Develop Reference

Making a character land on a platform

Im trying to code a simple 2D game. I have a Square that you can move with a/w/d. I got jumping working with a sort of gravity but now I cant get myself to land on a platform. I know how to detect collision between two things but even still idk what to do. My gravity always pulls me down until I reach groundLevel which is part of the problem. Here is my code so far. There's a lot of experimenting happing so its pretty messy.
import javax.swing.Timer;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.geom.*;
/**
* Custom Graphics Example: Using key/button to move a line left or right.
*/
public class PlatformingGame extends JFrame implements ActionListener, KeyListener{
// Name-constants for the various dimensions
public static final int CANVAS_WIDTH = 800;
public static final int CANVAS_HEIGHT = 400;
public static final Color LINE_COLOR = Color.BLACK;
public static final Color CANVAS_BACKGROUND = Color.WHITE;
public int GRAVITY = 10;
public int TERMINAL_VELOCITY = 300;
public int vertical_speed = 0;
public int jumpSpeed;
public int groundLevel = CANVAS_HEIGHT;
int Shapes;
private DrawCanvas canvas; // the custom drawing canvas (extends JPanel)
public enum STATE {
PLAYING,
PAUSED,
ONGROUND,
INAIR
};
JButton btnStartRestat, btnExit;
Timer timer;
Rectangle2D.Double guy, platform, platform2;
Shape[] shapeArr = new Shape[10];
int dx, dy;
/** Constructor to set up the GUI */
ArrayList myKeys = new ArrayList<Character>();
public static STATE gameState = STATE.PAUSED;
//public static STATE playerState = STATE.ONGROUND;
public PlatformingGame() {
dx = 3;
dy = 3;
guy = new Rectangle2D.Double( CANVAS_WIDTH/2 - 20, CANVAS_HEIGHT, 30, 20);
platform2 = new Rectangle2D.Double( CANVAS_WIDTH/4, CANVAS_HEIGHT/2+130, 50, 10);
platform = new Rectangle2D.Double( CANVAS_WIDTH/3, CANVAS_HEIGHT/2+50, 50, 10);
timer = new Timer(10, this);
// Set up a panel for the buttons
JPanel btnPanel = new JPanel();
// btnPanel.setPreferredSize(new Dimension(CANVAS_WIDTH/2, CANVAS_HEIGHT));
btnPanel.setLayout(new FlowLayout());
btnStartRestat = new JButton("Start/Restart");
btnExit = new JButton("Exit");
btnPanel.add(btnStartRestat);
btnPanel.add(btnExit);
btnStartRestat.addActionListener(this);
btnExit.addActionListener(this);
// Set up a custom drawing JPanel
canvas = new DrawCanvas();
canvas.setPreferredSize(new Dimension(CANVAS_WIDTH, CANVAS_HEIGHT));
// Add both panels to this JFrame
Container cp = getContentPane();
cp.setLayout(new BorderLayout());
cp.add(canvas, BorderLayout.CENTER);
cp.add(btnPanel, BorderLayout.SOUTH);
// "this" JFrame fires KeyEvent
addKeyListener(this);
requestFocus(); // set the focus to JFrame to receive KeyEvent
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Handle the CLOSE button
pack(); // pack all the components in the JFrame
setVisible(true); // show it
}
public void generateSpikes(){
Rectangle2D.Double spikes = null;
for (int i = 0; i < 10; i++) {
spikes = new Rectangle2D.Double (CANVAS_WIDTH - 300 + i*20 , CANVAS_HEIGHT - 30 , 20, 30);
shapeArr[i] = spikes;
}
}
public void actionPerformed(ActionEvent e)
{
if (e.getSource()==btnStartRestat)
{
generateSpikes();
dx = 3;
dy = 3;
guy = new Rectangle2D.Double( 100, CANVAS_HEIGHT - guy.height, 15, 30);
platform = new Rectangle2D.Double( CANVAS_WIDTH/3, CANVAS_HEIGHT/2+50, 50, 10);
platform2 = new Rectangle2D.Double( CANVAS_WIDTH/4, CANVAS_HEIGHT/2+130, 50, 10);
gameState = STATE.PLAYING;
}
else if (e.getSource()==btnExit)
{
// requestFocus(); // change the focus to JFrame to receive KeyEvent
}
else if (e.getSource()== timer){
if (isHitDetected(platform2, guy)){
// playerState = STATE.ONGROUND;
guy.y = platform2.y;
}
if (myKeys.contains('a')
&& (guy.x > 0)){
guy.x = guy.x - 5; }
if (myKeys.contains('d')
&& (guy.x < CANVAS_WIDTH - guy.width)){
guy.x = guy.x + 5; }
{
updateGuyPosition();
}
requestFocus();
canvas.repaint();
}
}
public void updateGuyPosition(){
double guyHeight = guy.height;
if (guy.x >= CANVAS_WIDTH - guy.width){
}
if(gameState == STATE.PLAYING) {
guy.y += jumpSpeed;
if (guy.y < groundLevel - guyHeight) {
// if(playerState == STATE.INAIR) {
jumpSpeed += 1;
}
// }
else {
// if(playerState == STATE.INAIR) {
//playerState = STATE.ONGROUND;
jumpSpeed = 0;
guy.y = groundLevel - guyHeight;
}
// }
if (myKeys.contains('w') == true && guy.y == groundLevel - guyHeight) {
jumpSpeed = -15;
// playerState = STATE.INAIR;
}
}
}
public static boolean isHitDetected(Shape shapeA, Shape shapeB) {
Area areaA = new Area(shapeA);
areaA.intersect(new Area(shapeB));
return !areaA.isEmpty();
}
public void keyPressed(KeyEvent evt) {
if (!myKeys.contains(evt.getKeyChar())){
myKeys.add(evt.getKeyChar());
}
}
public void keyReleased(KeyEvent evt) {
myKeys.remove(myKeys.indexOf(evt.getKeyChar()));
}
public void keyTyped(KeyEvent evt) {
}
/** The entry main() method */
public static void main(String[] args) {
PlatformingGame myProg = new PlatformingGame(); // Let the constructor do the job
myProg.timer.start();
}
/**
* DrawCanvas (inner class) is a JPanel used for custom drawing
*/
class DrawCanvas extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
setBackground(CANVAS_BACKGROUND);
g.setColor(LINE_COLOR);
Graphics2D g2d = (Graphics2D)g;
if(gameState == STATE.PLAYING) {
g2d.fill(guy);
g.setColor(Color.lightGray);
g2d.fill(platform);
g2d.fill(platform2);
for (int i = 0; i < 10; i++) {
g2d.fill(shapeArr[i]);
}
}
if(gameState == STATE.PAUSED) {
g.drawString("Game Paused", CANVAS_WIDTH/2, CANVAS_HEIGHT/2);
}
}
}
}

