Add UI event subsystem

Right now, there is just one concrete event type called UIShownEvent
that fires when UIService#showUI is called.

Author: ctrueden

src/main/java/org/scijava/ui/DefaultUIService.java

@@ -67,6 +67,7 @@
 import org.scijava.ui.DialogPrompt.MessageType;
 import org.scijava.ui.DialogPrompt.OptionType;
 import org.scijava.ui.DialogPrompt.Result;
+import org.scijava.ui.event.UIShownEvent;
 import org.scijava.ui.viewer.DisplayViewer;
 
 /**
@@ -177,6 +178,7 @@ public void showUI(final UserInterface ui) {
 		for (final Display<?> display : displayService.getDisplays()) {
 			ui.show(display);
 		}
+		eventService.publish(new UIShownEvent(ui));
 	}
 
 	@Override

src/main/java/org/scijava/ui/event/UIEvent.java

@@ -0,0 +1,64 @@
+/*
+ * #%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.ui.event;
+
+import org.scijava.event.SciJavaEvent;
+import org.scijava.ui.UserInterface;
+
+/**
+ * An event indicating activity relating to a {@link UserInterface}.
+ * 
+ * @author Curtis Rueden
+ */
+public abstract class UIEvent extends SciJavaEvent {
+
+	private final UserInterface ui;
+
+	public UIEvent(final UserInterface ui) {
+		this.ui = ui;
+	}
+
+	// -- UIEvent methods --
+
+	/** Gets the user interface. */
+	public UserInterface getUI() {
+		return ui;
+	}
+
+	// -- Object methods --
+
+	@Override
+	public String toString() {
+		return super.toString() + "\n\tui = " + ui;
+	}
+
+}

src/main/java/org/scijava/ui/event/UIShownEvent.java

@@ -0,0 +1,49 @@
+/*
+ * #%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.ui.event;
+
+import org.scijava.ui.UIService;
+import org.scijava.ui.UserInterface;
+
+/**
+ * An event indicating a user interface was shown.
+ * 
+ * @author Curtis Rueden
+ * @see UIService#showUI
+ */
+public class UIShownEvent extends UIEvent {
+
+	public UIShownEvent(final UserInterface ui) {
+		super(ui);
+	}
+
+}