Merge branch 'refactoring'

Kieker.WebGUI/bin/data/Advanced Example/meta.dat

-#
-#Sun May 19 16:38:30 CEST 2013
-owner=admin
-last\ user=admin
-analysis\ layout=id0 -593 -253 348 72;id1 -611 -32 312 72;id2 -243 -32 336 72;id3 133 -38 288 132;id4 479 -26 276 108;id5 1187 -41 468 96;id6 2055 -23 816 144;id7 1119 213 876 84;id8 2033 365 804 84;id9 2051 201 840 144;id10 2817 44 564 72;id11 2919 -71 360 72;id12 3349 -50 372 72;\#id2.2 id3.6 -43.5 -20 -43.5 10;id2.2 id3.5 -43.5 -20 -43.5 -14;id4.12 id5.14 648.5 -26 648.5 -29;id4.12 id7.20 648.5 -26 648.5 225;id5.0 id12.R 1588.5 -47 1588.5 -177 3130.5 -177 3130.5 -38;id6.1 id12.R 2502.5 -53 2502.5 -38;id6.17 id10.29 2502.5 -17 2502.5 56;id7.21 id8.23 1598.5 213 1598.5 365;id7.22 id8.24 1588.5 237 1588.5 389;id9.2 id12.R 3130.5 171 3130.5 -38;id9.27 id10.29 2502.5 231 2502.5 56;id10.3 id12.R 3130.5 56 3130.5 -38;id11.4 id12.R 3130.5 -59 3130.5 -38;

Kieker.WebGUI/bin/data/Bookstore-Example/Bookstore-Example.kax

@@ -48,12 +48,6 @@
   </plugins>
   <dependencies filePath="BookstoreApplication.jar"/>
   <dependencies filePath="commons-cli-1.2.jar"/>
-  <views name="Counter View" description="Shows the available counters">
-    <displayConnectors name="Invalid Counter" display="//@plugins.3/@displays.2"/>
-    <displayConnectors name="Valid Counter" display="//@plugins.4/@displays.2"/>
-    <displayConnectors name="Global Counter" display="//@plugins.5/@displays.2"/>
-    <displayConnectors name="Global Counter (Meter Gauge)" display="//@plugins.5/@displays.3"/>
-  </views>
   <properties name="recordsTimeUnit" value="NANOSECONDS"/>
   <properties name="projectName" value="AnalysisProject"/>
 </Project>

Kieker.WebGUI/bin/data/Bookstore-Example/meta.dat

 #
-#Tue Jun 04 10:45:34 CEST 2013
+#Thu Jun 06 21:28:46 CEST 2013
 owner=admin
-cockpit\ layout=0 0 0 1 1 0 1 1 
 last\ user=user
+cockpit\ layout=
 analysis\ layout=id0 -593 -253 348 72;id1 -671 -51 192 72;id2 -55 -63 336 84;id3 655 35 276 72;id4 315 47 276 84;id5 315 -93 252 84;id6 -399 -51 264 84;id7 643 -97 252 72;\#id2.2 id5.8 144.5 -63 144.5 -81;id2.3 id4.5 144.5 -39 144.5 59;id5.9 id7.14 484.5 -93 484.5 -85;

Kieker.WebGUI/bin/data/CPU-and-Memory-Example/CPU-and-Memory-Example.kax

@@ -10,12 +10,22 @@
   <plugins xsi:type="Reader" name="FSReader" classname="kieker.analysis.plugin.reader.filesystem.FSReader">
     <properties name="inputDirs" value="data/CPU-and-Memory-Example/testdata"/>
     <properties name="ignoreUnknownRecordTypes" value="false"/>
-    <outputPorts name="monitoringRecords" subscribers="//@plugins.0/@inputPorts.0"/>
+    <outputPorts name="monitoringRecords" subscribers="//@plugins.2/@inputPorts.0"/>
   </plugins>
-  <views name="View" description="No description available.">
+  <plugins xsi:type="Filter" name="RealtimeRecordDelayFilter" classname="kieker.analysis.plugin.filter.forward.RealtimeRecordDelayFilter">
+    <properties name="numWorkers" value="1"/>
+    <properties name="additionalShutdownDelaySeconds" value="5"/>
+    <properties name="warnOnNegativeSchedTimeSeconds" value="2"/>
+    <properties name="timerPrecision" value="MILLISECONDS"/>
+    <outputPorts name="outputRecords" subscribers="//@plugins.0/@inputPorts.0"/>
+    <inputPorts name="inputRecords"/>
+  </plugins>
+  <views name="CPU View" description="No description available.">
     <displayConnectors name="XYPlot CPU utilization Display" display="//@plugins.0/@displays.0"/>
     <displayConnectors name="Meter Gauge CPU total utilization Display" display="//@plugins.0/@displays.1"/>
   </views>
+  <views name="Memory View" description="No description available.">
+  </views>
   <properties name="recordsTimeUnit" value="NANOSECONDS"/>
   <properties name="projectName" value="AnalysisProject"/>
 </Project>

