How to use

MayContainNull

in

com.igormaznitsa.meta.annotation

 boolean doPlatformMenuAction(@Nonnull PlatformMenuEvent event, @Nullable @MayContainNull Object ... args);
}

@Nullable
protected static File findExisting(@Nonnull @MayContainNull final File... files) {
 File result = null;
 for (final File f : files) {
  if (f != null && f.isFile()) {
   result = f;
   break;
  }
 }
 return result;
}

@Nullable
public abstract MindMap doImport(@Nonnull final MindMapPanel panel,
                 @Nonnull final DialogProvider dialogProvider,
                 @Nullable final Topic actionTopic,
                 @Nonnull @MayContainNull final Topic[] selectedTopics) throws Exception;

public Topic(@Nonnull final MindMap map, @Nullable final Topic parent, @Nonnull final String text, @Nonnull @MayContainNull final Extra<?>... extras) {
 this(map, text, extras);
 this.parent = parent;
 if (parent != null) {
  if (parent.getMap() != map) {
   throw new IllegalArgumentException("Parent must belong to the same mind map");
  }
  parent.children.add(this);
 }
}

/**
 * Append elements to the end of an array
 *
 * @param <T> type of array elements
 * @param array target array
 * @param elements elements to be added to the end of the target array
 * @return new array where elements are placed in the end
 * @since 1.1.3
 */
@Nonnull
@MayContainNull
@Weight(Weight.Unit.NORMAL)
public static <T> T[] append(@MayContainNull @Nonnull final T[] array, @MayContainNull final T... elements) {
 @SuppressWarnings("unchecked")
 final T[] result = (T[]) Array.newInstance(array.getClass().getComponentType(), array.length + elements.length);
 System.arraycopy(array, 0, result, 0, array.length);
 int index = array.length;
 for (final T element : elements) {
  result[index++] = element;
 }
 return result;
}

/**
 * Append element to the start of an array.
 *
 * @param <T> type of array elements
 * @param element element to be added into start of array, can be null
 * @param array target array
 * @return new array where the element on the first position
 * @since 1.1.3
 */
@Nonnull
@MayContainNull
@Weight(Weight.Unit.NORMAL)
public static <T> T[] append(@Nullable final T element, @MayContainNull @Nonnull final T[] array) {
 @SuppressWarnings("unchecked")
 final T[] result = (T[]) Array.newInstance(array.getClass().getComponentType(), array.length + 1);
 System.arraycopy(array, 0, result, 1, array.length);
 result[0] = element;
 return result;
}

/**
 * Make file path from provided strings
 * @param paths path elements
 * @return joined file path with OS file separator
 * @since 2.1.7
 */
@Nonnull
public static String makeOsFilePathWithoutDuplications(@Nonnull @MayContainNull final String... paths) {
 final StringBuilder result = new StringBuilder();
 final Set<String> alreadyAdded = new HashSet<>();
 for (final String s : paths) {
  if (s != null && !s.isEmpty() && !alreadyAdded.contains(s)) {
   alreadyAdded.add(s);
   if (result.length() > 0) {
    result.append(File.pathSeparatorChar);
   }
   result.append(s);
  }
 }
 return result.toString();
}

/**
 * Make file path appropriate for current OS.
 *
 * @param files files which will be added in the path
 * @return joined file path with OS file separator
 * @since 2.1.7
 */
@Nonnull
public static String makeOsFilePathWithoutDuplications(@Nonnull @MayContainNull final File[] files) {
 final StringBuilder result = new StringBuilder();
 final Set<File> alreadyAdded = new HashSet<>();
 for (final File f : files) {
  if (f == null || alreadyAdded.contains(f)) {
   continue;
  }
  alreadyAdded.add(f);
  if (result.length() > 0) {
   result.append(File.pathSeparatorChar);
  }
  result.append(f.getAbsolutePath());
 }
 return result.toString();
}

private Topic(@Nonnull final MindMap map, @Nonnull final String text, @Nonnull @MayContainNull final Extra<?>... extras) {
 this.map = Assertions.assertNotNull(map);
 this.text = Assertions.assertNotNull(text);
 for (final Extra<?> e : extras) {
  if (e != null) {
   this.extras.put(e.getType(), e);
  }
 }
}

