SwingMessageWidget: make hyperlinks work

This replaces JLabel by JEditorPane to allow HTML rendering including hyperlinks.
We refer to PlatformService to open any clicked URLs.

Note that this makes hyperlinks work in 'value', but not in 'label' attributes of message (String) parameters.

Author: imagejan

src/main/java/org/scijava/ui/swing/widget/SwingMessageWidget.java

@@ -29,10 +29,17 @@
 
 package org.scijava.ui.swing.widget;
 
-import javax.swing.JLabel;
+import java.io.IOException;
+
+import javax.swing.JEditorPane;
 import javax.swing.JPanel;
+import javax.swing.event.HyperlinkEvent;
+import javax.swing.event.HyperlinkListener;
 
 import org.scijava.Priority;
+import org.scijava.log.LogService;
+import org.scijava.platform.PlatformService;
+import org.scijava.plugin.Parameter;
 import org.scijava.plugin.Plugin;
 import org.scijava.widget.InputWidget;
 import org.scijava.widget.MessageWidget;
@@ -47,8 +54,13 @@
 public class SwingMessageWidget extends SwingInputWidget<String> implements
 	MessageWidget<JPanel>
 {
+	@Parameter
+	private PlatformService platformService;
+
+	@Parameter
+	private LogService logService;
 
-	private JLabel label;
+	private JEditorPane pane;
 
 	// -- InputWidget methods --
 
@@ -76,8 +88,28 @@ public void set(final WidgetModel model) {
 
 		final String text = model.getText();
 
-		label = new JLabel(text);
-		getComponent().add(label);
+		pane = new JEditorPane("text/html", text);
+
+		// NB: use format (font etc.) from parent component
+		pane.putClientProperty(JEditorPane.HONOR_DISPLAY_PROPERTIES, Boolean.TRUE);
+
+		pane.setEditable(false);
+		pane.setOpaque(false);
+		pane.addHyperlinkListener(new HyperlinkListener() {
+
+			@Override
+			public void hyperlinkUpdate(HyperlinkEvent hle) {
+				if (HyperlinkEvent.EventType.ACTIVATED.equals(hle.getEventType())) {
+					try {
+						platformService.open(hle.getURL());
+					}
+					catch (IOException exc) {
+						logService.error("Error while opening " + hle.getURL(), exc);
+					}
+				}
+			}
+		});
+		getComponent().add(pane);
 	}
 
 	// -- Typed methods --
@@ -92,6 +124,6 @@ public boolean supports(final WidgetModel model) {
 	@Override
 	public void doRefresh() {
 		// maybe dialog owner changed message content
-		label.setText(get().getText());
+		pane.setText(get().getText());
 	}
 }