangeLog
examples/pdf-bookmarks.cc
examples/pdf-count-strings.cc
examples/pdf-create.cc
examples/pdf-double-page-size.cc
examples/pdf-filter-tokens.cc
examples/pdf-invert-images.cc
examples/pdf-parse-content.cc
examples/pdf-split-pages.cc
@@ -7,7 +7,9 @@
 	of structural features of PDF while still staying true to qpdf's
 	philosophy of not isolating the user from the underlying
 	structure. Please see the chapter in the documentation entitled
-	"Design and Library Notes" for additional discussion.
+	"Design and Library Notes" for additional discussion. The examples
+	have also been updated to use QPDFPageDocumentHelper and
+	QPDFPageObjctHelper when performing page-level operations.
 2018-06-19  Jay Berkenbilt  <ejb@ql.org>
@@ -2,6 +2,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/QTC.hh>
@@ -44,12 +45,13 @@ void print_lines(std::vector&lt;int&gt;&amp; numbers)
 void generate_page_map(QPDF& qpdf)
 {
-    std::vector<QPDFObjectHandle> pages = qpdf.getAllPages();
+    QPDFPageDocumentHelper dh(qpdf);
+    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
     int n = 0;
-    for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin();
+    for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
 	 iter != pages.end(); ++iter)
     {
-	QPDFObjectHandle& oh = *iter;
+	QPDFObjectHandle oh = (*iter).getObjectHandle();
 	page_map[oh.getObjGen()] = ++n;
     }
 }
@@ -10,6 +10,8 @@
 #include <stdlib.h>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/Pl_StdioFile.hh>
@@ -90,12 +92,13 @@ int main(int argc, char* argv[])
     {
 	QPDF pdf;
 	pdf.processFile(infilename);
-        std::vector<QPDFObjectHandle> pages = pdf.getAllPages();
+        std::vector<QPDFPageObjectHelper> pages =
+            QPDFPageDocumentHelper(pdf).getAllPages();
         int pageno = 0;
-        for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin();
+        for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
              iter != pages.end(); ++iter)
         {
-            QPDFObjectHandle page = *iter;
+            QPDFPageObjectHelper& ph(*iter);
             ++pageno;
             // Pass the contents of a page through our string counter.
             // If it's an even page, capture the output. This
@@ -105,14 +108,14 @@ int main(int argc, char* argv[])
             if (pageno % 2)
             {
                 // Ignore output for odd pages.
-                page.filterPageContents(&counter);
+                ph.filterPageContents(&counter);
             }
             else
             {
                 // Write output to stdout for even pages.
                 Pl_StdioFile out("stdout", stdout);
                 std::cout << "% Contents of page " << pageno << std::endl;
-                page.filterPageContents(&counter, &out);
+                ph.filterPageContents(&counter, &out);
                 std::cout << "\n% end " << pageno << std::endl;
             }
             std::cout << "Page " << pageno
@@ -6,6 +6,8 @@
 //
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QUtil.hh>
@@ -158,10 +160,12 @@ QPDFObjectHandle newInteger(int val)
     return QPDFObjectHandle::newInteger(val);
 }
-void add_page(QPDF& pdf, QPDFObjectHandle font,
+void add_page(QPDFPageDocumentHelper& dh, QPDFObjectHandle font,
               std::string const& color_space,
               std::string const& filter)
 {
+    QPDF& pdf(dh.getQPDF());
+
     // Create a stream to encode our image. QPDFWriter will fill in
     // the length and will respect our filters based on stream data
     // mode. Since we are not specifying, QPDFWriter will compress
@@ -222,7 +226,7 @@ void add_page(QPDF&amp; pdf, QPDFObjectHandle font,
     page.replaceKey("/Resources", resources);
     // Add the page to the PDF file
-    pdf.addPage(page, false);
+    dh.addPage(page, false);
 }
 static void check(char const* filename,
@@ -249,18 +253,19 @@ static void check(char const* filename,
     QPDF pdf;
     pdf.processFile(filename);
-    std::vector<QPDFObjectHandle> const& pages = pdf.getAllPages();
+    QPDFPageDocumentHelper dh(pdf);
+    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
     if (n_color_spaces * n_filters != pages.size())
     {
         throw std::logic_error("incorrect number of pages");
     }
     size_t pageno = 1;
     bool errors = false;
-    for (std::vector<QPDFObjectHandle>::const_iterator page_iter =
+    for (std::vector<QPDFPageObjectHelper>::iterator page_iter =
              pages.begin();
          page_iter != pages.end(); ++page_iter)
     {
-        QPDFObjectHandle page = *page_iter;
+        QPDFPageObjectHelper& page(*page_iter);
         std::map<std::string, QPDFObjectHandle> images = page.getPageImages();
         if (images.size() != 1)
         {
@@ -391,13 +396,14 @@ static void create_pdf(char const* filename)
     filters.push_back("null");
     filters.push_back("/DCTDecode");
     filters.push_back("/RunLengthDecode");
+    QPDFPageDocumentHelper dh(pdf);
     for (std::vector<std::string>::iterator c_iter = color_spaces.begin();
