[client] reworked lecture details window

now uses tabs for subsets of options - clearing up the gui a bit

1 files changed, 213 insertions, 138 deletions

diff --git a/dozentenmodul/src/main/java/org/openslx/dozmod/gui/window/LectureDetailsWindow.java b/dozentenmodul/src/main/java/org/openslx/dozmod/gui/window/LectureDetailsWindow.java
index df91e811..c4b3700e 100644
--- a/dozentenmodul/src/main/java/org/openslx/dozmod/gui/window/LectureDetailsWindow.java
+++ b/dozentenmodul/src/main/java/org/openslx/dozmod/gui/window/LectureDetailsWindow.java
@@ -6,6 +6,8 @@ import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.awt.event.ItemEvent;
 import java.awt.event.ItemListener;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
 import java.util.ArrayList;
@@ -22,6 +24,7 @@ import java.util.Map.Entry;
 import javax.swing.DefaultComboBoxModel;
 import javax.swing.JFrame;
 import javax.swing.JOptionPane;
+import javax.swing.JRadioButton;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 
@@ -37,6 +40,12 @@ import org.openslx.bwlp.thrift.iface.UserInfo;
 import org.openslx.dozmod.gui.Gui;
 import org.openslx.dozmod.gui.MainWindow;
 import org.openslx.dozmod.gui.control.AdvancedConfigurator.AdvancedConfiguration;
+import org.openslx.dozmod.gui.control.AdvancedConfigurator.AdvancedConfigurationChangeEvent;
+import org.openslx.dozmod.gui.control.AdvancedConfigurator.AdvancedConfigurationChangeEventListener;
+import org.openslx.dozmod.gui.control.JCheckBoxTree.CheckChangeEvent;
+import org.openslx.dozmod.gui.control.JCheckBoxTree.CheckChangeEventListener;
+import org.openslx.dozmod.gui.control.LectureCustomPermissionManager.UserChangeEvent;
+import org.openslx.dozmod.gui.control.LectureCustomPermissionManager.UserChangeEventListener;
 import org.openslx.dozmod.gui.helper.DateTimeHelper;
 import org.openslx.dozmod.gui.helper.MessageType;
 import org.openslx.dozmod.gui.helper.TextChangeListener;
@@ -50,7 +59,6 @@ import org.openslx.dozmod.thrift.ThriftActions;
 import org.openslx.dozmod.thrift.ThriftActions.DownloadCallback;
 import org.openslx.dozmod.thrift.ThriftActions.LectureMetaCallback;
 import org.openslx.dozmod.thrift.ThriftError;
-import org.openslx.dozmod.thrift.cache.MetaDataCache;
 import org.openslx.dozmod.thrift.cache.UserCache;
 import org.openslx.dozmod.util.FormatHelper;
 import org.openslx.dozmod.util.MapHelper;
@@ -105,20 +113,36 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 	 */
 	private ImageDetailsRead image = null;
 
+	/**
+	 * Flag indicating a change in this lecture's linked image
+	 */
 	private boolean imageLinkChanged = false;
 
+	/**
+	 * Flag indicating a change in this lecture's metadata
+	 */
 	private boolean metadataChanged = false;
 
+	/**
+	 * Flag indicating a change in this lecture's permissions
+	 */
 	private boolean permissionsChanged = false;
 
+	/**
+	 * Holder of the location information of this lecture
+	 */
 	private LocationInfo locationInfo = null;
 
+	/**
+	 * Holder of the netrules/runscript of this lecture
+	 */
 	private AdvancedConfiguration currentAdvConf = null;
 
