text: #ifndef __DALI_INTERNAL_OBJECT_H__
  #define __DALI_INTERNAL_OBJECT_H__
  
  /*
   * Copyright (c) 2016 Samsung Electronics Co., Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  // INTERNAL INCLUDES
  #include <dali/public-api/animation/constraint.h>
  #include <dali/public-api/common/dali-vector.h>
  #include <dali/public-api/common/vector-wrapper.h>
  #include <dali/public-api/object/base-object.h>
  #include <dali/public-api/object/handle.h>
  #include <dali/public-api/object/property.h>
  #include <dali/public-api/object/property-index-ranges.h>
  #include <dali/public-api/object/property-input.h>
  #include <dali/public-api/object/property-notification.h>
  #include <dali/devel-api/common/owner-container.h>
  #include <dali/internal/event/common/event-thread-services.h>
  #include <dali/internal/event/common/property-input-impl.h>
  #include <dali/internal/event/common/property-metadata.h>
  #include <dali/internal/update/common/property-base.h>
  
  namespace Dali
  {
  
  class PropertyNotification;
  
  namespace Internal
  {
  class ConstraintBase;
  class EventThreadServices;
  class Handle;
  class PropertyCondition;
  class PropertyInputImpl;
  class Stage;
  class TypeInfo;
  
  namespace SceneGraph
  {
  class PropertyBase;
  class PropertyOwner;
  }
  
  typedef std::vector< Dali::Constraint >     ConstraintContainer;
  typedef ConstraintContainer::iterator       ConstraintIter;
  typedef ConstraintContainer::const_iterator ConstraintConstIter;
  
  
  /**
   * A base class for objects which optionally provide properties.
   * The concrete derived class is responsible for implementing the property system methods.
   * Classes may derive from Dali::BaseObject, until any properties are required.
   *
   * An object for a property-owning object in the scene-graph.
   * This provides an interface for observing the addition/removal of scene-objects.
   *
   * The concrete derived class is responsible for:
   *   1) Adding & removing an object from the scene-graph. The OnSceneObjectAdd() and OnSceneObjectRemove()
   *      methods should be called by the derived class, to trigger observer callbacks.
   *   3) Implementing the GetSceneObject() methods, used to access the scene-object.
   *   4) Providing access to properties stored by the scene-graph object. These should match the properties
   *      reported by the base Dali::Internal::Object methods.
   *
   */
  class Object : public Dali::BaseObject
  {
  public:
  
    typedef Dali::Handle::Capability Capability;
  
    class Observer
    {
    public:
  
      /**
       * Called immediately after the object has created & passed ownership of a scene-graph object.
       * @param[in] object The object object.
       */
      virtual void SceneObjectAdded(Object& object) = 0;
  
      /**
       * Called shortly before the object sends a message to remove its scene object.
       * @param[in] object The object object.
       */
      virtual void SceneObjectRemoved(Object& object) = 0;
  
      /**
       * Called shortly before the object itself is destroyed; no further callbacks will be received.
       * @param[in] object The object object.
       */
      virtual void ObjectDestroyed(Object& object) = 0;
  
    protected:
  
      /**
       * Virtual destructor
       */
      virtual ~Observer(){}
    };
  
    /**
     * Constructor.
     */
    Object();
  
    /**
     * Add an observer to the object.
     * @param[in] observer The observer to add.
     */
    virtual void AddObserver( Observer& observer );
  
    /**
     * Remove an observer from the object
     * @pre The observer has already been added.
     * @param[in] observer The observer to remove.
     */
    virtual void RemoveObserver( Observer& observer );
  
    /**
     * @copydoc Dali::Handle::Supports()
     */
    virtual bool Supports( Capability capability ) const;
  
    /**
     * @copydoc Dali::Handle::GetPropertyCount()
     */
    virtual unsigned int GetPropertyCount() const;
  
    /**
     * @copydoc Dali::Handle::GetPropertyName()
     */
    virtual std::string GetPropertyName( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::GetPropertyIndex()
     */
    virtual Property::Index GetPropertyIndex( const std::string& name ) const;
  
    /**
     * @copydoc Dali::Handle::IsPropertyWritable()
     */
    virtual bool IsPropertyWritable( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::IsPropertyAnimatable()
     */
    virtual bool IsPropertyAnimatable( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::IsPropertyAConstraintInput()
     */
    virtual bool IsPropertyAConstraintInput( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::GetPropertyType()
     */
    virtual Property::Type GetPropertyType( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::SetProperty()
     */
    virtual void SetProperty( Property::Index index, const Property::Value& propertyValue );
  
