Improved random ship positioning

src/main/java/de/tims/fleetstorm/gui/GameLogic.java

@@ -194,10 +194,10 @@ public class GameLogic extends JPanel {
 		// create player matchfield and set ships
 		this.matchfield = new Matchfield(matchfieldSize);
 		this.matchfield.createMatchfield();
-		this.matchfield.setShip(new Coordinate(4, 6), 2, 0);
-		this.matchfield.setShip(new Coordinate(1, 3), 3, 0);
-		this.matchfield.setShip(new Coordinate(9, 1), 4, 1);
-		this.matchfield.setShip(new Coordinate(0, 0), 5, 0);
+		this.matchfield.setShipOnRandomPosition(2);
+		this.matchfield.setShipOnRandomPosition(3);
+		this.matchfield.setShipOnRandomPosition(4);
+		this.matchfield.setShipOnRandomPosition(5);
 
 		this.aiLogic = new Logic();
 		this.aiLogic.setMatchfield(this.matchfield);
@@ -206,10 +206,10 @@ public class GameLogic extends JPanel {
 		// matchfield)
 		this.enemyMatchfield = new Matchfield(matchfieldSize);
 		this.enemyMatchfield.createMatchfield();
-		this.enemyMatchfield.setShip(new Coordinate(8, 9), 2, 0);
-		this.enemyMatchfield.setShip(new Coordinate(0, 2), 3, 1);
-		this.enemyMatchfield.setShip(new Coordinate(7, 0), 4, 1);
-		this.enemyMatchfield.setShip(new Coordinate(3, 6), 5, 0);
+		this.enemyMatchfield.setShipOnRandomPosition(2);
+		this.enemyMatchfield.setShipOnRandomPosition(3);
+		this.enemyMatchfield.setShipOnRandomPosition(4);
+		this.enemyMatchfield.setShipOnRandomPosition(5);
 
 		// enter game loop
 		this.gameState = GameLogic.RUNNING;

src/main/java/de/tims/fleetstorm/matchfield/Matchfield.java

@@ -1,5 +1,7 @@
 package de.tims.fleetstorm.matchfield;
 
+import java.util.Random;
+
 public class Matchfield {
 
 	private Coordinate[][] matchfield;
@@ -110,4 +112,53 @@ public class Matchfield {
 		return shipCounter == 0;
 	}
 
+	public boolean isFreePosition(Coordinate next, int length, int direction) {
+
+		for (int i = 0; i < length; i++) {
+
+			if (this.getState(next.getX(), next.getY()) != Coordinate.EMPTY)
+				return false;
+
+			if (direction == 0) {
+				next = new Coordinate(next.getX() + 1, next.getY());
+			} else if (direction == 1) {
+				next = new Coordinate(next.getX(), next.getY() + 1);
+			}
+		}
+
+		return true;
+	}
+
+	public boolean setShipOnRandomPosition(int length) {
+		boolean success = false;
+		Coordinate origin = null;
+		int randomDirection;
+
+		do {
+
+			Random random = new Random();
+
+			randomDirection = random.nextInt(2);
+
+			int randomX = 0, randomY = 0;
+
+			if (randomDirection == 0) {
+				randomX = random.nextInt(this.size - length);
+				randomY = random.nextInt(this.size);
+			} else if (randomDirection == 1) {
+				randomX = random.nextInt(this.size);
+				randomY = random.nextInt(this.size - length);
+			}
+
+			origin = new Coordinate(randomX, randomY);
+
+			if (this.isFreePosition(origin, length, randomDirection)) {
+				success = this.setShip(new Coordinate(randomX, randomY), length, randomDirection);
+			}
+
+		} while (!success);
+
+		return true;
+	}
+
 }

src/test/java/de/tims/fleetstorm/matchfield/MatchfieldShipTest.java

@@ -3,9 +3,8 @@ package de.tims.fleetstorm.matchfield;
 
 import static org.junit.jupiter.api.Assertions.*;
 import static org.assertj.core.api.Assertions.assertThat;
-
 import java.util.stream.Stream;
-
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
@@ -13,20 +12,28 @@ import org.junit.jupiter.params.provider.MethodSource;
 
