// Abstract Factory classes are often implemented with Factory Methods, but they
// can also be implemented using Prototype. [GOF, p95] Abstract Factory might
// store a set of Prototypes from which to clone and return product objects.
// [GOF, p126] Factory Method: creation through inheritance. Protoype: creation
// through delegation. Virtual constructor: defer choice of object to create
// until run-time.

public class FactoryFmProto {

static class Expression {
protected String str;
public Expression( String s ) { str = s; }
public Expression cloan() { return null; }
public String toString() { return str; }
}

static abstract class Factory {
protected Expression prototype = null;
public Expression makePhrase() { return prototype.cloan(); }
public abstract Expression makeCompromise();
public abstract Expression makeGrade();
}

static class PCFactory extends Factory {
public PCFactory() { prototype = new PCPhrase(); }
public Expression makeCompromise() {
return new Expression( "\"do it your way, any way, or no way\"" ); }
public Expression makeGrade() {
return new Expression( "\"you pass, self-esteem intact\"" ); }
}

static class NotPCFactory extends Factory {
public NotPCFactory() { prototype = new NotPCPhrase(); }
public Expression makeCompromise() {
return new Expression( "\"my way, or the highway\"" ); }
public Expression makeGrade() {
return new Expression( "\"take test, deal with the results\"" ); }
}

public static void main( String[] args ) {
Factory factory;
if (args.length > 0) factory = new PCFactory();
else factory = new NotPCFactory();
for (int i=0; i < 3; i++) System.out.print( factory.makePhrase() + " " );
System.out.println();
System.out.println( factory.makeCompromise() );
System.out.println( factory.makeGrade() );
}

// D:\Java\patterns> java FactoryFmProto
// "short" "lie" "old"
// "my way, or the highway"
// "take test, deal with the results"
//
// D:\Java\patterns> java FactoryFmProto 1
// "vertically challenged" "factually inaccurate" "chronologically gifted"
// "do it your way, any way, or no way"
// "you pass, self-esteem intact"

static class PCPhrase extends Expression {
static String[] list = { "\"animal companion\"", "\"vertically challenged\"",
"\"factually inaccurate\"", "\"chronologically gifted\"" };
private static int next = 0;
public PCPhrase() { super( list[next] ); next = (next+1) % list.length; }
public Expression cloan() { return new PCPhrase(); }
}

static class NotPCPhrase extends Expression {
private static String[] list = { "\"pet\"", "\"short\"", "\"lie\"", "\"old\"" };
private static int next = 0;
public NotPCPhrase() { super( list[next] ); next = (next+1) % list.length; }
public Expression cloan() { return new NotPCPhrase(); }
}}