    /**
     * @copydoc Dali::Handle::GetProperty()
     */
    virtual Property::Value GetProperty( Property::Index index ) const;
  
    /**
     * @copydoc Dali::Handle::GetPropertyIndices()
     */
    virtual void GetPropertyIndices( Property::IndexContainer& indices ) const;
  
    /**
     * @copydoc Dali::Handle::RegisterProperty()
     */
    virtual Property::Index RegisterProperty( const std::string& name, const Property::Value& propertyValue );
  
    /**
     * @copydoc Dali::Handle::RegisterProperty(std::string name, Property::Value propertyValue, Property::AccessMode accessMode)
     */
    virtual Property::Index RegisterProperty( const std::string& name, const Property::Value& propertyValue, Property::AccessMode accessMode );
  
    /**
     * @copydoc Dali::Handle::AddPropertyNotification()
     */
    virtual Dali::PropertyNotification AddPropertyNotification( Property::Index index,
                                                                int componentIndex,
                                                                const Dali::PropertyCondition& condition );
  
    /**
     * @copydoc Dali::Handle::RemovePropertyNotification()
     */
    virtual void RemovePropertyNotification( Dali::PropertyNotification propertyNotification );
  
    /**
     * @copydoc Dali::Handle::RemovePropertyNotifications()
     */
    virtual void RemovePropertyNotifications();
  
    /******************************** Uniform Mappings ********************************/
  
    /**
     * @copydoc Dali::Handle::AddUniformMapping()
     */
    void AddUniformMapping( Property::Index propertyIndex, const std::string& uniformName ) const;
  
    /**
     * @copydoc Dali::Handle::RemoveUniformMapping( )
     */
    void RemoveUniformMapping( const std::string& uniformName );
  
    /******************************** Constraints ********************************/
  
    /**
     * Apply a constraint to an Object.
     * @param[in] constraint The constraint to apply.
     */
    void ApplyConstraint( ConstraintBase& constraint );
  
    /**
     * Remove one constraint from an Object.
     * @param[in] constraint The constraint to remove.
     */
    void RemoveConstraint( ConstraintBase& constraint );
  
    /**
     * Remove all constraints from a Object.
     */
    void RemoveConstraints();
  
    /**
     * Remove all constraints from a Object with a matching tag
     */
    void RemoveConstraints( unsigned int tag );
  
    /**
     * Called by TypeInfo to set the type-info that this object-impl is created by.
     * @param[in] typeInfo The TypeInfo that creates this object-impl.
     */
    void SetTypeInfo( const TypeInfo* typeInfo );
  
    /**
     * @return the index from which custom properties start
     */
    unsigned int CustomPropertyStartIndex()
    {
      return PROPERTY_CUSTOM_START_INDEX;
    }
  
    /********************  To be overridden by deriving classes ********************/
  
    /**
     * Retrieve the scene-graph object added by this object.
     * @return A pointer to the object, or NULL if no object has been added to the scene-graph.
     */
    virtual const SceneGraph::PropertyOwner* GetSceneObject() const = 0;
  
    /**
     * Retrieve an animatable property owned by the scene-graph object.
     * @pre -1 < index < GetPropertyCount().
     * @param[in] index The index of the property.
     * @return A dereferenceable pointer to a property, or NULL if a scene-object does not exist with this property.
     */
    virtual const SceneGraph::PropertyBase* GetSceneObjectAnimatableProperty( Property::Index index ) const = 0;
  
    /**
     * Retrieve a constraint input-property owned by the scene-graph object.
     * @pre -1 < index < GetPropertyCount().
     * @param[in] index The index of the property.
     * @return A dereferenceable pointer to an input property, or NULL if a scene-object does not exist with this property.
     */
    virtual const PropertyInputImpl* GetSceneObjectInputProperty( Property::Index index ) const = 0;
  
    /**
     * Query whether the property is a component of a scene-graph property.
     * @pre -1 < index < GetPropertyCount().
     * @param[in] index The index of the property.
     * @return The index or Property::INVALID_COMPONENT_INDEX.
     */
    virtual int GetPropertyComponentIndex( Property::Index index ) const;
  
  protected:
  
    /**
     * A reference counted object may only be deleted by calling Unreference()
     */
    virtual ~Object();
  
