Refactor calls to createObserver

modules/DesktopAppearance/src/main/java/org/gephi/desktop/appearance/AppearanceUIController.java

@@ -287,8 +287,8 @@ public class AppearanceUIController {
 
         public ColumnObserver(Workspace workspace) {
             timer = new Timer("RankingColumnObserver", true);
-            nodeObserver = gc.getAttributeModel(workspace).getNodeTable().getTableObserver();
-            edgeObserver = gc.getAttributeModel(workspace).getEdgeTable().getTableObserver();
+            nodeObserver = gc.getAttributeModel(workspace).getNodeTable().newTableObserver();
+            edgeObserver = gc.getAttributeModel(workspace).getEdgeTable().newTableObserver();
         }
 
         @Override

modules/DesktopContext/src/main/java/org/gephi/desktop/context/ContextRefreshThread.java

@@ -69,7 +69,7 @@ public class ContextRefreshThread extends TimerTask {
 
     private void initObserver() {
         if (observer == null || observer.isDestroyed()) {
-            observer = graphModel.getGraphObserver(graphModel.getGraphVisible(), false);
+            observer = graphModel.createGraphObserver(graphModel.getGraphVisible(), false);
         }
     }
 

modules/VisualizationImpl/src/main/java/org/gephi/visualization/bridge/DataBridge.java

@@ -184,7 +184,7 @@ public class DataBridge implements VizArchitecture {
         nodes = new NodeModel[10];
         edges = new EdgeModel[10];
         if (graphModel != null) {
-            observer = graphModel.getGraphObserver(graph, false);
+            observer = graphModel.createGraphObserver(graph, false);
         }
     }