Initial commit of libimage_io

Image_io is a library for manipulating image files, especially XMP
metadata within them.

Test: m libimage_io
Bug: 109735087
Bug: 119211681
Change-Id: I657f307be0459fe40154806c7cd388b97bcb0ea5

1 files changed, 44 insertions, 0 deletions

diff --git a/includes/image_io/jpeg/jpeg_segment_processor.h b/includes/image_io/jpeg/jpeg_segment_processor.h
new file mode 100644
index 0000000..a193797
--- /dev/null
+++ b/includes/image_io/jpeg/jpeg_segment_processor.h
@@ -0,0 +1,44 @@
+#ifndef IMAGE_IO_JPEG_JPEG_SEGMENT_PROCESSOR_H_  // NOLINT
+#define IMAGE_IO_JPEG_JPEG_SEGMENT_PROCESSOR_H_  // NOLINT
+
+#include "image_io/jpeg/jpeg_segment.h"
+
+namespace photos_editing_formats {
+namespace image_io {
+
+class JpegScanner;
+
+/// JpegSegmentProcessor is the abstract base class for implementations that do
+/// something with the JPEG segments that the JpegScanner identifies.
+class JpegSegmentProcessor {
+ public:
+  virtual ~JpegSegmentProcessor() = default;
+
+  /// This function is called at the start of the JPegScanner::Run() function to
+  /// allow this JpegProcessor to initialize its data structures. It can also
+  /// inform the JpegScanner about preferences for the types of segments it is
+  /// interested in by calling the JpegScanner::UpdateInterestingMarkerFlags()
+  /// function.
+  /// @param scanner The scanner that is starting the JpegProcessor.
+  virtual void Start(JpegScanner* scanner) = 0;
+
+  /// This function is called repeatedly by the JpegScanner as it identifies
+  /// segments in the JPEG file. The JpegProcessor can access the data in the
+  /// segment to do interesting things, or can update the scanner's preferences
+  /// like in the Start() function.
+  /// @param scanner The scanner that is providing the segment to the processor.
+  /// @param segment The segment provided by the scanner to the processor.
+  virtual void Process(JpegScanner* scanner, const JpegSegment& segment) = 0;
+
+  /// This function is called after the JpegScanner has provided all the
+  /// segments to the JpegProcessor to allow the processor to finish its work
+  /// processing the segments.
+  /// @param scanner The scanner that is informing the processor that it is done
+  ///     finding segments.
+  virtual void Finish(JpegScanner* scanner) = 0;
+};
+
+}  // namespace image_io
+}  // namespace photos_editing_formats
+
+#endif // IMAGE_IO_JPEG_JPEG_SEGMENT_PROCESSOR_H_  // NOLINT