My GUI is acting really weird

The first image shows what the GUI looks like when I just start it, the second shows what happens when I click around the board. The chess pieces show up at the top row after I click a piece and then click on a button on the top row. What is happening here?!
The code is below; this class is where I have most of my code. The rest of the classes are just loading images at this point. The Board constructor is called in the main to build the GUI.
public class BoardPanel extends JPanel {
public BoardPanel() {
createBoard();
}
private void createBoard(){
setLayout(new GridLayout(10, 10));
// Makes a 10 x 10 grid of black and white colors
for (int i = 0; i<10; i++){
for (int j = 0; j<10; j++){
square[i][j] = new JButton();
square[i][j].setRolloverEnabled(false);
if ((i+j)%2 == 0)
square[i][j].setBackground(Color.WHITE);
else
square[i][j].setBackground(Color.LIGHT_GRAY);
add(square[i][j]);
}
}
addLabels();
//Colors the corner squares
square[0][0].setBackground(new Color(155, 234, 242, 100));
square[0][9].setBackground(new Color(155, 234, 242, 100));
square[9][0].setBackground(new Color(155, 234, 242, 100));
square[9][9].setBackground(new Color(155, 234, 242, 100));
}
private void addLabels(){
//Adds labels to the ranks
for (int i =1 ; i< 9; i++){
square[i][0].setBackground(new Color(155, 234, 242, 100));
square[i][0].setText(rank[8-i]);
square[i][0].setHorizontalTextPosition(SwingConstants.RIGHT);
square[i][9].setBackground(new Color(155, 234, 242, 100));
square[i][9].setText(rank[8-i]);
square[i][9].setHorizontalTextPosition(SwingConstants.LEFT);
}
//Adds labels to the files
for (int j = 1; j<9;j++){
square[0][j].setBackground(new Color(155, 234, 242, 100));
square[0][j].setText(file[j-1]);
square[0][j].setVerticalTextPosition(SwingConstants.BOTTOM);
square[9][j].setBackground(new Color(155, 234, 242, 100));
square[9][j].setText(file[j-1]);
square[9][j].setVerticalTextPosition(SwingConstants.TOP);
}
JButton square[][] = new JButton[10][10];
String[] rank = {"1","2","3","4","5","6","7","8"};
String[] file = {"a","b","c","d","e","f","g","h"};
}
}
The main class
public class Board {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.add(new BoardPanel());
frame.setVisible(true);
frame.setSize(900, 700);
}
}

