Reuse map fragment on orientation change

Author: Pygmalion69

app/src/main/java/org/nitri/opentopo/MainActivity.java

@@ -87,10 +87,14 @@ private void addMapFragment() {
             return;
         }
         MapFragment mapFragment;
-        if (mGeoPointFromIntent == null)
-            mapFragment = MapFragment.newInstance();
-        else
+        if (mGeoPointFromIntent == null) {
+            mapFragment = (MapFragment) getSupportFragmentManager().findFragmentByTag(MAP_FRAGMENT_TAG);
+            if (mapFragment == null) {
+                mapFragment = MapFragment.newInstance();
+            }
+        } else {
             mapFragment = MapFragment.newInstance(mGeoPointFromIntent.getLatitude(), mGeoPointFromIntent.getLongitude());
+        }
         getSupportFragmentManager().beginTransaction()
                 .add(R.id.map_container, mapFragment, MAP_FRAGMENT_TAG)
                 .commit();
@@ -148,10 +152,10 @@ public void onActivityResult(int requestCode, int resultCode,
         if (requestCode == READ_REQUEST_CODE && resultCode == AppCompatActivity.RESULT_OK) {
             if (resultData != null) {
                 mGpxUri = resultData.getData();
+                mZoomToGpx = true;
                 if (mGpxUri != null) {
                     Log.i(TAG, "Uri: " + mGpxUri.toString());
                     parseGpx(mGpxUri);
-                    mZoomToGpx = true;
                 }
             }
         }