Update title in MarkerDetailActivity when viewpager changes.

src/main/java/de/dennisguse/opentracks/MarkerDetailActivity.java

@@ -21,6 +21,7 @@ import android.os.Bundle;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentStatePagerAdapter;
@@ -36,7 +37,7 @@ import de.dennisguse.opentracks.fragments.MarkerDetailFragment;
 
 /**
  * An activity to display marker detail info.
- *
+ * <p>
  * Allows to swipe to the next and previous marker.
  *
  * @author Leif Hendrik Wilden
@@ -83,11 +84,25 @@ public class MarkerDetailActivity extends AbstractActivity implements DeleteMark
             }
         }
 
-        ViewPager viewPager = findViewById(R.id.maker_detail_activity_view_pager);
-        viewPager.setAdapter(new MarkerDetailPagerAdapter(getSupportFragmentManager()));
-        if (markerIndex != -1) {
-            viewPager.setCurrentItem(markerIndex);
-        }
+        final ViewPager viewPager = findViewById(R.id.maker_detail_activity_view_pager);
+        final MarkerDetailPagerAdapter markerAdapter = new MarkerDetailPagerAdapter(getSupportFragmentManager());
+        viewPager.setAdapter(markerAdapter);
+        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
+
+            @Override
+            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+            }
+
+            @Override
+            public void onPageSelected(int position) {
+                setTitle(markerAdapter.getPageTitle(position));
+            }
+
+            @Override
+            public void onPageScrollStateChanged(int state) {
+            }
+        });
+        viewPager.setCurrentItem(markerIndex == -1 ? 0 : markerIndex);
     }
 
     @Override
@@ -119,8 +134,13 @@ public class MarkerDetailActivity extends AbstractActivity implements DeleteMark
         @Override
         @NonNull
         public Fragment getItem(int position) {
-            String title = getString(R.string.marker_title, position + 1, getCount());
-            return MarkerDetailFragment.newInstance(markerIds.get(position), title);
+            return MarkerDetailFragment.newInstance(markerIds.get(position));
+        }
+
+        @Nullable
+        @Override
+        public CharSequence getPageTitle(int position) {
+            return getString(R.string.marker_title, position + 1, getCount());
         }
 
         @Override

src/main/java/de/dennisguse/opentracks/fragments/MarkerDetailFragment.java

@@ -48,6 +48,7 @@ import de.dennisguse.opentracks.util.IntentUtils;
 import de.dennisguse.opentracks.util.ListItemUtils;
 import de.dennisguse.opentracks.util.StatsUtils;
 import de.dennisguse.opentracks.util.StringUtils;
+import de.dennisguse.opentracks.util.UnitConversions;
 
 /**
  * A fragment to show marker details.
@@ -58,8 +59,7 @@ public class MarkerDetailFragment extends Fragment {
 
     private static final String TAG = MarkerDetailFragment.class.getSimpleName();
     private static final String KEY_MARKER_ID = "markerId";
-    private static final String KEY_TITLE = "title";
-    private static final long HIDE_TEXT_DELAY = 4000L; // 4 seconds
+    private static final long HIDE_TEXT_DELAY = 4 * UnitConversions.ONE_SECOND;
     private ContentProviderUtils contentProviderUtils;
     private Handler handler;
     private ImageView photo;
@@ -91,10 +91,9 @@ public class MarkerDetailFragment extends Fragment {
         }
     };
 
-    public static MarkerDetailFragment newInstance(long markerId, String title) {
+    public static MarkerDetailFragment newInstance(long markerId) {
         Bundle bundle = new Bundle();
         bundle.putLong(KEY_MARKER_ID, markerId);
-        bundle.putString(KEY_TITLE, title);
 
         MarkerDetailFragment fragment = new MarkerDetailFragment();
         fragment.setArguments(bundle);
@@ -120,8 +119,6 @@ public class MarkerDetailFragment extends Fragment {
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View view = inflater.inflate(R.layout.marker_detail_fragment, container, false);
 
-        getActivity().setTitle(getArguments().getString(KEY_TITLE));
-
         photo = view.findViewById(R.id.marker_detail_waypoint_photo);
         textGradient = view.findViewById(R.id.marker_detail_waypoint_text_gradient);
         waypointInfo = view.findViewById(R.id.marker_detail_waypoint_info);

src/main/java/de/dennisguse/opentracks/util/UnitConversions.java

@@ -23,11 +23,11 @@ package de.dennisguse.opentracks.util;
 public class UnitConversions {
 
     // multiplication factor to convert seconds to milliseconds
-    public static final double S_TO_MS = 1000.0;
+    public static final long S_TO_MS = 1000;
 
     // Time
     // 1 second in milliseconds
-    public static final long ONE_SECOND = (long) UnitConversions.S_TO_MS;
+    public static final long ONE_SECOND = UnitConversions.S_TO_MS;
     // multiplication factor to convert milliseconds to seconds
     public static final double MS_TO_S = 1 / S_TO_MS;
     // multiplication factor to convert minutes to seconds