Revert of Media Galleries Partial Deprecation: Remove image metadata & libexif.

chrome/utility/media_galleries/image_metadata_extractor.h

+// 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.
+
+#ifndef CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_
+#define CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_
+
+#include <string>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+
+namespace media {
+class DataSource;
+}
+
+namespace net {
+class DrainableIOBuffer;
+}
+
+namespace metadata {
+
+// Extracts a basic set of image metadata tags. Users must initialize the
+// library before use. Each class instance is 'one-time-use', and cannot be used
+// to extract metadata from multiple images.
+class ImageMetadataExtractor {
+ public:
+  typedef base::Callback<void(bool)> DoneCallback;
+
+  // One of these two is required before use of this class.
+  static bool InitializeLibrary();
+  static bool InitializeLibraryForTesting();
+
+  ImageMetadataExtractor();
+  ~ImageMetadataExtractor();
+
+  // |callback| called with whether or not the extraction succeeded. Should
+  // only be called once.
+  void Extract(media::DataSource* source, const DoneCallback& callback);
+
+  // All below methods require Extract to have already succeeded.
+  // Returns -1 if file does not define a width or height.
+  int width() const;
+  int height() const;
+
+  // In degrees.
+  int rotation() const;
+
+  // In pixels per inch.
+  double x_resolution() const;
+  double y_resolution() const;
+
+  // In the same string form as the original file.
+  const std::string& date() const;
+
+  const std::string& camera_make() const;
+  const std::string& camera_model() const;
+  double exposure_time_sec() const;
+  bool flash_fired() const;
+  double f_number() const;
+  double focal_length_mm() const;
+  int iso_equivalent() const;
+
+ private:
+  // Second half of the Extract method.
+  void FinishExtraction(const DoneCallback& callback,
+                        const scoped_refptr<net::DrainableIOBuffer>& buffer);
+
+  bool extracted_;
+
+  int width_;
+  int height_;
+
+  int rotation_;
+
+  double x_resolution_;
+  double y_resolution_;
+
+  std::string date_;
+
+  std::string camera_make_;
+  std::string camera_model_;
+  double exposure_time_sec_;
+  bool flash_fired_;
+  double f_number_;
+  double focal_length_mm_;
+  int iso_equivalent_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageMetadataExtractor);
+};
+
+}  // namespace metadata
+
+#endif  // CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_