Package org.codehaus.groovy.transform.trait

## Class Traits

- java.lang.Object
- - org.codehaus.groovy.transform.trait.Traits

-     public abstract class Traits
      extends Object

  A collection of utility methods used to deal with traits.
  Since:
    2.3.0

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class | Description
    --- | --- | ---
    `static interface` | `Traits.Implemented` | Internal annotation used to indicate which methods in a trait interface have a default implementation.
    `static interface` | `Traits.TraitBridge` | Internal annotation used to indicate that a method is a bridge method to a trait default implementation.

  - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `static ClassNode` | `GENERATED_PROXY_CLASSNODE` |
    `static ClassNode` | `IMPLEMENTED_CLASSNODE` |
    `static ClassNode` | `SELFTYPE_CLASSNODE` |
    `static String` | `STATIC_THIS_OBJECT` |
    `static String` | `THIS_OBJECT` |
    `static Class<Trait>` | `TRAIT_CLASS` |
    `static ClassNode` | `TRAIT_CLASSNODE` |
    `static ClassNode` | `TRAITBRIDGE_CLASSNODE` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `Traits()` |

  - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `static LinkedHashSet<ClassNode>` | `collectAllInterfacesReverseOrder​(ClassNode cNode, LinkedHashSet<ClassNode> interfaces)` | Collects all interfaces of a class node, but reverses the order of the declaration of direct interfaces of this class node.
    `static LinkedHashSet<ClassNode>` | `collectSelfTypes​(ClassNode receiver, LinkedHashSet<ClassNode> selfTypes)` | Collects all the self types that a type should extend or implement, given the traits is implements.
    `static LinkedHashSet<ClassNode>` | `collectSelfTypes​(ClassNode receiver, LinkedHashSet<ClassNode> selfTypes, boolean checkInterfaces, boolean checkSuper)` | Collects all the self types that a type should extend or implement, given the traits is implements.
    `static String[]` | `decomposeSuperCallName​(String methodName)` | Returns the trait and method names derived from super-trait name scheme or `null` if the method name doesn't correspond to a trait method.
    `static ClassNode` | `findFieldHelper​(ClassNode trait)` |
    `static ClassNode` | `findHelper​(ClassNode trait)` |
    `static ClassNode` | `findStaticFieldHelper​(ClassNode trait)` |
    `static List<ClassNode>` | `findTraits​(ClassNode cNode)` | Find all traits associated with the given classnode
    `static <T> T` | `getAsType​(Object self, Class<T> clazz)` | Converts a class implementing some trait into a target class.
    `static Method` | `getBridgeMethodTarget​(Method someMethod)` | Reflection API to find the method corresponding to the default implementation of a trait, given a bridge method.
    `static boolean` | `hasDefaultImplementation​(Method method)` | Indicates whether a method in a trait interface has a default implementation.
    `static boolean` | `hasDefaultImplementation​(MethodNode method)` | Indicates whether a method in a trait interface has a default implementation.
    `static boolean` | `isAnnotatedWithTrait​(ClassNode cNode)` | Returns true if the specified class node is annotated with the `Trait` interface.
    `static boolean` | `isBridgeMethod​(Method someMethod)` | Reflection API to indicate whether some method is a bridge method to the default implementation of a trait.
    `static boolean` | `isTrait​(Class<?> clazz)` | Returns true if the specified class is a trait.
    `static boolean` | `isTrait​(ClassNode cNode)` | Returns true if the specified class node is a trait.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### IMPLEMENTED_CLASSNODE

          public static final ClassNode IMPLEMENTED_CLASSNODE

    - #### TRAITBRIDGE_CLASSNODE

          public static final ClassNode TRAITBRIDGE_CLASSNODE

    - #### TRAIT_CLASS

          public static final Class<Trait> TRAIT_CLASS

    - #### TRAIT_CLASSNODE

          public static final ClassNode TRAIT_CLASSNODE

    - #### GENERATED_PROXY_CLASSNODE

          public static final ClassNode GENERATED_PROXY_CLASSNODE

    - #### SELFTYPE_CLASSNODE

          public static final ClassNode SELFTYPE_CLASSNODE

    - #### THIS_OBJECT

          public static final String THIS_OBJECT

      See Also:
        Constant Field Values

    - #### STATIC_THIS_OBJECT

          public static final String STATIC_THIS_OBJECT

      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### Traits

          public Traits()

  - ### Method Detail

    - #### findHelper

          public static ClassNode findHelper​(ClassNode trait)

    - #### findFieldHelper

          public static ClassNode findFieldHelper​(ClassNode trait)

    - #### findStaticFieldHelper

          public static ClassNode findStaticFieldHelper​(ClassNode trait)

    - #### isTrait

          public static boolean isTrait​(ClassNode cNode)

      Returns true if the specified class node is a trait.
      Parameters:
        `cNode` - a class node to test
      Returns:
        true if the classnode represents a trait

    - #### isTrait

          public static boolean isTrait​(Class<?> clazz)

      Returns true if the specified class is a trait.
      Parameters:
        `clazz` - a class to test
      Returns:
        true if the classnode represents a trait

    - #### isAnnotatedWithTrait

          public static boolean isAnnotatedWithTrait​(ClassNode cNode)

      Returns true if the specified class node is annotated with the `Trait` interface.
      Parameters:
        `cNode` - a class node
      Returns:
        true if the specified class node is annotated with the `Trait` interface.

    - #### hasDefaultImplementation

          public static boolean hasDefaultImplementation​(MethodNode method)

      Indicates whether a method in a trait interface has a default implementation.
      Parameters:
        `method` - a method node
      Returns:
        true if the method has a default implementation in the trait

    - #### hasDefaultImplementation

          public static boolean hasDefaultImplementation​(Method method)

      Indicates whether a method in a trait interface has a default implementation.
      Parameters:
        `method` - a method node
      Returns:
        true if the method has a default implementation in the trait

    - #### isBridgeMethod

          public static boolean isBridgeMethod​(Method someMethod)

      Reflection API to indicate whether some method is a bridge method to the default implementation of a trait.
      Parameters:
        `someMethod` - a method node
      Returns:
        null if it is not a method implemented in a trait. If it is, returns the method from the trait class.

    - #### getBridgeMethodTarget

          public static Method getBridgeMethodTarget​(Method someMethod)

      Reflection API to find the method corresponding to the default implementation of a trait, given a bridge method.
      Parameters:
        `someMethod` - a method node
      Returns:
        null if it is not a method implemented in a trait. If it is, returns the method from the trait class.

    - #### getAsType

          public static <T> T getAsType​(Object self,
                                        Class<T> clazz)

      Converts a class implementing some trait into a target class. If the trait is a dynamic proxy and that the target class is assignable to the target object of the proxy, then the target object is returned. Otherwise, falls back to `DefaultGroovyMethods.asType(java.lang.Object, Class)`
      Parameters:
        `self` - an object to be coerced to some class
        `clazz` - the class to be coerced to
      Returns:
        the object coerced to the target class, or the proxy instance if it is compatible with the target class.

    - #### decomposeSuperCallName

          public static String[] decomposeSuperCallName​(String methodName)

      Returns the trait and method names derived from super-trait name scheme or `null` if the method name doesn't correspond to a trait method.

    - #### collectAllInterfacesReverseOrder

          public static LinkedHashSet<ClassNode> collectAllInterfacesReverseOrder​(ClassNode cNode,
                                                                                  LinkedHashSet<ClassNode> interfaces)

      Collects all interfaces of a class node, but reverses the order of the declaration of direct interfaces of this class node. This is used to make sure a trait implementing A,B where both A and B have the same method will take the method from B (latest), aligning the behavior with categories.
      Parameters:
        `cNode` - a class node
        `interfaces` - ordered set of interfaces

    - #### collectSelfTypes

          public static LinkedHashSet<ClassNode> collectSelfTypes​(ClassNode receiver,
                                                                  LinkedHashSet<ClassNode> selfTypes)

      Collects all the self types that a type should extend or implement, given the traits is implements. Collects from interfaces and superclasses too.
      Parameters:
        `receiver` - a class node that may implement a trait
        `selfTypes` - a collection where the list of self types will be written
      Returns:
        the selfTypes collection itself
      Since:
        2.4.0

    - #### collectSelfTypes

          public static LinkedHashSet<ClassNode> collectSelfTypes​(ClassNode receiver,
                                                                  LinkedHashSet<ClassNode> selfTypes,
                                                                  boolean checkInterfaces,
                                                                  boolean checkSuper)

      Collects all the self types that a type should extend or implement, given the traits is implements.
      Parameters:
        `receiver` - a class node that may implement a trait
        `selfTypes` - a collection where the list of self types will be written
        `checkInterfaces` - should the interfaces that the node implements be collected too
        `checkSuper` - should we collect from the superclass too
      Returns:
        the selfTypes collection itself
      Since:
        2.4.0

    - #### findTraits

          public static List<ClassNode> findTraits​(ClassNode cNode)

      Find all traits associated with the given classnode
      Parameters:
        `cNode` - the given classnode
      Returns:
        the list of ordered trait classnodes