--- a/flys-client/src/main/java/de/intevation/flys/client/client/FLYS.java	Wed Jun 08 12:43:38 2011 +0000
+++ b/flys-client/src/main/java/de/intevation/flys/client/client/FLYS.java	Wed Jun 08 13:21:46 2011 +0000
@@ -1,5 +1,8 @@
 package de.intevation.flys.client.client;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import com.google.gwt.core.client.EntryPoint;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.user.client.rpc.AsyncCallback;
@@ -9,6 +12,8 @@
 import com.smartgwt.client.util.SC;
 import com.smartgwt.client.widgets.layout.VLayout;
 import com.smartgwt.client.widgets.layout.HLayout;
+import com.smartgwt.client.widgets.events.CloseClickHandler;
+import com.smartgwt.client.widgets.events.CloseClientEvent;
 
 import de.intevation.flys.client.shared.model.Artifact;
 import de.intevation.flys.client.shared.model.Collection;
@@ -85,11 +90,15 @@
     /** The list of rivers supported by the server.*/
     protected River[] rivers;
 
+    /** This list is used to track the opened projects.*/
+    protected List<String> openProjects;
+
 
     /**
      * This is the entry point method.
      */
     public void onModuleLoad() {
+        openProjects = new ArrayList<String>();
 
         VLayout vertical = new VLayout();
         vertical.setLayoutMargin(1);
@@ -231,17 +240,43 @@
         }
 
         CollectionView view = new CollectionView(this);
-        workspace.addView(view);
+        workspace.addView("new-project", view);
 
         view.addCollectionChangeHandler(getProjectList());
     }
 
 
-    public void openProject(String collectionID) {
+    protected void lockProject(String uuid) {
+        if (isProjectLocked(uuid)) {
+            return;
+        }
+
+        openProjects.add(uuid);
+    }
+
+
+    protected void unlockProject(String uuid) {
+        openProjects.remove(uuid);
+    }
+
+
+    protected boolean isProjectLocked(String uuid) {
+        return openProjects.contains(uuid);
+    }
+
+
+    public void openProject(final String collectionID) {
         if (collectionID == null) {
             return;
         }
 
+        if (isProjectLocked(collectionID)) {
+            workspace.bringUp(collectionID);
+            return;
+        }
+
+        lockProject(collectionID);
+
         GWT.log("Open existing project: " + collectionID);
 
         Config config       = Config.getInstance();
@@ -270,6 +305,7 @@
                         item.hash(),
                         new AsyncCallback<Artifact>() {
                             public void onFailure(Throwable caught) {
+                                unlockProject(collectionID);
                                 SC.warn(MSG.getString(caught.getMessage()));
                             }
 
@@ -279,8 +315,11 @@
 
                                 view.addCollectionChangeHandler(
                                     getProjectList());
+                                view.addCloseClickHandler(
+                                    new CloseCollectionViewHandler(
+                                        FLYS.this, collectionID));
 
-                                workspace.addView(view);
+                                workspace.addView(collectionID, view);
                             }
                     });
 
@@ -309,5 +348,26 @@
                 }
         });
     }
+
+
+
+    /**
+     * This CloseClickHandler is used to remove lock on a specific Collection so
+     * that is might be opened again.
+     */
+    private class CloseCollectionViewHandler implements CloseClickHandler {
+        protected FLYS   flys;
+        protected String uuid;
+
+        public CloseCollectionViewHandler(FLYS flys, String uuid) {
+            this.flys = flys;
+            this.uuid = uuid;
+        }
+
+        public void onCloseClick(CloseClientEvent event) {
+            flys.unlockProject(uuid);
+            workspace.removeProject(uuid);
+        }
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :