gecko-dev/widget/windows/PDFViaEMFPrintHelper.h
Farmer Tseng f5f7370562 Bug 1359713 - Stop loading the contents of PDF files into memory in PDFViaEMFPrintHelper r=jwatt
This change changes PDFViaEMFPrintHelper so that instead of loading the entire
contents of a PDF document into memory to pass to PDFium, it now simply passes
PDFium a file system path to load the PDF from. This should help us reduce
memory use (and potentially avoid running out of memory) when larger PDFs are
printed.


MozReview-Commit-ID: GISolZYC2GJ

--HG--
extra : rebase_source : a59925542b6c075cd14c67577653163cc2d49c0f
2017-05-12 12:42:20 +08:00

65 lines
1.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef PDFVIAEMFPRINTHELPER_H_
#define PDFVIAEMFPRINTHELPER_H_
#include "nsCOMPtr.h"
#include "PDFiumEngineShim.h"
#include "mozilla/Vector.h"
/* include windows.h for the HDC definitions that we need. */
#include <windows.h>
class nsIFile;
class nsFileInputStream;
namespace mozilla {
namespace widget {
/**
* This class helps draw a PDF file to a given Windows DC.
* To do that it first converts the PDF file to EMF.
* Windows EMF:
* https://msdn.microsoft.com/en-us/windows/hardware/drivers/print/emf-data-type
*/
class PDFViaEMFPrintHelper
{
public:
explicit PDFViaEMFPrintHelper(PRLibrary* aPDFiumLibrary);
~PDFViaEMFPrintHelper();
/** Loads the specified PDF file. */
NS_IMETHOD OpenDocument(nsIFile *aFile);
/** Releases document buffer. */
void CloseDocument();
int GetPageCount() { return mPDFiumEngine->GetPageCount(mPDFDoc); }
/** Convert specified PDF page to EMF and draw the EMF onto the given DC. */
bool DrawPage(HDC aPrinterDC, unsigned int aPageIndex,
int aPageWidth, int aPageHeight);
/** Convert specified PDF page to EMF and save it to file. */
bool DrawPageToFile(const wchar_t* aFilePath, unsigned int aPageIndex,
int aPageWidth, int aPageHeight);
private:
bool LoadPDFDataToBuffer(nsIFile *aFile);
bool RenderPageToDC(HDC aDC, unsigned int aPageIndex,
int aPageWidth, int aPageHeight);
UniquePtr<PDFiumEngineShim> mPDFiumEngine;
FPDF_DOCUMENT mPDFDoc;
PRLibrary* mPDFiumLibrary;
};
} // namespace widget
} // namespace mozilla
#endif /* PDFVIAEMFPRINTHELPER_H_ */