printing/page_setup.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "printing/page_setup.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10
  11 namespace printing {
  12
  13 namespace {
  14
  15 // Checks whether |printable_area| can be used to form a valid symmetrical
  16 // printable area, so that margin_left equals margin_right, and margin_top
  17 // equals margin_bottom.  For example if
  18 // printable_area.x() * 2 >= page_size.width(), then the
  19 // content_width = page_size.width() - 2 * printable_area.x() would be zero or
  20 // negative, which is invalid.
  21 // |page_size| is the physical page size that includes margins.
  22 bool IsValidPrintableArea(const gfx::Size& page_size,
  23                           const gfx::Rect& printable_area) {
  24   return !printable_area.IsEmpty() && printable_area.x() >= 0 &&
  25          printable_area.y() >= 0 &&
  26          printable_area.right() <= page_size.width() &&
  27          printable_area.bottom() <= page_size.height() &&
  28          printable_area.x() * 2 < page_size.width() &&
  29          printable_area.y() * 2 < page_size.height() &&
  30          printable_area.right() * 2 > page_size.width() &&
  31          printable_area.bottom() * 2 > page_size.height();
  32 }
  33
  34 }  // namespace
  35
  36 PageMargins::PageMargins()
  37     : header(0),
  38       footer(0),
  39       left(0),
  40       right(0),
  41       top(0),
  42       bottom(0) {
  43 }
  44
  45 void PageMargins::Clear() {
  46   header = 0;
  47   footer = 0;
  48   left = 0;
  49   right = 0;
  50   top = 0;
  51   bottom = 0;
  52 }
  53
  54 bool PageMargins::Equals(const PageMargins& rhs) const {
  55   return header == rhs.header &&
  56       footer == rhs.footer &&
  57       left == rhs.left &&
  58       top == rhs.top &&
  59       right == rhs.right &&
  60       bottom == rhs.bottom;
  61 }
  62
  63 PageSetup::PageSetup() {
  64   Clear();
  65 }
  66
  67 PageSetup::PageSetup(const PageSetup& other) = default;
  68
  69 PageSetup::~PageSetup() = default;
  70
  71 // static
  72 gfx::Rect PageSetup::GetSymmetricalPrintableArea(
  73     const gfx::Size& page_size,
  74     const gfx::Rect& printable_area) {
  75   if (!IsValidPrintableArea(page_size, printable_area))
  76     return gfx::Rect();
  77
  78   int left_right_margin =
  79       std::max(printable_area.x(), page_size.width() - printable_area.right());
  80   int top_bottom_margin = std::max(
  81       printable_area.y(), page_size.height() - printable_area.bottom());
  82   int width = page_size.width() - 2 * left_right_margin;
  83   int height = page_size.height() - 2 * top_bottom_margin;
  84
  85   gfx::Rect symmetrical_printable_area = gfx::Rect(page_size);
  86   symmetrical_printable_area.ClampToCenteredSize(gfx::Size(width, height));
  87
  88   return symmetrical_printable_area;
  89 }
  90
  91 void PageSetup::Clear() {
  92   physical_size_.SetSize(0, 0);
  93   printable_area_.SetRect(0, 0, 0, 0);
  94   overlay_area_.SetRect(0, 0, 0, 0);
  95   content_area_.SetRect(0, 0, 0, 0);
  96   effective_margins_.Clear();
  97   text_height_ = 0;
  98   forced_margins_ = false;
  99 }
 100
 101 bool PageSetup::Equals(const PageSetup& rhs) const {
 102   return physical_size_ == rhs.physical_size_ &&
 103       printable_area_ == rhs.printable_area_ &&
 104       overlay_area_ == rhs.overlay_area_ &&
 105       content_area_ == rhs.content_area_ &&
 106       effective_margins_.Equals(rhs.effective_margins_) &&
 107       requested_margins_.Equals(rhs.requested_margins_) &&
 108       text_height_ == rhs.text_height_;
 109 }
 110
 111 void PageSetup::Init(const gfx::Size& physical_size,
 112                      const gfx::Rect& printable_area,
 113                      int text_height) {
 114   DCHECK_LE(printable_area.right(), physical_size.width());
 115   // I've seen this assert triggers on Canon GP160PF PCL 5e and HP LaserJet 5.
