improved the way the UI informed about the change of the selected leaderboard in a multileaderobard

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/home/desktop/partials/old/multileaderboard/OldMultiLeaderboard.java

@@ -28,6 +28,8 @@ import com.sap.sailing.gwt.home.desktop.partials.old.LeaderboardDelegate;
 import com.sap.sailing.gwt.ui.client.DebugIdHelper;
 import com.sap.sailing.gwt.ui.client.StringMessages;
 import com.sap.sailing.gwt.ui.common.client.DateAndTimeFormatterUtil;
+import com.sap.sailing.gwt.ui.leaderboard.LeaderboardPanel;
+import com.sap.sailing.gwt.ui.leaderboard.SelectedLeaderboardChangeListener;
 import com.sap.sailing.gwt.ui.leaderboard.LeaderboardSettings;
 import com.sap.sailing.gwt.ui.leaderboard.MultiLeaderboardPanel;
 import com.sap.sailing.gwt.ui.leaderboard.ScoringSchemeTypeFormatter;
@@ -36,7 +38,7 @@ import com.sap.sse.gwt.client.player.Timer.PlayModes;
 import com.sap.sse.gwt.client.player.Timer.PlayStates;
 import com.sap.sse.gwt.client.shared.components.SettingsDialog;
 
-public class OldMultiLeaderboard extends Composite {
+public class OldMultiLeaderboard extends Composite implements SelectedLeaderboardChangeListener {
     private static OldMultiLeaderboardUiBinder uiBinder = GWT.create(OldMultiLeaderboardUiBinder.class);
 
     interface OldMultiLeaderboardUiBinder extends UiBinder<Widget, OldMultiLeaderboard> {
@@ -169,16 +171,12 @@ public class OldMultiLeaderboard extends Composite {
     public void setMultiLeaderboard(MultiLeaderboardPanel multiLeaderboardPanel, final Timer timer) {
         this.autoRefreshTimer = timer;
         this.multiLeaderboardPanel = multiLeaderboardPanel;
+        this.multiLeaderboardPanel.addSelectedLeaderboardChangeListener(this);
 
         oldMultiLeaderboardPanel.add(multiLeaderboardPanel);
     }
 
     public void updatedMultiLeaderboard(LeaderboardDTO leaderboard, boolean hasLiveRace) {
-        if(multiLeaderboardPanel.getSelectedLeaderboardPanel() != null) {
-            busyIndicatorDiv.removeAllChildren();
-            busyIndicatorDiv.appendChild(multiLeaderboardPanel.getSelectedLeaderboardPanel().getBusyIndicator().getElement());
-            busyIndicatorDiv.appendChild(emptyDivElement);
-        }
         if(leaderboard != null) {
             String comment = leaderboard.getComment() != null ? leaderboard.getComment() : "";
             String scoringScheme = leaderboard.scoringScheme != null ? ScoringSchemeTypeFormatter.getDescription(leaderboard.scoringScheme, StringMessages.INSTANCE) : "";
@@ -209,6 +207,13 @@ public class OldMultiLeaderboard extends Composite {
             }
         }
     }
+
+    @Override
+    public void onSelectedLeaderboardChanged(LeaderboardPanel selectedLeaderboard) {
+        busyIndicatorDiv.removeAllChildren();
+        busyIndicatorDiv.appendChild(selectedLeaderboard.getBusyIndicator().getElement());
+        busyIndicatorDiv.appendChild(emptyDivElement);
+    }
     
     public interface OldMultiLeaderboardDelegate extends LeaderboardDelegate<MultiLeaderboardPanel>{
     }

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/leaderboard/MultiLeaderboardPanel.java

@@ -3,8 +3,10 @@ package com.sap.sailing.gwt.ui.leaderboard;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import com.google.gwt.core.shared.GWT;
 import com.google.gwt.dom.client.Style.FontWeight;
@@ -35,7 +37,7 @@ import com.sap.sse.gwt.client.useragent.UserAgentDetails;
  * A panel managing multiple {@link LeaderboardPanel}s (e.g. from a meta leaderboard) so that the user can switch between them. 
  * @author Frank
  */
-public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSettings> implements TimeListener {
+public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSettings> implements TimeListener, SelectedLeaderboardChangeProvider {
 
     private LeaderboardPanel selectedLeaderboardPanel;
     private FlowPanel selectedLeaderboardFlowPanel;
@@ -60,7 +62,8 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
     private final String metaLeaderboardName;
     private final boolean isEmbedded;
 
-    private List<LeaderboardUpdateListener> leaderboardUpdateListener;
+    private final Set<LeaderboardUpdateListener> leaderboardUpdateListeners;
+    private final Set<SelectedLeaderboardChangeListener> selectedLeaderboardChangeListeners;
 
     public MultiLeaderboardPanel(SailingServiceAsync sailingService, String metaLeaderboardName, AsyncActionsExecutor asyncActionsExecutor,
             Timer timer, boolean isEmbedded, String preselectedLeaderboardName, RaceIdentifier preselectedRace, 
@@ -81,7 +84,8 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
         selectedLeaderboardPanel = null;
         leaderboardNamesAndDisplayNames = new ArrayList<Util.Pair<String, String>>();
         leaderboardNamesAndSettings = new HashMap<String, LeaderboardSettings>();
-        leaderboardUpdateListener = new ArrayList<LeaderboardUpdateListener>();
+        leaderboardUpdateListeners = new HashSet<LeaderboardUpdateListener>();
+        selectedLeaderboardChangeListeners = new HashSet<SelectedLeaderboardChangeListener>();
     }
 
