Package com.project.snakeGame

Class GamePanel

java.lang.Object

java.awt.Component

java.awt.Container

javax.swing.JComponent

javax.swing.JPanel

com.project.snakeGame.GamePanel

All Implemented Interfaces:

ActionListener, ImageObserver, MenuContainer, Serializable, EventListener, Accessible

public class GamePanel
extends JPanel
implements ActionListener

The GamePanel class handles the gameplay logic and rendering for the Snake Game. It manages:

• Snake movement and collision detection
• Apple generation and score tracking
• Game rendering and updating

The game can run in two modes:

• EASY mode: Slower snake speed
• HARD mode: Faster snake speed

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	GamePanel.Mode	Enum for game difficulty modes.
class	GamePanel.MyKeyAdapter	The MyKeyAdapter class handles keyboard inputs to control the snake's direction.

Nested classes/interfaces inherited from class javax.swing.JPanel

JPanel.AccessibleJPanel

Nested classes/interfaces inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes/interfaces inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields

Modifier and Type	Field	Description
private int	applesEaten	Score - number of apples eaten.
private int	appleX	X and Y positions of the apple.
private int	appleY	X and Y positions of the apple.
private static final int	boardHeight	Height of the game board (rounded to fit units).
private static final int	boardWidth	Width of the game board (rounded to fit units).
private int	bodyParts	Initial length of the snake.
private char	direction	Current direction of the snake's movement.
private static GamePanel.Mode	gameMode	Current game mode (default: EASY).
private boolean	isRunning	Game running state.
private static final int	maxUnits	Maximum number of units (board area divided by unit size).
private Random	random	Random number generator for apple positioning.
private Timer	timer	Timer to control the game speed and refresh rate.
private static final int	unitSize	Size of each unit (square) on the game board.
private final int[]	x	Arrays storing the snake's X and Y coordinates.
private final int[]	y

Fields inherited from class javax.swing.JComponent

listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

Constructors

Constructor	Description
GamePanel()	Constructs the GamePanel, initializes the game settings, and starts the game.

Method Summary

Modifier and Type	Method	Description
void	actionPerformed(ActionEvent e)	Handles the game loop by updating the snake's position, checking for collisions, and determining if the snake has eaten an apple.
protected void	checkApple()	Checks if the snake has eaten an apple.
private void	checkCollisions()	Checks for collisions with the snake itself or the game boundaries.
protected void	draw(Graphics g)	Draws the game elements: Apple Snake body Game over message (if the game ends)
private void	gameOver(Graphics g)	Displays the "Game Over" message.
protected void	move()	Moves the snake in the current direction.
protected void	newApple()	Spawns a new apple at a random location, ensuring it doesn't overlap with the snake's body.
protected void	paintComponent(Graphics g)	Handles the painting of the game board.
private void	setGameSpeed()	Configures the game speed based on the selected mode.
protected static void	setMode(GamePanel.Mode mode)	Sets the game mode (difficulty).
protected void	startGame()	Starts the game by: Resetting snake length and score Setting the initial direction to 'R' Spawning the first apple Starting the game timer

Methods inherited from class javax.swing.JPanel

getAccessibleContext, getUI, getUIClassID, paramString, setUI, updateUI

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

gameMode

private static GamePanel.Mode gameMode

Current game mode (default: EASY).

unitSize

private static final int unitSize

Size of each unit (square) on the game board.

See Also:

• Constant Field Values

boardWidth

private static final int boardWidth

Width of the game board (rounded to fit units).

See Also:

• Constant Field Values

boardHeight

private static final int boardHeight

Height of the game board (rounded to fit units).

See Also:

• Constant Field Values

maxUnits

private static final int maxUnits

Maximum number of units (board area divided by unit size).

See Also:

• Constant Field Values

bodyParts

private int bodyParts

Initial length of the snake.

applesEaten

private int applesEaten

Score - number of apples eaten.

appleX

private int appleX

X and Y positions of the apple.

appleY

private int appleY

X and Y positions of the apple.

direction

private char direction

Current direction of the snake's movement.

isRunning

private boolean isRunning

Game running state.

x

private final int[] x

Arrays storing the snake's X and Y coordinates.

y

private final int[] y

timer

private Timer timer

Timer to control the game speed and refresh rate.

random

private Random random

Random number generator for apple positioning.

Constructor Details

GamePanel

GamePanel()

Constructs the GamePanel, initializes the game settings, and starts the game.

Method Details

setMode

protected static void setMode(GamePanel.Mode mode)

Sets the game mode (difficulty).

Parameters:

mode - The selected game mode (EASY or HARD).

setGameSpeed

private void setGameSpeed()

Configures the game speed based on the selected mode.

• EASY mode: 300ms delay
• HARD mode: 150ms delay

startGame

protected void startGame()

Starts the game by:

• Resetting snake length and score
• Setting the initial direction to 'R'
• Spawning the first apple
• Starting the game timer

paintComponent

protected void paintComponent(Graphics g)

Handles the painting of the game board.

Overrides:

paintComponent in class JComponent

Parameters:

g - The Graphics object used for rendering.

draw

protected void draw(Graphics g)

Draws the game elements:

• Apple
• Snake body
• Game over message (if the game ends)

Parameters:

g - The Graphics object used for rendering.

newApple

protected void newApple()

Spawns a new apple at a random location, ensuring it doesn't overlap with the snake's body.

move

protected void move()

Moves the snake in the current direction.

checkApple

protected void checkApple()

Checks if the snake has eaten an apple. Increases the snake's length and score if true.

checkCollisions

private void checkCollisions()

Checks for collisions with the snake itself or the game boundaries. Stops the game if a collision occurs.

gameOver

private void gameOver(Graphics g)

Displays the "Game Over" message.

Parameters:

g - The Graphics object used for rendering.

actionPerformed

public void actionPerformed(ActionEvent e)

Handles the game loop by updating the snake's position, checking for collisions, and determining if the snake has eaten an apple. The game is repainted after each tick.

Specified by:

actionPerformed in interface ActionListener

Parameters:

e - The ActionEvent triggered by the timer.