1 files changed, 103 insertions, 0 deletions
diff --git a/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/AbstractHelpListener.java b/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/AbstractHelpListener.java
new file mode 100644
index 00000000..6fd1ffea
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+++ b/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/AbstractHelpListener.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2008 Federal Chancellery Austria and
+ * Graz University of Technology
+ * 
+ * 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 at.gv.egiz.bku.gui;
+
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Locale;
+import java.util.ResourceBundle;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Implement the showDocument(URL) method to provide an actual HelpListener.
+ * This class does not keep a GUI reference and subclasses should not interfere with the GUI.
+ * Therefore, any errors occurring in showDocument() should be handled/displayed within
+ * showDocument() and exceptions thrown from showDocument() are logged, not displayed in the GUI.
+ * <br/>
+ * The help URL is build as [baseURL]/[locale]/[helpTopic].html
+ * (note that no session information is contained).
+ * 
+ * @author Clemens Orthacker <clemens.orthacker@iaik.tugraz.at>
+ */
+public abstract class AbstractHelpListener implements ActionListener {
+
+  /**
+   * any locale not in the list will be mapped to 'de'
+   */
+  public static final String[] SUPPORTED_LANGUAGES = new String[] { "de" };
+  
+  protected final static Log log = LogFactory.getLog(AbstractHelpListener.class);
+  protected URL baseURL;
+  protected Locale locale;
+  protected ResourceBundle messages;
+
+  public AbstractHelpListener(URL baseURL, Locale locale) {
+    if (baseURL == null || "".equals(baseURL.toString())) {
+      throw new RuntimeException("no help URL provided");
+    }
+    this.baseURL = baseURL;
+    this.locale = locale;
+    if (locale != null) {
+      messages = ResourceBundle.getBundle(BKUGUIFacade.MESSAGES_BUNDLE, locale);
+    } else {
+      messages = ResourceBundle.getBundle(BKUGUIFacade.MESSAGES_BUNDLE);
+    }
+  }
+
+  @Override
+  public void actionPerformed(ActionEvent e) {
+    log.debug("received help action: " + e.getActionCommand());
+    URL helpURL = constructHelpURL(baseURL, e.getActionCommand());
+    try {
+      showDocument(helpURL, e.getActionCommand());
+    } catch (Exception ex) {
+      log.error("could not display help document " + helpURL + ": " + ex.getMessage());
+    }
+  }
+
+  private URL constructHelpURL(URL baseURL, String helpTopic) {
+    URL helpURL = baseURL;
+    log.trace("constructing help URL: " + helpURL);
+    try {
+      // not localized for now
+      //check if locale.getLanguage() supported and add default if not
+//      if (locale != null) {
+//        helpURL = new URL(helpURL, locale.toString() + "/");
+//        log.trace("constructing help URL: " + helpURL);
+//      }
+      if (helpTopic != null && !"".equals(helpTopic)) {
+        helpURL = new URL(helpURL, "de/" + helpTopic + ".html");
+        log.trace("constructing help URL: " + helpURL);
+      }
+    } catch (MalformedURLException ex) {
+      log.error("Failed to construct help URL for help item " + helpTopic + ": " + ex.getMessage());
+    }
+    return helpURL;
+  }
+
+  /**
+   * Errors from HelpListeners should not (are not) displayed in the applet, 
+   * but should rather be in the HelpListener specific way.
+   * Therefore, implementations SHOULD NOT throw exceptions (these are only logged).
+   * @param helpDocument
+   * @throws java.lang.Exception
+   */
+  public abstract void showDocument(URL helpDocument, String helpTopic) throws Exception;
+}