Create a new print backend for the updated CUPS APIs

printing/backend/cups_ipp_util.cc

+// Copyright 2016 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 "printing/backend/cups_ipp_util.h"
+
+#include <cups/cups.h>
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "printing/backend/cups_printer.h"
+#include "printing/backend/print_backend_consts.h"
+#include "printing/units.h"
+
+namespace printing {
+
+namespace {
+
+const char kIppCollate[] = "sheet-collate";  // RFC 3381
+const char kIppCopies[] = CUPS_COPIES;
+const char kIppColor[] = CUPS_PRINT_COLOR_MODE;
+const char kIppMedia[] = CUPS_MEDIA;
+const char kIppDuplex[] = CUPS_SIDES;
+
+const char kCollated[] = "collated";
+
+const int kMicronsPerMM = 1000;
+const double kMMPerInch = 25.4;
+const double kMicronsPerInch = kMMPerInch * kMicronsPerMM;
+
+enum Unit {
+  INCHES,
+  MILLIMETERS,
+};
+
+struct ColorMap {
+  const char* color;
+  ColorModel model;
+};
+
+const ColorMap kColorList[]{
+    {CUPS_PRINT_COLOR_MODE_COLOR, COLORMODE_COLOR},
+    {CUPS_PRINT_COLOR_MODE_MONOCHROME, COLORMODE_MONOCHROME},
+};
+
+ColorModel ColorModelFromIppColor(base::StringPiece ippColor) {
+  for (const ColorMap color : kColorList) {

[Lei Zhang, 2016/07/21 00:46:19]

const ColorMap&

[skau, 2016/07/21 20:07:30]

Done.

+    if (ippColor.compare(color.color) == 0) {
+      return color.model;
+    }
+  }
+
+  return UNKNOWN_COLOR_MODEL;
+}
+
+bool PrinterSupportsValue(const CupsOptionProvider& printer,
+                          base::StringPiece name,
+                          base::StringPiece value) {
+  std::vector<base::StringPiece> values =
+      printer.GetSupportedOptionValueStrings(name);
+  return ContainsValue(values, value);
+}
+
+DuplexMode PrinterDefaultDuplex(const CupsOptionProvider& printer) {
+  ipp_attribute_t* attr = printer.GetDefaultOptionValue(kIppDuplex);
+  if (!attr)
+    return UNKNOWN_DUPLEX_MODE;
+
+  const char* value = ippGetString(attr, 0, nullptr);
+  if (base::EqualsCaseInsensitiveASCII(value, CUPS_SIDES_ONE_SIDED))
+    return SIMPLEX;
+
+  if (base::EqualsCaseInsensitiveASCII(value, CUPS_SIDES_TWO_SIDED_PORTRAIT))
+    return LONG_EDGE;
+
+  if (base::EqualsCaseInsensitiveASCII(value, CUPS_SIDES_TWO_SIDED_LANDSCAPE))
+    return SHORT_EDGE;
+
+  return UNKNOWN_DUPLEX_MODE;
+}
+
+gfx::Size DimensionsToMicrons(base::StringPiece value) {
+  Unit unit;
+  base::StringPiece dims;
+  size_t unit_position;
+  if ((unit_position = value.find("mm")) != base::StringPiece::npos) {
+    unit = MILLIMETERS;
+    dims = value.substr(0, unit_position);
+  } else if ((unit_position = value.find("in")) != base::StringPiece::npos) {
+    unit = INCHES;
+    dims = value.substr(0, unit_position);
+  } else {
+    LOG(WARNING) << "Could not parse paper dimensions";
+    return {0, 0};
+  }
+
+  std::vector<std::string> pieces = base::SplitString(
+      dims, "x", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+  double width;
+  double height;
+
+  if (pieces.size() != 2 || !base::StringToDouble(pieces[0], &width) ||
+      !base::StringToDouble(pieces[1], &height)) {
+    return {0, 0};
+  }
+
+  int width_microns;
+  int height_microns;
+
+  switch (unit) {
+    case MILLIMETERS:
+      width_microns = width * kMicronsPerMM;
+      height_microns = height * kMicronsPerMM;
+      break;
+    case INCHES:
+      width_microns = width * kMicronsPerInch;
+      height_microns = height * kMicronsPerInch;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+
+  return gfx::Size{width_microns, height_microns};
+}
+
+PrinterSemanticCapsAndDefaults::Paper ParsePaper(base::StringPiece value) {
+  // <name>_<width>x<height>{in,mm}
+  // e.g. na_letter_8.5x11in, iso_a4_210x297mm
+
+  std::vector<base::StringPiece> pieces = base::SplitStringPiece(
+      value, "_", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+  // we expect at least a display string and a dimension string
+  if (pieces.size() < 2)
+    return PrinterSemanticCapsAndDefaults::Paper();
+
+  base::StringPiece dimensions = pieces.back();
+
+  std::string display = pieces[0].as_string();
+  for (size_t i = 1; i <= pieces.size() - 2; ++i) {
+    display.append(" ");
+    pieces[i].AppendToString(&display);
+  }
+
+  PrinterSemanticCapsAndDefaults::Paper paper;
+  paper.display_name = display;
+  paper.vendor_id = value.as_string();
+  paper.size_um = DimensionsToMicrons(dimensions);
+
+  return paper;
+}
+
+void ExtractColor(const CupsOptionProvider& printer,
+                  PrinterSemanticCapsAndDefaults* printer_info) {
+  printer_info->bw_model = UNKNOWN_COLOR_MODEL;
+  printer_info->color_model = UNKNOWN_COLOR_MODEL;
+
+  // color and b&w
+  std::vector<ColorModel> color_models = SupportedColorModels(printer);
+  for (ColorModel color : color_models) {
+    switch (color) {
+      case COLORMODE_COLOR:
+        printer_info->color_model = COLORMODE_COLOR;
+        break;
+      case COLORMODE_MONOCHROME:
+        printer_info->bw_model = COLORMODE_MONOCHROME;
+        break;
+      default:
+        // value not needed
+        break;
+    }
+  }
+
+  // changeable
+  printer_info->color_changeable =
+      (printer_info->color_model != UNKNOWN_COLOR_MODEL &&
+       printer_info->bw_model != UNKNOWN_COLOR_MODEL);
+
+  // default color
+  printer_info->color_default = DefaultColorModel(printer) == COLORMODE_COLOR;
+}
+
+void ExtractCopies(const CupsOptionProvider& printer,
+                   PrinterSemanticCapsAndDefaults* printer_info) {
+  // copies
+  int upper_bound;
+  int lower_bound;
+  CopiesRange(printer, &lower_bound, &upper_bound);
+  printer_info->copies_capable = (lower_bound != -1) && (upper_bound >= 2);
+}
+
+}  // namespace
+
+ColorModel DefaultColorModel(const CupsOptionProvider& printer) {
+  // default color
+  ipp_attribute_t* attr = printer.GetDefaultOptionValue(kIppColor);
+  if (!attr)
+    return UNKNOWN_COLOR_MODEL;
+
+  return ColorModelFromIppColor(ippGetString(attr, 0, nullptr));
+}
+
+std::vector<ColorModel> SupportedColorModels(
+    const CupsOptionProvider& printer) {
+  std::vector<ColorModel> colors;
+
+  std::vector<base::StringPiece> color_modes =
+      printer.GetSupportedOptionValueStrings(kIppColor);
+
+  for (base::StringPiece color : color_modes) {
+    ColorModel color_model = ColorModelFromIppColor(color);
+    if (color_model != UNKNOWN_COLOR_MODEL) {
+      colors.push_back(color_model);
+    }
+  }
+
+  return colors;
+}
+
+PrinterSemanticCapsAndDefaults::Paper DefaultPaper(
+    const CupsOptionProvider& printer) {
+  ipp_attribute_t* attr = printer.GetDefaultOptionValue(kIppMedia);
+  if (!attr)
+    return PrinterSemanticCapsAndDefaults::Paper();
+
+  return ParsePaper(ippGetString(attr, 0, nullptr));
+}
+
+std::vector<PrinterSemanticCapsAndDefaults::Paper> SupportedPapers(
+    const CupsOptionProvider& printer) {
+  std::vector<base::StringPiece> papers =
+      printer.GetSupportedOptionValueStrings(kIppMedia);
+  std::vector<PrinterSemanticCapsAndDefaults::Paper> parsed_papers;
+  for (base::StringPiece paper : papers) {
+    parsed_papers.push_back(ParsePaper(paper));
+  }
+
+  return parsed_papers;
+}
+
+// Retrieves the supported number of copies from |printer| and writing the

