summaryrefslogtreecommitdiff
path: root/vcl/source/filter/ipdf/pdfread.cxx
blob: 7083c4a9cc99b2353cdfd57223d2a876f6879c37 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * 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/.
 */

#include <vcl/pdfread.hxx>

#include <config_features.h>

#if HAVE_FEATURE_PDFIUM
#include <fpdfview.h>
#include <fpdf_edit.h>
#include <fpdf_save.h>
#endif

#include <vcl/bitmapaccess.hxx>
#include <vcl/graph.hxx>
#include <bitmapwriteaccess.hxx>
#include <unotools/ucbstreamhelper.hxx>

using namespace com::sun::star;

namespace
{
#if HAVE_FEATURE_PDFIUM

/// Callback class to be used with FPDF_SaveWithVersion().
struct CompatibleWriter : public FPDF_FILEWRITE
{
public:
    CompatibleWriter();
    static int WriteBlockCallback(FPDF_FILEWRITE* pFileWrite, const void* pData,
                                  unsigned long nSize);

    SvMemoryStream m_aStream;
};

CompatibleWriter::CompatibleWriter()
{
    FPDF_FILEWRITE::version = 1;
    FPDF_FILEWRITE::WriteBlock = CompatibleWriter::WriteBlockCallback;
}

int CompatibleWriter::WriteBlockCallback(FPDF_FILEWRITE* pFileWrite, const void* pData,
                                         unsigned long nSize)
{
    auto pImpl = static_cast<CompatibleWriter*>(pFileWrite);
    pImpl->m_aStream.WriteBytes(pData, nSize);
    return 1;
}

/// Convert to inch, then assume 96 DPI.
double pointToPixel(double fPoint) { return fPoint / 72 * 96; }

/// Does PDF to bitmap conversion using pdfium.
size_t generatePreview(SvStream& rStream, std::vector<Bitmap>& rBitmaps, sal_uInt64 nPos,
                       sal_uInt64 nSize, const size_t nFirstPage, int nPages)
{
    FPDF_LIBRARY_CONFIG aConfig;
    aConfig.version = 2;
    aConfig.m_pUserFontPaths = nullptr;
    aConfig.m_pIsolate = nullptr;
    aConfig.m_v8EmbedderSlot = 0;
    FPDF_InitLibraryWithConfig(&aConfig);

    // Read input into a buffer.
    SvMemoryStream aInBuffer;
    rStream.Seek(nPos);
    aInBuffer.WriteStream(rStream, nSize);

    // Load the buffer using pdfium.
    FPDF_DOCUMENT pPdfDocument
        = FPDF_LoadMemDocument(aInBuffer.GetData(), aInBuffer.GetSize(), /*password=*/nullptr);
    if (!pPdfDocument)
        return 0;

    const int nPageCount = FPDF_GetPageCount(pPdfDocument);
    if (nPages <= 0)
        nPages = nPageCount;
    const size_t nLastPage = std::min<int>(nPageCount, nFirstPage + nPages) - 1;
    for (size_t nPageIndex = nFirstPage; nPageIndex <= nLastPage; ++nPageIndex)
    {
        // Render next page.
        FPDF_PAGE pPdfPage = FPDF_LoadPage(pPdfDocument, nPageIndex);
        if (!pPdfPage)
            break;

        // Returned unit is points, convert that to pixel.
        const size_t nPageWidth = pointToPixel(FPDF_GetPageWidth(pPdfPage));
        const size_t nPageHeight = pointToPixel(FPDF_GetPageHeight(pPdfPage));
        FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1);
        if (!pPdfBitmap)
            break;

        const FPDF_DWORD nColor = FPDFPage_HasTransparency(pPdfPage) ? 0x00000000 : 0xFFFFFFFF;
        FPDFBitmap_FillRect(pPdfBitmap, 0, 0, nPageWidth, nPageHeight, nColor);
        FPDF_RenderPageBitmap(pPdfBitmap, pPdfPage, /*start_x=*/0, /*start_y=*/0, nPageWidth,
                              nPageHeight, /*rotate=*/0, /*flags=*/0);

        // Save the buffer as a bitmap.
        Bitmap aBitmap(Size(nPageWidth, nPageHeight), 24);
        {
            BitmapScopedWriteAccess pWriteAccess(aBitmap);
            const auto pPdfBuffer = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap));
            const int nStride = FPDFBitmap_GetStride(pPdfBitmap);
            for (size_t nRow = 0; nRow < nPageHeight; ++nRow)
            {
                ConstScanline pPdfLine = pPdfBuffer + (nStride * nRow);
                // pdfium byte order is BGRA.
                pWriteAccess->CopyScanline(nRow, pPdfLine, ScanlineFormat::N32BitTcBgra, nStride);
            }
        }

        rBitmaps.emplace_back(std::move(aBitmap));
        FPDFBitmap_Destroy(pPdfBitmap);
        FPDF_ClosePage(pPdfPage);
    }

    FPDF_CloseDocument(pPdfDocument);
    FPDF_DestroyLibrary();

    return rBitmaps.size();
}

/// Decide if PDF data is old enough to be compatible.
bool isCompatible(SvStream& rInStream, sal_uInt64 nPos, sal_uInt64 nSize)
{
    if (nSize < 8)
        return false;