     private LeaderboardSettings getOrCreateLeaderboardSettings(String leaderboardName, LeaderboardSettings currentLeaderboardSettings) {
@@ -152,7 +156,7 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
     }
 
     public void addLeaderboardUpdateListener(LeaderboardUpdateListener listener) {
-        this.leaderboardUpdateListener.add(listener);
+        this.leaderboardUpdateListeners.add(listener);
     }
 
     public void setLeaderboardNames(List<Util.Pair<String, String>> newLeaderboardNamesAndDisplayNames) {
@@ -177,10 +181,10 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
         });
     }
     
-    public LeaderboardPanel getSelectedLeaderboardPanel() {
-        return selectedLeaderboardPanel;
-    }
-    
+//    public LeaderboardPanel getSelectedLeaderboardPanel() {
+//        return selectedLeaderboardPanel;
+//    }
+//    
     private void updateLeaderboardSelection() {
         if(leaderboardsTabPanel != null) {
             leaderboardsTabPanel.clear();
@@ -219,16 +223,16 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
             
             selectedLeaderboardFlowPanel = (FlowPanel) leaderboardsTabPanel.getWidget(newTabIndex);
             LeaderboardSettings newLeaderboardSettings = getOrCreateLeaderboardSettings(newSelectedLeaderboardName, leaderboardNamesAndSettings.get(selectedLeaderboardName));
-            selectedLeaderboardPanel = new LeaderboardPanel(sailingService, asyncActionsExecutor, newLeaderboardSettings, isEmbedded,
+            LeaderboardPanel newSelectedLeaderboardPanel = new LeaderboardPanel(sailingService, asyncActionsExecutor, newLeaderboardSettings, isEmbedded,
                     /* preselectedRace*/ null, new CompetitorSelectionModel(true), timer,
                     null, newSelectedLeaderboardName, errorReporter, stringMessages, userAgent,
                     showRaceDetails, /* competitorSearchTextBox */ null, /* showSelectionCheckbox */ true,  /* raceTimesInfoProvider */null, 
                     false, /* adjustTimerDelay */ true, /*autoApplyTopNFilter*/ false, false);
-            selectedLeaderboardFlowPanel.add(selectedLeaderboardPanel);
-            for(LeaderboardUpdateListener listener: leaderboardUpdateListener) {
-                selectedLeaderboardPanel.addLeaderboardUpdateListener(listener);
+            selectedLeaderboardFlowPanel.add(newSelectedLeaderboardPanel);
+            for(LeaderboardUpdateListener listener: leaderboardUpdateListeners) {
+                newSelectedLeaderboardPanel.addLeaderboardUpdateListener(listener);
             }
-            
+            setSelectedLeaderboard(newSelectedLeaderboardPanel);
         } else {
             if(selectedLeaderboardPanel != null && selectedLeaderboardFlowPanel != null) {
                 selectedLeaderboardPanel.removeAllListeners();
@@ -258,4 +262,23 @@ public class MultiLeaderboardPanel extends AbstractLazyComponent<LeaderboardSett
         }
     }
 
+    @Override
+    public void addSelectedLeaderboardChangeListener(SelectedLeaderboardChangeListener listener) {
+        selectedLeaderboardChangeListeners.add(listener);
+    }
+
+    @Override
+    public void removeSelectedLeaderboardChangeListener(SelectedLeaderboardChangeListener listener) {
+        selectedLeaderboardChangeListeners.remove(listener);
+    }
+
+    @Override
+    public void setSelectedLeaderboard(LeaderboardPanel selectedLeaderboard) {
+        if(this.selectedLeaderboardPanel != selectedLeaderboard) {
+            this.selectedLeaderboardPanel = selectedLeaderboard;
+            for (SelectedLeaderboardChangeListener listener : selectedLeaderboardChangeListeners) {
+                listener.onSelectedLeaderboardChanged(selectedLeaderboardPanel);
+            }
+        }
+    }
 }

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/leaderboard/SelectedLeaderboardChangeListener.java

@@ -0,0 +1,14 @@
+package com.sap.sailing.gwt.ui.leaderboard;
+
+
+/**
+ * Allows UI components to observe a change of the selected leaderboard in a Multi-Leaderboard scenario.
+ */
+public interface SelectedLeaderboardChangeListener {
+
+    /**
+     * @param selectedLeaderboard the selected non-<code>null</code> LeaderboardPanel 
+     */
+    void onSelectedLeaderboardChanged(LeaderboardPanel selectedLeaderboard);
+
+}

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/leaderboard/SelectedLeaderboardChangeProvider.java

@@ -0,0 +1,11 @@
+package com.sap.sailing.gwt.ui.leaderboard;
+
+
+public interface SelectedLeaderboardChangeProvider {
+
+    void addSelectedLeaderboardChangeListener(SelectedLeaderboardChangeListener listener);
+
+    void removeSelectedLeaderboardChangeListener(SelectedLeaderboardChangeListener listener);
+    
+    void setSelectedLeaderboard(LeaderboardPanel selectedLeaderboard);
+}