  	/**
 	 * Constructor
 	 * 
 	 * @param modalParent parent of this popup window
+	 * @param callback function to be called when a lecture update occured
 	 */
 	public LectureDetailsWindow(Frame modalParent, LectureUpdatedCallback callback) {
 		super(modalParent);
@@ -127,6 +151,7 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 		this.callback = callback;
 
 		setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
+
 		addWindowListener(new WindowAdapter() {
 			@Override
 			public void windowClosing(WindowEvent e) {
@@ -176,16 +201,6 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 				cboVersions.setEnabled(!chkAutoUpdate.isSelected());
 			}
 		});
-		btnAdvancedOptions.addActionListener(new ActionListener() {
-			@Override
-			public void actionPerformed(ActionEvent e) {
-				AdvancedConfiguration conf = LectureAdvancedSettingsWindow.open(JOptionPane.getFrameForComponent(me), currentAdvConf);
-				if (conf == null)
-					return;
-				currentAdvConf = conf;
-				reactToChange();
-			}
-		});
 		btnChangeOwner.addActionListener(new ActionListener() {
 			@Override
 			public void actionPerformed(ActionEvent e) {
@@ -201,48 +216,61 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 				}, "Besitzer festlegen", lecture.ownerId);
 			}
 		});
-		btnPermissions.addActionListener(new ActionListener() {
+
+		final ActionListener changeReacter = new ActionListener() {
 			@Override
-			public void actionPerformed(ActionEvent arg0) {
-				// NOTE once the following window is closed, customPermissions and lecture.defaultPermissions
-				// objects will contain the changes the user did. We will later only compare these with
-				// the original values as saved in originalCustomPermissions and originalDefaultPermissions
-				LecturePermissionWindow.open(me, customPermissions, lecture.defaultPermissions,
-						lecture.ownerId);
+			public void actionPerformed(ActionEvent e) {
 				reactToChange();
 			}
-		});
-		btnLocations.addActionListener(new ActionListener() {
+		};
+		
+		ctlLocationSelector.getTree().addCheckChangeEventListener(new CheckChangeEventListener() {
 			@Override
-			public void actionPerformed(ActionEvent e) {
-				LocationInfo ret = LocationSelectionWindow.open(me, locationInfo.locationList, locationInfo.limitToLocations);
-				if (ret == null) {
-					// nothing changed
-					return;
-				}
-				// TODO check size of returns
-				locationInfo = ret;
+			public void checkStateChanged(CheckChangeEvent event) {
 				reactToChange();
 			}
 		});
-		if (MetaDataCache.getLocations() == null || MetaDataCache.getLocations().isEmpty()) {
-			btnLocations.setVisible(false);
+		for (JRadioButton btn : ctlLocationSelector.getButtons()) {
+			btn.addActionListener(changeReacter);
 		}
-			
-		btnSaveChanges.addActionListener(new ActionListener() {
+		final ActionListener updateDefaultPermissionListener = new ActionListener() {
 			@Override
 			public void actionPerformed(ActionEvent e) {
-				saveChanges();
+				ctlPermissionManager.updateDefaultPermissions(chkCustomPermAdmin.isSelected(),
+						chkCustomPermEdit.isSelected());
+				reactToChange();
+			}
+		};
+		chkCustomPermAdmin.addActionListener(updateDefaultPermissionListener);
+		chkCustomPermEdit.addActionListener(updateDefaultPermissionListener);
+		ctlPermissionManager.getTable().addMouseListener(new MouseAdapter() {
+			@Override
+			public void mouseClicked(MouseEvent e) {
+				reactToChange();
+			}
+		});
+		ctlPermissionManager.addUserChangeEventListener(new UserChangeEventListener() {			
+			@Override
+			public void stateChanged(UserChangeEvent event) {
+				reactToChange();
 			}
 		});
+		chkCustomPermAdmin.addActionListener(changeReacter);
+		chkCustomPermEdit.addActionListener(changeReacter);
 
-		// final step, add listeners to react to change
+		ctlAdvancedConfigurator.addAdvancedConfigurationChangeEventListener(new AdvancedConfigurationChangeEventListener() {
+			@Override
+			public void stateChanged(AdvancedConfigurationChangeEvent event) {
+				btnSaveChanges.setEnabled(ctlAdvancedConfigurator.hasChanged());
+			}
+		});
 		final TextChangeListener docListener = new TextChangeListener() {
 			@Override
 			public void changed() {
 				reactToChange();
 			}
 		};
+
 		txtTitle.getDocument().addDocumentListener(docListener);
 		txtDescription.getDocument().addDocumentListener(docListener);
 