Kieker.WebGUI/bin/data/CPU-and-Memory-Example/meta.dat

 #
-#Thu Jun 06 09:16:16 CEST 2013
+#Thu Jun 06 12:48:33 CEST 2013
 owner=admin
+last\ user=user
 cockpit\ layout=0 0 1 0 0 1 
-last\ user=admin
-analysis\ layout=id0 -1418 -586 336 72;id1 -1140 -428 420 72;id2 -1490 -428 192 72;\#;
+analysis\ layout=id0 -495 -241 336 72;id1 223 -83 420 72;id2 -567 -83 192 72;id3 -229 -83 396 72;\#;

Kieker.WebGUI/bin/data/Timer-Counter-Example/Timer-Counter-Example.kax

@@ -47,9 +47,6 @@
     <displayConnectors name="Timestamp Records (Meter Gauge)" display="//@plugins.3/@displays.3"/>
     <displayConnectors name="Timestamps (Meter Gauge)" display="//@plugins.4/@displays.3"/>
   </views>
-  <views name="Only Records View" description="No description available.">
-    <displayConnectors name="Timestamp Records" display="//@plugins.3/@displays.1"/>
-  </views>
   <properties name="recordsTimeUnit" value="NANOSECONDS"/>
   <properties name="projectName" value="AnalysisProject"/>
 </Project>

Kieker.WebGUI/bin/data/Timer-Counter-Example/meta.dat

 #
-#Sun Jun 02 11:24:25 CEST 2013
+#Thu Jun 06 21:29:55 CEST 2013
 owner=admin
-last\ user=admin
-cockpit\ layout=0 0 0 1 0 2 1 0 1 1 1 2 0 3 1 3 0 0 
+cockpit\ layout=0 0 0 1 0 2 1 0 1 1 1 2 0 3 1 3 
+last\ user=user
 analysis\ layout=id0 -2221 -900 336 72;id1 -2281 -618 216 84;id2 -1547 -748 204 72;id3 -1547 -618 204 72;id4 -1911 -606 396 84;id5 -1911 -740 312 84;\#id1.0 id5.9 -2142.5 -619.5 -2142.5 -729.5;id5.10 id2.2 -1682.5 -741.5 -1682.5 -737.5;

Kieker.WebGUI/bin/data/Trace-Reconstruction-Example/meta.dat

+#
+#Thu Jun 06 21:28:29 CEST 2013
+owner=admin
+last\ user=user
+analysis\ layout=id0 -495 -241 336 72;id1 -507 -20 312 72;id2 -139 -20 336 72;id3 237 -26 288 132;id4 583 -14 276 108;id5 1291 -29 468 96;id6 2159 -11 816 144;id7 1223 225 876 84;id8 2137 377 804 84;id9 2155 213 840 144;id10 2921 56 564 72;id11 3023 -59 360 72;id12 3453 -38 372 72;\#id2.2 id3.6 60.5 -8.5 60.5 21.5;id2.2 id3.5 60.5 -8.5 60.5 -2.5;id4.12 id5.15 752.5 -14.5 752.5 -17.5;id4.12 id7.22 752.5 -14.5 752.5 236.5;id5.14 id12.R 1692.5 -35.5 1692.5 -165.5 3234.5 -165.5 3234.5 -26.5;id6.17 id12.R 2606.5 -41.5 2606.5 -26.5;id6.19 id10.33 2606.5 -5.5 2606.5 67.5;id7.23 id8.25 1702.5 224.5 1702.5 376.5;id7.24 id8.26 1692.5 248.5 1692.5 400.5;id9.27 id12.R 3234.5 182.5 3234.5 -26.5;id9.30 id10.33 2606.5 242.5 2606.5 67.5;id10.32 id12.R 3234.5 67.5 3234.5 -26.5;id11.34 id12.R 3234.5 -47.5 3234.5 -26.5;

