writableConfigurable.h

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file writableConfigurable.h
 * @author jason
 * @date 2000-06-19
 */


#ifndef WRITABLECONFIGURABLE_H
#define WRITABLECONFIGURABLE_H
// Includes

#include "pandabase.h"

#include "typedWritable.h"

// Defines

/**
 * Defined as a fix to allow creating Configurable and Writable objects.
 * Otherwise the compiler gets confused since both TypedWritable and
 * Configurable inherit from TypedObject.
 *
 * An object that has data or parameters that are set less frequently (at
 * least occasionally) than every frame.  We can cache the configuration info
 * by by using the "dirty" flag.
 */
class EXPCL_PANDA_PUTIL WritableConfigurable : public TypedWritable {

public:
  WritableConfigurable( void ) { make_dirty(); }
  virtual void config( void ) { _dirty = false; }
  INLINE void check_config() const {
    if (_dirty) {
      // This is a sneaky trick to allow check_config() to be called from a
      // const member function.  Even though we will be calling config(), a
      // non-const function that modifies the class object, in some sense it's
      // not really modifying the class object--it's just updating a few
      // internal settings for consistency.
      ((WritableConfigurable *)this)->config();
    }
  }

  INLINE bool is_dirty() const { return _dirty; }
  INLINE void make_dirty() { _dirty = true; }

private:
  bool _dirty;

public:
  virtual void write_datagram(BamWriter*, Datagram&) = 0;

PUBLISHED:
  static TypeHandle get_class_type() {
    return _type_handle;
  }

public:
  static void init_type() {
    TypedWritable::init_type();
    register_type(_type_handle, "WritableConfigurable",
                  TypedWritable::get_class_type());
    TypeRegistry::ptr()->record_alternate_name(_type_handle,
                                               "WriteableConfigurable");
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }
  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}


private:
  static TypeHandle _type_handle;
};

#endif