Gateway: add missing UIService accessor

Author: ctrueden

src/main/java/org/scijava/AbstractGateway.java

@@ -61,6 +61,7 @@
 import org.scijava.thread.ThreadService;
 import org.scijava.tool.IconService;
 import org.scijava.tool.ToolService;
+import org.scijava.ui.UIService;
 import org.scijava.widget.WidgetService;
 
 /**
@@ -233,6 +234,11 @@ public ToolService tool() {
 		return get(ToolService.class);
 	}
 
+	@Override
+	public UIService ui() {
+		return get(UIService.class);
+	}
+
 	@Override
 	public WidgetService widget() {
 		return get(WidgetService.class);

src/main/java/org/scijava/Gateway.java

@@ -59,6 +59,7 @@
 import org.scijava.thread.ThreadService;
 import org.scijava.tool.IconService;
 import org.scijava.tool.ToolService;
+import org.scijava.ui.UIService;
 import org.scijava.widget.WidgetService;
 
 /**
@@ -318,6 +319,13 @@ public interface Gateway extends RichPlugin, Versioned {
 	 */
 	ToolService tool();
 
+	/**
+	 * Gets this application context's {@link UIService}.
+	 *
+	 * @return The {@link UIService} of this application context.
+	 */
+	UIService ui();
+
 	/**
 	 * Gets this application context's {@link WidgetService}.
 	 *