Kieker.WebGUI/pom.xml

@@ -133,12 +133,12 @@
         <dependency>
             <groupId>com.sun.faces</groupId>
             <artifactId>jsf-api</artifactId>
-            <version>2.1.7</version>
+            <version>2.1.22</version>
         </dependency>
         <dependency>
             <groupId>com.sun.faces</groupId>
             <artifactId>jsf-impl</artifactId>
-            <version>2.1.7</version>
+            <version>2.1.22</version>
         </dependency>
         <dependency>
             <groupId>junit</groupId>

Kieker.WebGUI/src/main/java/kieker/webgui/common/ClassContainer.java

@@ -24,6 +24,7 @@ import kieker.analysis.display.HtmlText;
 import kieker.analysis.display.Image;
 import kieker.analysis.display.MeterGauge;
 import kieker.analysis.display.PlainText;
+import kieker.analysis.display.TagCloud;
 import kieker.analysis.display.XYPlot;
 import kieker.analysis.display.annotation.Display;
 import kieker.analysis.plugin.AbstractPlugin;
@@ -66,6 +67,7 @@ public class ClassContainer {
 	private Class<?> htmlTextClass;
 	private Class<?> xyPlotClass;
 	private Class<?> meterGaugeClass;
+	private Class<?> tagCloudClass;
 
 	private Class<? extends Annotation> pluginAnnotationClass;
 	private Class<? extends Annotation> repositoryAnnotationClass;
@@ -101,6 +103,7 @@ public class ClassContainer {
 			this.imageClass = classLoader.loadClass(Image.class.getName());
 			this.xyPlotClass = classLoader.loadClass(XYPlot.class.getName());
 			this.meterGaugeClass = classLoader.loadClass(MeterGauge.class.getName());
+			this.tagCloudClass = classLoader.loadClass(TagCloud.class.getName());
 
 			// Now we load the more specific annotation classes
 			this.pluginAnnotationClass = (Class<? extends Annotation>) classLoader.loadClass(Plugin.class.getName());
@@ -197,4 +200,8 @@ public class ClassContainer {
 		return this.meterGaugeClass;
 	}
 
+	public Class<?> getTagCloudClass() {
+		return this.tagCloudClass;
+	}
+
 }

Kieker.WebGUI/src/main/java/kieker/webgui/domain/DisplayType.java

@@ -32,6 +32,7 @@ public enum DisplayType {
 	/** Represents the image display type. */
 	IMAGE,
 	/** Represents the meter gauge display type. */
-	METER_GAUGE
-
+	METER_GAUGE,
+	/** Represents the tag cloud display type. */
+	TAG_CLOUD
 }

Kieker.WebGUI/src/main/java/kieker/webgui/service/impl/utility/Analysis.java

@@ -186,6 +186,9 @@ public class Analysis {
 				if (STATE.TERMINATED.toString().equals(state.toString())) {
 					retState = STATE.TERMINATED;
 				}
+				if (STATE.TERMINATING.toString().equals(state.toString())) {
+					retState = STATE.TERMINATING;
+				}
 			}
 			return retState;
 		} catch (final MirrorException ex) {
@@ -250,6 +253,8 @@ public class Analysis {
 			return DisplayType.XY_PLOT;
 		} else if (parameter == this.classContainer.getMeterGaugeClass()) {
 			return DisplayType.METER_GAUGE;
+		} else if (parameter == this.classContainer.getTagCloudClass()) {
+			return DisplayType.TAG_CLOUD;
 		} else {
 			return null;
 		}

Kieker.WebGUI/src/main/java/kieker/webgui/web/beans/view/CurrentAnalysisEditorBean.java

