Package org.robolectric.internal.bytecode

Interface ClassHandler

  • All Known Implementing Classes:
    ShadowWrangler
    public interface ClassHandler
    This interface is used by Robolectric when instrumented classes are created and interacted with.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Interface Description
      static interface  ClassHandler.Plan
      An execution plan, which can be invoked to satisfy a requested method call.

    • Method Detail

      • classInitializing

        void classInitializing​(Class clazz)
        Called by Robolectric when an instrumented class is first loaded into a sandbox and is ready to be statically initialized.

        This happens *in place of* any static initialization that may be performed by the class being loaded. The class will have a method named __staticInitializer__ which may be invoked to perform its normal initialization from <clinit>.

        Parameters:
        clazz - the class being loaded

      • initializing

        Object initializing​(Object instance)
        Called by Robolectric when a new instance of an instrumented class has been created and is ready to be initialized (but only on JVMs which don't support the invokedynamic instruction).

        This happens before constructor code executes on the new instance.

        Implementations may return an object which will be associated with the new instance and passed along on future calls to methodInvoked(String, boolean, Class).

        Parameters:
        instance - the newly-created instance
        Returns:
        a data value to be associated with the new instance
        See Also:
        for newer JVMs

      • methodInvoked

        ClassHandler.Plan methodInvoked​(String signature,
                                boolean isStatic,
                                Class<?> theClass)
        Called by Robolectric when an instrumented method is invoked.

        Implementations should return an ClassHandler.Plan, which will be invoked with details about the current instance and parameters.

        Implementations may also return null, in which case the method's original code will be executed.

        Parameters:
        signature - the JVM internal-format signature of the method being invoked (e.g. android/view/View/measure(II)V)
        isStatic - true if the method is static
        theClass - the class on which the method is declared
        Returns:
        an execution plan, or null if the original method's code should be executed
        See Also:
        for newer JVMs

      • getShadowCreator

        MethodHandle getShadowCreator​(Class<?> theClass)
        Called by Robolectric to determine how to create and initialize a shadow object when a new instance of an instrumented class has been instantiated. (but only on JVMs which support the invokedynamic instruction).

        The returned MethodHandle will be invoked after the new object has been allocated but before its constructor code is executed.

        Note that this is not directly analogous to initializing(Object); the return value from this method will be cached and used again for other instantiations of instances of the same class.

        Parameters:
        theClass - the instrumented class
        Returns:
        a data value to be associated with the new instance
        See Also:
        for older JVMs, for invalidating the returned

      • findShadowMethodHandle

        MethodHandle findShadowMethodHandle​(Class<?> theClass,
                                    String name,
                                    MethodType methodType,
                                    boolean isStatic)
                             throws IllegalAccessException
        Called by Robolectric when an instrumented method is invoked.

        Implementations should return an MethodHandle, which will be invoked with details about the current instance and parameters.

        Implementations may also return null, in which case the method's original code will be executed.

        Parameters:
        theClass - the class on which the method is declared
        name - the name of the method
        methodType - the method type
        isStatic - true if the method is static
        Returns:
        a method handle to invoke, or null if the original method's code should be executed
        Throws:
        IllegalAccessException
        See Also:
        for older JVMs, for invalidating the returned

      • intercept

        Object intercept​(String signature,
                 Object instance,
                 Object[] params,
                 Class<?> theClass)
          throws Throwable
        Called by Robolectric when an intercepted method is invoked.

        Unlike instrumented methods, calls to intercepted methods are modified in place by Robolectric in the calling code. This is useful when the method about to be invoked doesn't exist in the current JVM (e.g. because of Android differences).

        Parameters:
        signature - the JVM internal-format signature of the method being invoked (e.g. android/view/View/measure(II)V)
        instance - the instance on which the method would have been invoked
        params - the parameters to the method
        theClass - the class on which the method is declared
        Returns:
        the value to be returned
        Throws:
        Throwable - if anything bad happens

      • stripStackTrace

        <T extends Throwable> T stripStackTrace​(T throwable)
        Removes Robolectric noise from stack traces.
        Type Parameters:
        T - the type of exception
        Parameters:
        throwable - the exception to be stripped
        Returns:
        the stripped stack trace