 class MatchfieldShipTest {
 
+	private Matchfield matchfield;
+	private int matchfieldSize = 10;
+
+	@BeforeEach
+	void setup() {
+		matchfield = new Matchfield(matchfieldSize);
+		matchfield.createMatchfield();
+	}
+
 	@ParameterizedTest(name = "ship was set on the correct positions")
 	@MethodSource("testShipPositioning")
-	void testMatchfieldShipSetHasCorrectPositions(String testName, int matchfieldSize, Coordinate coordinate,
-			int direction, int length, Coordinate[] coordinatesWithShip) {
-		Matchfield matchfield = new Matchfield(matchfieldSize);
-		matchfield.createMatchfield();
+	void testMatchfieldShipSetHasCorrectPositions(String testName, Coordinate coordinate, int direction, int length,
+			Coordinate[] coordinatesWithShip) {
 
 		matchfield.setShip(coordinate, length, direction);
 
 		int shipSetCounter = 0;
 		for (Coordinate toCheckCoordinate : coordinatesWithShip) {
-			if (matchfield.getField(toCheckCoordinate).getState() == Coordinate.SHIP)
+			if (matchfield.getField(toCheckCoordinate).getState() == Coordinate.SHIP) {
 				shipSetCounter++;
 			}
+		}
 
 		assertThat(shipSetCounter).describedAs(testName).isEqualTo(length);
 	}
@@ -39,42 +46,33 @@ class MatchfieldShipTest {
 				new Coordinate(0, 4), new Coordinate(0, 5) };
 
 		return Stream.of(
-				Arguments.of("set ship from 0:0, length 2, direction 0", 10, new Coordinate(0, 0), 0, 2,
+				Arguments.of("set ship from 0:0, length 2, direction 0", new Coordinate(0, 0), 0, 2,
 						coordinatesWithShip00_2_0),
-				Arguments.of("set ship from 0:1, length 3, direction 0", 10, new Coordinate(0, 1), 0, 3,
+				Arguments.of("set ship from 0:1, length 3, direction 0", new Coordinate(0, 1), 0, 3,
 						coordinatesWithShip01_3_0),
-				Arguments.of("set ship from 0:2, length 4, direction 1", 10, new Coordinate(0, 2), 1, 4,
+				Arguments.of("set ship from 0:2, length 4, direction 1", new Coordinate(0, 2), 1, 4,
 						coordinatesWithShip02_4_1));
 	}
 
 	@ParameterizedTest(name = "ship positioning on invalid or valid coordinates")
 	@MethodSource("testShipPositioningFailed")
-	void testMatchfieldShipSetWithInvalidOrValidCoordinates(String testName, int matchfieldSize, Coordinate coordinate,
-			int direction, int length, boolean expectedResult) {
-		Matchfield matchfield = new Matchfield(matchfieldSize);
-		matchfield.createMatchfield();
+	void testMatchfieldShipSetWithInvalidOrValidCoordinates(String testName, Coordinate coordinate, int direction,
+			int length, boolean expectedResult) {
 
 		boolean calculatedResult = matchfield.setShip(coordinate, length, direction);
-
-		if (expectedResult)
-			assertThat(calculatedResult).describedAs(testName).isEqualTo(true);
-
-		if (!expectedResult)
-			assertThat(calculatedResult).describedAs(testName).isEqualTo(false);
+		assertThat(calculatedResult).describedAs(testName).isEqualTo(expectedResult);
 	}
 
 	static Stream<Arguments> testShipPositioningFailed() {
 		return Stream.of(
-				Arguments.of("invalid ship position from 9:0, length 2, direction 0", 10, new Coordinate(9, 0), 0, 2,
-						false),
-				Arguments.of("valid ship position from 8:0, length 5, direction 1", 10, new Coordinate(9, 0), 1, 5,
+				Arguments.of("invalid ship position from 9:0, length 2, direction 0 (x-axis)", new Coordinate(9, 0), 0,
+						2, false),
+				Arguments.of("valid ship position from 8:0, length 5, direction 1 (y-axis)", new Coordinate(9, 0), 1, 5,
 						true));
 	}
 
 	@Test
 	void testShipPositionAlreadySetWithShip() {
-		Matchfield matchfield = new Matchfield(10);
-		matchfield.createMatchfield();
 
 		matchfield.setShip(new Coordinate(0, 0), 5, 1);
 		assertThat(matchfield.setShip(new Coordinate(0, 1), 5, 1)).describedAs("set ship on coordinate with ship")
@@ -88,9 +86,6 @@ class MatchfieldShipTest {
 
