flightgear/src/Network/props.cxx

// props.hxx -- FGFS property manager interaction class
//
// Written by Curtis Olson, started September 2000.
//
// Copyright (C) 2000  Curtis L. Olson - curt@flightgear.org
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$


#include <simgear/compiler.h>
#include <simgear/debug/logstream.hxx>
#include <simgear/io/iochannel.hxx>
#include <simgear/math/sg_types.hxx>
#include <simgear/misc/props.hxx>

#include <stdlib.h>		// atoi() atof()

#include <strstream>

#include "props.hxx"

FG_USING_STD(cout);
FG_USING_STD(istrstream);

FGProps::FGProps() {
}

FGProps::~FGProps() {
}


// open hailing frequencies
bool FGProps::open() {
    path = "/";

    if ( is_enabled() ) {
	FG_LOG( FG_IO, FG_ALERT, "This shouldn't happen, but the channel " 
		<< "is already in use, ignoring" );
	return false;
    }

    SGIOChannel *io = get_io_channel();

    if ( ! io->open( get_direction() ) ) {
	FG_LOG( FG_IO, FG_ALERT, "Error opening channel communication layer." );
	return false;
    }

    set_enabled( true );

    return true;
}


// return a human readable form of the value "type"
static string getValueTypeString( const SGValue *v ) {
    string result;

    if ( v == NULL ) {
	return "unknown";
    }

    SGValue::Type type = v->getType();
    if ( type == SGValue::UNKNOWN ) {
	result = "unknown";
    } else if ( type == SGValue::BOOL ) {
	result = "bool";
    } else if ( type == SGValue::INT ) {
	result = "int";
    } else if ( type == SGValue::FLOAT ) {
	result = "float";
    } else if ( type == SGValue::DOUBLE ) {
	result = "double";
    } else if ( type == SGValue::STRING ) {
	result = "string";
    }

    return result;
}


bool FGProps::process_command( const char *cmd ) {
    SGIOChannel *io = get_io_channel();

    cout << "processing command = " << cmd;
    string_list tokens;
    tokens.clear();

    istrstream in(cmd);
    
    while ( !in.eof() ) {
	string token;
	in >> token;
	tokens.push_back( token );
    }

    string command = tokens[0];

    SGPropertyNode node( path, &current_properties );
    if ( node.getPath() == "" ) {
	node.setPath( "/" );
    }

    if ( command == "ls" ) {
	for (int i = 0; i < (int)node.size(); i++) {
	    SGPropertyNode child = node.getChild(i);
	    string name = child.getName();
	    string line = name;
	    if ( child.size() > 0 ) {
		line += "/\n";
	    } else {
		string value = node.getStringValue ( name, "" );
		line += " =\t'" + value + "'\t(";
		line += getValueTypeString( node.getValue( name ) );
		line += ")\n";
	    }
	    io->writestring( line.c_str() );
	}
    } else if ( command == "cd" ) {
	// string tmp = "current path = " + node.getPath() + "\n";
	// io->writestring( tmp.c_str() );

	if ( tokens.size() <= 1 ) {
	    // do nothing
	} else if ( tokens[1] == "." ) {
	    // do nothing
	} else if ( tokens[1] == ".." ) {
	    // go back one level
	    string current = node.getPath();
	    int pos = current.rfind("/");
	    // cout << "path = " << current << endl;
	    // cout << "new path = " << current.substr(0, pos) << endl;d
	    string tmp = current.substr(0, pos);
	    node.setPath( tmp );
	    path = tmp;
	} else {
	    // decend to specified child
	    string tmp = node.getPath();
	    tmp += "/" + tokens[1];
	    node.setPath( tmp );
	    path = tmp;
	}
    } else if ( command == "show" ) {
	if ( tokens.size() <= 1 ) {
	    // do nothing
	} else {
	    string ttt = "debug = '" + tokens[1] + "'\n";
	    io->writestring( ttt.c_str() );

	    string value = node.getStringValue ( tokens[1], "" );
	    string tmp = tokens[1] + " = '" + value + "' (";
	    tmp += getValueTypeString( node.getValue( tokens[1] ) );
	    tmp += ")\n";
 
	    io->writestring( tmp.c_str() );
	}
    } else if ( command == "set" ) {
	if ( tokens.size() <= 2 ) {
	    // do nothing
	} else {
	    SGValue *v = node.getValue( tokens[1] );
	    if ( v != NULL ) {
		SGValue::Type type = v->getType();
		if ( type == SGValue::UNKNOWN ) {
		    v->setUnknownValue( tokens[2] );
		} else if ( type == SGValue::BOOL ) {
		    if ( tokens[2] == "true" ) {
			v->setBoolValue( true );
		    } else if ( tokens[2] == "false" ) {
			v->setBoolValue( false );
		    } else {
			v->setBoolValue( atoi( tokens[2].c_str() ) );
		    }
		} else if ( type == SGValue::INT ) {
		    v->setIntValue( atoi( tokens[2].c_str() ) );
		} else if ( type == SGValue::FLOAT ) {
		    v->setFloatValue( atof( tokens[2].c_str() ) );
		} else if ( type == SGValue::DOUBLE ) {
		    v->setDoubleValue( atof( tokens[2].c_str() ) );
		} else if ( type == SGValue::STRING ) {
		    v->setStringValue( tokens[2] );
		}

		// now fetch and write out the new value as confirmation
		// of the change
		string value = node.getStringValue ( tokens[1], "" );
		string tmp = tokens[1] + " = '" + value + "' (";
		tmp += getValueTypeString( node.getValue( tokens[1] ) );
		tmp += ")\n";
 
		io->writestring( tmp.c_str() );
	    } else {
		string tmp = tokens[1] + " is unknown.\n";

		io->writestring( tmp.c_str() );
	    }

	}
    } else if ( command == "quit" ) {
	close();
    } else {
	io->writestring( "\n" );
	io->writestring( "Valid commands are:\n" );
	io->writestring( "\n" );
	io->writestring( "help             show help message\n" );
	io->writestring( "ls               list current directory\n" );
	io->writestring( "cd <dir>         cd to a directory, '..' to move back\n" );
	io->writestring( "show <var>       show the value of a parameter\n" );
	io->writestring( "set <var> <val>  set <var> to a new <val>\n" );
	io->writestring( "quit             terminate connection\n" );
	io->writestring( "\n" );
    }

    string prompt = node.getPath();
    if ( prompt == "" ) {
	prompt = "/";
    }
    prompt += "> ";
    io->writestring( prompt.c_str() );

    return true;
}


// process work for this port
bool FGProps::process() {
    SGIOChannel *io = get_io_channel();

    // cout << "processing incoming props command" << endl;

    if ( get_direction() == SG_IO_BI ) {
	// cout << "  (bi directional)" << endl;
	while ( io->readline( buf, max_cmd_len ) > 0 ) {
	    FG_LOG( FG_IO, FG_ALERT, "Success reading data." );
	    process_command( buf );
	}
    } else {
	FG_LOG( FG_IO, FG_ALERT, 
		"in or out direction not supported for FGProps." );
    }

    return true;
}


// close the channel
bool FGProps::close() {
    SGIOChannel *io = get_io_channel();

    set_enabled( false );

    if ( ! io->close() ) {
	return false;
    }

    cout << "successfully closed channel\n";

    return true;
}