[client] Common parent class for pages shown in the main window. Do not dispose and create pages every time, instead show and hide them as needed

1 files changed, 50 insertions, 16 deletions

diff --git a/dozentenmodul/src/main/java/org/openslx/dozmod/gui/MainWindow.java b/dozentenmodul/src/main/java/org/openslx/dozmod/gui/MainWindow.java
index aef307d6..2aed0ff5 100644
--- a/dozentenmodul/src/main/java/org/openslx/dozmod/gui/MainWindow.java
+++ b/dozentenmodul/src/main/java/org/openslx/dozmod/gui/MainWindow.java
@@ -1,6 +1,8 @@
 package org.openslx.dozmod.gui;
 
 import java.lang.reflect.Constructor;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.log4j.Logger;
 import org.eclipse.swt.SWT;
@@ -15,10 +17,12 @@ import org.eclipse.swt.widgets.Menu;
 import org.eclipse.swt.widgets.MenuItem;
 import org.eclipse.swt.widgets.Shell;
 import org.openslx.dozmod.Config;
+import org.openslx.dozmod.gui.helper.CompositePage;
 import org.openslx.dozmod.gui.helper.Gui;
 import org.openslx.dozmod.gui.helper.Gui.GuiCallable;
 import org.openslx.dozmod.gui.helper.MessageType;
 import org.openslx.dozmod.gui.window.DisclaimerWindow;
+import org.openslx.dozmod.gui.window.ImageListWindow;
 import org.openslx.dozmod.gui.window.LoginWindow;
 import org.openslx.dozmod.gui.window.MainMenuWindow;
 import org.openslx.dozmod.gui.window.VirtualizerNoticeWindow;
@@ -31,26 +35,36 @@ public abstract class MainWindow {
 	private final static Logger LOGGER = Logger.getLogger(MainWindow.class);
 
 	private static final Shell mainShell;
-	private static Composite contentComposite;
+	private static CompositePage currentPage;
+
+	private static final Map<Class<? extends CompositePage>, CompositePage> pages = new ConcurrentHashMap<>();
 
 	private static final String THRIFT_CONNECTION_ERROR = "Lost connection to the masterserver. Do you want to retry?";
 
 	/**
-	 * Add a new composite with content to the main Shell
+	 * Set the visible page of the main window.
 	 * 
-	 * @param The composite to add, should be a GUI
+	 * @param clazz
 	 */
-	public static void setContent(Composite contentComposite) {
-
-		if (contentComposite == null)
-			return;
-		if (MainWindow.contentComposite != null)
-			MainWindow.contentComposite.dispose();
+	public static void showPage(Class<? extends CompositePage> clazz) {
+		if (currentPage != null && currentPage.getLayoutData() != null) {
+			if (!currentPage.hide()) {
+				return; // Canceled by currently shown page
+			}
+			((GridData) currentPage.getLayoutData()).exclude = true;
+			currentPage.setVisible(false);
+		}
 
-		MainWindow.contentComposite = contentComposite;
+		currentPage = pages.get(clazz);
+		if (currentPage == null) {
+			showMessageBox("Tried to show unknown page " + clazz.getSimpleName(), MessageType.ERROR, LOGGER, null);
+			System.exit(1);
+		}
 
 		// sets the starting preferred size.
-		contentComposite.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true));
+		currentPage.show();
+		((GridData)currentPage.getLayoutData()).exclude = false;
+		currentPage.setVisible(true);
 		mainShell.layout();
 	}
 
@@ -68,7 +82,8 @@ public abstract class MainWindow {
 			con = clazz.getConstructor(Shell.class);
 			con.newInstance(dialogShell);
 		} catch (Exception e1) {
-			Gui.showMessageBox(mainShell, "Cannot show popup " + clazz.getName(), MessageType.DEBUG, LOGGER, e1);
+			Gui.showMessageBox(mainShell, "Cannot show popup " + clazz.getName(), MessageType.DEBUG, LOGGER,
+					e1);
 			return;
 		}
 
@@ -96,8 +111,8 @@ public abstract class MainWindow {
 				return Gui.syncExec(new GuiCallable<Boolean>() {
 					@Override
 					public Boolean run() {
-						return Gui.showMessageBox(mainShell, THRIFT_CONNECTION_ERROR, MessageType.ERROR_RETRY,
-								LOGGER, t);
+						return Gui.showMessageBox(mainShell, THRIFT_CONNECTION_ERROR,
+								MessageType.ERROR_RETRY, LOGGER, t);
 					}
 				});
 			}
@@ -134,8 +149,11 @@ public abstract class MainWindow {
 		mainShell.setLayout(new GridLayout(1, true));
 		mainShell.setMinimumSize(850, 650);
 
-		// always show the main menu
-		setContent(new MainMenuWindow(mainShell));
+		// register all pages of the main window
+		registerPage(new MainMenuWindow(mainShell));
+		registerPage(new ImageListWindow(mainShell));
+		// Show main menu by default
+		showPage(MainMenuWindow.class);
 
 		// center the window on the primary monitor
 		Gui.centerShell(mainShell);
@@ -160,6 +178,22 @@ public abstract class MainWindow {
 		}
 	}
 
+	/**
+	 * Register a page that can be displayed in the main window.
+	 * 
+	 * @param window
+	 */
+	private static synchronized void registerPage(CompositePage window) {
+		Class<? extends CompositePage> clazz = window.getClass();
+		if (pages.containsKey(clazz))
+			throw new IllegalArgumentException("Page " + clazz.getSimpleName() + " already registered!");
+		pages.put(clazz, window);
+		GridData gd = new GridData(GridData.FILL, GridData.FILL, true, true);
+		gd.exclude = true;
+		window.setLayoutData(gd);
+		window.setVisible(false);
+	}
+
 	private static void createMenu() {
 		// the File menu button
 		Menu menuBar = new Menu(mainShell, SWT.BAR);