Aggregated stats: ordered by number number of tracks per category.

src/main/java/de/dennisguse/opentracks/viewmodels/AggregatedStatistics.java

@@ -1,6 +1,10 @@
 package de.dennisguse.opentracks.viewmodels;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -10,50 +14,62 @@ import de.dennisguse.opentracks.stats.TrackStatistics;
 
 public class AggregatedStatistics {
 
-    private final Map<String, AggregatedStatistic> aggregatedStatistics = new HashMap<>();
+    private final Map<String, AggregatedStatistic> dataMap = new HashMap<>();
 
-    public void aggregate(List<Track> tracks) {
+    private final List<AggregatedStatistic> dataList = new ArrayList<>();
+
+    public AggregatedStatistics(@NonNull List<Track> tracks) {
         for (Track track : tracks) {
             aggregate(track);
         }
+
+        dataList.addAll(dataMap.values());
+        Collections.sort(dataList, (o1, o2) -> {
+            if (o1.getCountTracks() == o2.getCountTracks()) {
+                return o1.getCategory().compareTo(o2.getCategory());
+            }
+            return (o1.getCountTracks() < o2.getCountTracks() ? 1 : -1);
+        });
     }
 
-    public void aggregate(Track track) {
+    @VisibleForTesting
+    public void aggregate(@NonNull Track track) {
         String category = track.getCategory();
-        if (aggregatedStatistics.containsKey(category)) {
-            aggregatedStatistics.get(category).add(track.getTrackStatistics());
+        if (dataMap.containsKey(category)) {
+            dataMap.get(category).add(track.getTrackStatistics());
         } else {
-            aggregatedStatistics.put(category, new AggregatedStatistic(track.getTrackStatistics()));
+            dataMap.put(category, new AggregatedStatistic(category, track.getTrackStatistics()));
         }
     }
 
     public int getCount() {
-        return aggregatedStatistics.size();
-    }
-
-    public String getSportName(int position) {
-        return getKey(position);
+        return dataMap.size();
     }
 
     public AggregatedStatistic get(String category) {
-        return aggregatedStatistics.get(category);
+        return dataMap.get(category);
     }
 
-    private String getKey(int position) {
-        return (new ArrayList<>(aggregatedStatistics.keySet())).get(position);
+    public String getCategory(int position) {
+        return dataList.get(position).getCategory();
     }
 
     public AggregatedStatistic getItem(int position) {
-        return (new ArrayList<>(aggregatedStatistics.values())).get(position);
+        return dataList.get(position);
     }
 
     public static class AggregatedStatistic {
+        private final String category;
         private final TrackStatistics trackStatistics;
-        private int countTracks;
+        private int countTracks = 1;
 
-        public AggregatedStatistic(TrackStatistics trackStatistics) {
+        public AggregatedStatistic(String category, TrackStatistics trackStatistics) {
+            this.category = category;
             this.trackStatistics = trackStatistics;
-            this.countTracks = 1;
+        }
+
+        public String getCategory() {
+            return category;
         }
 
         public TrackStatistics getTrackStatistics() {