[JGIT PATCH 0/3] Request for help: graph-based UI

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import java.awt.Dimension;

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import java.awt.Dimension;

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import java.awt.Color;

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import java.util.ArrayList;

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import org.spearce.jgit.lib.AnyObjectId;

@@ -1,3 +1,40 @@
+/*
+ * Copyright (C) 2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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.gui;
 
 import java.io.IOException;

@@ -0,0 +1,27 @@
+package org.spearce.jgit.gui;
+
+import java.awt.Dimension;
+import java.awt.Rectangle;
+
+import java.io.IOException;
+
+import javax.swing.JPanel;
+import javax.swing.JScrollPane;
+
+import org.spearce.jgit.lib.Repository;
+import org.spearce.jgit.errors.MissingObjectException;
+
+public class CommitGraph extends JScrollPane {
+
+	protected GraphWalk walk;
+	protected CommitGrid grid;
+
+	public CommitGraph(GraphWalk walk)
+			throws IOException, MissingObjectException {
+		super(new CommitGrid(walk));
+	}
+
+	public Dimension getPreferredSize() {
+		return new Dimension(300, 600);
+	}
+}

@@ -0,0 +1,147 @@
+package org.spearce.jgit.gui;
+
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.Rectangle;
+
+import java.io.IOException;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import javax.swing.JComponent;
+
+import org.spearce.jgit.lib.Repository;
+
+import org.spearce.jgit.revwalk.RevSort;
+
+public class CommitGrid extends JComponent {
+	protected GraphWalk walk;
+	protected List<CommitRow> rows;
+	protected CommitPainter painter;
+	protected Rectangle clip;
+
+	protected Dimension size;
+	protected int minColumn = 0, maxColumn = 0;
+
+	// commit dimensions
+	protected int w = 200;
+	protected int h = 30;
+	protected int spacing = 20;
+
+	public CommitGrid(GraphWalk walk) {
+		this.walk = walk;
+		rows = new ArrayList<CommitRow>();
+		painter = new CommitPainter();
+		clip = new Rectangle();
+		size = new Dimension(0, 0);
+	}
+
+	public Dimension getMinimumSize() {
+		return new Dimension((maxColumn - minColumn) * (w + spacing),
+			rows.size() * (h + spacing));
+	}
+
+	public Dimension getPreferredSize() {
+		return new Dimension((maxColumn - minColumn) * (w + spacing),
+			rows.size() * (h + spacing));
+	}
+
+	// TODO: public void resetWalk(Graphwalk walk)
+
+	protected void readCommits(int maxRow) {
+		if (rows.size() > maxRow)
+			return;
+		for (;;) {
+			GraphCommit commit;
+			try {
+				commit = (GraphCommit)walk.next();
+				if (commit == null)
+					return;
+			} catch (IOException e) {
+				// TODO: show error
+				continue;
+			}
+			commit.calculateColumn();
+			int row = commit.getRow();
+			while (row >= rows.size()) {
+				rows.add(new CommitRow());
+				size.height += h + spacing;
+				resize(getMinimumSize());
+				revalidate();
+			}
+			commit.column =
+				rows.get(row).add(commit, commit.getColumn());
+			commit.childrenCount = -1;
+			maxColumn = Math.max(maxColumn, commit.column);
+			minColumn = Math.min(minColumn, commit.column);
+		}
+	}
+
+	int x2column(int x) { return x / (w + spacing); }
+	int y2row(int y) { return y / (h + spacing); }
+	int column2x(int column) { return column * (w + spacing); }
+	int row2y(int row) { return row * (h + spacing); }
+
+	class CommitsInRectangle implements Iterator<GraphCommit> {
+		int minRow, maxRow, minColumn, maxColumn;
+		int row, column;
+
+		CommitsInRectangle(int minRow, int maxRow,
+				int minColumn, int maxColumn) {
+			this.minRow = minRow;
+			this.maxRow = maxRow;
+			this.minColumn = minColumn;
+			this.maxColumn = maxColumn;
+			row = minRow;
+			column = minColumn - 1;
+
+			readCommits(maxRow);
+			maxRow = Math.min(maxRow, rows.size());
+		}
+
+		CommitsInRectangle(Rectangle r) {
+			this(y2row(r.y), y2row(r.y + r.height - 1),
+				x2column(r.x), x2column(r.x + r.width - 1));
+		}
+
+		public boolean hasNext() {
+			for (; row <= maxRow; row++, column = minColumn - 1)
+				while (++column <= maxColumn)
+					if (rows.get(row).get(column) != null)
+						return true;
+			return false;
+		}
+
+		public GraphCommit next() {
+			return rows.get(row).get(column);
+		}
+
+		public void remove() throws UnsupportedOperationException {
+			throw new UnsupportedOperationException();
+		}
+	}
+
+	public void paintComponent(Graphics g) {
+		g.getClipBounds(clip);
+		CommitsInRectangle iter = new CommitsInRectangle(clip);
+		while (iter.hasNext()) {
+			GraphCommit commit = iter.next();
+			painter.paint((Graphics2D)g, commit,
+					column2x(iter.column), row2y(iter.row),
+					w, h);
+			for (int i = 0; i < commit.getParentCount(); i++) {
+				GraphCommit parent =
+					(GraphCommit)commit.getParent(i);
+				parent.calculateColumn();
+				g.setColor(painter.foreground);
+				g.drawLine(column2x(commit.column) + w / 2,
+					row2y(commit.row) + h,
+					column2x(parent.column) + w / 2,
+					row2y(parent.row));
+			}
+		}
+	}
+}

