graph panel default message for no results (#20)

* graph panel default message for no results
* use intellij UIUtil to determine theme

Author: gdalecka

ui/jetbrains/src/main/java/com/neueda/jetbrains/plugin/graphdb/jetbrains/ui/console/graph/GraphPanel.java

@@ -44,11 +44,9 @@ public class GraphPanel {
     private GraphPanelInteractions interactions;
     private Tree entityDetailsTree;
     private DefaultTreeModel entityDetailsTreeModel;
-    private PatchedDefaultMutableTreeNode noEntityRoot;
 
     public GraphPanel() {
-        noEntityRoot = new PatchedDefaultMutableTreeNode("Select entity...");
-        entityDetailsTreeModel = new DefaultTreeModel(noEntityRoot);
+        entityDetailsTreeModel = new DefaultTreeModel(null);
     }
 
     public void initialize(GraphConsoleView graphConsoleView, Project project) {
@@ -66,11 +64,16 @@ public void initialize(GraphConsoleView graphConsoleView, Project project) {
         messageBus.connect().subscribe(QueryExecutionProcessEvent.QUERY_EXECUTION_PROCESS_TOPIC, new QueryExecutionProcessEvent() {
             @Override
             public void executionStarted(ExecuteQueryPayload payload) {
-                entityDetailsTreeModel.setRoot(noEntityRoot);
+                entityDetailsTreeModel.setRoot(null);
             }
 
             @Override
             public void resultReceived(ExecuteQueryPayload payload, GraphQueryResult result) {
+                if (result.getNodes().isEmpty()) {
+                    entityDetailsTreeModel.setRoot(null);
+                } else {
+                    entityDetailsTreeModel.setRoot(new PatchedDefaultMutableTreeNode("Select an item in the graph to view details..."));
+                }
             }
 
             @Override
@@ -96,10 +99,6 @@ public void executionCompleted(ExecuteQueryPayload payload) {
                 visualization);
     }
 
-    public void handleClick(GraphNode node, VisualItem item, MouseEvent e) {
-        showNodeData(node, item, e);
-    }
-
     public void showNodeData(GraphNode node, VisualItem item, MouseEvent e) {
         PatchedDefaultMutableTreeNode root = UiHelper.nodeToTreeNode(node.getRepresentation(), node);
         entityDetailsTreeModel.setRoot(root);

ui/visualization/src/main/java/com/neueda/jetbrains/plugin/graphdb/visualization/GraphDisplay.java

@@ -1,5 +1,6 @@
 package com.neueda.jetbrains.plugin.graphdb.visualization;
 
+import com.intellij.util.ui.UIUtil;
 import com.neueda.jetbrains.plugin.graphdb.database.api.data.GraphNode;
 import com.neueda.jetbrains.plugin.graphdb.database.api.data.GraphRelationship;
 import com.neueda.jetbrains.plugin.graphdb.visualization.controls.CustomNeighborHighlightControl;
@@ -34,7 +35,7 @@
 import static com.neueda.jetbrains.plugin.graphdb.visualization.constants.GraphColumns.*;
 import static com.neueda.jetbrains.plugin.graphdb.visualization.constants.GraphGroups.*;
 import static com.neueda.jetbrains.plugin.graphdb.visualization.settings.RendererProvider.*;
-import static prefuse.Constants.SHAPE_ELLIPSE;
+import static prefuse.Constants.*;
 
 public class GraphDisplay extends Display {
 
@@ -53,7 +54,11 @@ public class GraphDisplay extends Display {
     public GraphDisplay(LookAndFeelService lookAndFeel) {
         super(new Visualization());
 
-        setBackground(lookAndFeel.getBackgroundColor());
+        if (UIUtil.isUnderDarcula()) {
+            setBackground(lookAndFeel.getBackgroundColor().brighter());
+        } else {
+            setBackground(lookAndFeel.getBackgroundColor());
+        }
 
         graph = new Graph(DIRECTED);
         graph.addColumn(ID, String.class);