swfdec_as_native_function.c

Swfdec is a decoder/renderer for Macromedia Flash animations. The decoding and rendering engine is

/* Swfdec
 * Copyright (C) 2007 Benjamin Otte <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 
 * Boston, MA  02110-1301  USA
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "swfdec_as_native_function.h"
#include "swfdec_as_context.h"
#include "swfdec_as_frame_internal.h"
#include "swfdec_as_internal.h"
#include "swfdec_as_stack.h"
#include "swfdec_as_strings.h"
#include "swfdec_debug.h"

/*** GTK-DOC ***/

/**
 * SwfdecAsNative:
 * @context: #SwfdecAsContext
 * @thisp: the this object. <warning>Can be %NULL.</warning>
 * @argc: number of arguments passed to this function
 * @argv: the @argc arguments passed to this function
 * @retval: set to the return value. Initialized to undefined by default
 *
 * This is the prototype for all native functions.
 */

/**
 * SwfdecAsNativeFunction:
 *
 * This is the object type for native functions.
 */

/*** IMPLEMENTATION ***/

G_DEFINE_TYPE (SwfdecAsNativeFunction, swfdec_as_native_function, SWFDEC_TYPE_AS_FUNCTION)

static SwfdecAsFrame *
swfdec_as_native_function_call (SwfdecAsFunction *function)
{
  SwfdecAsNativeFunction *native = SWFDEC_AS_NATIVE_FUNCTION (function);
  SwfdecAsFrame *frame;

  frame = swfdec_as_frame_new_native (SWFDEC_AS_OBJECT (function)->context);
  if (frame == NULL)
    return NULL;
  g_assert (native->name);
  frame->function_name = native->name;
  frame->function = function;
  return frame;
}

static char *
swfdec_as_native_function_debug (SwfdecAsObject *object)
{
  SwfdecAsNativeFunction *native = SWFDEC_AS_NATIVE_FUNCTION (object);

  return g_strdup_printf ("%s ()", native->name);
}

static void
swfdec_as_native_function_dispose (GObject *object)
{
  SwfdecAsNativeFunction *function = SWFDEC_AS_NATIVE_FUNCTION (object);

  g_free (function->name);
  function->name = NULL;

  G_OBJECT_CLASS (swfdec_as_native_function_parent_class)->dispose (object);
}

static void
swfdec_as_native_function_class_init (SwfdecAsNativeFunctionClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  SwfdecAsObjectClass *asobject_class = SWFDEC_AS_OBJECT_CLASS (klass);
  SwfdecAsFunctionClass *function_class = SWFDEC_AS_FUNCTION_CLASS (klass);

  object_class->dispose = swfdec_as_native_function_dispose;

  asobject_class->debug = swfdec_as_native_function_debug;

  function_class->call = swfdec_as_native_function_call;
}

static void
swfdec_as_native_function_init (SwfdecAsNativeFunction *function)
{
}

/**
 * swfdec_as_native_function_new:
 * @context: a #SwfdecAsContext
 * @name: name of the function
 * @native: function to call when executed
 * @min_args: minimum number of arguments required
 * @prototype: The object to be used as "prototype" property for the created 
 *             function or %NULL for none.
 *
 * Creates a new native function, that will execute @native when called. The
 * @min_args parameter sets a requirement for the minimum number of arguments
 * to pass to @native. If the function gets called with less arguments, it
 * will just redurn undefined. You might want to use 
 * swfdec_as_object_add_function() instead of this function.
 *
 * Returns: a new #SwfdecAsFunction or %NULL on OOM
 **/
SwfdecAsFunction *
swfdec_as_native_function_new (SwfdecAsContext *context, const char *name,
    SwfdecAsNative native, guint min_args, SwfdecAsObject *prototype)
{
  SwfdecAsNativeFunction *fun;

  g_return_val_if_fail (SWFDEC_IS_AS_CONTEXT (context), NULL);
  g_return_val_if_fail (native != NULL, NULL);
  g_return_val_if_fail (prototype == NULL || SWFDEC_IS_AS_OBJECT (prototype), NULL);

  if (!swfdec_as_context_use_mem (context, sizeof (SwfdecAsNativeFunction)))
    return NULL;
  fun = g_object_new (SWFDEC_TYPE_AS_NATIVE_FUNCTION, NULL);
  if (fun == NULL)
    return NULL;
  fun->native = native;
  fun->min_args = min_args;
  fun->name = g_strdup (name);
  swfdec_as_object_add (SWFDEC_AS_OBJECT (fun), context, sizeof (SwfdecAsNativeFunction));
  /* need to set prototype before setting the constructor or Function.constructor 
   * being CONSTANT disallows setting it. */
  if (prototype) {
    SwfdecAsValue val;
    SWFDEC_AS_VALUE_SET_OBJECT (&val, prototype);
    swfdec_as_object_set_variable_and_flags (SWFDEC_AS_OBJECT (fun), SWFDEC_AS_STR_prototype, 
	&val, SWFDEC_AS_VARIABLE_HIDDEN | SWFDEC_AS_VARIABLE_PERMANENT);
  }
  swfdec_as_function_set_constructor (SWFDEC_AS_FUNCTION (fun));

  return SWFDEC_AS_FUNCTION (fun);
}

/**
 * swfdec_as_native_function_set_object_type:
 * @function: a #SwfdecAsNativeFunction
 * @type: required #GType for the this object
 *
 * Sets the required type for the this object to @type. If the this object 
 * isn't of the required type, the function will not be called and its
 * return value will be undefined.
 **/
void
swfdec_as_native_function_set_object_type (SwfdecAsNativeFunction *function, GType type)
{
  GTypeQuery query;

  g_return_if_fail (SWFDEC_IS_AS_NATIVE_FUNCTION (function));
  g_return_if_fail (g_type_is_a (type, SWFDEC_TYPE_AS_OBJECT));

  g_type_query (type, &query);
  function->type = type;
}

/**
 * swfdec_as_native_function_set_construct_type:
 * @function: a #SwfdecAsNativeFunction
 * @type: #GType used when constructing an object with @function
 *
 * Sets the @type to be used when using @function as a constructor. If this is
 * not set, using @function as a constructor will create a #SwfdecAsObject.
 **/
void
swfdec_as_native_function_set_construct_type (SwfdecAsNativeFunction *function, GType type)
{
  GTypeQuery query;

  g_return_if_fail (SWFDEC_IS_AS_NATIVE_FUNCTION (function));
  g_return_if_fail (g_type_is_a (type, SWFDEC_TYPE_AS_OBJECT));

  g_type_query (type, &query);
  function->construct_type = type;
  function->construct_size = query.instance_size;
}