add the action in the context menu

src/com/owncloud/android/files/FileOperationsHelper.java

@@ -40,6 +40,7 @@ import com.owncloud.android.lib.common.network.WebdavUtils;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 import com.owncloud.android.services.OperationsService;
+import com.owncloud.android.services.observer.FileObserverService;
 import com.owncloud.android.ui.activity.FileActivity;
 import com.owncloud.android.ui.dialog.ShareLinkToDialog;
 
@@ -223,6 +224,25 @@ public class FileOperationsHelper {
             mFileActivity.startService(intent);
         }
     }
+
+    public void toggleKeepInSync(OCFile file, boolean isFavorite) {
+        Log_OC.e(TAG, "KeepInSync");
+        file.setKeepInSync(isFavorite);
+        mFileActivity.getStorageManager().saveFile(file);
+
+        /// register the OCFile instance in the observer service to monitor local updates
+        Intent observedFileIntent = FileObserverService.makeObservedFileIntent(
+                mFileActivity,
+                file,
+                mFileActivity.getAccount(),
+                isFavorite);
+        mFileActivity.startService(observedFileIntent);
+
+        /// immediate content synchronization
+        if (file.keepInSync()) {
+            syncFile(file);
+        }
+    }
     
     public void renameFile(OCFile file, String newFilename) {
         // RenameFile

src/com/owncloud/android/ui/fragment/FileDetailFragment.java

@@ -282,6 +282,7 @@ public class FileDetailFragment extends FileFragment implements OnClickListener
     
     
     private void toggleKeepInSync() {
+        Log_OC.e(TAG, "toggleKeepInSync");
         CheckBox cb = (CheckBox) getView().findViewById(R.id.fdKeepInSync);
         OCFile file = getFile();
         file.setKeepInSync(cb.isChecked());

src/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -42,6 +42,7 @@ import com.owncloud.android.datamodel.OCFile;
 import com.owncloud.android.files.FileMenuFilter;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
+import com.owncloud.android.services.observer.FileObserverService;
 import com.owncloud.android.ui.activity.FileActivity;
 import com.owncloud.android.ui.activity.FileDisplayActivity;
 import com.owncloud.android.ui.activity.FolderPickerActivity;
@@ -341,6 +342,14 @@ public class OCFileListFragment extends ExtendedListFragment {
                 getActivity().startActivityForResult(action, FileDisplayActivity.ACTION_MOVE_FILES);
                 return true;
             }
+            case R.id.action_favorite_file:{
+                mContainerActivity.getFileOperationsHelper().toggleKeepInSync(mTargetFile, true);
+                return true;
+            }
+            case R.id.action_unfavorite_file:{
+                mContainerActivity.getFileOperationsHelper().toggleKeepInSync(mTargetFile, false);
+                return true;
+            }
             default:
                 return super.onContextItemSelected(item); 
         }
@@ -492,8 +501,7 @@ public class OCFileListFragment extends ExtendedListFragment {
 
     public void sortBySize(boolean descending) {
         mAdapter.setSortOrder(FileStorageUtils.SORT_SIZE, descending);
-    }  
-    
-   
+    }
+
     
 }