@@ -0,0 +1,43 @@
+package org.spearce.jgit.gui;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics2D;
+import java.awt.GradientPaint;
+import java.awt.Rectangle;
+import java.awt.Shape;
+
+import java.awt.geom.Area;
+
+class CommitPainter {
+
+	protected Color background1, background2, foreground;
+	protected int margin = 2;
+
+	public CommitPainter() {
+		background1 = Color.LIGHT_GRAY;
+		background2 = background1.darker();
+		foreground = Color.BLACK;
+	}
+
+	public void paint(Graphics2D g, GraphCommit commit,
+			int x, int y, int w, int h) {
+
+		GradientPaint gradient = new GradientPaint(x, y, background1,
+				x + w, y + h, background2);
+
+		g.setPaint(gradient);
+		g.fillRect(x, y, w, h);
+		g.setColor(foreground);
+		g.drawRect(x, y, w, h);
+
+		Shape clip = g.getClip();
+		Area area = new Area(new Rectangle(x + margin, y + margin,
+					w - 2 * margin, h - 2 * margin));
+		area.intersect(new Area(clip));
+		g.setClip(area);
+		g.drawString(commit.getShortMessage(),
+				x + margin, y + margin + h / 2);
+		g.setClip(clip);
+	}
+}

@@ -0,0 +1,32 @@
+package org.spearce.jgit.gui;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CommitRow {
+	protected List<GraphCommit> left, right;
+
+	public CommitRow() {
+		left = new ArrayList<GraphCommit>();
+		right = new ArrayList<GraphCommit>();
+	}
+
+	public GraphCommit get(int index) {
+		if (index < 0) {
+			index = -1 - index;
+			return index < left.size() ? left.get(index) : null;
+		}
+		return index < right.size() ? right.get(index) : null;
+	}
+
+	public int add(GraphCommit commit, int desiredColumn) {
+		int leftIndex = -1 - desiredColumn;
+		if (Math.abs(-1 - desiredColumn - left.size()) <
+				Math.abs(desiredColumn - right.size())) {
+			left.add(commit);
+			return -left.size();
+		}
+		right.add(commit);
+		return right.size() - 1;
+	}
+}

