Add a SciJava gateway

We had a gateway for ImageJ and one for SCIFIO, but no easy-to-use
entry point for SciJava Common itself. This gateway changes that!

Author: ctrueden

src/main/java/org/scijava/SciJava.java

@@ -0,0 +1,115 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2014 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;
+
+import java.util.Collection;
+
+import org.scijava.app.SciJavaApp;
+import org.scijava.plugin.Plugin;
+import org.scijava.service.Service;
+
+/**
+ * Main entry point into SciJava. This class enables working with SciJava
+ * services in a simple way, while retaining extensibility (i.e., access to
+ * third-party services).
+ * 
+ * @author Curtis Rueden
+ */
+@Plugin(type = Gateway.class)
+public class SciJava extends AbstractGateway {
+
+	// -- Constructors --
+
+	/** Creates a new SciJava application context with all available services. */
+	public SciJava() {
+		this(new Context());
+	}
+
+	/**
+	 * Creates a new Scijava application context.
+	 * 
+	 * @param empty If true, the context will be empty; otherwise, it will be
+	 *          initialized with all available services.
+	 */
+	public SciJava(final boolean empty) {
+		this(new Context(empty));
+	}
+
+	/**
+	 * Creates a new SciJava application context with the specified services (and
+	 * any required service dependencies).
+	 * <p>
+	 * <b>Developer's note:</b> This constructor's argument is raw (i.e.,
+	 * {@code Class...} instead of {@code Class<? extends Service>...}) because
+	 * otherwise, downstream invocations (e.g.,
+	 * {@code new SciJava(LogService.class)}) yield the potentially confusing
+	 * warning:
+	 * </p>
+	 * <blockquote>Type safety: A generic array of Class<? extends Service> is
+	 * created for a varargs parameter</blockquote>
+	 * <p>
+	 * To avoid this, we have opted to use raw types and suppress the relevant
+	 * warning here instead.
+	 * </p>
+	 * 
+	 * @param serviceClasses A list of types that implement the {@link Service}
+	 *          interface (e.g., {@code LogService.class}).
+	 * @throws ClassCastException If any of the given arguments do not implement
+	 *           the {@link Service} interface.
+	 */
+	@SuppressWarnings({ "rawtypes" })
+	public SciJava(final Class... serviceClasses) {
+		this(new Context(serviceClasses));
+	}
+
+	/**
+	 * Creates a new SciJava application context with the specified services (and
+	 * any required service dependencies).
+	 * 
+	 * @param serviceClasses A collection of types that implement the
+	 *          {@link Service} interface (e.g., {@code LogService.class}).
+	 */
+	public SciJava(final Collection<Class<? extends Service>> serviceClasses) {
+		this(new Context(serviceClasses));
+	}
+
+	/**
+	 * Creates a new SciJava application context which wraps the given existing
+	 * SciJava context.
+	 * 
+	 * @see Context
+	 */
+	public SciJava(final Context context) {
+		super(SciJavaApp.NAME, context);
+	}
+
+}