Your problem is with the button thinking that it is fully opaque when it is in fact not opaque. As per Kleopatra in this answer, you must make the button non-opaque and take over the painting mechanisms
square[i][j] = new JButton() {
#Override // !! add this:
protected void paintComponent(Graphics g) {
if (!isOpaque() && getBackground().getAlpha() < 255) {
g.setColor(getBackground());
g.fillRect(0, 0, getWidth(), getHeight());
}
super.paintComponent(g);
}
};
square[i][j].setRolloverEnabled(false);
square[i][j].setOpaque(false); // !! and also add this *******
As a side note, I wouldn't be using JButtons for this type of problem, but rather I'd be using JPanels, and would place my chess pieces as ImageIcons displayed in JLabels, labels that are added to or removed from the appropriate chess-board squares.
A board without buttons and without use of alpha colors:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.*;
#SuppressWarnings("serial")
public class Board2 extends JPanel {
private static final int SIDE_LEN = 80;
private static final Dimension SQUARE_SZ = new Dimension(SIDE_LEN, SIDE_LEN);
private static final Color EDGE_COLOR = new Color(165, 245, 250);
private static final Color DARK_SQR_COLOR = Color.LIGHT_GRAY;
private static final Color LIGHT_SQR_COLOR = Color.WHITE;
private JPanel[][] chessSquares = new JPanel[8][8];
public Board2() {
setLayout(new GridLayout(10, 10)); // sorry for magic numbers
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
if ((i == 0 || i == 9) && (j == 0 || j == 9)) {
add(createEdgePanel(""));
} else if (i == 0 || i == 9) {
String text = String.valueOf((char) (j + 'a' - 1));
add(createEdgePanel(text));
} else if (j == 0 || j == 9) {
String text = String.valueOf(8 - i + 1);
add(createEdgePanel(text));
} else {
JPanel panel = createSquare(i, j);
add(panel);
}
}
}
}
private JPanel createSquare(int i, int j) {
JPanel panel = new JPanel(new GridBagLayout());
Color c = (i % 2 == j % 2) ? LIGHT_SQR_COLOR : DARK_SQR_COLOR;
panel.setBackground(c);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private JPanel createEdgePanel(String text) {
JLabel label = new JLabel(text, SwingConstants.CENTER);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(label);
panel.setBackground(EDGE_COLOR);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private static void createAndShowGui() {
Board2 mainPanel = new Board2();
JFrame frame = new JFrame("Board2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Which on my system looks like:
Now with some pieces added:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class Board2 extends JPanel {
private static final int SIDE_LEN = 80;
private static final Dimension SQUARE_SZ = new Dimension(SIDE_LEN, SIDE_LEN);
private static final String SPRITE_PATH = "http://i.stack.imgur.com/memI0.png";
private static final int SPRITE_ROWS = 2;
private static final int SPRITE_COLS = 6;
private static final Color EDGE_COLOR = new Color(165, 245, 250);
private static final Color DARK_SQR_COLOR = Color.LIGHT_GRAY;
private static final Color LIGHT_SQR_COLOR = Color.WHITE;
private static final int ROWS = 8;
private JLabel[][] chessSquares = new JLabel[ROWS][ROWS];
private BufferedImage bigImage;
private List<Icon> icons = new ArrayList<>();
public Board2() throws IOException {
URL imgUrl = new URL(SPRITE_PATH);
bigImage = ImageIO.read(imgUrl);
int w = bigImage.getWidth() / SPRITE_COLS;
int h = bigImage.getHeight() / SPRITE_ROWS;
for (int i = 0; i < SPRITE_ROWS; i++) {
for (int j = 0; j < SPRITE_COLS; j++) {
int x = (j * bigImage.getWidth()) / SPRITE_COLS;
int y = (i * bigImage.getHeight()) / SPRITE_ROWS;
BufferedImage spriteImg = bigImage.getSubimage(x, y, w, h);
Icon spriteIcon = new ImageIcon(spriteImg);
icons.add(spriteIcon);
}
}
for (int i = 0; i < chessSquares.length; i++) {
for (int j = 0; j < chessSquares[i].length; j++) {
chessSquares[i][j] = new JLabel();
}
}
setLayout(new GridLayout(ROWS + 2, ROWS + 2)); // sorry for magic numbers
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
if ((i == 0 || i == ROWS + 1) && (j == 0 || j == ROWS + 1)) {
add(createEdgePanel(""));
} else if (i == 0 || i == ROWS + 1) {
String text = String.valueOf((char) (j + 'a' - 1));
add(createEdgePanel(text));
} else if (j == 0 || j == ROWS + 1) {
String text = String.valueOf(ROWS - i + 1);
add(createEdgePanel(text));
} else {
JPanel panel = createSquare(i, j);
panel.add(chessSquares[i - 1][j - 1]);
add(panel);
}
}
}
setPieces(0, 0, 2); // rooks
setPieces(1, 0, 3); // knights
setPieces(2, 0, 4); // bishops
// kings and queens
chessSquares[0][3].setIcon(icons.get(1));
chessSquares[7][3].setIcon(icons.get(6 + 1));
chessSquares[0][4].setIcon(icons.get(0));
chessSquares[7][4].setIcon(icons.get(6 + 0));
// pawns
for (int i = 0; i < ROWS / 2; i++) {
setPieces(i, 1, 5);
}
}
private void setPieces(int colPos, int rowPos, int pieceIndex) {
chessSquares[rowPos][colPos].setIcon(icons.get(pieceIndex));
chessSquares[rowPos][ROWS - 1 - colPos].setIcon(icons.get(pieceIndex));
chessSquares[ROWS - 1 - rowPos][colPos].setIcon(icons.get(6 + pieceIndex));
chessSquares[ROWS - 1 - rowPos][ROWS - 1 - colPos].setIcon(icons
.get(6 + pieceIndex));
}
private void setPiece(int colPos, int pieceIndex) {
chessSquares[0][colPos].setIcon(icons.get(pieceIndex));
chessSquares[ROWS - 1][ROWS - 1 - colPos].setIcon(icons.get(6 + pieceIndex));
}
private JPanel createSquare(int i, int j) {
JPanel panel = new JPanel(new GridBagLayout());
Color c = (i % 2 == j % 2) ? LIGHT_SQR_COLOR : DARK_SQR_COLOR;
panel.setBackground(c);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private JPanel createEdgePanel(String text) {
JLabel label = new JLabel(text, SwingConstants.CENTER);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(label);
panel.setBackground(EDGE_COLOR);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private static void createAndShowGui() {
Board2 mainPanel = null;
try {
mainPanel = new Board2();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("Board2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