    // %PDF-x.y
    sal_uInt8 aFirstBytes[8];
    rInStream.Seek(nPos);
    sal_uLong nRead = rInStream.ReadBytes(aFirstBytes, 8);
    if (nRead < 8)
        return false;

    if (aFirstBytes[0] != '%' || aFirstBytes[1] != 'P' || aFirstBytes[2] != 'D'
        || aFirstBytes[3] != 'F' || aFirstBytes[4] != '-')
        return false;

    sal_Int32 nMajor = OString(aFirstBytes[5]).toInt32();
    sal_Int32 nMinor = OString(aFirstBytes[7]).toInt32();
    return !(nMajor > 1 || (nMajor == 1 && nMinor > 5));
}

/// Takes care of transparently downgrading the version of the PDF stream in
/// case it's too new for our PDF export.
bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream, sal_uInt64 nPos,
                         sal_uInt64 nSize)
{
    bool bCompatible = isCompatible(rInStream, nPos, nSize);
    rInStream.Seek(nPos);
    if (bCompatible)
        // Not converting.
        rOutStream.WriteStream(rInStream, nSize);
    else
    {
        // Downconvert to PDF-1.5.
        FPDF_LIBRARY_CONFIG aConfig;
        aConfig.version = 2;
        aConfig.m_pUserFontPaths = nullptr;
        aConfig.m_pIsolate = nullptr;
        aConfig.m_v8EmbedderSlot = 0;
        FPDF_InitLibraryWithConfig(&aConfig);

        // Read input into a buffer.
        SvMemoryStream aInBuffer;
        aInBuffer.WriteStream(rInStream, nSize);

        // Load the buffer using pdfium.
        FPDF_DOCUMENT pPdfDocument
            = FPDF_LoadMemDocument(aInBuffer.GetData(), aInBuffer.GetSize(), /*password=*/nullptr);
        if (!pPdfDocument)
            return false;

        CompatibleWriter aWriter;
        // 15 means PDF-1.5.
        if (!FPDF_SaveWithVersion(pPdfDocument, &aWriter, 0, 15))
            return false;

        FPDF_CloseDocument(pPdfDocument);
        FPDF_DestroyLibrary();

        aWriter.m_aStream.Seek(STREAM_SEEK_TO_BEGIN);
        rOutStream.WriteStream(aWriter.m_aStream);
    }

    return rOutStream.good();
}
#else
size_t generatePreview(SvStream&, std::vector<Bitmap>&, sal_uInt64 nPos, sal_uInt64 nSize,
                       size_t nFirstPage = 0, int nLastPage = 0)
{
    (void)rStream;
    (void)rBitmap;
    (void)nPos;
    (void)nSize;

    return 0;
}

bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream, sal_uInt64 nPos,
                         sal_uInt64 nSize)
{
    rInStream.Seek(nPos);
    rOutStream.WriteStream(rInStream, nSize);
    return rOutStream.good();
}
#endif // HAVE_FEATURE_PDFIUM
}

namespace vcl
{
bool ImportPDF(SvStream& rStream, Bitmap& rBitmap, css::uno::Sequence<sal_Int8>& rPdfData,
               sal_uInt64 nPos, sal_uInt64 nSize)
{
    // Get the preview of the first page.
    std::vector<Bitmap> aBitmaps;
    if (generatePreview(rStream, aBitmaps, nPos, nSize, 0, 1) != 1)
        return false;

    rBitmap = aBitmaps[0];

    // Save the original PDF stream for later use.
    SvMemoryStream aMemoryStream;
    if (!getCompatibleStream(rStream, aMemoryStream, nPos, nSize))
        return false;

    aMemoryStream.Seek(STREAM_SEEK_TO_END);
    rPdfData = css::uno::Sequence<sal_Int8>(aMemoryStream.Tell());
    aMemoryStream.Seek(STREAM_SEEK_TO_BEGIN);
    aMemoryStream.ReadBytes(rPdfData.getArray(), rPdfData.getLength());

    return true;
}

bool ImportPDF(SvStream& rStream, Graphic& rGraphic)
{
    uno::Sequence<sal_Int8> aPdfData;
    Bitmap aBitmap;
    const bool bRet = ImportPDF(rStream, aBitmap, aPdfData);
    rGraphic = aBitmap;
    rGraphic.setPdfData(std::make_shared<css::uno::Sequence<sal_Int8>>(aPdfData));
    rGraphic.setPageNumber(0); // We currently import only the first page.
    return bRet;
}

size_t ImportPDF(const OUString& rURL, std::vector<Bitmap>& rBitmaps,
                 css::uno::Sequence<sal_Int8>& rPdfData)
{
    std::unique_ptr<SvStream> xStream(
        ::utl::UcbStreamHelper::CreateStream(rURL, StreamMode::READ | StreamMode::SHARE_DENYNONE));

    if (generatePreview(*xStream, rBitmaps, STREAM_SEEK_TO_BEGIN, STREAM_SEEK_TO_END, 0, -1) == 0)
        return 0;

    // Save the original PDF stream for later use.
    SvMemoryStream aMemoryStream;
    if (!getCompatibleStream(*xStream, aMemoryStream, STREAM_SEEK_TO_BEGIN, STREAM_SEEK_TO_END))
        return 0;

    aMemoryStream.Seek(STREAM_SEEK_TO_END);
    rPdfData = css::uno::Sequence<sal_Int8>(aMemoryStream.Tell());
    aMemoryStream.Seek(STREAM_SEEK_TO_BEGIN);
    aMemoryStream.ReadBytes(rPdfData.getArray(), rPdfData.getLength());

    return rBitmaps.size();
}
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */