fix #3122: Trail jumps to 0° and back.

1 files changed, 63 insertions, 0 deletions

diff --git a/main/src/cgeo/geocaching/maps/PositionHistory.java b/main/src/cgeo/geocaching/maps/PositionHistory.java
new file mode 100644
index 0000000..9b090fc
--- /dev/null
+++ b/main/src/cgeo/geocaching/maps/PositionHistory.java
@@ -0,0 +1,63 @@
+package cgeo.geocaching.maps;
+
+import android.location.Location;
+
+import java.util.ArrayList;
+
+/**
+ * Map trail history
+ */
+public class PositionHistory {
+
+    /**
+     * minimum distance between two recorded points of the trail
+     */
+    private static final double MINIMUM_DISTANCE_METERS = 10.0;
+
+    /**
+     * maximum number of positions to remember
+     */
+    private static final int MAX_POSITIONS = 700;
+
+    private ArrayList<Location> history = new ArrayList<Location>();
+
+    /**
+     * Adds the current position to the trail history to be able to show the trail on the map.
+     */
+    void rememberTrailPosition(Location coordinates) {
+        if (coordinates.getAccuracy() >= 50f) {
+            return;
+        }
+        if (coordinates.getLatitude() == 0.0 && coordinates.getLatitude() == 0.0) {
+            return;
+        }
+        if (history.isEmpty()) {
+            history.add(coordinates);
+            return;
+        }
+
+        Location historyRecent = history.get(history.size() - 1);
+        if (historyRecent.distanceTo(coordinates) <= MINIMUM_DISTANCE_METERS) {
+            return;
+        }
+
+        history.add(coordinates);
+
+        // avoid running out of memory
+        final int itemsToRemove = getHistory().size() - MAX_POSITIONS;
+        if (itemsToRemove > 0) {
+            for (int i = 0; i < itemsToRemove; i++) {
+                getHistory().remove(0);
+            }
+        }
+    }
+
+    public ArrayList<Location> getHistory() {
+        return history;
+    }
+
+    public void setHistory(ArrayList<Location> history) {
+        this.history = history;
+    }
+
+}
\ No newline at end of file