JPanel doesn't fit in the Frame

The panel doesn't fit in the frame, and when I change the size of the frame a new panel is painted. I want the panel to fit and also to change the size on the frame without painting a new panel.
Here is the code:
import java.awt.*;
import javax.swing.*;
public class ColorGrid extends JPanel {
int length=200;
int width=200;
double stokastik;
public ColorGrid(int x,int y) {
setSize(200,200);
width=18*x;
length=18*y;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for(int row=0; row <=length;row+=20) {
for(int col=0; col <=width;col+=20) {
stokastik= Math.random();
if(stokastik < 0.25){
g.setColor(Color.YELLOW);
}
else if (stokastik < 0.5) {
g.setColor(Color.BLUE);
}
else if (stokastik < 0.75) {
g.setColor(Color.GREEN);
} else {
g.setColor(Color.RED);
}
g.fillRect(row, col, 18, 18);
}
}
}
public static void main(String args[]) {
JFrame frame = new JFrame();
frame.setBounds(300,300,300,300);
ColorGrid grid = new ColorGrid(10,10);
frame.add(grid);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
}
}

Your code is confusing because you call setBounds/setSize, but eventually, you call pack() which will just resize everything according to preferred size of components.
The proper way to go is to override getPreferredSize() in your custom component. By all means, avoid calling setSize/setBounds/setLocation. This is the job of the LayoutManager.
Regarding the repaint of the panel, you don't have a choice. A panel can get repainted many times independently of your will. So the only way to avoid the change of colors when the repaint occurs, is to pre-calculate the colors upfront and then only iterate over the same colors when performing the custom painting.
Small demo code illustrating this:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ColorGrid extends JPanel {
double stokastik;
private int width;
private int length;
private Dimension preferredSize;
private Color[][] colors;
public ColorGrid(int x, int y) {
width = 20 * x;
length = 20 * y;
preferredSize = new Dimension(width, length);
colors = new Color[x][y];
for (int row = 0; row < x; row++) {
for (int col = 0; col < y; col++) {
stokastik = Math.random();
if (stokastik < 0.25) {
colors[row][col] = (Color.YELLOW);
} else if (stokastik < 0.5) {
colors[row][col] = (Color.BLUE);
} else if (stokastik < 0.75) {
colors[row][col] = (Color.GREEN);
} else {
colors[row][col] = (Color.RED);
}
}
}
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int row = 0; row < colors.length; row++) {
for (int col = 0; col < colors[row].length; col++) {
g.setColor(colors[row][col]);
g.fillRect(row * 20, col * 20, 18, 18);
}
}
}
#Override
public Dimension getPreferredSize() {
return preferredSize;
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ColorGrid grid = new ColorGrid(10, 10);
frame.add(grid);
frame.pack();
frame.setVisible(true);
}
});
}
}

In your constructor set the preferred size.
public ColorGrid(int x, int y) {
setSize(200, 200);
setPreferredSize(new Dimension(200, 200));
width = 18 * x;
length = 18 * y;
}
Then it will show correctly on initial load..
As mentioned by another answer, also have your length and width defined proportionally.

Java - JPanel contains point method error

I have a 2d array of Grids (JPanels) that are added to another JPanel using the GridLayout. That JPanel is added to the JFrame. Whenever a click happens on the JFrame I'm attempting to take the Point of the click and determine if any of those Grids in the 2d array contain that Point.
I'm attempting to do this inside frame.addMouseListener...
I know the frame is registering the mouse clicks. For some reason the Grids don't register that they should be containing that Point. Can anyone explain this? if(theView[i][j].contains(me.getPoint())){ This is the line of code that seems to be failing me.