@@ -58,6 +58,7 @@ import kieker.webgui.service.IProjectService;
 import kieker.webgui.web.beans.application.GlobalPropertiesBean;
 import kieker.webgui.web.beans.application.ProjectsBean;
 import kieker.webgui.web.beans.session.UserBean;
+import kieker.webgui.web.utility.IGraphListener;
 
 import org.primefaces.context.RequestContext;
 import org.primefaces.event.FileUploadEvent;
@@ -79,7 +80,7 @@ import org.springframework.stereotype.Component;
  */
 @Component
 @Scope("view")
-public class CurrentAnalysisEditorBean {
+public class CurrentAnalysisEditorBean implements IGraphListener {
 
 	private static final MIAnalysisMetaModelFactory MODEL_FACTORY = MAnalysisMetaModelFactory.eINSTANCE;
 	private static final Log LOG = LogFactory.getLog(CurrentAnalysisEditorBean.class);
@@ -148,9 +149,6 @@ public class CurrentAnalysisEditorBean {
 	 */
 	public void initializeGraph() {
 		try {
-			// Make sure that the currentAnalysisEditorGraphBean knows "this" as well.
-			this.currentAnalysisEditorGraphBean.setCurrentAnalysisEditorBean(this);
-
 			// Initialize the graph
 			this.currentAnalysisEditorGraphBean.declareGraph();
 
@@ -158,41 +156,7 @@ public class CurrentAnalysisEditorBean {
 			this.initializeGlobalConfigurationInstance();
 			this.currentAnalysisEditorGraphBean.addGlobalConfigurationInstance(this.globalConfigurationInstance);
 
-			// Initialize the reader, filter and repositories
-			for (final MIPlugin plugin : this.project.getPlugins()) {
-				if (plugin instanceof MIReader) {
-					this.currentAnalysisEditorGraphBean.addReader((MIReader) plugin);
-				} else {
-					this.currentAnalysisEditorGraphBean.addFilter((MIFilter) plugin);
-				}
-			}
-
-			for (final MIRepository repository : this.project.getRepositories()) {
-				this.currentAnalysisEditorGraphBean.addRepository(repository);
-			}
-
-			// Now initialize the connections between filters...
-			for (final MIPlugin plugin : this.project.getPlugins()) {
-				for (final MIOutputPort oPort : plugin.getOutputPorts()) {
-					for (final MIInputPort iPort : oPort.getSubscribers()) {
-						this.currentAnalysisEditorGraphBean.addConnection(plugin, iPort.getParent(), oPort, iPort);
-					}
-				}
-			}
-
-			// ...and between filters and repositories
-			for (final MIPlugin plugin : this.project.getPlugins()) {
-				for (final MIRepositoryConnector rPort : plugin.getRepositories()) {
-					// It is possible that the connected repository is null, if it hasn't been set yet. Check this.
-					if (rPort.getRepository() != null) {
-						this.currentAnalysisEditorGraphBean.addConnection(plugin, rPort.getRepository(), rPort);
-					}
-				}
-			}
-
-			// Initialize the mouse click and the edge constraint listeners
-			this.currentAnalysisEditorGraphBean.initListeners();
-			this.currentAnalysisEditorGraphBean.initEdgeConstraints();
+			this.currentAnalysisEditorGraphBean.addProject(this.project);
 
 			// Now we have to set the default grid size and color of the user
 			this.currentAnalysisEditorGraphBean.setGridColor(this.userBean.getGridColor());
@@ -207,11 +171,13 @@ public class CurrentAnalysisEditorBean {
 				this.currentAnalysisEditorGraphBean.startAutoLayout();
 			}
 
-			// Make sure that guests cannot modify the graph
-			this.currentAnalysisEditorGraphBean.checkReadOnlyForGuests();
+			// Make sure that the currentAnalysisEditorGraphBean knows "this" as well.
+			this.currentAnalysisEditorGraphBean.addGraphListener(this);
+
+			this.currentAnalysisEditorGraphBean.initializeListeners();
 		} catch (final NullPointerException ex) {
 			// This exception can occur when a property has not been initialized
-			CurrentAnalysisEditorBean.LOG.error("An error occured while initializing the graph.", ex);
+			LOG.error("An error occured while initializing the graph.", ex);
 		}
 	}
 
@@ -340,7 +306,7 @@ public class CurrentAnalysisEditorBean {
 
 		// Add it to the project - and to the graph
 		this.project.getRepositories().add(repository);
-		this.currentAnalysisEditorGraphBean.addRepository(repository);
+		this.currentAnalysisEditorGraphBean.addComponent(repository);
 
 		this.setModificationsFlag();
 	}
@@ -357,7 +323,7 @@ public class CurrentAnalysisEditorBean {
 
