printing/page_setup.cc

   1 // Copyright 2011 The Chromium Authors
   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/check_op.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), footer(0), left(0), right(0), top(0), bottom(0) {}
  38
  39 PageMargins::PageMargins(int header,
  40                          int footer,
  41                          int left,
  42                          int right,
  43                          int top,
  44                          int bottom)
  45     : header(header),
  46       footer(footer),
  47       left(left),
  48       right(right),
  49       top(top),
  50       bottom(bottom) {}
  51
  52 void PageMargins::Clear() {
  53   header = 0;
  54   footer = 0;
  55   left = 0;
  56   right = 0;
  57   top = 0;
  58   bottom = 0;
  59 }
  60
  61 bool PageMargins::Equals(const PageMargins& rhs) const {
  62   return header == rhs.header && footer == rhs.footer && left == rhs.left &&
  63          top == rhs.top && right == rhs.right && bottom == rhs.bottom;
  64 }
  65
  66 PageSetup::PageSetup() {
  67   Clear();
  68 }
  69
  70 PageSetup::PageSetup(const gfx::Size& physical_size,
  71                      const gfx::Rect& printable_area,
  72                      const PageMargins& requested_margins,
  73                      bool forced_margins,
  74                      int text_height)
  75     : requested_margins_(requested_margins), forced_margins_(forced_margins) {
  76   Init(physical_size, printable_area, text_height);
  77 }
  78
  79 PageSetup::PageSetup(const PageSetup& other) = default;
  80
  81 PageSetup::~PageSetup() = default;
  82
  83 // static
  84 gfx::Rect PageSetup::GetSymmetricalPrintableArea(
  85     const gfx::Size& page_size,
  86     const gfx::Rect& printable_area) {
  87   if (!IsValidPrintableArea(page_size, printable_area))
  88     return gfx::Rect();
  89
  90   int left_right_margin =
  91       std::max(printable_area.x(), page_size.width() - printable_area.right());
  92   int top_bottom_margin = std::max(
  93       printable_area.y(), page_size.height() - printable_area.bottom());
  94   int width = page_size.width() - 2 * left_right_margin;
  95   int height = page_size.height() - 2 * top_bottom_margin;
  96
  97   gfx::Rect symmetrical_printable_area = gfx::Rect(page_size);
  98   symmetrical_printable_area.ClampToCenteredSize(gfx::Size(width, height));
  99
 100   return symmetrical_printable_area;
 101 }
 102
 103 void PageSetup::Clear() {
 104   physical_size_.SetSize(0, 0);
 105   printable_area_.SetRect(0, 0, 0, 0);
 106   overlay_area_.SetRect(0, 0, 0, 0);
 107   content_area_.SetRect(0, 0, 0, 0);
 108   effective_margins_.Clear();
 109   text_height_ = 0;
 110   forced_margins_ = false;
 111 }
 112
 113 bool PageSetup::Equals(const PageSetup& rhs) const {
 114   return physical_size_ == rhs.physical_size_ &&
 115          printable_area_ == rhs.printable_area_ &&
 116          overlay_area_ == rhs.overlay_area_ &&
 117          content_area_ == rhs.content_area_ &&
 118          effective_margins_.Equals(rhs.effective_margins_) &&
 119          requested_margins_.Equals(rhs.requested_margins_) &&
 120          text_height_ == rhs.text_height_;
 121 }
 122
 123 void PageSetup::Init(const gfx::Size& physical_size,
 124                      const gfx::Rect& printable_area,
 125                      int text_height) {
 126   DCHECK_LE(printable_area.right(), physical_size.width());
 127   // I've seen this assert triggers on Canon GP160PF PCL 5e and HP LaserJet 5.
 128   // Since we don't know the dpi here, just disable the check.
 129   // DCHECK_LE(printable_area.bottom(), physical_size.height());
 130   DCHECK_GE(printable_area.x(), 0);
 131   DCHECK_GE(printable_area.y(), 0);
 132   DCHECK_GE(text_height, 0);
 133   physical_size_ = physical_size;
 134   printable_area_ = printable_area;
 135   text_height_ = text_height;
 136
 137   SetRequestedMarginsAndCalculateSizes(requested_margins_);
 138 }
 139
 140 void PageSetup::SetRequestedMargins(const PageMargins& requested_margins) {
 141   forced_margins_ = false;
 142   SetRequestedMarginsAndCalculateSizes(requested_margins);
 143 }
 144
 145 void PageSetup::ForceRequestedMargins(const PageMargins& requested_margins) {
 146   forced_margins_ = true;
 147   SetRequestedMarginsAndCalculateSizes(requested_margins);
 148 }
 149
 150 void PageSetup::FlipOrientation() {
 151   if (physical_size_.width() && physical_size_.height()) {
 152     gfx::Size new_size(physical_size_.height(), physical_size_.width());
 153     int new_y = physical_size_.width() -
 154                 (printable_area_.width() + printable_area_.x());
 155     gfx::Rect new_printable_area(printable_area_.y(), new_y,
 156                                  printable_area_.height(),
 157                                  printable_area_.width());
 158     Init(new_size, new_printable_area, text_height_);
 159   }
 160 }
 161
 162 void PageSetup::SetRequestedMarginsAndCalculateSizes(
 163     const PageMargins& requested_margins) {
 164   requested_margins_ = requested_margins;
 165   if (physical_size_.width() && physical_size_.height()) {
 166     if (forced_margins_)
 167       CalculateSizesWithinRect(gfx::Rect(physical_size_), 0);
 168     else
 169       CalculateSizesWithinRect(printable_area_, text_height_);
 170   }
 171 }
 172
 173 void PageSetup::CalculateSizesWithinRect(const gfx::Rect& bounds,
 174                                          int text_height) {
 175   // Calculate the effective margins. The tricky part.
 176   effective_margins_.header = std::max(requested_margins_.header, bounds.y());
 177   effective_margins_.footer = std::max(
 178       requested_margins_.footer, physical_size_.height() - bounds.bottom());
 179   effective_margins_.left = std::max(requested_margins_.left, bounds.x());
 180   effective_margins_.top = std::max({requested_margins_.top, bounds.y(),
 181                                      effective_margins_.header + text_height});
 182   effective_margins_.right = std::max(requested_margins_.right,
 183                                       physical_size_.width() - bounds.right());
 184   effective_margins_.bottom = std::max(
 185       {requested_margins_.bottom, physical_size_.height() - bounds.bottom(),
 186        effective_margins_.footer + text_height});
 187
 188   // Calculate the overlay area. If the margins are excessive, the overlay_area
 189   // size will be (0, 0).
 190   overlay_area_.set_x(effective_margins_.left);
 191   overlay_area_.set_y(effective_margins_.header);
 192   overlay_area_.set_width(std::max(
 193       0,
 194       physical_size_.width() - effective_margins_.right - overlay_area_.x()));
 195   overlay_area_.set_height(std::max(
 196       0,
 197       physical_size_.height() - effective_margins_.footer - overlay_area_.y()));
 198
 199   // Calculate the content area. If the margins are excessive, the content_area
 200   // size will be (0, 0).
 201   content_area_.set_x(effective_margins_.left);
 202   content_area_.set_y(effective_margins_.top);
 203   content_area_.set_width(std::max(
 204       0,
 205       physical_size_.width() - effective_margins_.right - content_area_.x()));
 206   content_area_.set_height(std::max(
 207       0,
 208       physical_size_.height() - effective_margins_.bottom - content_area_.y()));
 209 }
 210
 211 }  // namespace printing