class Chain {
private State current;
public Chain() { current = new Off(); }
public void setState( State s ) { current = s; }
public void pull() { current.pull( this ); }
}
abstract class State {
public void pull( Chain wrapper ) {
wrapper.setState( new Off() );
System.out.println( " turning off" );
} }
class Off extends State {
public void pull( Chain wrapper ) {
wrapper.setState( new Low() );
System.out.println( " low speed" );
} }
class Low extends State {
public void pull( Chain wrapper ) {
wrapper.setState( new Medium() );
System.out.println( " medium speed" );
} }
class Medium extends State {
public void pull( Chain wrapper ) {
wrapper.setState( new High() );
System.out.println( " high speed" );
} }
class High extends State { }
public class StateDisc {
public static void main( String[] args ) throws IOException {
InputStreamReader is = new InputStreamReader( System.in );
int ch;
Chain chain = new Chain();
while (true) {
System.out.print( "Press 'Enter'" );
ch = is.read(); ch = is.read();
chain.pull();
} } }
