Extract Image class so it can be used in more tests.

BUG=none
TEST=none (no functional change).

Review URL: http://codereview.chromium.org/149410

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@20491 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 75 insertions, 0 deletions

diff --git a/printing/image.h b/printing/image.h
new file mode 100644
index 0000000..8ef1007
--- /dev/null
+++ b/printing/image.h
@@ -0,0 +1,75 @@
+// Copyright (c) 2009 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.
+
+#ifndef PRINTING_IMAGE_H_
+#define PRINTING_IMAGE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/gfx/size.h"
+#include "base/logging.h"
+
+namespace printing {
+
+// Lightweight raw-bitmap management. The image, once initialized, is immuable.
+// The main purpose is testing image contents.
+class Image {
+ public:
+  // Creates the image from the given filename on disk.  Uses extension to
+  // defer file type. PNG and EMF (on Windows) currently supported.
+  // If image loading fails size().IsEmpty() will be true.
+  explicit Image(const std::wstring& filename);
+
+  const gfx::Size& size() const {
+    return size_;
+  }
+
+  // Save image as PNG.
+  bool SaveToPng(const std::wstring& filename);
+
+  // Returns % of pixels different
+  double PercentageDifferent(const Image& rhs) const;
+
+  // Returns the 0x0RGB or 0xARGB value of the pixel at the given location.
+  uint32 Color(uint32 color) const {
+    if (ignore_alpha_)
+      return color & 0xFFFFFF;  // Strip out A.
+    else
+      return color;
+  }
+
+  uint32 pixel_at(int x, int y) const {
+    DCHECK(x >= 0 && x < size_.width());
+    DCHECK(y >= 0 && y < size_.height());
+    const uint32* data = reinterpret_cast<const uint32*>(&*data_.begin());
+    const uint32* data_row = data + y * row_length_ / sizeof(uint32);
+    return Color(data_row[x]);
+  }
+
+ private:
+  bool LoadPng(const std::string& compressed);
+
+  bool LoadMetafile(const std::string& data);
+
+  // Pixel dimensions of the image.
+  gfx::Size size_;
+
+  // Length of a line in bytes.
+  int row_length_;
+
+  // Actual bitmap data in arrays of RGBAs (so when loaded as uint32, it's
+  // 0xABGR).
+  std::vector<unsigned char> data_;
+
+  // Flag to signal if the comparison functions should ignore the alpha channel.
+  const bool ignore_alpha_;  // Currently always true.
+
+  DISALLOW_EVIL_CONSTRUCTORS(Image);
+};
+
+}  // namespace printing
+
+#endif  // PRINTING_IMAGE_H_