Bug395283 - Persistence realized (variant 2)

bundles/org.eclipse.e4.tools.emf.ui/src/org/eclipse/e4/tools/emf/ui/internal/ToolsEmfUiPlugin.java

@@ -10,24 +10,35 @@
  ******************************************************************************/
 package org.eclipse.e4.tools.emf.ui.internal;
 
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import org.eclipse.core.runtime.URIUtil;
 import org.eclipse.jface.dialogs.DialogSettings;
 import org.eclipse.jface.dialogs.IDialogSettings;
+import org.eclipse.osgi.service.datalocation.Location;
 import org.osgi.framework.BundleActivator;
 import org.osgi.framework.BundleContext;
+import org.osgi.framework.Filter;
+import org.osgi.framework.InvalidSyntaxException;
+import org.osgi.util.tracker.ServiceTracker;
 
 public class ToolsEmfUiPlugin implements BundleActivator {
 	// The plug-in ID
 	public static final String PLUGIN_ID = "org.eclipse.e4.tools.emf.ui"; //$NON-NLS-1$
 
 	private static ToolsEmfUiPlugin plugin;
+	private BundleContext context;
 
-	public static DialogSettings dialogSettings;
+	private ServiceTracker locationTracker;
 
 	public void start(BundleContext context) throws Exception {
 		plugin = this;
+		this.context = context;
 	}
 
 	public void stop(BundleContext context) throws Exception {
+		saveDialogSettings();
 		plugin = null;
 	}
 
@@ -40,19 +51,94 @@ public static ToolsEmfUiPlugin getDefault() {
 		return plugin;
 	}
 
+	/**
+	 * @return the instance Location service
+	 */
+	private Location getInstanceLocation() {
+		if (locationTracker == null) {
+			Filter filter = null;
+			try {
+				filter = context.createFilter(Location.INSTANCE_FILTER);
+			} catch (InvalidSyntaxException e) {
+				// ignore this. It should never happen as we have tested the
+				// above format.
+			}
+			locationTracker = new ServiceTracker(context, filter, null);
+			locationTracker.open();
+		}
+		return (Location) locationTracker.getService();
+	}
+
+	private void loadDialogSettings() {
+		dialogSettings = new DialogSettings(PLUGIN_ID);
+
+		File dialogSettingsFile = getDialogSettingsFile();
+
+		if (dialogSettingsFile.exists()) {
+			try {
+				dialogSettings.load(dialogSettingsFile.getAbsolutePath());
+			} catch (IOException e) {
+				// load failed spec'ed to ignore problems
+			}
+			return;
+		}
+
+	}
+
+	private void saveDialogSettings() {
+		if (dialogSettings == null) {
+			return;
+		}
+
+		File dialogSettingsFile = getDialogSettingsFile();
+
+		try {
+			dialogSettings.save(dialogSettingsFile.getAbsolutePath());
+		} catch (IOException e) {
+			e.printStackTrace();
+			// spec'ed to ignore problems
+		}
+	}
+
+	private File getDialogSettingsFile() {
+		File baseLocation;
+		try {
+			baseLocation = new File(URIUtil.toURI(getInstanceLocation().getURL()));
+		} catch (URISyntaxException e) {
+			throw new RuntimeException(e);
+		}
+		baseLocation = new File(baseLocation, ".metadata"); //$NON-NLS-1$
+		baseLocation = new File(baseLocation, ".plugins"); //$NON-NLS-1$
+		baseLocation = new File(baseLocation, PLUGIN_ID);
+		File dialogSettingsFile = new File(baseLocation, FN_DIALOG_SETTINGS);
+		if (!dialogSettingsFile.exists())
+			dialogSettingsFile.getParentFile().mkdirs();
+		return dialogSettingsFile;
+	}
+
+	// //////////////////////////////////////////////////////////////////////
+	// The following code was copied from AbstractUIPlugin class.
+	/**
+	 * The name of the dialog settings file (value
+	 * <code>"dialog_settings.xml"</code>).
+	 */
+	private static final String FN_DIALOG_SETTINGS = "dialog_settings.xml"; //$NON-NLS-1$
+	/**
+	 * Storage for dialog and wizard data; <code>null</code> if not yet
+	 * initialized.
+	 */
+	private IDialogSettings dialogSettings = null;
+
 	/**
 	 * @see AbstractUiPlugin#getDialogSettings()
 	 * @return the dialog settings
 	 */
 	public IDialogSettings getDialogSettings() {
-		if (dialogSettings == null)
+		if (dialogSettings == null) {
 			loadDialogSettings();
-		return dialogSettings;
-	}
+		}
 
-	private void loadDialogSettings() {
-		// copy from AbstracUiPlugin
-		dialogSettings = new DialogSettings(PLUGIN_ID);
+		return dialogSettings;
 	}
 
 }