[Lei Zhang, 2016/07/21 00:46:19]

Comments to describe a function go where it is declared, in this case, in the
header.

[skau, 2016/07/21 20:07:30]

Done.

+// extremeties of the range into |lower_bound| and |upper_bound|  Values are set
+// to -1 if there is an error.
+void CopiesRange(const CupsOptionProvider& printer,
+                 int* lower_bound,
+                 int* upper_bound) {
+  ipp_attribute_t* attr = printer.GetSupportedOptionValues(kIppCopies);
+  if (!attr) {
+    *lower_bound = -1;
+    *upper_bound = -1;
+  }
+
+  *lower_bound = ippGetRange(attr, 0, upper_bound);
+}
+
+bool CollateCapable(const CupsOptionProvider& printer) {
+  std::vector<base::StringPiece> values =
+      printer.GetSupportedOptionValueStrings(kIppCollate);
+  auto iter = std::find(values.begin(), values.end(), kCollated);
+  return iter != values.end();
+}
+
+bool CollateDefault(const CupsOptionProvider& printer) {
+  ipp_attribute_t* attr = printer.GetDefaultOptionValue(kIppCollate);
+  if (!attr)
+    return false;
+
+  base::StringPiece name = ippGetString(attr, 0, nullptr);
+  return name.compare(kCollated) == 0;
+}
+
+void CapsAndDefaultsFromPrinter(const CupsOptionProvider& printer,
+                                PrinterSemanticCapsAndDefaults* printer_info) {
+  // duplex
+  printer_info->duplex_default = PrinterDefaultDuplex(printer);
+  printer_info->duplex_capable =
+      PrinterSupportsValue(printer, kIppDuplex, CUPS_SIDES_TWO_SIDED_PORTRAIT);
+
+  // collate
+  printer_info->collate_default = CollateDefault(printer);
+  printer_info->collate_capable = CollateCapable(printer);
+
+  // paper
+  printer_info->default_paper = DefaultPaper(printer);
+  printer_info->papers = SupportedPapers(printer);
+
+  ExtractCopies(printer, printer_info);
+  ExtractColor(printer, printer_info);
+
+  // TODO(skau): Add dpi and default_dpi
+}
+
+}  //  namespace printing