--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/core/HgBlameInspector.java	Wed May 22 16:46:15 2013 +0200
@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2013 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.core;
+
+import org.tmatesoft.hg.core.HgCallbackTargetException;
+import org.tmatesoft.hg.internal.Callback;
+import org.tmatesoft.hg.internal.Experimental;
+import org.tmatesoft.hg.repo.HgDataFile;
+import org.tmatesoft.hg.util.Adaptable;
+
+/**
+ * Client's sink for revision differences, diff/annotate functionality.
+ * 
+ * When implemented, clients shall not expect new {@link Block blocks} instances in each call.
+ * 
+ * In case more information about annotated revision is needed, inspector instances may supply 
+ * {@link RevisionDescriptor.Recipient} through {@link Adaptable}.  
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ * @since 1.1
+ */
+@Callback
+@Experimental(reason="Unstable API")
+public interface HgBlameInspector {
+
+	void same(EqualBlock block) throws HgCallbackTargetException;
+	void added(AddBlock block) throws HgCallbackTargetException;
+	void changed(ChangeBlock block) throws HgCallbackTargetException;
+	void deleted(DeleteBlock block) throws HgCallbackTargetException;
+	
+	/**
+	 * Represents content of a block, either as a sequence of bytes or a 
+	 * sequence of smaller blocks (lines), if appropriate (according to usage context).
+	 * 
+	 * This approach allows line-by-line access to content data along with complete byte sequence for the whole block, i.e.
+	 * <pre>
+	 *    BlockData bd = addBlock.addedLines()
+	 *    // bd describes data from the addition completely.
+	 *    // elements of the BlockData are lines
+	 *    bd.elementCount() == addBlock.totalAddedLines();
+	 *    // one cat obtain complete addition with
+	 *    byte[] everythingAdded = bd.asArray();
+	 *    // or iterate line by line
+	 *    for (int i = 0; i < bd.elementCount(); i++) {
+	 *    	 byte[] lineContent = bd.elementAt(i);
+	 *       String line = new String(lineContent, fileEncodingCharset);
+	 *    }
+	 *    where bd.elementAt(0) is the line at index addBlock.firstAddedLine() 
+	 * </pre> 
+	 * 
+	 * LineData or ChunkData? 
+	 */
+	public interface BlockData {
+		BlockData elementAt(int index);
+		int elementCount();
+		byte[] asArray();
+	}
+	
+	/**
+	 * {@link HgBlameInspector} may optionally request extra information about revisions
+	 * being inspected, denoting itself as a {@link RevisionDescriptor.Recipient}. This class 
+	 * provides complete information about file revision under annotation now. 
+	 */
+	public interface RevisionDescriptor {
+		/**
+		 * @return complete source of the diff origin, never <code>null</code>
+		 */
+		BlockData origin();
+		/**
+		 * @return complete source of the diff target, never <code>null</code>
+		 */
+		BlockData target();
+		/**
+		 * @return changeset revision index of original file, or {@link HgRepository#NO_REVISION} if it's the very first revision
+		 */
+		int originChangesetIndex();
+		/**
+		 * @return changeset revision index of the target file
+		 */
+		int targetChangesetIndex();
+		/**
+		 * @return <code>true</code> if this revision is merge
+		 */
+		boolean isMerge();
+		/**
+		 * @return changeset revision index of the second, merged parent
+		 */
+		int mergeChangesetIndex();
+		/**
+		 * @return revision index of the change in target file's revlog
+		 */
+		int fileRevisionIndex();
+
+		/**
+		 * @return file object under blame (target file)
+		 */
+		HgDataFile file();
+
+		/**
+		 * Implement to indicate interest in {@link RevisionDescriptor}.
+		 * 
+		 * Note, instance of {@link RevisionDescriptor} is the same for 
+		 * {@link #start(RevisionDescriptor)} and {@link #done(RevisionDescriptor)} 
+		 * methods, and not necessarily a new one (i.e. <code>==</code>) for the next
+		 * revision announced.
+		 */
+		@Callback
+		public interface Recipient {
+			/**
+			 * Comes prior to any change {@link Block blocks}
+			 */
+			void start(RevisionDescriptor revisionDescription) throws HgCallbackTargetException;
+			/**
+			 * Comes after all change {@link Block blocks} were dispatched
+			 */
+			void done(RevisionDescriptor revisionDescription) throws HgCallbackTargetException;
+		}
+	}
+	
+	/**
+	 * Each change block comes from a single origin, blocks that are result of a merge
+	 * have {@link #originChangesetIndex()} equal to {@link RevisionDescriptor#mergeChangesetIndex()}.
+	 */
+	public interface Block {
+		int originChangesetIndex();
+		int targetChangesetIndex();
+	}
+	
+	public interface EqualBlock extends Block {
+		int originStart();
+		int targetStart();
+		int length();
+		BlockData content();
+	}
+	
+	public interface AddBlock extends Block {
+		/**
+		 * @return line index in the origin where this block is inserted
+		 */
+		int insertedAt();  
+		/**
+		 * @return line index of the first added line in the target revision
+		 */
+		int firstAddedLine();
+		/**
+		 * @return number of added lines in this block
+		 */
+		int totalAddedLines();
+		/**
+		 * @return content of added lines
+		 */
+		BlockData addedLines();
+	}
+	public interface DeleteBlock extends Block {
+		/**
+		 * @return line index in the target revision were this deleted block would be
+		 */
+		int removedAt();
+		/**
+		 * @return line index of the first removed line in the original revision
+		 */
+		int firstRemovedLine();
+		/**
+		 * @return number of deleted lines in this block
+		 */
+		int totalRemovedLines();
+		/**
+		 * @return content of deleted lines
+		 */
+		BlockData removedLines();
+	}
+	public interface ChangeBlock extends AddBlock, DeleteBlock {
+	}
+}