 		// Add it to the project - and to the graph
 		this.project.getPlugins().add(plugin);
-		this.currentAnalysisEditorGraphBean.addReader((MIReader) plugin);
+		this.currentAnalysisEditorGraphBean.addComponent((MIReader) plugin);
 
 		this.setModificationsFlag();
 	}
@@ -374,7 +340,7 @@ public class CurrentAnalysisEditorBean {
 
 		// Add it to the project - and to the graph
 		this.project.getPlugins().add(plugin);
-		this.currentAnalysisEditorGraphBean.addFilter((MIFilter) plugin);
+		this.currentAnalysisEditorGraphBean.addComponent((MIFilter) plugin);
 
 		this.setModificationsFlag();
 	}
@@ -451,26 +417,16 @@ public class CurrentAnalysisEditorBean {
 		return "No description available.";
 	}
 
-	/**
-	 * This method should be called if a node (plugin, repository) has been selected.
-	 * 
-	 * @param node
-	 *            The new node to be selected.
-	 */
-	public void nodeSelected(final MIAnalysisComponent node) {
-		this.selectedComponent = node;
+	@Override
+	public void componentSelectedEvent(final MIAnalysisComponent newSelectedComponent) {
+		this.selectedComponent = newSelectedComponent;
 	}
 
-	/**
-	 * This method should be called if a node (plugin, repository) has been removed.
-	 * 
-	 * @param node
-	 *            The new node to be removed.
-	 */
-	public void nodeRemoved(final MIAnalysisComponent node) {
+	@Override
+	public void componentDeletedEvent(final MIAnalysisComponent deletedComponent) {
 		// Remove the component from the project
-		if (node instanceof MIPlugin) {
-			this.project.getPlugins().remove(node);
+		if (deletedComponent instanceof MIPlugin) {
+			this.project.getPlugins().remove(deletedComponent);
 
 			// Remove the corresponding connections
 			final List<MIInputPort> toBeRemoved = new ArrayList<MIInputPort>();
@@ -478,7 +434,7 @@ public class CurrentAnalysisEditorBean {
 				for (final MIOutputPort oPort : plugin.getOutputPorts()) {
 					toBeRemoved.clear();
 					for (final MIInputPort iPort : oPort.getSubscribers()) {
-						if (iPort.getParent() == node) {
+						if (iPort.getParent() == deletedComponent) {
 							toBeRemoved.add(iPort);
 						}
 					}
@@ -486,12 +442,12 @@ public class CurrentAnalysisEditorBean {
 				}
 			}
 		} else {
-			this.project.getRepositories().remove(node);
+			this.project.getRepositories().remove(deletedComponent);
 
 			// Remove the corresponding connections
 			for (final MIPlugin plugin : this.project.getPlugins()) {
 				for (final MIRepositoryConnector repoConn : plugin.getRepositories()) {
-					if (repoConn.getRepository() == node) {
+					if (repoConn.getRepository() == deletedComponent) {
 						repoConn.setRepository(null);
 					}
 				}
@@ -502,7 +458,7 @@ public class CurrentAnalysisEditorBean {
 		for (final MIView view : this.project.getViews()) {
 			final Collection<MIDisplayConnector> toBeRemoved = new ArrayList<MIDisplayConnector>();
 			for (final MIDisplayConnector connector : view.getDisplayConnectors()) {
-				if (connector.getDisplay().getParent() == node) {
+				if (connector.getDisplay().getParent() == deletedComponent) {
 					toBeRemoved.add(connector);
 				}
 			}
@@ -510,65 +466,37 @@ public class CurrentAnalysisEditorBean {
 		}
 
 		// Deselect the currently selected node if it is the one which has just been removed
-		if (this.selectedComponent == node) {
+		if (this.selectedComponent == deletedComponent) {
 			this.selectedComponent = null; // NOPMD
 		}
 
 		this.setModificationsFlag();
 	}
 
-	/**
-	 * This method should be delivered if an edge between two plugins has been created.
-	 * 
-	 * @param sourcePort
-	 *            The source port.
-	 * @param targetPort
-	 *            The target port.
-	 */
-	public void edgeCreated(final MIOutputPort sourcePort, final MIInputPort targetPort) {
-		sourcePort.getSubscribers().add(targetPort);
+	@Override
+	public void connectionAddedEvent(final MIRepositoryConnector sourcePort, final MIRepository target) {
+		sourcePort.setRepository(target);
 
