Closes #507

protege-editor-owl/src/main/java/org/protege/editor/owl/ui/util/NothingSelectedPanel.java

@@ -0,0 +1,47 @@
+package org.protege.editor.owl.ui.util;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.geom.Rectangle2D;
+
+/**
+ * Matthew Horridge
+ * Stanford Center for Biomedical Informatics Research
+ * 8 Aug 16
+ */
+public class NothingSelectedPanel extends JPanel {
+
+    public static final String NOTHING_SELECTED = "Nothing Selected";
+
+    private static final Color BORDER_COLOR = new Color(220, 220, 220);
+
+    private static final Color TEXT_COLOR = new Color(200, 200, 200);
+
+    private static final int BORDER_MARGIN = 20;
+
+    private static final int BORDER_THICKNESS = 8;
+
+    private static final Font FONT = new Font("Sans-serif", Font.PLAIN, 40);
+
+    public NothingSelectedPanel() {
+    }
+
+    @Override
+    protected void paintComponent(Graphics g) {
+        super.paintComponent(g);
+        Graphics2D g2 = (Graphics2D) g;
+        Stroke currentStroke = g2.getStroke();
+        g2.setStroke(new BasicStroke(BORDER_THICKNESS));
+        g2.setColor(BORDER_COLOR);
+        int borderWidth = getWidth() - 2 * BORDER_MARGIN;
+        int borderHeight = getHeight() - 2 * BORDER_MARGIN;
+        g2.drawRoundRect(BORDER_MARGIN, BORDER_MARGIN, borderWidth, borderHeight, BORDER_MARGIN, BORDER_MARGIN);
+        g2.setStroke(currentStroke);
+        g2.setColor(TEXT_COLOR);
+        g2.setFont(FONT);
+        Rectangle2D rectangle = g2.getFontMetrics().getStringBounds(NOTHING_SELECTED, g2);
+        int stringX = (int) (getWidth() - rectangle.getWidth()) / 2;
+        int stringY = (int) (getHeight() - rectangle.getHeight()) / 2;
+        g2.drawString(NOTHING_SELECTED, stringX, stringY);
+    }
+}

protege-editor-owl/src/main/java/org/protege/editor/owl/ui/view/SelectedEntityCardView.java

@@ -4,6 +4,7 @@
 import org.protege.editor.core.ui.view.ViewsPane;
 import org.protege.editor.core.ui.view.ViewsPaneMemento;
 import org.protege.editor.owl.model.selection.OWLSelectionModelListener;
+import org.protege.editor.owl.ui.util.NothingSelectedPanel;
 import org.semanticweb.owlapi.model.*;
 
 import javax.swing.*;
@@ -21,16 +22,11 @@
  */
 public class SelectedEntityCardView extends AbstractOWLViewComponent implements Resettable {
 
-    /**
-     * 
-     */
-    private static final long serialVersionUID = -287697571704681093L;
-
     public static final String ID = "org.protege.editor.owl.SelectedEntityView";
 
-    private CardLayout cardLayout = new CardLayout();
+    private final CardLayout cardLayout = new CardLayout();
 
-    private JPanel cardPanel;
+    private final JPanel cardPanel = new JPanel();
 
     private List<ViewsPane> viewsPanes = new ArrayList<>();
 
@@ -52,14 +48,11 @@ public class SelectedEntityCardView extends AbstractOWLViewComponent implements
 
     protected void initialiseOWLView() throws Exception {
         setLayout(new BorderLayout());
-        cardPanel = new JPanel();
         add(cardPanel);
         cardPanel.setLayout(cardLayout);
-        cardPanel.add(new JPanel(), BLANK_PANEL);
+        cardPanel.add(new NothingSelectedPanel(), BLANK_PANEL);
         createViewPanes(false);
-        getOWLWorkspace().getOWLSelectionModel().addListener(() -> {
-            processSelection();
-        });
+        getOWLWorkspace().getOWLSelectionModel().addListener(this::processSelection);
         getView().setShowViewBar(false);
         processSelection();
     }