I originally attempted to have the Grids know when they were clicked on so I wouldn't have to coordinate between the frame and grids, but I couldn't get that to work.
Here's the level designer.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.*;
import javax.swing.*;
public class LevelDesigner extends JPanel implements ButtonListener{
private final int SIZE = 12;
private int [][] thePit;
private Grid [][] theView;
private ButtonPanel bp;
public static int val;
private int rows, cols;
private JPanel gridPanel;
private JFrame frame;
public LevelDesigner(int r, int c){
frame = new JFrame();
int h = 10, w = 10;
setVisible(true);
setLayout(new BorderLayout());
setBackground(Color.BLUE);
rows = r;
cols = c;
thePit = new int[r][c];
theView = new Grid[r][c];
gridPanel = new JPanel();
gridPanel.setVisible(true);
gridPanel.setBackground(Color.BLACK);
gridPanel.setPreferredSize(getMaximumSize());
GridLayout gridLayout = new GridLayout();
gridLayout.setColumns(cols);
gridLayout.setRows(rows);
gridPanel.setLayout(gridLayout);
for(int i = 0; i < r; i++){
for(int j = 0; j < c; j++){
theView[i][j] = new Grid(i, j, SIZE, this);
gridPanel.add(theView[i][j]);
}
}
String test [] = {"0", "1","2","3","4","save"};
bp = new ButtonPanel(test, this);
this.add(bp, BorderLayout.SOUTH);
this.add(gridPanel, BorderLayout.CENTER);
frame.addMouseListener(new MouseAdapter(){
public void mousePressed(MouseEvent me) {
for(int i = 0; i < rows; ++i){
for(int j = 0; j < cols; ++j){
if(theView[i][j].contains(me.getPoint())){
theView[i][j].actionPerformed(null);
return;
}
}
}
}
});
frame.setVisible(true);
frame.setExtendedState(java.awt.Frame.MAXIMIZED_BOTH);
frame.setTitle("Epic Crawl - Main Menu");
frame.pack();
frame.setLocationRelativeTo(null);
frame.repaint();
frame.add(this);
}
public String toString(){
int noRows = thePit.length;
int noColumns = thePit[0].length;
String s="";
for (int r=0;r<noRows;r++){
for (int c=0;c<noColumns;c++){
s=s + thePit[r][c] + " ";
}
s=s+"\n";
}
return(s);
}
public void notify( int i, int j){
thePit[i][j] = val;
}
public void print(){
final JFileChooser fc = new JFileChooser();
fc.setCurrentDirectory(new java.io.File("."));
int returnVal = fc.showSaveDialog( null);
if( returnVal == JFileChooser.APPROVE_OPTION ){
try{
PrintWriter p = new PrintWriter(
new File( fc.getSelectedFile().getName() ) );
System.out.println(" printing");
p.println( this );
p.close();
}
catch( Exception e){
System.out.println("ERROR: file not saved");
}
}
}
public void buttonPressed(String buttonLabel, int id){
if(id == 5)
print();
else
val = id;
}
public void buttonReleased( String buttonLabel, int buttonId ){}
public void buttonClicked( String buttonLabel, int buttonId ){}
public static void main(String arg[]){
LevelDesigner levelDesigner = new LevelDesigner(4, 4);
}
}
And here is the Grid.
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Grid extends JPanel implements ActionListener{
LevelDesigner grid;
int myI, myJ;
private String[] imageNames = {"dirt.png", "grass.png", "Door.png", "woodfloor.png", "32x32WoodFloor.png"};
BufferedImage gridImage;
private String imagePath;
public Grid(int i, int j, int size, LevelDesigner m){
imagePath = "";
grid = m;
myI = i;
myJ = j;
setBackground(Color.RED);
this.setBorder(BorderFactory.createLineBorder(Color.black));
this.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent ae){
grid.notify(myI, myJ);
imagePath = "Images/" + imageNames[LevelDesigner.val];
gridImage = null;
InputStream input = this.getClass().getClassLoader().getResourceAsStream(imagePath);
try{
gridImage = ImageIO.read(input);
}catch(Exception e){System.err.println("Failed to load image");}
}
public void paintComponent(Graphics g){
super.paintComponent(g); // Important to call super class method
g.clearRect(0, 0, getWidth(), getHeight()); // Clear the board
g.drawImage(gridImage, 0, 0, getWidth(), getHeight(), null);
}
}