 		this.setModificationsFlag();
 	}
 
-	/**
-	 * This method should be delivered if an edge between two plugins has been removed.
-	 * 
-	 * @param sourcePort
-	 *            The source port.
-	 * @param targetPort
-	 *            The target port.
-	 */
-	public void edgeRemoved(final MIOutputPort sourcePort, final MIInputPort targetPort) {
-		sourcePort.getSubscribers().remove(targetPort);
+	@Override
+	public void connectionAddedEvent(final MIOutputPort outputPort, final MIInputPort targetPort) {
+		outputPort.getSubscribers().add(targetPort);
 
 		this.setModificationsFlag();
 	}
 
-	/**
-	 * This method should be delivered if an edge between a plugin and a repository has been created.
-	 * 
-	 * @param sourcePort
-	 *            The source port.
-	 * @param target
-	 *            The target repository.
-	 */
-	public void edgeCreated(final MIRepositoryConnector sourcePort, final MIRepository target) {
-		sourcePort.setRepository(target);
+	@Override
+	public void connectionDeletedEvent(final MIRepositoryConnector sourcePort, final MIRepository targetRepo) {
+		sourcePort.setRepository(null);
 
 		this.setModificationsFlag();
 	}
 
-	/**
-	 * This method should be delivered if an edge between a plugin and a repository has been removed.
-	 * 
-	 * @param sourcePort
-	 *            The source port.
-	 * @param target
-	 *            The target repository.
-	 */
-	public void edgeRemoved(final MIRepositoryConnector sourcePort, final MIRepository target) {
-		sourcePort.setRepository(null);
+	@Override
+	public void connectionDeletedEvent(final MIOutputPort sourcePort, final MIInputPort targetPort) {
+		sourcePort.getSubscribers().remove(targetPort);
 
 		this.setModificationsFlag();
 	}

Kieker.WebGUI/src/main/java/kieker/webgui/web/beans/view/CurrentAnalysisEditorHistoryBean.java

+/***************************************************************************
+ * Copyright 2013 Kieker Project (http://kieker-monitoring.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ***************************************************************************/
+
+package kieker.webgui.web.beans.view;
+
+import java.util.Stack;
+
+import kieker.webgui.web.utility.command.AbstractEditorCommand;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Component;
+
+/**
+ * This bean contains the necessary data behind an instance of the analysis editor for the undo and redo operations.<br>
+ * </br>
+ * 
+ * The class is a Spring managed bean with view scope to make sure that one user (even in one session) can open multiple projects at a time without causing any
+ * problems.
+ * 
+ * @author Nils Christian Ehmke
+ */
+@Component
+@Scope("view")
+public class CurrentAnalysisEditorHistoryBean {
+
+	private final Stack<AbstractEditorCommand> undoCommands = new Stack<AbstractEditorCommand>();
+	private final Stack<AbstractEditorCommand> redoCommands = new Stack<AbstractEditorCommand>();
+
+	/**
+	 * Creates a new instance of this class. <b>Do not call this constructor manually. It will only be accessed by Spring.</b>
+	 */
+	public CurrentAnalysisEditorHistoryBean() {
+		// No code necessary
+	}
+
+	/**
+	 * Undos the last command.
+	 */
+	public void undoLastCommand() {
+		if (!this.undoCommands.isEmpty()) {
+			final AbstractEditorCommand command = this.undoCommands.pop();
+
+			command.execute();
+
+			this.redoCommands.push(this.invertCommand(command));
+		}
+	}
+
+	/**
+	 * Redos the last command.
+	 */
+	public void redoLastCommand() {
+		if (!this.redoCommands.isEmpty()) {
+			final AbstractEditorCommand command = this.redoCommands.pop();
+
+			command.execute();
+
+			this.undoCommands.push(this.invertCommand(command));
+		}
+	}
+
+	/**
+	 * Tells whether the undo stack is empty or not.
+	 * 
+	 * @return true iff the undo stack is empty.
+	 */
+	public boolean isUndoStackEmpty() {
+		return this.undoCommands.isEmpty();
+	}
+
+	/**
+	 * Tells whether the redo stack is empty or not.
+	 * 
+	 * @return true iff the redo stack is empty.
+	 */
+	public boolean isRedoStackEmpty() {
+		return this.redoCommands.isEmpty();
+	}
+
+	private AbstractEditorCommand invertCommand(final AbstractEditorCommand command) {
+		return command;
+	}
+
+}