/**
 * Join arrays provided as parameters, all arrays must be the same type, null
 * values allowed.
 *
 * @param <T> type of array
 * @param arrays array of arrays to be joined
 * @return all joined arrays as single array
 * @since 1.0
 */
@Nonnull
@MayContainNull
@Weight(Weight.Unit.NORMAL)
public static <T> T[] joinArrays(@MayContainNull final T[]... arrays) {
 int commonLength = 0;
 for (final T[] array : arrays) {
  if (array != null) {
   commonLength += array.length;
  }
 }
 @SuppressWarnings("unchecked")
 final T[] result = (T[]) Array.newInstance(arrays.getClass().getComponentType().getComponentType(), commonLength);
 int position = 0;
 for (final T[] array : arrays) {
  if (array != null) {
   System.arraycopy(array, 0, result, position, array.length);
   position += array.length;
  }
 }
 return result;
}

private boolean processMenuEvent(@Nonnull final PlatformMenuEvent event, @Nullable @MayContainNull final Object... args) {
 final PlatformMenuAction action = this.actions.get(event);
 boolean handled = false;
 if (action == null) {
  LOGGER.info("No registered menu event handler : " + event);//NOI18N
 } else {
  handled = action.doPlatformMenuAction(event, args);
  LOGGER.info("Processed menu event : " + event); //NOI18N
 }
 return handled;
}

private boolean processMenuEvent(@Nonnull final PlatformMenuEvent event, @Nullable @MayContainNull final Object... args) {
 final PlatformMenuAction action = this.actions.get(event);
 boolean handled = false;
 if (action == null) {
  LOGGER.info("No registered menu event handler : " + event);//NOI18N
 } else {
  handled = action.doPlatformMenuAction(event, args);
  LOGGER.info("Processed menu event : " + event); //NOI18N
 }
 return handled;
}

/**
 * Check that object is presented among provided elements and replace the object by equal element from the list.
 *
 * @param <T> type of object
 * @param obj object to be checked
 * @param list list of elements for checking
 * @return equal element provided in the list
 * @throws AssertionError if object is not found among defined ones
 * @since 1.0.2
 */
@Nullable
public static <T> T assertAmong(@Nullable T obj, @MayContainNull @Nonnull final T... list) {
 if (obj == null) {
  for (final T i : assertNotNull(list)) {
   if (i == null) {
    return i;
   }
  }
 } else {
  final int objHash = obj.hashCode();
  for (final T i : assertNotNull(list)) {
   if (obj == i || (i!=null && objHash == i.hashCode() && obj.equals(i))) {
    return i;
   }
  }
 }
 final AssertionError error = new AssertionError("Object is not found among elements");
 MetaErrorListeners.fireError("Asserion error", error);
 throw error;
}

 @Nonnull final DialogProvider dialogProvider,
 @Nullable final Topic actionTopic,
 @Nonnull @MayContainNull final Topic[] selectedTopics,
 @Nullable final CustomJob processor) {
final JMenuItem result = UI_COMPO_FACTORY.makeMenuItem(getName(panel, actionTopic, selectedTopics), getIcon(panel, actionTopic, selectedTopics));

 @Nonnull final DialogProvider dialogProvider,
 @Nullable final Topic actionTopic,
 @Nonnull @MayContainNull final Topic[] selectedTopics,
 @Nullable final CustomJob processor) {
final JMenuItem result = UI_COMPO_FACTORY.makeMenuItem(getName(panel, actionTopic, selectedTopics), getIcon(panel, actionTopic, selectedTopics));

@Nonnull final PopUpSection section,
final boolean fullScreenModeActive,
@Nonnull @MayContainNull final List<JMenuItem> list,
@Nonnull DialogProvider dialogProvider,
@Nullable final Topic topicUnderMouse,

@Override
public boolean doPlatformMenuAction(@Nonnull final PlatformMenuEvent event, @Nullable @MayContainNull final Object... args) {
 boolean handled = false;
 switch (event) {
  case ABOUT: {
   this.menuAboutActionPerformed(new ActionEvent(this, 0, "about")); //NOI18N
   handled = true;
  }
  break;
  case QUIT: {
   handled = doClosing();
   if (handled) {
    dispose();
   }
  }
  break;
  case REOPEN_APPLICATION: {
   this.setVisible(true);
   handled = true;
  }
  break;
  case PREFERENCES: {
   editPreferences();
   handled = true;
  }
  break;
 }
 return handled;
}

public void removeExtras(@Nullable @MayContainNull final Extra<?>... extras) {
 this.map.lock();
 try {
  if (extras == null || extras.length == 0) {
   this.extras.clear();
  } else {
   for (final Extra<?> e : extras) {
    if (e != null) {
     this.extras.remove(e.getType());
    }
   }
  }
 }
 finally {
  this.map.unlock();
 }
}