@@ -282,10 +310,17 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 
 		// save default color of date/time stuff to reset the background later
 		dateTimeTextColor = dtpStartDate.getForeground();
+		// last step, the save button
+		btnSaveChanges.addActionListener(new ActionListener() {
+			@Override
+			public void actionPerformed(ActionEvent e) {
+				saveChanges();
+			}
+		});
 		// disable save button
 		btnSaveChanges.setEnabled(false);
 		// wait for the image to be loaded before (potentially) enabling fields
-		makeEditable(false);
+		toggleEditable(false);
 	}
 
 	/**
@@ -308,28 +343,30 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 							if (lecture != null) {
 								customPermissions = ThriftActions.getLecturePermissions(
 										JOptionPane.getFrameForComponent(me), lecture.lectureId);
-								locationInfo = new LocationInfo(lecture.locationIds, lecture.limitToLocations);
 							}
+							fillDetails();
 						}
-						fillDetails();
 					}
 				});
 	}
 
 	/**
-	 * callback function when we received the lecture's details from the server
+	 * Internal callback function when we received the lecture's details from the server
 	 */
 	private void fillDetails() {
 		if (lecture == null) {
 			txtTitle.setText("-");
-			makeEditable(false);
+			lblTitleInfo.setText("-");
+			toggleEditable(false);
 			return;
 		}
-
+		LOGGER.debug("LECT: " + lecture);
 		if (image == null) {
 			txtImageName.setText("-");
+			lblImageNameInfo.setText("-");
 		} else {
 			txtImageName.setText(image.getImageName());
+			lblImageNameInfo.setText(image.getImageName());
 		}
 		// remember original advanced config
 		currentAdvConf = new AdvancedConfiguration(lecture.networkExceptions, lecture.runscript);
@@ -350,10 +387,24 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 				originalCustomPermissions.put(entry.getKey(), new LecturePermissions(entry.getValue()));
 			}
 		}
-
+		// init permission info
+		ctlPermissionManager.initPanel(customPermissions, lecture.defaultPermissions, lecture.ownerId);
+		chkCustomPermAdmin.setSelected(lecture.defaultPermissions.admin);
+		chkCustomPermEdit.setSelected(lecture.defaultPermissions.edit);
+		// init location info
+		locationInfo = new LocationInfo(lecture.locationIds, lecture.limitToLocations);
+		ctlLocationSelector.setOnlyInSelection(locationInfo.limitToLocations);
+		ctlLocationSelector.setSelectedLocationsAsIds(locationInfo.locationList);
+		// advanced config stuff, save current information
+		currentAdvConf = new AdvancedConfiguration(lecture.networkExceptions, lecture.runscript);
+		// init advanced info
+		ctlAdvancedConfigurator.setState(new AdvancedConfiguration(lecture.networkExceptions, lecture.runscript));
+		
 		txtTitle.setText(lecture.getLectureName());
+		lblTitleInfo.setText(lecture.getLectureName());
 		txtDescription.setText(lecture.getDescription());
 		lblOwner.setUser(UserCache.find(lecture.getOwnerId()));
+		lblOwnerInfo.setUser(UserCache.find(lecture.getOwnerId()));
 		lblUpdater.setUser(UserCache.find(lecture.getUpdaterId()));
 		lblCreateTime.setText(FormatHelper.longDate(lecture.getCreateTime()));
 		lblUpdateTime.setText(FormatHelper.longDate(lecture.getUpdateTime()));
@@ -369,7 +420,6 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 		cboVersions.setEnabled(!lecture.autoUpdate);
 
 		lblUseCount.setText(Integer.toString(lecture.useCount));
-
 		fillVersionsCombo();
 
 		Calendar startCal = Calendar.getInstance();
@@ -384,7 +434,10 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 				endCal.get(Calendar.DATE));
 		spnEndTime.getModel().setValue(endCal.getTime());
 
-		makeEditable(true);
+		// now enable the tabs the user can see given its permissions
+		toggleEditable(true);
+		// and always switch to the "About" tab
+		pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Übersicht"));
 		setVisible(true);
 	}
 