    /**
     * Called immediately by derived classes, after the scene-object has been created & passed to the scene-graph.
     */
    void OnSceneObjectAdd();
  
    /**
     * Called by derived classes, shortly before send a message to remove the scene-object.
     */
    void OnSceneObjectRemove();
  
    /**
     * For overriding by derived classes to return the parent of this object.
     */
    virtual Object* GetParentObject() const
    {
      // By default the Object does not have a parent
      return NULL;
    };
  
    /**
     * For use in derived classes.
     * This is called after a property is set.
     * @param [in] index The index of the property.
     * @param [in] propertyValue The value of the property.
     */
    virtual void OnPropertySet( Property::Index index, Property::Value propertyValue ) {}
  
    /**
     * Retrieves the TypeInfo for this object. Only retrieves it from the type-registry once and then stores a pointer
     * to it locally there-after. The type info will not change during the life-time of the application.
     * @return The type-info for this object (Can be NULL)
     */
    const TypeInfo* GetTypeInfo() const;
  
    /**
     * Helper to find custom property
     * @param index
     * @return pointer to the property
     */
    CustomPropertyMetadata* FindCustomProperty( Property::Index index ) const;
  
    /**
     * Helper to find animatable property
     * @param index
     * @return pointer to the property
     */
    AnimatablePropertyMetadata* FindAnimatableProperty( Property::Index index ) const;
  
    /**
     * Helper to register a scene-graph property
     * @param [in] name The name of the property.
     * @param [in] index The index of the property
     * @param [in] value The value of the property.
     * @return The index of the registered property or Property::INVALID_INDEX if registration failed.
     */
    Property::Index RegisterSceneGraphProperty(const std::string& name, Property::Index index, const Property::Value& propertyValue) const;
  
    /**
     * Check whether the animatable property is registered already, if not then register one.
     * @param [in] index The index of the property
     * @return pointer to the property.
     */
    AnimatablePropertyMetadata* RegisterAnimatableProperty(Property::Index index) const;
  
    /**
     * Resolve the index and name of child properties if any.
     */
    void ResolveChildProperties();
  
  private: // Default property extensions for derived classes
  
    /**
     * Query how many default properties the derived class supports.
     * @return The number of default properties.
     */
    virtual unsigned int GetDefaultPropertyCount() const = 0;
  
    /**
     * Retrieve all the indices that are associated with the default properties supported by the derived class.
     * @return A container of default property indices.
     * @note The deriving class must not modify the existing elements in the container.
     */
    virtual void GetDefaultPropertyIndices( Property::IndexContainer& indices ) const = 0;
  
    /**
     * Query how many default properties the derived class supports.
     * @return The number of default properties.
     */
    virtual const char* GetDefaultPropertyName( Property::Index index ) const = 0;
  
    /**
     * Query the index of a default property.
     * @param [in] name The name of the property.
     * @return The index of the property, or Property::INVALID_INDEX if no default property exists with the given name.
     */
    virtual Property::Index GetDefaultPropertyIndex( const std::string& name ) const = 0;
  
    /**
     * Query whether a default property is writable.
     * @param [in] index The index of the property.
     * @return True if the property is animatable.
     */
    virtual bool IsDefaultPropertyWritable( Property::Index index ) const = 0;
  
    /**
     * Query whether a default property is animatable.
     * This determines whether the property can be the target of an animation or constraint.
     * @param [in] index The index of the property.
     * @return True if the property is animatable.
     */
    virtual bool IsDefaultPropertyAnimatable( Property::Index index ) const = 0;
  
    /**
     * @brief Query whether a default property can be used as an input to a constraint.
     *
     * @param [in] index The index of the property.
     * @return True if the property can be used as an input to a constraint.
     */
    virtual bool IsDefaultPropertyAConstraintInput( Property::Index index ) const = 0;
  
    /**
     * Query the type of a default property.
     * @param [in] index The index of the property.
     * @return The type of the property.
     */
    virtual Property::Type GetDefaultPropertyType( Property::Index index ) const = 0;
  
    /**
     * Set the value of a default property.
     * @pre The property types match i.e. propertyValue.GetType() is equal to GetPropertyType(index).
     * @param [in] index The index of the property.
     * @param [in] propertyValue The new value of the property.
     */
    virtual void SetDefaultProperty( Property::Index index, const Property::Value& propertyValue ) = 0;
  
