ui/gtk/printing_gtk_util.cc

// Copyright 2014 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 "ui/gtk/printing_gtk_util.h"

#include <gtk/gtk.h>
#include <gtk/gtkunixprint.h>

#include "base/strings/string16.h"
#include "base/strings/utf_string_conversions.h"
#include "printing/print_settings.h"
#include "printing/printing_context_linux.h"
#include "printing/units.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/geometry/size_f.h"

namespace {

const double kTopMarginInInch = 0.25;
const double kBottomMarginInInch = 0.56;
const double kLeftMarginInInch = 0.25;
const double kRightMarginInInch = 0.25;

}  // namespace

gfx::Size GetPdfPaperSizeDeviceUnitsGtk(
    printing::PrintingContextLinux* context) {
  GtkPageSetup* page_setup = gtk_page_setup_new();

  gfx::SizeF paper_size(
      gtk_page_setup_get_paper_width(page_setup, GTK_UNIT_INCH),
      gtk_page_setup_get_paper_height(page_setup, GTK_UNIT_INCH));

  g_object_unref(page_setup);

  const printing::PrintSettings& settings = context->settings();

  return gfx::Size(paper_size.width() * settings.device_units_per_inch(),
                   paper_size.height() * settings.device_units_per_inch());
}

void InitPrintSettingsGtk(GtkPrintSettings* settings,
                          GtkPageSetup* page_setup,
                          printing::PrintSettings* print_settings) {
  DCHECK(settings);
  DCHECK(page_setup);
  DCHECK(print_settings);

  base::string16 name(base::UTF8ToUTF16(
      static_cast<const char*>(gtk_print_settings_get_printer(settings))));
  print_settings->set_device_name(name);

  gfx::Size physical_size_device_units;
  gfx::Rect printable_area_device_units;
  int dpi = gtk_print_settings_get_resolution(settings);
  if (dpi) {
    // Initialize page_setup_device_units_.
    physical_size_device_units.SetSize(
        gtk_page_setup_get_paper_width(page_setup, GTK_UNIT_INCH) * dpi,
        gtk_page_setup_get_paper_height(page_setup, GTK_UNIT_INCH) * dpi);
    printable_area_device_units.SetRect(
        gtk_page_setup_get_left_margin(page_setup, GTK_UNIT_INCH) * dpi,
        gtk_page_setup_get_top_margin(page_setup, GTK_UNIT_INCH) * dpi,
        gtk_page_setup_get_page_width(page_setup, GTK_UNIT_INCH) * dpi,
        gtk_page_setup_get_page_height(page_setup, GTK_UNIT_INCH) * dpi);
  } else {
    // Use default values if we cannot get valid values from the print dialog.
    dpi = printing::kPixelsPerInch;
    double page_width_in_pixel = printing::kLetterWidthInch * dpi;
    double page_height_in_pixel = printing::kLetterHeightInch * dpi;
    physical_size_device_units.SetSize(static_cast<int>(page_width_in_pixel),
                                       static_cast<int>(page_height_in_pixel));
    printable_area_device_units.SetRect(
        static_cast<int>(kLeftMarginInInch * dpi),
        static_cast<int>(kTopMarginInInch * dpi),
        page_width_in_pixel - (kLeftMarginInInch + kRightMarginInInch) * dpi,
        page_height_in_pixel - (kTopMarginInInch + kBottomMarginInInch) * dpi);
  }

  print_settings->set_dpi(dpi);

  // Note: With the normal GTK print dialog, when the user selects the landscape
  // orientation, all that does is change the paper size. Which seems to be
  // enough to render the right output and send it to the printer.
  // The orientation value stays as portrait and does not actually affect
  // printing.
  // Thus this is only useful in print preview mode, where we manually set the
  // orientation and change the paper size ourselves.
  GtkPageOrientation orientation = gtk_print_settings_get_orientation(settings);
  // Set before SetPrinterPrintableArea to make it flip area if necessary.
  print_settings->SetOrientation(orientation == GTK_PAGE_ORIENTATION_LANDSCAPE);
  DCHECK_EQ(print_settings->device_units_per_inch(), dpi);
  print_settings->SetPrinterPrintableArea(physical_size_device_units,
                                          printable_area_device_units, true);
}