@@ -433,7 +486,7 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 		// success
 		Gui.showMessageBox(me, "Besitzrechte übertragen an " + FormatHelper.userName(user), MessageType.INFO,
 				null, null);
-		makeEditable(false);
+		toggleEditable(false);
 		String lectureId = lecture.getLectureId();
 		synchronized (me) {
 			image = null;
@@ -484,7 +537,87 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 	}
 
 	/**
-	 * Push the changes of the image details to the satellite
+	 * Checks whether the user changed any fields of the image details and
+	 * enables the save button if so.
+	 */
+	private void reactToChange() {
+		// before checks we need to update the local objects holding the information of the "widgets"
+		// update the location information
+		locationInfo = new LocationInfo(ctlLocationSelector.getSelectedLocationsAsIds(),
+				ctlLocationSelector.getOnlyInSelection());
+		// update the custom permissions
+		customPermissions = ctlPermissionManager.updatePermissionReferences();
+		// NOTE: AdvancedConfiguration stuff will only get checked when clicking "Save" since
+		// checking for rules syntax while the user is still typing does not make much sense...
+		// now we can check for changes
+		metadataChanged = reactToChangeInternal();
+		permissionsChanged = MapHelper.hasChanged(originalCustomPermissions, customPermissions);
+		btnSaveChanges.setEnabled(metadataChanged || permissionsChanged);
+	}
+
+	/**
+	 * Checks whether the user changed any fields of the image details and
+	 * enables the save button if so.
+	 */
+	private boolean reactToChangeInternal() {
+		if (lecture == null)
+			return false;
+
+		boolean changed = false;
+		// mandatory fields checks
+		if (txtTitle.getText().isEmpty()) {
+			pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Allgemein"));
+			lblError.setText("Kein Veranstaltungsname gesetzt!");
+			return false;
+		}
+		if (txtDescription.getText().isEmpty()) {
+			pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Allgemein"));
+			lblError.setText("Keine Beschreibung angegeben!");
+			return false;
+		}
+		// version checkbox changed?
+		ImageVersionDetails currentVersion = cboVersions.getItemAt(cboVersions.getSelectedIndex());
+		if (currentVersion == null) {
+			pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Allgemein"));
+			lblError.setText("Keine Version ausgewählt!");
+			return false;
+		}
+		// Date stuff
+		Date start = DateTimeHelper.getDateFrom(dtpStartDate, spnStartTime);
+		Date end = DateTimeHelper.getDateFrom(dtpEndDate, spnEndTime);
+		if (!isPeriodValid(start, end, false) && dateHasChanged()) {
+			pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Allgemein"));
+			lblError.setText("Ungültiger Zeitraum!");
+			return false;
+		}
+
+		// done with mandatory checks, remove error message
+		lblError.setText(null);
+
+		// check for changes in all fields
+		changed = !txtTitle.getText().equals(lecture.getLectureName())
+				|| !txtDescription.getText().equals(lecture.getDescription())
+				|| !currentVersion.getVersionId().equals(lecture.getImageVersionId())
+				|| (DateTimeHelper.getDateFrom(dtpStartDate, spnStartTime).getTime() / 1000L) != lecture.getStartTime()
+				|| (DateTimeHelper.getDateFrom(dtpEndDate, spnEndTime).getTime() / 1000L) != lecture.getEndTime()
+				|| chkAutoUpdate.isSelected() != lecture.autoUpdate
+				|| chkIsExam.isSelected() != lecture.isExam
+				|| chkHasInternetAccess.isSelected() != lecture.hasInternetAccess
+				|| chkHasUsbAccess.isSelected() != lecture.hasUsbAccess
+				|| chkIsActive.isSelected() != lecture.isEnabled
+				|| !lecture.defaultPermissions.equals(originalDefaultPermissions)
+				|| (locationInfo != null && lecture.locationIds != null && !lecture.locationIds.equals(locationInfo.locationList))
+				|| (locationInfo != null && lecture.limitToLocations != locationInfo.limitToLocations)
+				|| (currentAdvConf != null && lecture.networkExceptions != null && !lecture.networkExceptions.equals(currentAdvConf.netRulesList))
+				|| (currentAdvConf != null && lecture.runscript != null && !lecture.runscript.equals(currentAdvConf.runScriptText))
+				|| imageLinkChanged;
+
+		return changed;
+	}
+
+	/**
+	 * Triggers the saving of the changes of this lecture
+	 * And inform the callback function about the outcome
 	 */
 	private void saveChanges() {
 		boolean saved = saveChangesInternal();
@@ -495,14 +628,30 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 			btnSaveChanges.setEnabled(true);
 	}
 
