object_visitor.cpp

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// See ../license.txt for license information.
//
// object_visitor.cpp
//
// 4-Jul-2003  phamilton  Created
//

#define REFLECT_IN_LIBRARY_SOURCE

#include "object_visitor.hpp"
#include <iostream>
#include "../common/object.hpp"
#include "../common/comparable_object.hpp"
#include "../common/outerable_object.hpp"
#include "../common/visitable_object.hpp"
#include "../common/nameable_object.hpp"
#include "../common/pretendable_object.hpp"
#include "member_visitor.hpp"
#include "member.hpp"
#include <boost/bind.hpp>
#include <algorithm>

using namespace ph::reflect;

class dump_member_visitor : public ph::common::const_member_visitor
/**
        Concrete subclass of member_visitor used to dump the value of a member.
*/
{
public:
        dump_member_visitor(std::ostream *stream, int indent) :
                _stream(stream), _indent(indent)
                        {};
                                
        // member_visitor ovverides.
        virtual bool visit(const ph::common::object_base *obj, 
                const std::string &name, const ph::common::member_base *member);
        
private:
        std::ostream *_stream;
        int           _indent;
};

static std::string get_name(const ph::common::object_base *obj)
{
        if (!obj->nameable())
                return "object has no nameable interface.";
        return obj->nameable()->name();
}

static std::string get_type(const ph::common::object_base *obj)
{
        if (!obj->nameable())
                return "object has no nameable interface.";
        return obj->nameable()->type();
}

static bool obj_equal(const ph::common::object_base *o1, const ph::common::object_base *o2, std::ostream *debug)
{
        if (debug)
                *debug << ">> comparing [" << get_name(o1) << "] to [" << get_name(o2) << "]" << std::endl;
        
        // use equal interface if one exists.
        if (o1->comparable())
                return o1->comparable()->equal(o2);
        else
                return o1 == o2;
}

void dump_object_visitor::obj_out(const std::string &msg, const ph::common::object_base *obj)
{
        *_stream << ">> " << msg << " [" << get_name(obj) << "]" << std::endl;
}

void dump_object_visitor::close_stack()
{
        if (_debug)
                *_stream << ">> closing stack. " << std::endl;
        
        // pop the stack back out till it's empty.
        while (!_stack.empty())
        {
                _stack.pop_back();
                _indent--;
                indent();
                *_stream << "}" << std::endl;
        }
        if (_indent != 0)
                *_stream << ">> error after closing stack, indent is not 0?. " << std::endl;
}

void dump_object_visitor::calc_indent(const ph::common::object_base *obj)
{
        if (_debug)
                obj_out("calc_indent", obj);

        // we have a new object.
        if (!obj->outerable())
        {
                if (_debug)
                        obj_out("object has no parent interface. Can't calculate the indent.", obj);
                return;
        }
        
        ph::common::object_base *parent = obj->outerable()->outer();
        if (parent)
        {
                if (_debug)
                        obj_out("parent.", parent);
                
                // is the parent on the stack?
                if (std::find_if(_stack.rbegin(), _stack.rend(), 
                                boost::bind(obj_equal, _1, parent, _debug ? _stream : 0)) != _stack.rend())
                {
                        if (_debug)
                                obj_out("found parent on stack.", parent);
                
                        // pop the stack back till we get the parent.
                        while (!obj_equal(_stack.back(), parent, _debug ? _stream : 0))
                        {
                                if (_debug)
                                        obj_out("popping.", _stack.back());
                                _stack.pop_back();
                                _indent--;
                                indent();
                                *_stream << "}" << std::endl;
                        }
                        
                        if (_debug)
                                obj_out("pushing.", obj);
                        _stack.push_back(obj);
                }
                else
                {
                        if (_debug)
                                obj_out("not found on stack. pushing.", obj);
                        _stack.push_back(obj);
                        _indent++;
                }
        }
        else
        {
                if (_debug)
                        obj_out("no parent. pushing.", obj);
                close_stack();
                _stack.push_back(obj);
        }
}

void dump_object_visitor::indent()
{
        for (int i=0; i<_indent; i++)
                *_stream << " ";
}

dump_object_visitor::~dump_object_visitor()
{
        close_stack();
}

bool dump_object_visitor::visit(const ph::common::object_base *obj)
{
        if (_debug)
                obj_out("visit", obj);
        
        calc_indent(obj);

        indent();
        *_stream << get_type(obj) << "(name=" << get_name(obj) << ") { " << std::endl;
        
        _indent++;

        // dump members.
        dump_member_visitor v(_stream, _indent);
        if (obj->visitable())
                obj->visitable()->accept(&v);
        else
                obj_out("object can't be reflected.", obj);

        return true;
}

bool dump_object_visitor::visit_composite(const ph::common::object_base *obj)
{
        if (_debug)
                obj_out("visit_composite", obj);

        calc_indent(obj);

        indent();
        *_stream << get_name(obj) << " { " << std::endl;

        _indent++;

        return true;
}

// dump_member_visitor
bool dump_member_visitor::visit(const ph::common::object_base *obj, const std::string &name, 
                const ph::common::member_base *member)
{
        // skip over name and type properties
        if (name != "name" && name != "type")
        {
                for (int i=0; i<_indent; i++)
                        *_stream << " ";
                *_stream << name << "=" << member->get() << std::endl;
        }
        
        return true;
}

bool get_composite_object_visitor::visit_composite(const ph::common::object_base *obj, const ph::common::nameable_object_base *name)
{
        if (name->name() == _name)
        {       
                // although we don't modify any of the objects we visit, we do
                // need to return the actual object at the end, so
                // we cast out const.
                _obj = const_cast<ph::common::object_base *>(obj);

                // We check for pretendable objects to make
                // sure that we get the actual object.
                if (_obj->pretendable())
                        _obj = _obj->pretendable()->realobject();
                        
                return false;
        }
        return true;
}

bool get_object_visitor::visit(const ph::common::object_base *obj, const ph::common::nameable_object_base *name)
{
        if (name->name() == _name)
        {
                // although we don't modify any of the objects we visit, we do
                // need to return the actual object at the end, so
                // we cast out const.
                _obj = const_cast<ph::common::object_base *>(obj);

                // We check for pretendable objects to make
                // sure that we get the actual object.
                if (_obj->pretendable())
                        _obj = _obj->pretendable()->realobject();
                        
                return false;
        }
        return true;
}

bool get_object_with_type_visitor::visit(const ph::common::object_base *obj, const ph::common::nameable_object_base *name)
{
        // the order of these is very important. We often know the name of an object, but
        // not it's type, so if the name doesn't match, we don't want to even try to get it's 
        // type.
        if (name->name() == _name && name->type() == _type)
        {
                // although we don't modify any of the objects we visit, we do
                // need to return the actual object at the end, so
                // we cast out const.
                _obj = const_cast<ph::common::object_base *>(obj);

                // We check for pretendable objects to make
                // sure that we get the actual object.
                if (_obj->pretendable())
                        _obj = _obj->pretendable()->realobject();
                        
                return false;
        }
        return true;
}

bool get_nth_object_visitor::visit(const ph::common::object_base *obj, const ph::common::nameable_object_base *name)
{
        // when the index is 0, return the object.
        if (_index == 0)
        {
                // although we don't modify any of the objects we visit, we do
                // need to return the actual object at the end, so
                // we cast out const.
                _obj = const_cast<ph::common::object_base *>(obj);

                // We check for pretendable objects to make
                // sure that we get the actual object.
                if (_obj->pretendable())
                        _obj = _obj->pretendable()->realobject();
                        
                return false;
        }
        _index--;
        return true;
}

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