ctext_only_printer_driver.cpp

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// Copyright 2020 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "core/fxge/win32/ctext_only_printer_driver.h"
 
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
 
#include <algorithm>
 
#include "core/fxcrt/fx_string.h"
#include "core/fxcrt/fx_system.h"
#include "core/fxge/cfx_font.h"
#include "core/fxge/dib/cfx_dibbase.h"
#include "core/fxge/text_char_pos.h"
#include "third_party/base/check_op.h"
#include "third_party/base/notreached.h"
 
CTextOnlyPrinterDriver::CTextOnlyPrinterDriver(HDC hDC)
    : m_hDC(hDC),
      m_Width(INT_MAX),
      m_Height(INT_MAX),
      m_HorzSize(INT_MAX),
      m_VertSize(INT_MAX),
      m_OriginY(0.0f),
      m_SetOrigin(false) {
  m_nBitsPerPixel = ::GetDeviceCaps(m_hDC, BITSPIXEL);
}
 
CTextOnlyPrinterDriver::~CTextOnlyPrinterDriver() = default;
 
DeviceType CTextOnlyPrinterDriver::GetDeviceType() const {
  return DeviceType::kPrinter;
}
 
int CTextOnlyPrinterDriver::GetDeviceCaps(int caps_id) const {
  switch (caps_id) {
    case FXDC_PIXEL_WIDTH:
      return m_Width;
    case FXDC_PIXEL_HEIGHT:
      return m_Height;
    case FXDC_BITS_PIXEL:
      return m_nBitsPerPixel;
    case FXDC_RENDER_CAPS:
      return 0;
    case FXDC_HORZ_SIZE:
      return m_HorzSize;
    case FXDC_VERT_SIZE:
      return m_VertSize;
    default:
      NOTREACHED_NORETURN();
  }
}
 
void CTextOnlyPrinterDriver::SaveState() {}
 
void CTextOnlyPrinterDriver::RestoreState(bool bKeepSaved) {}
 
bool CTextOnlyPrinterDriver::SetClip_PathFill(
    const CFX_Path& path,
    const CFX_Matrix* pObject2Device,
    const CFX_FillRenderOptions& fill_options) {
  return true;
}
 
bool CTextOnlyPrinterDriver::SetClip_PathStroke(
    const CFX_Path& path,
    const CFX_Matrix* pObject2Device,
    const CFX_GraphStateData* pGraphState) {
  return false;
}
 
bool CTextOnlyPrinterDriver::DrawPath(const CFX_Path& path,
                                      const CFX_Matrix* pObject2Device,
                                      const CFX_GraphStateData* pGraphState,
                                      uint32_t fill_color,
                                      uint32_t stroke_color,
                                      const CFX_FillRenderOptions& fill_options,
                                      BlendMode blend_type) {
  return false;
}
 
bool CTextOnlyPrinterDriver::SetDIBits(
    const RetainPtr<const CFX_DIBBase>& pBitmap,
    uint32_t color,
    const FX_RECT& src_rect,
    int left,
    int top,
    BlendMode blend_type) {
  return false;
}
 
bool CTextOnlyPrinterDriver::GetClipBox(FX_RECT* pRect) {
  pRect->left = 0;
  pRect->right = m_Width;
  pRect->top = 0;
  pRect->bottom = m_Height;
  return true;
}
 
bool CTextOnlyPrinterDriver::StretchDIBits(RetainPtr<const CFX_DIBBase> bitmap,
                                           uint32_t color,
                                           int dest_left,
                                           int dest_top,
                                           int dest_width,
                                           int dest_height,
                                           const FX_RECT* pClipRect,
                                           const FXDIB_ResampleOptions& options,
                                           BlendMode blend_type) {
  return false;
}
 
bool CTextOnlyPrinterDriver::StartDIBits(
    RetainPtr<const CFX_DIBBase> bitmap,
    float alpha,
    uint32_t color,
    const CFX_Matrix& matrix,
    const FXDIB_ResampleOptions& options,
    std::unique_ptr<CFX_ImageRenderer>* handle,
    BlendMode blend_type) {
  return false;
}
 
bool CTextOnlyPrinterDriver::DrawDeviceText(
    pdfium::span<const TextCharPos> pCharPos,
    CFX_Font* pFont,
    const CFX_Matrix& mtObject2Device,
    float font_size,
    uint32_t color,
    const CFX_TextRenderOptions& /*options*/) {
  if (g_pdfium_print_mode != WindowsPrintMode::kTextOnly)
    return false;
  if (pCharPos.empty() || !pFont || !pFont->IsEmbedded() || !pFont->IsTTFont())
    return false;
 
  // Scale factor used to minimize the kerning problems caused by rounding
  // errors below. Value chosen based on the title of https://crbug.com/18383
  const double kScaleFactor = 10;
 
  // Detect new lines and add clrf characters (since this is Windows only).
  // These characters are removed by SkPDF, but the new line information is
  // preserved in the text location. clrf characters seem to be ignored by
  // label printers that use this driver.
  WideString wsText;
  size_t len = pCharPos.size();
  float fOffsetY = mtObject2Device.f * kScaleFactor;
  if (m_SetOrigin && FXSYS_roundf(m_OriginY) != FXSYS_roundf(fOffsetY)) {
    wsText += L"\r\n";
    len += 2;
  }
  wsText.Reserve(len);
  m_OriginY = fOffsetY;
  m_SetOrigin = true;
 
  // Text
  for (const auto& charpos : pCharPos) {
    // Only works with PDFs from Skia's PDF generator. Cannot handle arbitrary
    // values from PDFs.
    DCHECK_EQ(charpos.m_AdjustMatrix[0], 0);
    DCHECK_EQ(charpos.m_AdjustMatrix[1], 0);
    DCHECK_EQ(charpos.m_AdjustMatrix[2], 0);
    DCHECK_EQ(charpos.m_AdjustMatrix[3], 0);
    DCHECK_EQ(charpos.m_Origin.y, 0);
    wsText += charpos.m_Unicode;
  }
  ByteString text = wsText.ToDefANSI();
  auto text_span = text.span();
  while (!text_span.empty()) {
    uint8_t buffer[1026];
    size_t send_len = std::min<size_t>(text_span.size(), 1024);
    *(reinterpret_cast<uint16_t*>(buffer)) = static_cast<uint16_t>(send_len);
    memcpy(buffer + 2, text_span.data(), send_len);
    ::GdiComment(m_hDC, static_cast<UINT>(send_len + 2), buffer);
    text_span = text_span.subspan(send_len);
  }
  return true;
}
 
bool CTextOnlyPrinterDriver::MultiplyAlpha(float alpha) {
  // Not needed. All callers are using `CFX_DIBitmap`-backed raster devices
  // anyway.
  NOTREACHED_NORETURN();
}
 
bool CTextOnlyPrinterDriver::MultiplyAlphaMask(
    const RetainPtr<const CFX_DIBBase>& mask) {
  // Not needed. All callers are using `CFX_DIBitmap`-backed raster devices
  // anyway.
  NOTREACHED_NORETURN();
}