+	/**
+	 * Internal helper actually saving the changes to the satellite
+	 *
+	 * @return true if saving succeeded, false otherwise.
+	 */
 	private boolean saveChangesInternal() {
 		// check, whether autoupdate is selected and choose version accordingly
 		if (image != null) {
 			lecture.imageVersionId = chkAutoUpdate.isSelected() ? image.latestVersionId
 					: cboVersions.getItemAt(cboVersions.getSelectedIndex()).versionId;
 		}
+		// goto to advanced tab and check (by getting) the state of the textAreas
+		pnlTabs.setSelectedIndex(pnlTabs.indexOfTab("Erweitert"));
+		currentAdvConf = ctlAdvancedConfigurator.getState();
+		if (currentAdvConf == null) {
+			// getState() will return null only if it couldn't parse the rules
+			// which means that the user got informed about what was invalid
+			// So we just return here until the parsing works.
+			lblError.setText("Ungültiger Zeitraum!");
+			return false;
+		}
 		// now check if we need to push a new LectureWrite
 		if (metadataChanged) {
+			LOGGER.info("Trying to save...");
 			// first build the LectureWrite from the GUI fields
 			final LectureWrite metadata = new LectureWrite(txtTitle.getText(), txtDescription.getText(),
 					lecture.getImageVersionId(), chkAutoUpdate.isSelected(), chkIsActive.isSelected(),
@@ -588,100 +737,22 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 	}
 
