Started with the observer patterns

Kieker.WebGUI/src/main/java/kieker/webgui/beans/session/SelectedMainProjectBean.java

@@ -28,6 +28,7 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Observable;
 
 import javax.faces.application.FacesMessage;
 import javax.faces.bean.ManagedBean;
@@ -65,7 +66,7 @@ import org.eclipse.emf.common.util.EList;
  */
 @ManagedBean
 @SessionScoped
-public class SelectedMainProjectBean {
+public class SelectedMainProjectBean extends Observable {
 	/**
 	 * The logger within this class.
 	 */
@@ -95,6 +96,10 @@ public class SelectedMainProjectBean {
 	 */
 	private List<Connection> connections;
 
+    public enum UPDATE_MSG {
+        SELECTION_CHANGED
+    }
+    
 	/**
 	 * Creates a new instance of this class.
 	 */
@@ -121,7 +126,11 @@ public class SelectedMainProjectBean {
 		this.mainProject = mainProject;
 		this.connections = this.getConnectionsFromProject();
 		FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "", "New main project: " + mainProject.getName()));
-	}
+	
+        // Inform the observers
+        setChanged();
+        notifyObservers(UPDATE_MSG.SELECTION_CHANGED);
+    }
 
 	/**
 	 * This method delivers the available reader-plugins for the current main project. The delivered plugins are never abstract.

Kieker.WebGUI/src/main/java/kieker/webgui/beans/session/SelectedPluginBean.java

@@ -22,20 +22,40 @@ package kieker.webgui.beans.session;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Observable;
+import java.util.Observer;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
 import javax.faces.bean.ManagedBean;
 import javax.faces.bean.SessionScoped;
+import javax.faces.context.FacesContext;
 
 import kieker.analysis.model.analysisMetaModel.MIPlugin;
 
+import org.primefaces.context.RequestContext;
+
 /**
- * This bean can be used to save the currently selected plugin of the user.
+ * This bean can be used to save the currently selected plugin of the user. This bean registers to the user's instance of {@link SelectedMainProjectBean} as an
+ * observer. If the main project changes, the content of this bean changes as well. This bean also updates the properties form if the selection of the plugin
+ * changes.
  * 
  * @author Nils Christian Ehmke
  * @version 1.0
  */
 @ManagedBean
 @SessionScoped
-public final class SelectedPluginBean {
+public final class SelectedPluginBean implements Observer {
+
+	/**
+	 * This is the name of the target element to be updated when the plugin selection changes.
+	 */
+	private static final String UPDATE_TARGET = "propertiesForm";
+
+	/**
+	 * This is the main project bean where this instance registers as an observer.
+	 */
+	private final SelectedMainProjectBean observableBean;
 
 	/**
 	 * The plugin which is stored by this container.
@@ -46,7 +66,29 @@ public final class SelectedPluginBean {
 	 * Creates a new instance of this class.
 	 */
 	public SelectedPluginBean() {
-		/* No code necessary. */
+		// Try to get the main project bean.
+		final FacesContext context = FacesContext.getCurrentInstance();
+		this.observableBean = context.getApplication().evaluateExpressionGet(context, "#{selectedMainProjectBean}", SelectedMainProjectBean.class);
+	}
+
+	/**
+	 * This method is used to initialize the object after creation.
+	 */
+	@PostConstruct
+	@SuppressWarnings("FinalPrivateMethod")
+	private final void postConstruct() {
+		// Register this instance as an observer
+		this.observableBean.addObserver(this);
+	}
+
+	/**
+	 * This method is used to finalize the object before destruction.
+	 */
+	@PreDestroy
+	@SuppressWarnings("FinalPrivateMethod")
+	private final void preDestroy() {
+		// Unregister this instance as an observer
+		this.observableBean.deleteObserver(this);
 	}
 
 	/**
@@ -59,21 +101,39 @@ public final class SelectedPluginBean {
 	}
 
 	/**
-	 * Sets the plugin stored by this bean.
+	 * Sets the plugin stored by this bean and updates (if possible) the corresponding element in the current context.
 	 * 
 	 * @param plugin
 	 *            The new bean to be stored within this bean.
 	 */
 	public void setPlugin(final MIPlugin plugin) {
 		this.plugin = plugin;
+		// Update the element
+		final RequestContext requestContext = RequestContext.getCurrentInstance();
+		requestContext.addPartialUpdateTarget(SelectedPluginBean.UPDATE_TARGET);
 	}
 
+	/**
+	 * This method delivers a list containing all properties of the current plugin, but adds the name as a string to it.
+	 * 
+	 * @return A list with all properties plus the name (as a string). If no plugin is selected, this method returns an empty list, never null.
+	 */
 	public List<Object> getAdvancedProperties() {
 		final List<Object> resultList = new ArrayList<Object>();
 
-		resultList.add(plugin.getName());
-		resultList.addAll(plugin.getProperties());
+		if (this.plugin != null) {
+			resultList.add(this.plugin.getName());
+			resultList.addAll(this.plugin.getProperties());
+		}
 
 		return resultList;
 	}
+
+	@Override
+	public void update(final Observable o, final Object arg) {
+		// If the main project has been newly selected, we have to set the current plugin to null
+		if (arg == SelectedMainProjectBean.UPDATE_MSG.SELECTION_CHANGED) {
+			this.setPlugin(null);
+		}
+	}
 }

Kieker.WebGUI/src/main/webapp/main.xhtml

@@ -34,6 +34,7 @@
                         <p:menubar>
                             <p:submenu label="File">
                                 <p:menuitem value="New Project" onclick="newProjectDialog.show()" ajax="true" />
+                                <p:menuitem value="Import Project" ajax="true" />
                                 <p:menuitem value="Manage Dependencies" ajax="false" url="/Kieker.WebGUI/manageDependencies" />
                                 <p:separator />
                                 <p:menuitem value="Settings" onclick="settingsDialog.show()" ajax="true" />
@@ -114,7 +115,7 @@
                     <h:form id="centerForm" style="height: 100%">
                         <div class="canvas" id="mainCanvas" style="width : #{currentWorkspaceSizeBean.sizeX}px;height: #{currentWorkspaceSizeBean.sizeY}px">
                             <c:forEach items="#{selectedMainProjectBean.mainProject.plugins}" var="plugin" varStatus="counter">
-                                <p:remoteCommand name="setPlugin#{counter.index}" action="#{selectedPluginBean.setPlugin(plugin)}" update=":propertiesForm"/>
+                                <p:remoteCommand name="setPlugin#{counter.index}" action="#{selectedPluginBean.setPlugin(plugin)}"/>
                                 <!-- Netbeans reports an error here, but the code does still work though... -->
                                 <div onclick="setPlugin#{counter.index}();" class="ui-panel ui-widget ui-widget-content ui-corner-all block draggable" id="#{stringToIDBean.stringToID(plugin)}" >
                                     <div class="ui-panel-titlebar ui-widget-header ui-corner-all">