 116   // Since we don't know the dpi here, just disable the check.
 117   // DCHECK_LE(printable_area.bottom(), physical_size.height());
 118   DCHECK_GE(printable_area.x(), 0);
 119   DCHECK_GE(printable_area.y(), 0);
 120   DCHECK_GE(text_height, 0);
 121   physical_size_ = physical_size;
 122   printable_area_ = printable_area;
 123   text_height_ = text_height;
 124
 125   SetRequestedMarginsAndCalculateSizes(requested_margins_);
 126 }
 127
 128 void PageSetup::SetRequestedMargins(const PageMargins& requested_margins) {
 129   forced_margins_ = false;
 130   SetRequestedMarginsAndCalculateSizes(requested_margins);
 131 }
 132
 133 void PageSetup::ForceRequestedMargins(const PageMargins& requested_margins) {
 134   forced_margins_ = true;
 135   SetRequestedMarginsAndCalculateSizes(requested_margins);
 136 }
 137
 138 void PageSetup::FlipOrientation() {
 139   if (physical_size_.width() && physical_size_.height()) {
 140     gfx::Size new_size(physical_size_.height(), physical_size_.width());
 141     int new_y = physical_size_.width() -
 142                 (printable_area_.width() + printable_area_.x());
 143     gfx::Rect new_printable_area(printable_area_.y(),
 144                                  new_y,
 145                                  printable_area_.height(),
 146                                  printable_area_.width());
 147     Init(new_size, new_printable_area, text_height_);
 148   }
 149 }
 150
 151 void PageSetup::SetRequestedMarginsAndCalculateSizes(
 152     const PageMargins& requested_margins) {
 153   requested_margins_ = requested_margins;
 154   if (physical_size_.width() && physical_size_.height()) {
 155     if (forced_margins_)
 156       CalculateSizesWithinRect(gfx::Rect(physical_size_), 0);
 157     else
 158       CalculateSizesWithinRect(printable_area_, text_height_);
 159   }
 160 }
 161
 162 void PageSetup::CalculateSizesWithinRect(const gfx::Rect& bounds,
 163                                          int text_height) {
 164   // Calculate the effective margins. The tricky part.
 165   effective_margins_.header = std::max(requested_margins_.header,
 166                                        bounds.y());
 167   effective_margins_.footer = std::max(requested_margins_.footer,
 168                                        physical_size_.height() -
 169                                            bounds.bottom());
 170   effective_margins_.left = std::max(requested_margins_.left,
 171                                      bounds.x());
 172   effective_margins_.top = std::max(std::max(requested_margins_.top,
 173                                              bounds.y()),
 174                                     effective_margins_.header + text_height);
 175   effective_margins_.right = std::max(requested_margins_.right,
 176                                       physical_size_.width() -
 177                                           bounds.right());
 178   effective_margins_.bottom =
 179       std::max(std::max(requested_margins_.bottom,
 180                         physical_size_.height() - bounds.bottom()),
 181                effective_margins_.footer + text_height);
 182
 183   // Calculate the overlay area. If the margins are excessive, the overlay_area
 184   // size will be (0, 0).
 185   overlay_area_.set_x(effective_margins_.left);
 186   overlay_area_.set_y(effective_margins_.header);
 187   overlay_area_.set_width(std::max(0,
 188                                    physical_size_.width() -
 189                                        effective_margins_.right -
 190                                        overlay_area_.x()));
 191   overlay_area_.set_height(std::max(0,
 192                                     physical_size_.height() -
 193                                         effective_margins_.footer -
 194                                         overlay_area_.y()));
 195
 196   // Calculate the content area. If the margins are excessive, the content_area
 197   // size will be (0, 0).
 198   content_area_.set_x(effective_margins_.left);
 199   content_area_.set_y(effective_margins_.top);
 200   content_area_.set_width(std::max(0,
 201                                    physical_size_.width() -
 202                                        effective_margins_.right -
 203                                        content_area_.x()));
 204   content_area_.set_height(std::max(0,
 205                                     physical_size_.height() -
 206                                         effective_margins_.bottom -
 207                                         content_area_.y()));
 208 }
 209
 210 }  // namespace printing