The contains method checks if the Point is within the boundaries of the JPanel but using a coordinate system relative to the JPanel. Instead consider using findComponentAt(Point p).
For example:
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
public class TestMouseListener {
private static final int SIDE_COUNT = 4;
private JPanel mainPanel = new JPanel();
private MyGridCell[][] grid = new MyGridCell[SIDE_COUNT][SIDE_COUNT];
public TestMouseListener() {
mainPanel.setLayout(new GridLayout(SIDE_COUNT, SIDE_COUNT));
for (int i = 0; i < grid.length; i++) {
for (int j = 0; j < grid[i].length; j++) {
grid[i][j] = new MyGridCell();
mainPanel.add(grid[i][j].getMainComponent());
}
}
mainPanel.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
Point p = e.getPoint();
Component c = mainPanel.findComponentAt(p);
for (MyGridCell[] gridRow : grid) {
for (MyGridCell myGridCell : gridRow) {
if (c == myGridCell.getMainComponent()) {
myGridCell.setLabelText("Pressed!");
} else {
myGridCell.setLabelText("");
}
}
}
}
});
}
public Component getMainComponent() {
return mainPanel;
}
private static void createAndShowGui() {
TestMouseListener mainPanel = new TestMouseListener();
JFrame frame = new JFrame("TestMouseListener");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel.getMainComponent());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyGridCell {
private static final int PREF_W = 200;
private static final int PREF_H = PREF_W;
#SuppressWarnings("serial")
private JPanel mainPanel = new JPanel() {
public Dimension getPreferredSize() {
return MyGridCell.this.getPreferredSize();
};
};
private JLabel label = new JLabel();
public MyGridCell() {
mainPanel.setBorder(BorderFactory.createLineBorder(Color.black));
mainPanel.setLayout(new GridBagLayout());
mainPanel.add(label);
}
public Component getMainComponent() {
return mainPanel;
}
public void setLabelText(String text) {
label.setText(text);
}
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
}

