Printing: Move some printing code out of pdf/ and into printing/.

This code was stuck in pdf/ previously because the PDF plugin was
proprietary.

Add unit tests now that the code has been moved out.

Review URL: https://codereview.chromium.org/1421493002

Cr-Commit-Position: refs/heads/master@{#356600}

1 files changed, 123 insertions, 0 deletions

diff --git a/printing/pdf_transform.cc b/printing/pdf_transform.cc
new file mode 100644
index 0000000..f13a639
--- /dev/null
+++ b/printing/pdf_transform.cc
@@ -0,0 +1,123 @@
+// Copyright 2015 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/pdf_transform.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace printing {
+
+double CalculateScaleFactor(const gfx::Rect& content_rect,
+                            double src_width,
+                            double src_height,
+                            bool rotated) {
+  if (src_width == 0 || src_height == 0)
+    return 1.0;
+
+  double actual_source_page_width = rotated ? src_height : src_width;
+  double actual_source_page_height = rotated ? src_width : src_height;
+  double ratio_x = static_cast<double>(content_rect.width()) /
+                   actual_source_page_width;
+  double ratio_y = static_cast<double>(content_rect.height()) /
+                   actual_source_page_height;
+  return std::min(ratio_x, ratio_y);
+}
+
+void SetDefaultClipBox(bool rotated, ClipBox* clip_box) {
+  const int kDpi = 72;
+  const float kPaperWidth = 8.5 * kDpi;
+  const float kPaperHeight = 11 * kDpi;
+  clip_box->left = 0;
+  clip_box->bottom = 0;
+  clip_box->right = rotated ? kPaperHeight : kPaperWidth;
+  clip_box->top = rotated ? kPaperWidth : kPaperHeight;
+}
+
+void CalculateMediaBoxAndCropBox(bool rotated,
+                                 bool has_media_box,
+                                 bool has_crop_box,
+                                 printing::ClipBox* media_box,
+                                 printing::ClipBox* crop_box) {
+  if (!has_media_box && !has_crop_box) {
+    SetDefaultClipBox(rotated, crop_box);
+    SetDefaultClipBox(rotated, media_box);
+  } else if (has_crop_box && !has_media_box) {
+    *media_box = *crop_box;
+  } else if (has_media_box && !has_crop_box) {
+    *crop_box = *media_box;
+  }
+}
+
+ClipBox CalculateClipBoxBoundary(const ClipBox& media_box,
+                                 const ClipBox& crop_box) {
+  ClipBox clip_box;
+
+  // Clip |media_box| to the size of |crop_box|, but ignore |crop_box| if it is
+  // bigger than |media_box|.
+  clip_box.left =
+      (crop_box.left < media_box.left) ? media_box.left : crop_box.left;
+  clip_box.right =
+      (crop_box.right > media_box.right) ? media_box.right : crop_box.right;
+  clip_box.top = (crop_box.top > media_box.top) ? media_box.top : crop_box.top;
+  clip_box.bottom =
+      (crop_box.bottom < media_box.bottom) ? media_box.bottom : crop_box.bottom;
+  return clip_box;
+}
+
+void ScaleClipBox(double scale_factor, ClipBox* box) {
+  box->left *= scale_factor;
+  box->right *= scale_factor;
+  box->bottom *= scale_factor;
+  box->top *= scale_factor;
+}
+
+void CalculateScaledClipBoxOffset(const gfx::Rect& content_rect,
+                                  const ClipBox& source_clip_box,
+                                  double* offset_x,
+                                  double* offset_y) {
+  const float clip_box_width = source_clip_box.right - source_clip_box.left;
+  const float clip_box_height = source_clip_box.top - source_clip_box.bottom;
+
+  // Center the intended clip region to real clip region.
+  *offset_x = (content_rect.width() - clip_box_width) / 2 + content_rect.x() -
+              source_clip_box.left;
+  *offset_y = (content_rect.height() - clip_box_height) / 2 + content_rect.y() -
+              source_clip_box.bottom;
+}
+
+void CalculateNonScaledClipBoxOffset(const gfx::Rect& content_rect,
+                                     int rotation,
+                                     int page_width,
+                                     int page_height,
+                                     const ClipBox& source_clip_box,
+                                     double* offset_x,
+                                     double* offset_y) {
+  // Align the intended clip region to left-top corner of real clip region.
+  switch (rotation) {
+    case 0:
+      *offset_x = -1 * source_clip_box.left;
+      *offset_y = page_height - source_clip_box.top;
+      break;
+    case 1:
+      *offset_x = 0;
+      *offset_y = -1 * source_clip_box.bottom;
+      break;
+    case 2:
+      *offset_x = page_width - source_clip_box.right;
+      *offset_y = 0;
+      break;
+    case 3:
+      *offset_x = page_height - source_clip_box.right;
+      *offset_y = page_width - source_clip_box.top;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+}  // namespace printing