Making some more logs.

app/src/main/java/pl/tpolgrabia/urbanexplorer/MainActivity.java

@@ -40,6 +40,8 @@ import pl.tpolgrabia.urbanexplorer.utils.NumberUtils;
 import pl.tpolgrabia.urbanexplorer.views.CustomInterceptor;
 import pl.tpolgrabia.urbanexplorer.views.SwipeFrameLayout;
 
+import java.util.List;
+
 public class MainActivity extends ActionBarActivity {
 
     private static final Logger lg = LoggerFactory.getLogger(MainActivity.class);
@@ -245,11 +247,11 @@ public class MainActivity extends ActionBarActivity {
 
     }
 
-    private void switchFragment(Fragment fragment, String tag) {
+    private void switchFragment(Fragment newFragment, String tag) {
 
         FragmentManager fragmentManager = getSupportFragmentManager();
         FragmentTransaction ctx = fragmentManager.beginTransaction();
-        lg.trace("old fragment id: {}, current fragment id: {}", oldFragmentId, currentFragmentId);
+        lg.trace("old newFragment id: {}, current newFragment id: {}", oldFragmentId, currentFragmentId);
         if (oldFragmentId != currentFragmentId) {
             if (currentFragmentId < oldFragmentId) {
                 // slide left animation
@@ -270,11 +272,28 @@ public class MainActivity extends ActionBarActivity {
             }
         }
 
-        Fragment frag = fragmentManager.findFragmentByTag(tag);
+        final List<Fragment> fragments = fragmentManager.getFragments();
-        if (frag == null) {
+        if (fragments != null) {
-            ctx.replace(R.id.fragments, fragment, tag);
+            lg.trace("Available fragments {}", fragments.size());
+            for (Fragment frag : fragments) {
+                if (frag != null) {
+                    lg.trace("Available fragment with id: {}, tag: {}", frag.getId(), frag.getTag());
+                } else {
+                    lg.trace("Available null-fragment");
+                }
+            }
         } else {
-            ctx.replace(R.id.fragments, frag);
+            lg.trace("There are no fragments -> null");
+        }
+
+        lg.trace("Trying to search newFragment by tag {}", tag);
+        Fragment currFragment = fragmentManager.findFragmentByTag(tag);
+        if (currFragment == null) {
+            lg.trace("Using new newFragment: {}", System.identityHashCode(newFragment));
+            ctx.replace(R.id.fragments, newFragment, tag);
+        } else {
+            lg.trace("Reusing old newFragment: {}", System.identityHashCode(currFragment));
+            ctx.replace(R.id.fragments, currFragment);
         }
         // ctx.addToBackStack(MAIN_BACKSTACK);
         ctx.commit();
@@ -429,4 +448,17 @@ public class MainActivity extends ActionBarActivity {
         lg.trace("2 Saving current fragment id: {}", currentFragmentId);
     }
 
+    @Override
+    protected void onStop() {
+        super.onStop();
+
+        lg.trace("onStop {}", System.identityHashCode(this));
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+
+        lg.trace("onStart {}", System.identityHashCode(this));
+    }
 }

app/src/main/java/pl/tpolgrabia/urbanexplorer/fragments/HomeFragment.java

@@ -66,7 +66,7 @@ public class HomeFragment extends Fragment  {
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        lg.trace("onCreate");
+        lg.trace("onCreate {}", System.identityHashCode(this));
         pageId = 1L;
         loading = new Semaphore(1, true);
         noMorePhotos = false;
@@ -249,31 +249,39 @@ public class HomeFragment extends Fragment  {
             new PanoramioResponseCallback() {
                 @Override
                 public void callback(PanoramioResponseStatus status, List<PanoramioImageInfo> images, Long imagesCount) {
-                    lg.debug("Fetched with status: {}, images: {}, count: {}", status, images, imagesCount);
+                    try {
-                    if (status != PanoramioResponseStatus.SUCCESS) {
+                        lg.debug("Fetched with status: {}, images: {}, count: {}", status, images, imagesCount);
-                        return;
+                        if (status != PanoramioResponseStatus.SUCCESS) {
+                            return;
+                        }
+
+                        ListView locations = (ListView) getView().findViewById(R.id.locations);
+                        if (locations == null) {
+                            lg.trace("Empty locations");
+                            return;
+                        }
+                        ArrayAdapter<PanoramioImageInfo> adapter = (ArrayAdapter<PanoramioImageInfo>) locations.getAdapter();
+                        photos.addAll(images);
+                        if (photos.isEmpty()) {
+                            Toast.makeText(getActivity(), "No results", Toast.LENGTH_SHORT).show();
+                        }
+                        noMorePhotos = images.isEmpty();
+                        if (adapter == null) {
+                            locations.setAdapter(new PanoramioAdapter(activity, R.id.list_item, images));
+                        } else {
+                            adapter.addAll(images);
+                        }
+
+                        // TODO we can think about removing first items also and last if the number
+                        // TODO of items exceeds the limit (to save the memory)
+
+                        lg.debug("Finished Fetching additional photos count: {}", photos.size());
+
+                    } finally {
+                        lg.trace("Releasing fetching lock");
+                        loading.release();
                     }
 