Component#contains "Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component"
This means that the contains will only return true if the Point is within the bounds of 0 x 0 x width x height.
So if the component is position at 400x200 and is sized at 200x200 (for example). When you click within in, the mouse point will be between 400x200 and 600x400, which is actually out side of the relative position of the component (200x200) - confused yet...
Basically, you either need to convert the click point to a relative coordinate within the context of the component you are checking...
Point p = SwingUtilities.convertPoint(frame, me.getPoint(), theView[i][j])
if (theView[i][j].contains(p)) {...
Or use the components Rectangle bounds...
if (theView[i][j].getBounds().contains(me.getPoint())) {...
So, remember, mouse events are relative to the component that they were generated for

Java, Grid of Objects

I need help with drawing the grids to the GUI as well as the program later letting me change the colour of the boxes drawn. I know i will have to use paintComponent(Graphics g), but i have no idea how or where.
So here is a copy of the code i have got so far ( even though i have been told it can be quite daunting just being given code i think it is the best way for people to help and not just do it for me). From the top it sets values, creates the GUI, calls the GUI, fills a 2d array with boxes( i think). Then in the Boxes class setting values the boxes class will need, then the start of how to draw them (didn't know how to work it out), then some seta methods for the x and y coordinates.
what i would like you to do is show how to have the boxes be drawn to the Jpanel, to make a grid and then to show me how to change the colour to different shades of blue, depending on a external value.
import java.awt.*;
import java.awt.Graphics;
import java.util.*;
import javax.swing.*;
public class NewGrid {
Boxes[][] Boxs;
int BoxesX;
int BoxesY;
NewGrid() {
buildtheGUI();
}
JFrame frame = new JFrame();
JPanel panel = new JPanel();
public void buildtheGUI() {
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.setVisible(true);
}
public static void main(String[] args) {
new NewGrid();
}
public void addboxes() {
Boxs = new Boxes[panel.getWidth() / 10][panel.getHeight() / 10];
for (int i = 0; i < panel.getWidth() / 10; i++) {
for (int j = 0; j < panel.getHeight() / 10; j++) {
Boxs[i][j] = new Boxes();
Boxs[i][j].setx(i * (panel.getWidth() / 10));
Boxs[i][j].sety(j * (panel.getHeight() / 10));
Boxs[i][j].draw(null);
}
}
}
}
public class Boxes extends JPanel {
int x;
int y;
int width = 10;
int hieight = 10;
Color colour = Color.BLACK;
public void draw(Graphics g) {
g.setColor(colour);
g.fillRect(x, y, width, hieight);
}
public void setx(int i ){
x = i;
}
public void sety(int i ){
y = i;
}
}

I can't comment something, to try to make things easier,
I code there box.putClientProperty(unique_identifier, value_for_identifier), you can to multiple this method as you want
from every Swing Listener you can to get this and proper coordinated defined in putClientProperty
.
JComponent comp = event.getComponent();
String strRow = (String) comp.getClientProperty("row");
String strColumn = (String) comp.getClientProperty("column");
simple code
import java.awt.*;
import java.awt.Graphics;
import java.util.*;
import javax.swing.*;
public class NewGrid {
private int row = 10;
private int column = 10;
private JFrame frame = new JFrame();
private JPanel panel = new JPanel();
private NewGrid() {
addboxes();
panel.setLayout(new GridLayout(row, column));
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
private void addboxes() {
for (int i = 0; i < row; i++) {
for (int j = 0; j < column; j++) {
Boxes box = new Boxes();
box.putClientProperty("row", row);
box.putClientProperty("column", column);
panel.add(box);
}
}
}
public static void main(String[] args) {
Runnable doRun = new Runnable() {
#Override
public void run() {
new NewGrid();
}
};
SwingUtilities.invokeLater(doRun);
}
}
class Boxes extends JPanel {
private static final long serialVersionUID = 1L;
#Override
public Dimension getMinimumSize() {
return new Dimension(20, 20);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(20, 20);
}
#Override
public Dimension getMaximumSize() {
return new Dimension(20, 20);
}
#Override
public void paintComponent(Graphics g) {
int margin = 2;
Dimension dim = getSize();
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(margin, margin, dim.width - margin * 2,
dim.height - margin * 2);
}
}