implemented rank gain/loss column with icons

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/FormattedDoubleLegDetailColumn.java

@@ -1,15 +1,16 @@
 package com.sap.sailing.gwt.ui.client;
 
+import com.google.gwt.cell.client.TextCell;
 import com.google.gwt.i18n.client.NumberFormat;
 import com.sap.sailing.gwt.ui.shared.LeaderboardRowDAO;
 
-public class FormattedDoubleLegDetailColumn extends LegDetailColumn<Double> {
+public class FormattedDoubleLegDetailColumn extends LegDetailColumn<Double, String> {
     private final NumberFormat formatter;
     
     public FormattedDoubleLegDetailColumn(String title,
             com.sap.sailing.gwt.ui.client.LegDetailColumn.LegDetailField<Double> field,
             int decimals) {
-        super(title, field);
+        super(title, field, new TextCell());
         StringBuilder patternBuilder = new StringBuilder("0");
         if (decimals > 0) {
             patternBuilder.append('.');

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/LegColumn.java

@@ -60,7 +60,7 @@ public class LegColumn extends ExpandableSortableColumn<String> {
                 return null;
             } else {
                 LegEntryDAO previousEntry = getLegEntry(row, getLegIndex()-1);
-                return previousEntry == null ? null : previousEntry.rank - legEntry.rank;
+                return previousEntry == null ? null : legEntry.rank - previousEntry.rank;
             }
         }
     }
@@ -131,7 +131,7 @@ public class LegColumn extends ExpandableSortableColumn<String> {
         try {
             result.add(new FormattedDoubleLegDetailColumn(stringConstants.distanceInMeters(), new DistanceTraveledInMeters(), 1));
             result.add(new FormattedDoubleLegDetailColumn(stringConstants.averageSpeedInKnots(), new AverageSpeedOverGroundInKnots(), 2));
-            result.add(new LegDetailColumn<Integer>(stringConstants.rankGain(), new RankGain()));
+            result.add(new RankGainColumn(stringConstants.rankGain(), new RankGain()));
             return result;
         } catch (Exception e) {
             throw new RuntimeException(e);

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/LegDetailColumn.java

@@ -2,21 +2,21 @@ package com.sap.sailing.gwt.ui.client;
 
 import java.util.Comparator;
 
-import com.google.gwt.cell.client.TextCell;
+import com.google.gwt.cell.client.Cell;
 import com.google.gwt.user.cellview.client.Header;
 import com.google.gwt.user.cellview.client.TextHeader;
 import com.sap.sailing.gwt.ui.shared.LeaderboardRowDAO;
 
-public class LegDetailColumn<T> extends SortableColumn<LeaderboardRowDAO, String> {
+public abstract class LegDetailColumn<FieldType, RenderingType> extends SortableColumn<LeaderboardRowDAO, RenderingType> {
     private final String title;
-    private final LegDetailField<T> field;
+    private final LegDetailField<FieldType> field;
     
     public interface LegDetailField<T> {
         T get(LeaderboardRowDAO row);
     }
     
-    protected LegDetailColumn(String title, LegDetailField<T> field) {
-        super(new TextCell());
+    protected LegDetailColumn(String title, LegDetailField<FieldType> field, Cell<RenderingType> cell) {
+        super(cell);
         setHorizontalAlignment(ALIGN_RIGHT);
         this.title = title;
         this.field = field;
@@ -26,7 +26,7 @@ public class LegDetailColumn<T> extends SortableColumn<LeaderboardRowDAO, String
         return title;
     }
 
-    protected LegDetailField<T> getField() {
+    protected LegDetailField<FieldType> getField() {
         return field;
     }
 
@@ -37,8 +37,8 @@ public class LegDetailColumn<T> extends SortableColumn<LeaderboardRowDAO, String
             public int compare(LeaderboardRowDAO o1, LeaderboardRowDAO o2) {
                 try {
                     @SuppressWarnings("unchecked")
-                    Comparable<T> value1 = (Comparable<T>) field.get(o1);
-                    T value2 = field.get(o2);
+                    Comparable<FieldType> value1 = (Comparable<FieldType>) field.get(o1);
+                    FieldType value2 = field.get(o2);
                     return value1 == null ? value2 == null ? 0 : -1 : value2 == null ? 1 : value1.compareTo(value2);
                 } catch (Exception e) {
                     throw new RuntimeException(e);
@@ -52,9 +52,4 @@ public class LegDetailColumn<T> extends SortableColumn<LeaderboardRowDAO, String
         return new TextHeader(title);
     }
 
-    @Override
-    public String getValue(LeaderboardRowDAO row) {
-        T fieldValue = field.get(row);
-        return fieldValue == null ? "" : fieldValue.toString();
-    }
 }

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/RankGainColumn.java

@@ -0,0 +1,49 @@
+package com.sap.sailing.gwt.ui.client;
+
+import com.google.gwt.cell.client.AbstractSafeHtmlCell;
+import com.google.gwt.safehtml.shared.SafeHtml;
+import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
+import com.google.gwt.text.shared.SafeHtmlRenderer;
+import com.sap.sailing.gwt.ui.shared.LeaderboardRowDAO;
+
+public class RankGainColumn extends LegDetailColumn<Integer, Integer> {
+    public RankGainColumn(String title, LegDetailField<Integer> field) {
+        super(title, field, new RankGainCell());
+    }
+
+    @Override
+    public Integer getValue(LeaderboardRowDAO row) {
+        return getField().get(row);
+    }
+
+    private static class RankGainCell extends AbstractSafeHtmlCell<Integer> {
+        public RankGainCell() {
+            super(new SafeHtmlRenderer<Integer>() {
+                @Override
+                public SafeHtml render(Integer rank) {
+                    SafeHtmlBuilder builder = new SafeHtmlBuilder();
+                    render(rank, builder);
+                    return builder.toSafeHtml();
+                }
+
+                @Override
+                public void render(Integer rankDelta, SafeHtmlBuilder builder) {
+                    if (rankDelta != null) {
+                        if (rankDelta < 0) {
+                            builder.appendHtmlConstant("<img src=\"/images/arrow-gain.png\"/>");
+                        } else if (rankDelta > 0) {
+                            builder.appendHtmlConstant("<img src=\"/images/arrow-loss.png\"/>");
+                        }
+                        builder.append(Math.abs(rankDelta));
+                    }
+                }
+            });
+        }
+
+        @Override
+        protected void render(com.google.gwt.cell.client.Cell.Context context, SafeHtml data, SafeHtmlBuilder sb) {
+            sb.append(data);
+        }
+    }
+
+}

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/StringRenderingLegDetailColumn.java

@@ -0,0 +1,18 @@
+package com.sap.sailing.gwt.ui.client;
+
+import com.google.gwt.cell.client.TextCell;
+import com.sap.sailing.gwt.ui.shared.LeaderboardRowDAO;
+
+public class StringRenderingLegDetailColumn<FieldType> extends LegDetailColumn<FieldType, String> {
+
+    protected StringRenderingLegDetailColumn(String title,
+            com.sap.sailing.gwt.ui.client.LegDetailColumn.LegDetailField<FieldType> field) {
+        super(title, field, new TextCell());
+    }
+
+    @Override
+    public String getValue(LeaderboardRowDAO row) {
+        FieldType fieldValue = getField().get(row);
+        return fieldValue == null ? "" : fieldValue.toString();
+    }
+}