-                    ListView locations = (ListView) getView().findViewById(R.id.locations);
-                    ArrayAdapter<PanoramioImageInfo> adapter = (ArrayAdapter<PanoramioImageInfo>) locations.getAdapter();
-                    photos.addAll(images);
-                    if (photos.isEmpty()) {
-                        Toast.makeText(getActivity(), "No results", Toast.LENGTH_SHORT).show();
-                    }
-                    noMorePhotos = images.isEmpty();
-                    if (adapter == null) {
-                        locations.setAdapter(new PanoramioAdapter(activity, R.id.list_item, images));
-                    } else {
-                        adapter.addAll(images);
-                    }
-
-                    // TODO we can think about removing first items also and last if the number
-                    // TODO of items exceeds the limit (to save the memory)
-
-                    lg.debug("Finished Fetching additional photos count: {}", photos.size());
-
-                    loading.release();
-
                 }
             }
 
@@ -411,4 +419,17 @@ public class HomeFragment extends Fragment  {
         lg.trace("Saved photos: {}", photos);
     }
 
+    @Override
+    public void onStop() {
+        super.onStop();
+
+        lg.trace("onStop {}", System.identityHashCode(this));
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+
+        lg.trace("onStart {}", System.identityHashCode(this));
+    }
 }

app/src/main/java/pl/tpolgrabia/urbanexplorer/fragments/WikiLocationsFragment.java

@@ -56,7 +56,7 @@ public class WikiLocationsFragment extends Fragment {
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        lg.trace("onCreate");
+        lg.trace("onCreate {}", System.identityHashCode(this));
         appObjects = savedInstanceState == null ? new ArrayList<WikiAppObject>()
             : (ArrayList<WikiAppObject>)savedInstanceState.getSerializable(WIKI_APP_OBJECTS);;
     }
@@ -99,6 +99,12 @@ public class WikiLocationsFragment extends Fragment {
     public void fetchWikiLocations() {
         lg.trace("Fetch wiki locations");
 
+        final FragmentActivity activity = getActivity();
+        if (activity == null) {
+            lg.warn("Activity shouldn't be null. No headless fragment");
+            return;
+        }
+
         MainActivity mainActivity = (MainActivity) getActivity();
 
         if (lastFetchSize == 0) {
@@ -113,12 +119,6 @@ public class WikiLocationsFragment extends Fragment {
             return;
         }
 
-        final FragmentActivity activity = getActivity();
-        if (activity == null) {
-            lg.warn("Activity shouldn't be null. No headless fragment");
-            mainActivity.hideProgress();
-            return;
-        }
         final Location location = locationService.getLastKnownLocation(LocationUtils.getDefaultLocation(activity));
 
         if (location == null) {
@@ -192,6 +192,7 @@ public class WikiLocationsFragment extends Fragment {
         getActivity().setTitle("Wiki search");
         updateLocationInfo();
         fetchWikiLocations();
+        lg.trace("onResume {}", System.identityHashCode(this));
     }
 
     public void updateLocationInfo() {
@@ -212,6 +213,7 @@ public class WikiLocationsFragment extends Fragment {
     @Override
     public void onPause() {
         super.onPause();
+        lg.trace("onPause {}", System.identityHashCode(this));
     }
 
     @Override
@@ -221,4 +223,10 @@ public class WikiLocationsFragment extends Fragment {
 
         outState.putSerializable(WIKI_APP_OBJECTS, appObjects);
     }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        lg.trace("onDestroy {}", System.identityHashCode(this));
+    }
 }