[JGIT PATCH 09/28] Add option handler for AbstractTreeIterator values

["Shawn O. Pearce" <spearce@spearce.org>]

Converts String to AbstractTreeIterator on demand.  A string
that can be resolved as a RevTree is read with a canonical
tree iterator, as it is a standard Git tree already stored in
the object database.  Otherwise we assume it is a local file
and scan the filesystem, as it may be a working directory.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 .../jgit/pgm/opt/AbstractTreeIteratorHandler.java  |  121 ++++++++++++++++++++
 1 files changed, 121 insertions(+), 0 deletions(-)
 create mode 100644 org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/opt/AbstractTreeIteratorHandler.java

diff --git a/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/opt/AbstractTreeIteratorHandler.java b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/opt/AbstractTreeIteratorHandler.java
new file mode 100644
index 0000000..31d1c84
--- /dev/null
+++ b/org.spearce.jgit.pgm/src/org/spearce/jgit/pgm/opt/AbstractTreeIteratorHandler.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.spearce.jgit.pgm.opt;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.kohsuke.args4j.CmdLineException;
+import org.kohsuke.args4j.CmdLineParser;
+import org.kohsuke.args4j.OptionDef;
+import org.kohsuke.args4j.spi.OptionHandler;
+import org.kohsuke.args4j.spi.Parameters;
+import org.kohsuke.args4j.spi.Setter;
+import org.spearce.jgit.errors.IncorrectObjectTypeException;
+import org.spearce.jgit.errors.MissingObjectException;
+import org.spearce.jgit.lib.ObjectId;
+import org.spearce.jgit.treewalk.AbstractTreeIterator;
+import org.spearce.jgit.treewalk.CanonicalTreeParser;
+import org.spearce.jgit.treewalk.FileTreeIterator;
+
+/**
+ * Custom argument handler {@link AbstractTreeIterator} from string values.
+ * <p>
+ * Assumes the parser has been initialized with a Repository.
+ */
+public class AbstractTreeIteratorHandler extends
+		OptionHandler<AbstractTreeIterator> {
+	private final org.spearce.jgit.pgm.opt.CmdLineParser clp;
+
+	/**
+	 * Create a new handler for the command name.
+	 * <p>
+	 * This constructor is used only by args4j.
+	 * 
+	 * @param parser
+	 * @param option
+	 * @param setter
+	 */
+	public AbstractTreeIteratorHandler(final CmdLineParser parser,
+			final OptionDef option,
+			final Setter<? super AbstractTreeIterator> setter) {
+		super(parser, option, setter);
+		clp = (org.spearce.jgit.pgm.opt.CmdLineParser) parser;
+	}
+
+	@Override
+	public int parseArguments(final Parameters params) throws CmdLineException {
+		final String name = params.getParameter(0);
+
+		if (new File(name).isDirectory()) {
+			setter.addValue(new FileTreeIterator(new File(name)));
+			return 1;
+		}
+
+		final ObjectId id;
+		try {
+			id = clp.getRepository().resolve(name);
+		} catch (IOException e) {
+			throw new CmdLineException(e.getMessage());
+		}
+		if (id == null)
+			throw new CmdLineException(name + " is not a tree");
+
+		final CanonicalTreeParser p = new CanonicalTreeParser();
+		try {
+			p.reset(clp.getRepository(), clp.getRevWalk().parseTree(id));
+		} catch (ClassCastException e) {
+			throw new CmdLineException(name + " is not a tree");
+		} catch (MissingObjectException e) {
+			throw new CmdLineException(name + " is not a tree");
+		} catch (IncorrectObjectTypeException e) {
+			throw new CmdLineException(name + " is not a tree");
+		} catch (IOException e) {
+			throw new CmdLineException("cannot read " + name + ": "
+					+ e.getMessage());
+		}
+
+		setter.addValue(p);
+		return 1;
+	}
+
+	@Override
+	public String getDefaultMetaVariable() {
+		return "tree-ish";
+	}
+}
-- 
1.5.6.3.569.ga9185