Implement CGdiPrinterDriver::DrawDeviceText().

core/fxge/win32/fx_win32_print.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fxge/include/fx_ge.h"
 
 #if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_DESKTOP_
 
 #include <windows.h>
 
+#include <algorithm>
+
 #include "core/fxge/dib/dib_int.h"
 #include "core/fxge/ge/fx_text_int.h"
 #include "core/fxge/include/fx_freetype.h"
 #include "core/fxge/include/fx_ge_win32.h"
 #include "core/fxge/win32/win32_int.h"
 
+#if defined(PDFIUM_PRINT_TEXT_WITH_GDI)
+namespace {
+
+class ScopedState {
+ public:
+  ScopedState(HDC hDC, HFONT hFont) : m_hDC(hDC) {
+    m_iState = SaveDC(m_hDC);
+    m_hFont = SelectObject(m_hDC, hFont);
+  }
+
+  ~ScopedState() {
+    HGDIOBJ hFont = SelectObject(m_hDC, m_hFont);
+    DeleteObject(hFont);
+    RestoreDC(m_hDC, m_iState);
+  }
+
+ private:
+  HDC m_hDC;
+  HGDIOBJ m_hFont;
+  int m_iState;
+
+  ScopedState(const ScopedState&) = delete;
+  void operator=(const ScopedState&) = delete;
+};
+
+}  // namespace
+
+bool g_pdfium_print_text_with_gdi = false;
+
+PDFiumEnsureTypefaceCharactersAccessible g_pdfium_typeface_accessible_func =
+    nullptr;
+#endif
+
 CGdiPrinterDriver::CGdiPrinterDriver(HDC hDC)
     : CGdiDeviceDriver(hDC, FXDC_PRINTER),
       m_HorzSize(::GetDeviceCaps(m_hDC, HORZSIZE)),
       m_VertSize(::GetDeviceCaps(m_hDC, VERTSIZE)) {}
 
 CGdiPrinterDriver::~CGdiPrinterDriver() {}
 
 int CGdiPrinterDriver::GetDeviceCaps(int caps_id) const {
   if (caps_id == FXDC_HORZ_SIZE)
     return m_HorzSize;
@@ skipping 110 matching lines @@
       FXSYS_fabs(pMatrix->c) < 0.5f && pMatrix->d != 0) {
     FX_BOOL bFlipX = pMatrix->a < 0;
     FX_BOOL bFlipY = pMatrix->d > 0;
     return StretchDIBits(pSource, color,
                          bFlipX ? full_rect.right : full_rect.left,
                          bFlipY ? full_rect.bottom : full_rect.top,
                          bFlipX ? -full_rect.Width() : full_rect.Width(),
                          bFlipY ? -full_rect.Height() : full_rect.Height(),
                          nullptr, 0, blend_type);
   }
-  if (FXSYS_fabs(pMatrix->a) < 0.5f && FXSYS_fabs(pMatrix->d) < 0.5f) {
-    std::unique_ptr<CFX_DIBitmap> pTransformed(
-        pSource->SwapXY(pMatrix->c > 0, pMatrix->b < 0));
-    if (!pTransformed)
+  if (FXSYS_fabs(pMatrix->a) >= 0.5f || FXSYS_fabs(pMatrix->d) >= 0.5f)
+    return FALSE;
+
+  std::unique_ptr<CFX_DIBitmap> pTransformed(
+      pSource->SwapXY(pMatrix->c > 0, pMatrix->b < 0));
+  if (!pTransformed)
+    return FALSE;
+
+  return StretchDIBits(pTransformed.get(), color, full_rect.left, full_rect.top,
+                       full_rect.Width(), full_rect.Height(), nullptr, 0,
+                       blend_type);
+}
+
+FX_BOOL CGdiPrinterDriver::DrawDeviceText(int nChars,
+                                          const FXTEXT_CHARPOS* pCharPos,
+                                          CFX_Font* pFont,
+                                          CFX_FontCache* pCache,
+                                          const CFX_Matrix* pObject2Device,
+                                          FX_FLOAT font_size,
+                                          uint32_t color) {
+#if defined(PDFIUM_PRINT_TEXT_WITH_GDI)
+  if (!g_pdfium_print_text_with_gdi)
+    return FALSE;
+
+  if (nChars < 1 || !pFont || !pFont->IsEmbedded() || !pFont->IsTTFont())
+    return FALSE;
+
+  // Font
+  //
+  // Note that |pFont| has the actual font to render with embedded within, but
+  // but unfortunately AddFontMemResourceEx() does not seem to cooperate.
+  // Loading font data to memory seems to work, but then enumerating the fonts
+  // fails to find it. This requires more investigation. In the meanwhile,
+  // assume the printing is happening on the machine that generated the PDF, so
+  // the embedded font, if not a web font, is available through GDI anyway.
+  // TODO(thestig): Figure out why AddFontMemResourceEx() does not work.
+  // Generalize this method to work for all PDFs with embedded fonts.
+  // In sandboxed environments, font loading may not work at all, so this may be
+  // the best possible effort.
+  LOGFONT lf = {};
+  lf.lfHeight = -font_size;
+  lf.lfWeight = pFont->IsBold() ? FW_BOLD : FW_NORMAL;
+  lf.lfItalic = pFont->IsItalic();
+  lf.lfCharSet = DEFAULT_CHARSET;
+
+  const CFX_WideString wsName = pFont->GetFaceName().UTF8Decode();
+  int iNameLen = std::min(wsName.GetLength(), LF_FACESIZE - 1);
+  memcpy(lf.lfFaceName, wsName.c_str(), sizeof(lf.lfFaceName[0]) * iNameLen);
+  lf.lfFaceName[iNameLen] = 0;
+
+  HFONT hFont = CreateFontIndirect(&lf);
+  if (!hFont)
+    return FALSE;
+
+  ScopedState state(m_hDC, hFont);
+  size_t nTextMetricSize = GetOutlineTextMetrics(m_hDC, 0, nullptr);
+  if (nTextMetricSize == 0) {
+    // Give up and fail if there is no way to get the font to try again.
+    if (!g_pdfium_typeface_accessible_func)
       return FALSE;
 