 	/**
-	 * Checks whether the user changed any fields of the image details and
-	 * enables the save button if so.
-	 */
-	private void reactToChange() {
-		// check details fields
-		metadataChanged = reactToChangeInternal();
-		permissionsChanged = MapHelper.hasChanged(originalCustomPermissions, customPermissions);
-		btnSaveChanges.setEnabled(metadataChanged || permissionsChanged);
-	}
-
-	/**
-	 * Checks whether the user changed any fields of the image details and
-	 * enables the save button if so.
-	 */
-	private boolean reactToChangeInternal() {
-		if (lecture == null)
-			return false;
-
-		boolean changed = false;
-		// mandatory fields checks
-		if (txtTitle.getText().isEmpty()) {
-			lblError.setText("Kein Veranstaltungsname gesetzt!");
-			return false;
-		}
-		if (txtDescription.getText().isEmpty()) {
-			lblError.setText("Keine Beschreibung angegeben!");
-			return false;
-		}
-		// version checkbox changed?
-		ImageVersionDetails currentVersion = cboVersions.getItemAt(cboVersions.getSelectedIndex());
-		if (currentVersion == null) {
-			lblError.setText("Keine Version ausgewählt!");
-			return false;
-		}
-		// Date stuff
-		Date start = DateTimeHelper.getDateFrom(dtpStartDate, spnStartTime);
-		Date end = DateTimeHelper.getDateFrom(dtpEndDate, spnEndTime);
-		if (!isPeriodValid(start, end, false) && dateHasChanged()) {
-			lblError.setText("Ungültiger Zeitraum!");
-			return false;
-		}
-
-		// done with mandatory checks, remove error message
-		lblError.setText(null);
-
-		// check for changes in all fields
-		changed = !txtTitle.getText().equals(lecture.getLectureName())
-				|| !txtDescription.getText().equals(lecture.getDescription())
-				|| !currentVersion.getVersionId().equals(lecture.getImageVersionId())
-				|| (DateTimeHelper.getDateFrom(dtpStartDate, spnStartTime).getTime() / 1000L) != lecture.getStartTime()
-				|| (DateTimeHelper.getDateFrom(dtpEndDate, spnEndTime).getTime() / 1000L) != lecture.getEndTime()
-				|| chkAutoUpdate.isSelected() != lecture.autoUpdate
-				|| chkIsExam.isSelected() != lecture.isExam
-				|| chkHasInternetAccess.isSelected() != lecture.hasInternetAccess
-				|| chkHasUsbAccess.isSelected() != lecture.hasUsbAccess
-				|| chkIsActive.isSelected() != lecture.isEnabled
-				|| !lecture.defaultPermissions.equals(originalDefaultPermissions)
-				|| (locationInfo != null && lecture.locationIds != null && !lecture.locationIds.equals(locationInfo.locationList))
-				|| (locationInfo != null && lecture.limitToLocations != locationInfo.limitToLocations)
-				|| (currentAdvConf != null && lecture.networkExceptions != null && !lecture.networkExceptions.equals(currentAdvConf.netRulesList))
-				|| (currentAdvConf != null && lecture.runscript != null && !lecture.runscript.equals(currentAdvConf.runScriptText))
-				|| imageLinkChanged;
-
-		return changed;
-	}
-
-	/**
-	 * Enables/disables the editable fields based on 'editable'
-	 * 
-	 * @param editable true to make fields editable, false otherwise.
+	 * Enables/Disables the tabs based on the given flag 'editable'.
+	 *
+	 * @param editable when true, will enable the tabs if the user is allowed to see them.
+	 * If false, this will disable all tabs but the first tab "About".
 	 */
-	private void makeEditable(boolean editable) {
-		editable = editable && (LecturePerms.canEdit(lecture) || LecturePerms.canAdmin(lecture));
-		txtTitle.setEditable(editable);
-		txtDescription.setEditable(editable);
-		btnLinkImage.setEnabled(editable);
-		if (MetaDataCache.getLocations() == null)
-			btnLocations.setEnabled(editable);
-
-		//TODO Temporarily disabled until implemented
-		chkIsExam.setEnabled(false);
-		chkHasInternetAccess.setEnabled(false);
-//		chkIsExam.setEnabled(editable);
-//		chkHasInternetAccess.setEnabled(editable);
-		
-		chkIsActive.setEnabled(editable);
-		chkAutoUpdate.setEnabled(editable);
-		cboVersions.setEnabled(editable && !lecture.autoUpdate && image != null);
-		btnChangeOwner.setEnabled(editable && LecturePerms.canAdmin(lecture));
-		btnPermissions.setEnabled(editable && LecturePerms.canAdmin(lecture));
-		dtpStartDate.setEnabled(editable);
-		spnStartTime.setEnabled(editable);
-		dtpEndDate.setEnabled(editable);
-		spnEndTime.setEnabled(editable);
+	protected void toggleEditable(boolean editable) {
+		// if we don't have a lecture and an image set, just disable
+		editable &= (LecturePerms.canEdit(lecture));
+		// "Übersicht" is always enabled
+		pnlTabs.setEnabledAt(pnlTabs.indexOfTab("Allgemein"), editable);
+		pnlTabs.setEnabledAt(pnlTabs.indexOfTab("Beschränkungen"), editable);
+		pnlTabs.setEnabledAt(pnlTabs.indexOfTab("Berechtigungen"), editable && LecturePerms.canAdmin(lecture));
+		pnlTabs.setEnabledAt(pnlTabs.indexOfTab("Raumauswahl"), editable);
+		pnlTabs.setEnabledAt(pnlTabs.indexOfTab("Erweitert"), editable);
+		// special shit for those shitty special buttons....
+		btnChangeOwner.setEnabled(LecturePerms.canAdmin(lecture));
 		btnDownloadImage.setEnabled(ImagePerms.canDownload(image));
 	}
 
@@ -733,6 +804,10 @@ public class LectureDetailsWindow extends LectureDetailsWindowLayout implements
 				&& !Gui.showMessageBox(me, "Änderungen werden verworfen, wollen Sie wirklich schließen?",
 						MessageType.QUESTION_YESNO, null, null))
 			return;
+		synchronized(me) {
+			lecture = null;
+			image = null;
+		}
 		dispose();
 	}
 }