@Override
public <T> T get(Key<T> key) {
  Object value;
  if (myKey1.equals(key)) {
    value = myValue1;
  }
  else if (myKey2.equals(key)) {
    value = myValue2;
  }
  else {
    value = null;
  }

  if (value == null && key instanceof KeyWithDefaultValue) {
    return ((KeyWithDefaultValue<T>)key).getDefaultValue();
  }
  return (T)value;
}
 

public void readExternal(@Nonnull Element element) {
  List<Element> subPanes = element.getChildren(ELEMENT_SUB_PANE);
  for (Element subPane : subPanes) {
    String subId = subPane.getAttributeValue(ATTRIBUTE_SUB_ID);
    TreeState treeState = TreeState.createFrom(subPane);
    if (!treeState.isEmpty()) {
      myReadTreeState.put(subId, treeState);
    }
  }

  for (ProjectViewPaneOptionProvider provider : ProjectViewPaneOptionProvider.EX_NAME.getExtensionList()) {
    KeyWithDefaultValue key = provider.getKey();

    String valueOfKey = JDOMExternalizerUtil.readField(element, key.toString());
    if (valueOfKey != null) {
      putUserData(key, provider.parseValue(valueOfKey));
    }
  }
}
 

public void writeExternal(Element element) {
  saveExpandedPaths();
  for (Map.Entry<String, TreeState> entry : myReadTreeState.entrySet()) {
    String subId = entry.getKey();
    TreeState treeState = entry.getValue();
    Element subPane = new Element(ELEMENT_SUB_PANE);
    if (subId != null) {
      subPane.setAttribute(ATTRIBUTE_SUB_ID, subId);
    }
    treeState.writeExternal(subPane);
    element.addContent(subPane);
  }

  for (ProjectViewPaneOptionProvider provider : ProjectViewPaneOptionProvider.EX_NAME.getExtensionList()) {
    KeyWithDefaultValue key = provider.getKey();
    Object value = getUserData(key);
    //noinspection unchecked
    String stringValue = provider.toString(value);
    if (stringValue != null) {
      JDOMExternalizerUtil.writeField(element, key.toString(), stringValue);
    }
  }
}
 

@Override
public <T> T get(Key<T> key) {
  Object value = myKey.equals(key) ? myValue : null;
  if (value == null && key instanceof KeyWithDefaultValue) {
    return ((KeyWithDefaultValue<T>)key).getDefaultValue();
  }
  return (T)value;
}
 

@Override
public <T> T get(Key<T> key) {
  final T value = (T)myValues.get(key);
  if (value == null && key instanceof KeyWithDefaultValue) {
    return ((KeyWithDefaultValue<T>) key).getDefaultValue();
  }
  return value;
}
 

@Override
@SuppressWarnings("unchecked")
public <T> T getUserData(@Nonnull Key<T> key) {
  T value = super.getUserData(key);
  if (value == null && key instanceof KeyWithDefaultValue) {
    return (T)((KeyWithDefaultValue)key).getDefaultValue();
  }
  return value;
}
 

@Nonnull
@Override
public <T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option) {
  T value = ProjectViewPane.this.getUserData(option);
  assert value != null;
  return value;
}
 

@Nonnull
@Override
public KeyWithDefaultValue<Boolean> getKey()
{
	return KEY;
}
 

@Nonnull
<T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option);
 

@Nonnull
@Override
public <T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option) {
  return option.getDefaultValue();
}
 

public <T> T get(Key<T> key) {
  if (key instanceof KeyWithDefaultValue) {
    return ((KeyWithDefaultValue<T>)key).getDefaultValue();
  }
  return null;
}
 

@Nonnull
@Override
public <T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option) {
  return option.getDefaultValue();
}
 

@Nonnull
@Override
public KeyWithDefaultValue<Boolean> getKey() {
  return KEY;
}
 

@Nonnull
KeyWithDefaultValue<T> getKey();
 

@Nonnull
@Override
public <T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option) {
  return option.getDefaultValue();
}
 

@Nonnull
@Override
public <T> T getViewOption(@Nonnull KeyWithDefaultValue<T> option) {
  return option.getDefaultValue();
}