-    return StretchDIBits(pTransformed.get(), color, full_rect.left,
-                         full_rect.top, full_rect.Width(), full_rect.Height(),
-                         nullptr, 0, blend_type);
+    // Try to get the font. Any letter will do.
+    g_pdfium_typeface_accessible_func(&lf, L"A", 1);
+    nTextMetricSize = GetOutlineTextMetrics(m_hDC, 0, nullptr);
+    if (nTextMetricSize == 0)
+      return FALSE;
   }
+
+  std::vector<BYTE> buf(nTextMetricSize);
+  OUTLINETEXTMETRIC* pTextMetric =
+      reinterpret_cast<OUTLINETEXTMETRIC*>(buf.data());
+  if (GetOutlineTextMetrics(m_hDC, nTextMetricSize, pTextMetric) == 0)
+    return FALSE;
+
+  // If the selected font is not the requested font, then bail out. This can
+  // happen with web fonts, for example.
+  wchar_t* wsSelectedName = reinterpret_cast<wchar_t*>(
+      buf.data() + reinterpret_cast<size_t>(pTextMetric->otmpFaceName));
+  if (wsName != wsSelectedName)
+    return FALSE;
+
+  // Transforms
+  SetGraphicsMode(m_hDC, GM_ADVANCED);
+  XFORM xform;
+  xform.eM11 = pObject2Device->GetA();
+  xform.eM12 = pObject2Device->GetB();
+  xform.eM21 = -pObject2Device->GetC();
+  xform.eM22 = -pObject2Device->GetD();
+  xform.eDx = pObject2Device->GetE();
+  xform.eDy = pObject2Device->GetF();
+  ModifyWorldTransform(m_hDC, &xform, MWT_LEFTMULTIPLY);
+
+  // Color
+  int iUnusedAlpha;
+  FX_COLORREF rgb;
+  ArgbDecode(color, iUnusedAlpha, rgb);
+  SetTextColor(m_hDC, rgb);
+  SetBkMode(m_hDC, TRANSPARENT);
+
+  // Text
+  CFX_WideString wsText;
+  for (int i = 0; i < nChars; ++i) {
+    // Only works with PDFs from Skia's PDF generator. Cannot handle arbitrary
+    // values from PDFs.
+    const FXTEXT_CHARPOS& charpos = pCharPos[i];
+    ASSERT(charpos.m_OriginX == 0);
+    ASSERT(charpos.m_OriginY == 0);
+    ASSERT(charpos.m_AdjustMatrix[0] == 0);
+    ASSERT(charpos.m_AdjustMatrix[1] == 0);
+    ASSERT(charpos.m_AdjustMatrix[2] == 0);
+    ASSERT(charpos.m_AdjustMatrix[3] == 0);
+    wsText += charpos.m_GlyphIndex;
+  }
+
+  // Draw
+  SetTextAlign(m_hDC, TA_LEFT | TA_BASELINE);
+  if (ExtTextOutW(m_hDC, 0, 0, ETO_GLYPH_INDEX, nullptr, wsText.c_str(), nChars,
+                  nullptr)) {
+    return TRUE;
+  }
+
+  // Give up and fail if there is no way to get the font to try again.
+  if (!g_pdfium_typeface_accessible_func)
+    return FALSE;
+
+  // Try to get the font and draw again.
+  g_pdfium_typeface_accessible_func(&lf, wsText.c_str(), nChars);
+  return ExtTextOutW(m_hDC, 0, 0, ETO_GLYPH_INDEX, nullptr, wsText.c_str(),
+                     nChars, nullptr);
+#else
   return FALSE;
+#endif
 }
 
-#endif
+#endif  // _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_DESKTOP_