    /**
     * Retrieve a default property value.
     * @param [in] index The index of the property.
     * @return The property value.
     */
    virtual Property::Value GetDefaultProperty( Property::Index index ) const = 0;
  
    /**
     * @todo this is virtual so that for now actor can override it,
     * it needs to be removed and only have GetSceneObject but that requires changing actor and constraint logic
     * Retrieve the scene-graph object added by this object.
     * @return A pointer to the object, or NULL if no object has been added to the scene-graph.
     */
    virtual const SceneGraph::PropertyOwner* GetPropertyOwner() const
    {
      return GetSceneObject();
    }
  
    /**
     * Notify derived class of installation of a new scene-object property.
     * This method is called after the message is to sent to install the property
     * @param [in] newProperty A newly allocated scene-object property. Ownership is obviously not passed.
     * @param [in] name The name allocated to this custom property.
     * @param [in] index The index allocated to this custom property.
     */
    virtual void NotifyScenePropertyInstalled( const SceneGraph::PropertyBase& newProperty, const std::string& name, unsigned int index ) const
    { }
  
  private:
  
    // Not implemented
    Object(const Object& rhs);
  
    // Not implemented
    Object& operator=(const Object& rhs);
  
    /**
     * Enable property notifications in scene graph
     */
    void EnablePropertyNotifications();
  
    /**
     * Enable property notifications in scene graph
     */
    void DisablePropertyNotifications();
  
    /**
     * Get the value of the property.
     * @param [in] entry An entry from the property lookup container.
     * @return The new value of the property.
     */
    Property::Value GetPropertyValue( const PropertyMetadata* entry ) const;
  
    /**
     * Set the value of scene graph property.
     * @param [in] index The index of the property.
     * @param [in] entry An entry from the property lookup container.
     * @param [in] value The new value of the property.
     */
    virtual void SetSceneGraphProperty( Property::Index index, const PropertyMetadata& entry, const Property::Value& value );
  
  protected:
    /**
     * Get the event thread services object - used for sending messages to the scene graph
     * Assert if called from the wrong thread.
     * This is intentionally inline for performance reasons.
     *
     * @return The event thread services object
     */
    inline EventThreadServices& GetEventThreadServices()
    {
      DALI_ASSERT_DEBUG( EventThreadServices::IsCoreRunning() );
      return mEventThreadServices;
    }
  
    /**
     * Get the event thread services object - used for sending messages to the scene graph
     * Assert if called from the wrong thread
     * This is intentionally inline for performance reasons.
     *
     * @return The event thread services object
     */
    inline const EventThreadServices& GetEventThreadServices() const
    {
      DALI_ASSERT_DEBUG( EventThreadServices::IsCoreRunning() );
      return mEventThreadServices;
    }
  
  private:
    EventThreadServices& mEventThreadServices;
  
  private:
  
    typedef OwnerContainer<PropertyMetadata*> PropertyMetadataLookup;
    mutable PropertyMetadataLookup mCustomProperties; ///< Used for accessing custom Node properties
    mutable PropertyMetadataLookup mAnimatableProperties; ///< Used for accessing animatable Node properties
    mutable TypeInfo const *  mTypeInfo; ///< The type-info for this object, mutable so it can be lazy initialized from const method if it is required
  
    Dali::Vector<Observer*> mObservers;
  
    ConstraintContainer* mConstraints;               ///< Container of owned -constraints.
  
    typedef std::vector< Dali::PropertyNotification >     PropertyNotificationContainer;
    typedef PropertyNotificationContainer::iterator       PropertyNotificationContainerIter;
    typedef PropertyNotificationContainer::const_iterator PropertyNotificationContainerConstIter;
    PropertyNotificationContainer* mPropertyNotifications; ///< Container of owned property notifications.
  };
  } // namespace Internal
  
  // Helpers for public-api forwarding methods
  
  inline Internal::Object& GetImplementation(Dali::Handle& object)
  {
    DALI_ASSERT_ALWAYS( object && "Object handle is empty" );
  
    BaseObject& handle = object.GetBaseObject();
  
    return static_cast<Internal::Object&>(handle);
  }
  
  inline const Internal::Object& GetImplementation(const Dali::Handle& object)
  {
    DALI_ASSERT_ALWAYS( object && "Object handle is empty" );
  
    const BaseObject& handle = object.GetBaseObject();
  
    return static_cast<const Internal::Object&>(handle);
  }
  
  } // namespace Dali
  
  #endif // __DALI_INTERNAL_OBJECT_H__
  