Plugin: add extensible key/value pair list

ctrueden · ctrueden · commit 1eaf5de71df9 · 2013-02-18T13:38:46.000-06:00
This makes the annotation much more extensible, so that various sorts of
plugins can register various bits of information in a freeform way.
diff --git a/src/main/java/org/scijava/plugin/Attr.java b/src/main/java/org/scijava/plugin/Attr.java
@@ -0,0 +1,64 @@
+/*
+ * #%L
+ * ImageJ software for multidimensional image processing and analysis.
+ * %%
+ * Copyright (C) 2009 - 2013 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.
+ * 
+ * The views and conclusions contained in the software and documentation are
+ * those of the authors and should not be interpreted as representing official
+ * policies, either expressed or implied, of any organization.
+ * #L%
+ */
+
+package org.scijava.plugin;
+
+import java.lang.annotation.Target;
+
+/**
+ * A name/value attribute pair, used to extend the @{@link Plugin} annotation.
+ * 
+ * @author Curtis Rueden
+ * @see Plugin
+ * @see PluginInfo#get(String)
+ * @see PluginInfo#is(String)
+ */
+@Target({})
+public @interface Attr {
+
+	/** Name of the attribute. */
+	String name();
+
+	/**
+	 * The attribute's value, if applicable.
+	 * <p>
+	 * If set, the method {@link PluginInfo#get(String)} with the attribute's name
+	 * will retrieve the value; in any case, the method
+	 * {@link PluginInfo#is(String)} will return true.
+	 * </p>
+	 */
+	String value() default "";
+
+}
diff --git a/src/main/java/org/scijava/plugin/Plugin.java b/src/main/java/org/scijava/plugin/Plugin.java
@@ -180,4 +180,10 @@
 	 */
 	boolean activeInAppFrame() default false;
 
+	/**
+	 * A list of additional attributes which can be used to extend this annotation
+	 * beyond its built-in capabilities.
+	 */
+	Attr[] attrs() default {};
+
 }
diff --git a/src/main/java/org/scijava/plugin/PluginInfo.java b/src/main/java/org/scijava/plugin/PluginInfo.java
@@ -36,6 +36,8 @@
 package org.scijava.plugin;
 
 import java.net.URL;
+import java.util.HashMap;
+import java.util.Map;
 
 import org.scijava.AbstractUIDetails;
 import org.scijava.Instantiable;
@@ -74,6 +76,9 @@ public class PluginInfo<PT extends SciJavaPlugin> extends AbstractUIDetails
 	/** Type of this entry's plugin; e.g., {@link org.scijava.service.Service}. */
 	private Class<PT> pluginType;
 
+	/** Table of extra key/value pairs. */
+	private Map<String, String> values = new HashMap<String, String>();
+
 	/** Annotation describing the plugin. */
 	private Plugin annotation;
 
@@ -198,6 +203,16 @@ public Class<PT> getPluginType() {
 		return pluginType;
 	}
 
+	/** Returns true iff the the given key is defined by the metadata. */
+	public boolean is(final String key) {
+		return values.containsKey(key);
+	}
+
+	/** Returns the value of the given key, or null if undefined. */
+	public String get(final String key) {
+		return values.get(key);
+	}
+
 	/** Gets the associated @{@link Plugin} annotation. */
 	public Plugin getAnnotation() {
 		return annotation;
@@ -321,6 +336,13 @@ private void populateValues() {
 				menuLeaf.setIconPath(iconPath);
 			}
 		}
+
+		// populate extra attributes
+		for (final Attr attr : ann.attrs()) {
+			final String name = attr.name();
+			final String value = attr.value();
+			values.put(name, value);
+		}
 	}
 
 	private MenuPath parseMenuPath(final Menu[] menu) {