@@ -0,0 +1,41 @@
+package org.spearce.jgit.gui;
+
+import org.spearce.jgit.lib.AnyObjectId;
+import org.spearce.jgit.revwalk.RevCommit;
+
+public class GraphCommit extends RevCommit {
+
+	protected int column = 0, row = 0;
+
+	protected int childrenCount = 0;
+	protected int cumulatedChildColumn = 0;
+
+	protected GraphCommit(final AnyObjectId id) {
+		super(id);
+	}
+
+	public void addChild(GraphCommit child) {
+		cumulatedChildColumn += child.column;
+		this.row = Math.max(this.row, child.row + 1);
+		childrenCount++;
+	}
+
+	// TODO: CommitLayout argument
+	public void calculateColumn() {
+		if (childrenCount < 0)
+			return; // already assigned
+		if (childrenCount > 0)
+			column = cumulatedChildColumn / childrenCount;
+		else
+			column = 0;
+		// TODO: ask the layout for the position
+	}
+
+	public int getColumn() {
+		return column;
+	}
+
+	public int getRow() {
+		return row;
+	}
+}

@@ -0,0 +1,36 @@
+package org.spearce.jgit.gui;
+
+import java.io.IOException;
+
+import org.spearce.jgit.lib.AnyObjectId;
+import org.spearce.jgit.lib.Repository;
+import org.spearce.jgit.revwalk.RevSort;
+import org.spearce.jgit.revwalk.RevWalk;
+import org.spearce.jgit.revwalk.RevCommit;
+import org.spearce.jgit.errors.IncorrectObjectTypeException;
+import org.spearce.jgit.errors.MissingObjectException;
+
+public class GraphWalk extends RevWalk {
+	public GraphWalk(final Repository repo)
+			/* throws IOException, MissingObjectException */ {
+		super(repo);
+		sort(RevSort.COMMIT_TIME_DESC, true);
+	}
+	
+	protected RevCommit createCommit(final AnyObjectId id) {
+		return new GraphCommit(id);
+	}
+
+	public RevCommit next() throws MissingObjectException,
+			IncorrectObjectTypeException, IOException {
+		GraphCommit commit = (GraphCommit)super.next();
+		if (commit == null)
+			return null;
+
+		// Update all parents
+		for (int i = 0; i < commit.getParentCount(); i++)
+			((GraphCommit)commit.getParent(i)).addChild(commit);
+
+		return commit;
+	}
+}

@@ -4,6 +4,7 @@ org.spearce.jgit.pgm.Daemon
 org.spearce.jgit.pgm.DiffTree
 org.spearce.jgit.pgm.Fetch
 org.spearce.jgit.pgm.Glog
+org.spearce.jgit.pgm.Gui
 org.spearce.jgit.pgm.IndexPack
 org.spearce.jgit.pgm.Init
 org.spearce.jgit.pgm.Log

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2009, Shawn O. Pearce <spearce@spearce.org>,
+ *                     Johannes E. Schindelin <johannes.schindelin@gmx.de>
+ *
+ * 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;
+
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+
+import java.io.File;
+
+import javax.swing.JFrame;
+
+import org.spearce.jgit.gui.CommitGraph;
+import org.spearce.jgit.gui.GraphWalk;
+
+import org.spearce.jgit.revwalk.RevCommit;
+import org.spearce.jgit.revwalk.RevWalk;
+
+class Gui extends RevWalkTextBuiltin {
+	final JFrame frame;
+
+	CommitGraph graph;
+
+	Gui() {
+		frame = new JFrame();
+		frame.addWindowListener(new WindowAdapter() {
+			@Override
+			public void windowClosing(final WindowEvent e) {
+				frame.dispose();
+			}
+		});
+	}
+
+	@Override
+	protected int walkLoop() throws Exception {
+		graph = new CommitGraph((GraphWalk)walk);
+		frame.getContentPane().add(graph);
+
+		frame.setTitle("[" + repoName() + "]");
+		frame.pack();
+		frame.setVisible(true);
+		return 0;
+	}
+
+	@Override
+	protected void show(final RevCommit c) throws Exception {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	protected RevWalk createWalk() {
+		if (objects)
+			throw die("Cannot use --objects with gui");
+		final GraphWalk w = new GraphWalk(db);
+		return w;
+	}
+
+	private String repoName() {
+		final File f = db.getDirectory();
+		String n = f.getName();
+		if (".git".equals(n))
+			n = f.getParentFile().getName();
+		return n;
+	}
+}