diff --git a/.idea/migrations.xml b/.idea/migrations.xml
new file mode 100644
index 000000000..f8051a6f9
--- /dev/null
+++ b/.idea/migrations.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectMigrations">
+    <option name="MigrateToGradleLocalJavaHome">
+      <set>
+        <option value="$PROJECT_DIR$" />
+      </set>
+    </option>
+  </component>
+</project>
\ No newline at end of file
diff --git a/src/main/java/de/dennisguse/opentracks/chart/ChartView.java b/src/main/java/de/dennisguse/opentracks/chart/ChartView.java
index f32bb29ad..9f1ba37d4 100644
--- a/src/main/java/de/dennisguse/opentracks/chart/ChartView.java
+++ b/src/main/java/de/dennisguse/opentracks/chart/ChartView.java
@@ -879,7 +879,7 @@ private void drawPointer(Canvas canvas) {
                 break;
             }
         }
-        if (firstChartValueSeries != null && chartPoints.size() > 0) {
+        if (firstChartValueSeries != null && !chartPoints.isEmpty()) {
             int dx = getX(maxX) - pointer.getIntrinsicWidth() / 2;
             double value = firstChartValueSeries.extractDataFromChartPoint(last);
             int dy = getY(firstChartValueSeries, value) - pointer.getIntrinsicHeight();
diff --git a/src/main/java/de/dennisguse/opentracks/data/CustomContentProvider.java b/src/main/java/de/dennisguse/opentracks/data/CustomContentProvider.java
index e0922f538..08e63db2a 100644
--- a/src/main/java/de/dennisguse/opentracks/data/CustomContentProvider.java
+++ b/src/main/java/de/dennisguse/opentracks/data/CustomContentProvider.java
@@ -65,7 +65,7 @@ public class CustomContentProvider extends ContentProvider {
      * It computes the average for heart rate, cadence and power (duration-based average) and the maximum for heart rate, cadence and power.
      * Finally, it ignores manual pause (SEGMENT_START_MANUAL).
      */
-    private final String SENSOR_STATS_QUERY =
+    private final static String SENSOR_STATS_QUERY =
             "WITH time_select as " +
                 "(SELECT t1." + TrackPointsColumns.TIME + " * (t1." + TrackPointsColumns.TYPE + " NOT IN (" + TrackPoint.Type.SEGMENT_START_MANUAL.type_db + ")) time_value " +
                 "FROM " + TrackPointsColumns.TABLE_NAME + " t1 " +