Sort app list after smeared on screen

Then we could make sure the app list is sorted

Bug: 62035385
Test: RunSettingsRoboTests
Change-Id: I3fa3d6ffc5930cf011e382632143e459fdbc4369

src/com/android/settings/fuelgauge/BatteryUtils.java

@@ -33,6 +33,8 @@ import com.android.settings.overlay.FeatureFactory;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 
 /**
@@ -247,6 +249,18 @@ public class BatteryUtils {
         return ArrayUtils.isEmpty(packageNames) ? null : packageNames[0];
     }
 
+    /**
+     * Sort the {@code usageList} based on {@link BatterySipper#totalPowerMah}
+     */
+    public void sortUsageList(List<BatterySipper> usageList) {
+        Collections.sort(usageList, new Comparator<BatterySipper>() {
+            @Override
+            public int compare(BatterySipper a, BatterySipper b) {
+                return Double.compare(b.totalPowerMah, a.totalPowerMah);
+            }
+        });
+    }
+
     private long convertUsToMs(long timeUs) {
         return timeUs / 1000;
     }

src/com/android/settings/fuelgauge/PowerUsageSummary.java

@@ -77,8 +77,6 @@ import com.android.settingslib.widget.FooterPreferenceMixin;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
-import java.util.Comparator;
 import java.util.List;
 
 /**
@@ -401,7 +399,7 @@ public class PowerUsageSummary extends PowerUsageBase implements
      *
      * @return A sorted list of apps using power.
      */
-    private static List<BatterySipper> getCoalescedUsageList(final List<BatterySipper> sippers) {
+    private List<BatterySipper> getCoalescedUsageList(final List<BatterySipper> sippers) {
         final SparseArray<BatterySipper> uidList = new SparseArray<>();
 
         final ArrayList<BatterySipper> results = new ArrayList<>();
@@ -476,12 +474,7 @@ public class PowerUsageSummary extends PowerUsageBase implements
         }
 
         // The sort order must have changed, so re-sort based on total power use.
-        Collections.sort(results, new Comparator<BatterySipper>() {
+        mBatteryUtils.sortUsageList(results);
-            @Override
-            public int compare(BatterySipper a, BatterySipper b) {
-                return Double.compare(b.totalPowerMah, a.totalPowerMah);
-            }
-        });
         return results;
     }
 
@@ -532,9 +525,9 @@ public class PowerUsageSummary extends PowerUsageBase implements
         if (averagePower >= MIN_AVERAGE_POWER_THRESHOLD_MILLI_AMP || USE_FAKE_DATA) {
             final List<BatterySipper> usageList = getCoalescedUsageList(
                     USE_FAKE_DATA ? getFakeStats() : mStatsHelper.getUsageList());
-
             double hiddenPowerMah = mShowAllApps ? 0 :
                     mBatteryUtils.removeHiddenBatterySippers(usageList);
+            mBatteryUtils.sortUsageList(usageList);
 
             final int numSippers = usageList.size();
             for (int i = 0; i < numSippers; i++) {

tests/robotests/src/com/android/settings/fuelgauge/BatteryUtilsTest.java

@@ -292,6 +292,19 @@ public class BatteryUtilsTest {
                 BatteryStats.STATS_SINCE_CHARGED)).isEqualTo(TIME_SINCE_LAST_FULL_CHARGE_MS);
     }
 
+    @Test
+    public void testSortUsageList() {
+        final List<BatterySipper> sippers = new ArrayList<>();
+        sippers.add(mNormalBatterySipper);
+        sippers.add(mScreenBatterySipper);
+        sippers.add(mSystemBatterySipper);
+
+        mBatteryUtils.sortUsageList(sippers);
+
+        assertThat(sippers).containsExactly(mNormalBatterySipper, mSystemBatterySipper,
+                mScreenBatterySipper);
+    }
+
     private BatterySipper createTestSmearBatterySipper(long activityTime, double totalPowerMah,
             int uidCode, boolean isUidNull) {
         final BatterySipper sipper = mock(BatterySipper.class);