Add --pages option in pdfium_test so it renders only some of the pages.

samples/pdfium_test.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <map>
@@ skipping 46 matching lines @@
   OUTPUT_BMP,
   OUTPUT_EMF,
 #endif
 #ifdef PDF_ENABLE_SKIA
   OUTPUT_SKP,
 #endif
 };
 
 struct Options {
   Options()
-      : show_config(false), send_events(false), output_format(OUTPUT_NONE) {}
+      : show_config(false),
+        send_events(false),
+        pages(false),
+        output_format(OUTPUT_NONE) {}
 
   bool show_config;
   bool send_events;
+  bool pages;
   OutputFormat output_format;
   std::string scale_factor_as_string;
   std::string exe_path;
   std::string bin_directory;
   std::string font_directory;
+  int firstP;

[dsinclair, 2016/11/14 16:35:27]

size_t?

[npm, 2016/11/14 16:40:14]

RenderPage receives an int param. I don't think changing that is needed.

+  int lastP;
 };
 
 struct FPDF_FORMFILLINFO_PDFiumTest : public FPDF_FORMFILLINFO {
   // Hold a map of the currently loaded pages in order to avoid them
   // to get loaded twice.
   std::map<int, FPDF_PAGE> loadedPages;
 
   // Hold a pointer of FPDF_FORMHANDLE so that PDFium app hooks can
   // make use of it.
   FPDF_FORMHANDLE formHandle;
@@ skipping 373 matching lines @@
       options->bin_directory = cur_arg.substr(10);
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 #endif  // PDF_ENABLE_V8
 
     } else if (cur_arg.size() > 8 && cur_arg.compare(0, 8, "--scale=") == 0) {
       if (!options->scale_factor_as_string.empty()) {
         fprintf(stderr, "Duplicate --scale argument\n");
         return false;
       }
       options->scale_factor_as_string = cur_arg.substr(8);
+    } else if (cur_arg.size() > 8 && cur_arg.compare(0, 8, "--pages=") == 0) {
+      if (options->pages) {
+        fprintf(stderr, "Duplicate --pages argument\n");
+        return false;
+      }
+      options->pages = true;
+      const std::string pagesstring = cur_arg.substr(8);
+      size_t firstdash = pagesstring.find("-");
+      if (firstdash == std::string::npos) {
+        std::stringstream(pagesstring) >> options->firstP;
+        options->lastP = options->firstP;
+      }

[dsinclair, 2016/11/14 16:35:27]

Doesn't this need an else?

[npm, 2016/11/14 16:40:14]

Done.

+      std::stringstream(pagesstring.substr(0, firstdash)) >> options->firstP;
+      std::stringstream(pagesstring.substr(firstdash + 1)) >> options->lastP;
     } else if (cur_arg.size() >= 2 && cur_arg[0] == '-' && cur_arg[1] == '-') {
       fprintf(stderr, "Unrecognized argument %s\n", cur_arg.c_str());
       return false;
     } else {
       break;
     }
   }
   for (size_t i = cur_idx; i < args.size(); i++)
     files->push_back(args[i]);
 
@@ skipping 291 matching lines @@
 #endif  // PDF_ENABLE_XFA
   FPDF_SetFormFieldHighlightColor(form, 0, 0xFFE4DD);
   FPDF_SetFormFieldHighlightAlpha(form, 100);
 
   FORM_DoDocumentJSAction(form);
   FORM_DoDocumentOpenAction(form);
 
   int page_count = FPDF_GetPageCount(doc);
   int rendered_pages = 0;
   int bad_pages = 0;
-  for (int i = 0; i < page_count; ++i) {
+  int firstPage = options.pages ? options.firstP : 0;
+  int lastPage = options.pages ? options.lastP + 1 : page_count;

[dsinclair, 2016/11/14 16:35:27]

Why +1?

[npm, 2016/11/14 16:40:14]

To make the range inclusive. See the "i < lastPage" below.

+  for (int i = firstPage; i < lastPage; ++i) {
     if (bIsLinearized) {
       nRet = PDF_DATA_NOTAVAIL;
       while (nRet == PDF_DATA_NOTAVAIL)
         nRet = FPDFAvail_IsPageAvail(pdf_avail, i, &hints);
 
       if (nRet == PDF_DATA_ERROR) {
         fprintf(stderr, "Unknown error in checking if page %d is available.\n",
                 i);
         FPDFDOC_ExitFormFillEnvironment(form);
         FPDF_CloseDocument(doc);
@@ skipping 37 matching lines @@
   printf("%s\n", config.c_str());
 }
 
 static const char kUsageString[] =
     "Usage: pdfium_test [OPTION] [FILE]...\n"
     "  --show-config     - print build options and exit\n"
     "  --send-events     - send input described by .evt file\n"
     "  --bin-dir=<path>  - override path to v8 external data\n"
     "  --font-dir=<path> - override path to external fonts\n"
     "  --scale=<number>  - scale output size by number (e.g. 0.5)\n"
+    "  --pages=<number>(-<number>) - only render the given page(s)\n"
 #ifdef _WIN32
     "  --bmp - write page images <pdf-name>.<page-number>.bmp\n"
     "  --emf - write page meta files <pdf-name>.<page-number>.emf\n"
 #endif  // _WIN32
     "  --txt - write page text in UTF32-LE <pdf-name>.<page-number>.txt\n"
     "  --png - write page images <pdf-name>.<page-number>.png\n"
     "  --ppm - write page images <pdf-name>.<page-number>.ppm\n"
 #ifdef PDF_ENABLE_SKIA
     "  --skp - write page images <pdf-name>.<page-number>.skp\n"
 #endif
@@ skipping 86 matching lines @@
   delete platform;
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   free(const_cast<char*>(natives.data));
   free(const_cast<char*>(snapshot.data));
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 #endif  // PDF_ENABLE_V8
 
   return 0;
 }