 	@Test
 	void testIfAllShipsHitReturnsFalseWhenNoShipIsHit() {
-		Matchfield matchfield = new Matchfield(10);
-		matchfield.createMatchfield();
-
 		matchfield.setShip(new Coordinate(0, 0), 5, 1);
 		boolean calulatedResult = matchfield.areAllShipsHit();
 		assertFalse(calulatedResult);
@@ -98,15 +93,9 @@ class MatchfieldShipTest {
 
 	@Test
 	void testIfAllShipsHitReturnsTrueWhenAllShipsAreHit() {
-		Matchfield matchfield = new Matchfield(10);
-		matchfield.createMatchfield();
-
 		matchfield.setShip(new Coordinate(0, 0), 5, 1);
-		matchfield.getField(0, 0).setState(Coordinate.HIT);
-		matchfield.getField(0, 1).setState(Coordinate.HIT);
-		matchfield.getField(0, 2).setState(Coordinate.HIT);
-		matchfield.getField(0, 3).setState(Coordinate.HIT);
-		matchfield.getField(0, 4).setState(Coordinate.HIT);
+
+		setFieldRangeHit(matchfield);
 
 		boolean calulatedResult = matchfield.areAllShipsHit();
 		assertTrue(calulatedResult);
@@ -114,15 +103,9 @@ class MatchfieldShipTest {
 
 	@Test
 	void testIfAllShipsHitReturnsFalseWhenTwoShipsAreNotFullyHit() {
-		Matchfield matchfield = new Matchfield(10);
-		matchfield.createMatchfield();
-
 		matchfield.setShip(new Coordinate(0, 0), 5, 1);
-		matchfield.getField(0, 0).setState(Coordinate.HIT);
-		matchfield.getField(0, 1).setState(Coordinate.HIT);
-		matchfield.getField(0, 2).setState(Coordinate.HIT);
-		matchfield.getField(0, 3).setState(Coordinate.HIT);
-		matchfield.getField(0, 4).setState(Coordinate.HIT);
+
+		setFieldRangeHit(matchfield);
 
 		matchfield.setShip(new Coordinate(3, 4), 2, 0);
 		matchfield.getField(4, 4).setState(Coordinate.HIT);
@@ -130,4 +113,45 @@ class MatchfieldShipTest {
 		boolean calulatedResult = matchfield.areAllShipsHit();
 		assertFalse(calulatedResult);
 	}
+
+	void setFieldRangeHit(Matchfield matchfield) {
+		for (int i = 0; i <= 4; i++) {
+			matchfield.getField(0, i).setState(Coordinate.HIT);
+		}
+	}
+
+	@ParameterizedTest(name = "matchfield returns correct state if a position is free or not")
+	@MethodSource("testIsFreeMethod")
+	void testMatchfieldReturnsCorrectValueAboutFreeCoordinateSlots(String testName, Coordinate originCoordinate,
+			int direction, int length, Coordinate[] coordinatesWithShip, boolean expectedResult) {
+
+		Matchfield matchfield = new Matchfield(matchfieldSize);
+		matchfield.createMatchfield();
+
+		for (Coordinate coordinate : coordinatesWithShip) {
+			matchfield.getField(coordinate).setState(Coordinate.SHIP);
+		}
+
+		boolean calculatedResult = matchfield.isFreePosition(originCoordinate, length, direction);
+		assertThat(calculatedResult).describedAs(testName).isEqualTo(expectedResult);
+
+	}
+
+	static Stream<Arguments> testIsFreeMethod() {
+		return Stream.of(
+				Arguments.of("one ship is within the coordinates", new Coordinate(0, 0), 1, 2,
+						new Coordinate[] { new Coordinate(0, 0) }, false),
+				Arguments.of("no ship is within the coordinates", new Coordinate(1, 1), 0, 5, new Coordinate[] {},
+						true),
+				Arguments.of("one of the coordinates is hit, others on free fields", new Coordinate(5, 5), 1, 3,
+						new Coordinate[] { new Coordinate(5, 7), new Coordinate(5, 8), new Coordinate(5, 9) }, false));
+	}
+
+	@Test
+	void testIfRandomShipPositioningIsWorking() {
+		for (int shipLength = 2; shipLength <= 5; shipLength++) {
+			boolean calculatedResult = matchfield.setShipOnRandomPosition(shipLength);
+			assertTrue(calculatedResult);
+		}
+	}
 }