feat: dynamic constraints (Fixes #8)

app/src/main/java/sudoku/constraint/Constraint.java

@@ -0,0 +1,52 @@
+package sudoku.constraint;
+
+import java.util.List;
+
+import sudoku.structure.Sudoku;
+
+public enum Constraint {
+
+	Block("Bloc", new BlockConstraint()),
+	Column("Colonne", new ColumnConstraint()),
+	Line("Ligne", new LineConstraint()),
+	Diagonal("Diagonale", new DiagonalConstraint());
+
+	String displayName;
+	IConstraint constraint;
+
+	private Constraint(String displayName, IConstraint contraint) {
+		this.constraint = contraint;
+		this.displayName = displayName;
+	}
+
+	public boolean canBePlaced(Sudoku s, int x, int y, int newValue) {
+		return getConstraint().canBePlaced(s, x, y, newValue);
+	}
+
+	public List<Integer> getPossibleSymbols(final Sudoku s, int x, int y) {
+		return getConstraint().getPossibleSymbols(s, x, y);
+	}
+
+	public String getDisplayName() {
+		return displayName;
+	}
+
+	public IConstraint getConstraint() {
+		return constraint;
+	}
+
+	private static final String[] constraintNames;
+
+	static {
+		Constraint[] cons = Constraint.values();
+		constraintNames = new String[cons.length];
+		for (int i = 0; i < cons.length; i++) {
+			constraintNames[i] = cons[i].getDisplayName();
+		}
+	}
+
+	public static String[] getConstraintNames() {
+		return constraintNames;
+	}
+
+}