swig/Lib/java/enums.swg

/* -----------------------------------------------------------------------------
 * Include this file in order for C/C++ enums to be wrapped by proper Java enums.
 * Note that the JNI layer handles the enum as an int. The Java enum has extra
 * code generated to store the C++ int value. This is required for C++ enums that
 * specify a value for the enum item, as native Java enums do not support this.
 * ----------------------------------------------------------------------------- */

%typemap(jni) enum SWIGTYPE "jint"
%typemap(jtype) enum SWIGTYPE "int"
%typemap(jstype) enum SWIGTYPE "$javaclassname"

%typemap(in) enum SWIGTYPE  %{ $1 = ($1_ltype)$input; %}
%typemap(out) enum SWIGTYPE  %{ $result = (jint)$1; %}

%typemap(directorin, descriptor="L$packagepath/$javaclassname") enum SWIGTYPE    "$input = (jint) $1;"
%typemap(javadirectorin) enum SWIGTYPE "$javaclassname.swigToEnum($jniinput)"
%typemap(javadirectorout) enum SWIGTYPE "($javacall).swigValue()"

%typecheck(SWIG_TYPECHECK_INT32) enum SWIGTYPE ""

%typemap(throws) enum SWIGTYPE %{
  (void)$1;
  SWIG_JavaThrowException(jenv, SWIG_JavaRuntimeException, "C++ $1_type exception thrown");
%}

%typemap(javain) enum SWIGTYPE "$javainput.swigValue()"
%typemap(javaout) enum SWIGTYPE {
    return $javaclassname.swigToEnum($jnicall);
  }

%typemap(javaclassmodifiers) enum SWIGTYPE "public enum"

/*
 * SwigNext static inner class used instead of a static int as static fields cannot be accessed from enum initialisers.
 * The swigToEnum method is used to find the Java enum from a C++ enum integer value. The default one here takes 
 * advantage of the fact that most enums do not have initial values specified, so the lookup is fast. If initial
 * values are specified then a lengthy linear search through all possible enums might occur. Specific typemaps could be
 * written to possibly optimise this lookup by taking advantage of characteristics peculiar to the targeted enum.
 */
%typemap(javabody) enum SWIGTYPE %{
  public final int swigValue() {
    return swigValue;
  }

  public static $javaclassname swigToEnum(int swigValue) {
    $javaclassname[] swigValues = $javaclassname.class.getEnumConstants();
    if (swigValue < swigValues.length && swigValues[swigValue].swigValue == swigValue)
      return swigValues[swigValue];
    for ($javaclassname swigEnum : swigValues)
      if (swigEnum.swigValue == swigValue)
        return swigEnum;
    throw new IllegalArgumentException("No enum " + $javaclassname.class + " with value " + swigValue);
  }

  private $javaclassname() {
    this.swigValue = SwigNext.next++;
  }

  private $javaclassname(int swigValue) {
    this.swigValue = swigValue;
    SwigNext.next = swigValue+1;
  }

  private final int swigValue;

  private static class SwigNext {
    private static int next = 0;
  }
%}

%javaenum(proper);