          c_iter != color_spaces.end(); ++c_iter)
     {
         for (std::vector<std::string>::iterator f_iter = filters.begin();
              f_iter != filters.end(); ++f_iter)
         {
-            add_page(pdf, font, *c_iter, *f_iter);
+            add_page(dh, font, *c_iter, *f_iter);
         }
     }
@@ -2,6 +2,8 @@
 #include <string.h>
 #include <stdlib.h>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/Buffer.hh>
 #include <qpdf/QPDFWriter.hh>
@@ -77,14 +79,17 @@ int main(int argc, char* argv[])
 	QPDF qpdf;
 	qpdf.processFile(infilename, password);
-	std::vector<QPDFObjectHandle> pages = qpdf.getAllPages();
-	for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin();
+	std::vector<QPDFPageObjectHelper> pages =
+            QPDFPageDocumentHelper(qpdf).getAllPages();
+	for (std::vector<QPDFPageObjectHelper>::iterator iter =
+                 pages.begin();
 	     iter != pages.end(); ++iter)
 	{
-	    QPDFObjectHandle& page = *iter;
+            QPDFPageObjectHelper& ph(*iter);
+	    QPDFObjectHandle page = ph.getObjectHandle();
 	    // Prepend the buffer to the page's contents
-	    page.addPageContents(
+	    ph.addPageContents(
                 QPDFObjectHandle::newStream(&qpdf, content), true);
 	    // Double the size of each of the content boxes
@@ -12,6 +12,8 @@
 #include <deque>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QPDFObjectHandle.hh>
@@ -207,8 +209,9 @@ int main(int argc, char* argv[])
     {
 	QPDF pdf;
 	pdf.processFile(infilename);
-        std::vector<QPDFObjectHandle> pages = pdf.getAllPages();
-        for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin();
+        std::vector<QPDFPageObjectHelper> pages =
+            QPDFPageDocumentHelper(pdf).getAllPages();
+        for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
              iter != pages.end(); ++iter)
         {
             // Attach two token filters to each page of this file.
@@ -216,7 +219,7 @@ int main(int argc, char* argv[])
             // are retrieved in any other way, the filters will be
             // applied. See comments on the filters for additional
             // details.
-            QPDFObjectHandle page = *iter;
+            QPDFPageObjectHelper& page(*iter);
             page.addContentTokenFilter(new StringReverser);
             page.addContentTokenFilter(new ColorToGray);
         }
@@ -2,6 +2,8 @@
 #include <string.h>
 #include <stdlib.h>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/Buffer.hh>
 #include <qpdf/QPDFWriter.hh>
@@ -97,11 +99,12 @@ int main(int argc, char* argv[])
 	PointerHolder<QPDFObjectHandle::StreamDataProvider> p = inv;
 	// For each page...
-	std::vector<QPDFObjectHandle> pages = qpdf.getAllPages();
-	for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin();
+	std::vector<QPDFPageObjectHelper> pages =
+            QPDFPageDocumentHelper(qpdf).getAllPages();
+	for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
 	     iter != pages.end(); ++iter)
 	{
-	    QPDFObjectHandle& page = *iter;
+	    QPDFPageObjectHelper& page(*iter);
 	    // Get all images on the page.
 	    std::map<std::string, QPDFObjectHandle> images =
 		page.getPageImages();
@@ -3,6 +3,8 @@
 #include <stdlib.h>
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
+#include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 static char const* whoami = 0;
@@ -68,13 +70,14 @@ int main(int argc, char* argv[])
     {
 	QPDF pdf;
 	pdf.processFile(filename);
-        std::vector<QPDFObjectHandle> pages = pdf.getAllPages();
+        std::vector<QPDFPageObjectHelper> pages =
+            QPDFPageDocumentHelper(pdf).getAllPages();
         if ((pageno < 1) || (static_cast<size_t>(pageno) > pages.size()))
         {
             usage();
         }
-        QPDFObjectHandle page = pages.at(pageno-1);
+        QPDFPageObjectHelper& page = pages.at(pageno-1);
         ParserCallbacks cb;
         page.parsePageContents(&cb);
     }
@@ -5,6 +5,7 @@
 //
 #include <qpdf/QPDF.hh>
+#include <qpdf/QPDFPageDocumentHelper.hh>
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QUtil.hh>
 #include <string>
@@ -20,18 +21,19 @@ static void process(char const* whoami,
 {
     QPDF inpdf;
     inpdf.processFile(infile);
-    std::vector<QPDFObjectHandle> const& pages = inpdf.getAllPages();
+    std::vector<QPDFPageObjectHelper> pages =
+        QPDFPageDocumentHelper(inpdf).getAllPages();
     int pageno_len = QUtil::int_to_string(pages.size()).length();
     int pageno = 0;
-    for (std::vector<QPDFObjectHandle>::const_iterator iter = pages.begin();
+    for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
          iter != pages.end(); ++iter)
     {
-        QPDFObjectHandle page = *iter;
+        QPDFPageObjectHelper& page(*iter);
         std::string outfile =
             outprefix + QUtil::int_to_string(++pageno, pageno_len) + ".pdf";
         QPDF outpdf;
         outpdf.emptyPDF();
-        outpdf.addPage(page, false);
+        QPDFPageDocumentHelper(outpdf).addPage(page, false);
         QPDFWriter outpdfw(outpdf, outfile.c_str());
 	if (static_id)
 	{