Add an event for reporting on stdout/stderr output

This event, though it is a SciJavaEvent, is _not_ intended for
publication via the EventService, but rather via the ConsoleService.

Author: ctrueden

src/main/java/org/scijava/console/OutputEvent.java

@@ -0,0 +1,124 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2015 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 
+ * 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 HOLDERS 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.
+ * #L%
+ */
+
+package org.scijava.console;
+
+import org.scijava.Context;
+import org.scijava.event.EventService;
+import org.scijava.event.SciJavaEvent;
+
+/**
+ * An event indicating output occurred on {@code stdout} or {@code stderr}.
+ * <p>
+ * NB: This event is published <em>on the calling thread</em> by
+ * {@link ConsoleService#notifyListeners(OutputEvent)}, <em>not</em> on a
+ * dedicated event dispatch thread by the {@link EventService}. This is done to
+ * avoid the overhead of the event service's synchronized pub/sub
+ * implementation, as well as to avoid potential infinite output loops caused by
+ * debugging output surrounding event publication.
+ * </p>
+ *
+ * @author Curtis Rueden
+ */
+public class OutputEvent extends SciJavaEvent {
+
+	/** Possible output sources. */
+	public enum Source {
+		STDOUT, STDERR
+	}
+
+	/** The source of the output. */
+	private final Source source;
+
+	/** The output string. */
+	private final String output;
+
+	/**
+	 * Whether the output was produced within this specific SciJava
+	 * {@link Context}.
+	 */
+	private final boolean contextual;
+
+	/**
+	 * Creates a new output event.
+	 *
+	 * @param source The source of the output.
+	 * @param output The output string.
+	 * @param contextual Whether the output was produced within this specific
+	 *          SciJava {@link Context}.
+	 */
+	public OutputEvent(final Context context, final Source source,
+		final String output, final boolean contextual)
+	{
+		this.source = source;
+		this.output = output;
+		this.contextual = contextual;
+		setContext(context);
+		setCallingThread(Thread.currentThread());
+	}
+
+	/** Gets the source of the output. */
+	public Source getSource() {
+		return source;
+	}
+
+	/** Gets the output string. */
+	public String getOutput() {
+		return output;
+	}
+
+	/**
+	 * Returns true if the output was produced outside of a specific SciJava
+	 * {@link Context}.
+	 */
+	public boolean isContextual() {
+		return contextual;
+	}
+
+	/** Returns true of the source of the output is {@code stdout}. */
+	public boolean isStdout() {
+		return source == Source.STDOUT;
+	}
+
+	/** Returns true of the source of the output is {@code stderr}. */
+	public boolean isStderr() {
+		return source == Source.STDERR;
+	}
+
+	// -- Object methods --
+
+	@Override
+	public String toString() {
+		return super.toString() + "\n\tsource = " + source + "\n\toutput = " +
+			output + "\n\tcontextual = " + contextual;
+	}
+
+}