Develop Reference

Why is the MouseListner not working in my Java-JFrame project?

So I am trying to make a TicTacToe game in Java with JFrame and trying to implement a MouseListener so the player can click on the squares. I found one method on the internet but cant figure out why its not working for me. What I already did is I created a frame and draw the grid and background color. Maybe I missed something? Thanks for your time.
import java.awt.*;
import javax.swing.JFrame;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class Main extends JFrame
{
public static JFrame root = new JFrame("TicTacToe");
public static void main(String[] args)
{
int[] board = {
0, 0, 0,
0, 0, 0,
0, 0, 0
};
root.getContentPane().setBackground(new Color(232,209,197));
TicTacToeCanvas Canvas = new TicTacToeCanvas(board);
root.add(Canvas);
root.setSize(915,939);
root.setVisible(true);
root.setResizable(false);
root.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
root.pack();
MouseEventClass mouseEvents = new MouseEventClass(root);
}
}
class MouseEventClass implements MouseListener{
public MouseEventClass(JFrame frame){
frame.addMouseListener(this);
}
#Override
public void mouseExited(MouseEvent e){
}
#Override
public void mouseEntered(MouseEvent e){
}
#Override
public void mousePressed(MouseEvent e){
}
#Override
public void mouseReleased(MouseEvent e){
}
#Override
public void mouseClicked(MouseEvent e){
System.out.println("Click");
}
}
}

I would advise that you add the listener to the components held by the main JPanel so you can get individual clicked components more easily. For example:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
public class TicTacToePanel extends JPanel {
private static final long serialVersionUID = 1L;
private static final String ROW = "row";
private static final String COL = "col";
private static final Color BKGRD1 = new Color(230, 230, 230);
private static final Color BKGRD2 = new Color(180, 180, 180);
private static final Dimension CELL_SIZE = new Dimension(80, 80);
private JPanel[][] panelGrid = new JPanel[3][3];
public TicTacToePanel() {
setLayout(new GridLayout(3, 3, 1, 1));
setBackground(Color.BLACK);
setBorder(BorderFactory.createLineBorder(Color.BLACK));
MyMouse myMouse = new MyMouse();
for (int i = 0; i < panelGrid.length; i++) {
for (int j = 0; j < panelGrid[i].length; j++) {
JPanel cellPanel = new JPanel();
cellPanel.putClientProperty(ROW, i);
cellPanel.putClientProperty(COL, j);
cellPanel.setPreferredSize(CELL_SIZE);
cellPanel.setBackground(BKGRD1);
cellPanel.addMouseListener(myMouse);
add(cellPanel);
panelGrid[i][j] = cellPanel;
}
}
}
class MyMouse extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
JPanel cell = (JPanel) e.getComponent();
if (cell == null) {
return;
}
Color background = cell.getBackground().equals(BKGRD1) ? BKGRD2 : BKGRD1;
cell.setBackground(background);
int row = (int) cell.getClientProperty(ROW);
int col = (int) cell.getClientProperty(COL);
System.out.printf("cell row & column: [%d, %d]%n", row, col);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
TicTacToePanel mainPanel = new TicTacToePanel();
JFrame frame = new JFrame("GUI");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
}
Here, I create a 2D array of JPanels:
private JPanel[][] panelGrid = new JPanel[3][3];
and then in the main JPanel's constructor,
create individual "cell" JPanels in a nested for loop, adding them to the main JPanel
Adding my mouse listener to each individual cell.
This way, I can get each individual clicked cell cleanly and easily
public TicTacToePanel() {
// ....
// my mouse listener
MyMouse myMouse = new MyMouse();
// create cells and fill my grid with cells
for (int i = 0; i < panelGrid.length; i++) {
for (int j = 0; j < panelGrid[i].length; j++) {
JPanel cellPanel = new JPanel();
// gives each cell identifying information
cellPanel.putClientProperty(ROW, i);
cellPanel.putClientProperty(COL, j);
cellPanel.setPreferredSize(CELL_SIZE);
cellPanel.setBackground(BKGRD1);
// add the same mouse listener to all cells
cellPanel.addMouseListener(myMouse);
add(cellPanel); // add it to the main JPanel
panelGrid[i][j] = cellPanel; // and to a holding array
}
}
}
The mouse listener is simple:
class MyMouse extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
// get the cell clicked
JPanel cell = (JPanel) e.getComponent();
// make sure it's not null
if (cell == null) {
return;
}
// then do stuff to it
Color background = cell.getBackground().equals(BKGRD1) ? BKGRD2 : BKGRD1;
cell.setBackground(background);
int row = (int) cell.getClientProperty(ROW);
int col = (int) cell.getClientProperty(COL);
System.out.printf("cell row & column: [%d, %d]%n", row, col);
}
}

Java game: limit visibility of board dependent on location of player

I want to limit the visibility of the game board to X cells away from the player (and that this automatically is updated when the player moves). See also the image below...
For example, the area I have delineated with yellow lines) & automatic update of this when the player moves.
import java.io.*;
import java.lang.*;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.util.Random;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Mov {
private final MoveModel moveModel;
private final Showvisible showvisible;
public Mov() {
moveModel = new MoveModel();
showvisible = new Showvisible(moveModel);
showvisible.getRndMoverButton().addActionListener(e-> movePlayer());
showvisible.getMoveEastButton().addActionListener(e-> movePlayerX(50));
}
//move player to a random position (works fine)
private void movePlayer() {
final Random rnd = new Random();
moveModel.setPlayerX(rnd.nextInt(100));
moveModel.setPlayerY(rnd.nextInt(100));
showvisible.refresh();
}
//Move player in the x direction to the East (positive) or west (negative
private void movePlayerX(final int distance) {
moveModel.setPlayerX(moveModel.getPlayerX()+distance);
showvisible.refresh();
}
public static void main(final String[] args) {
new Mov();
}
}
class Showvisible {
private final static int GAP = 2;
MoveModel MoveModel;
private MainPanel mainPanel;
Showvisible(final MoveModel MoveModel){
this.MoveModel = MoveModel;
createAndShowGUI();
}
void refresh() {
mainPanel.repaint();
}
private void createAndShowGUI() {
final JFrame board = new JFrame("Single Player Game");
board.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPanel = new MainPanel();
board.add(mainPanel);
board.pack();
board.setVisible(true);
}
JButton getRndMoverButton() { return mainPanel.getRndMoverButton(); }
JButton getMoveEastButton() { return mainPanel.getMoveEastButton(); }
class MainPanel extends JPanel {
private final BottomPanel bPanel;
MainPanel() {
setLayout(new BorderLayout(GAP,GAP));
add(new TopPanel(), BorderLayout.PAGE_START);
add(new BoardPanel(), BorderLayout.CENTER);
bPanel = new BottomPanel();
add(bPanel, BorderLayout.PAGE_START);
}
JButton getRndMoverButton() { return bPanel.getRndMoverButton(); }
JButton getMoveEastButton() { return bPanel.getMoveEastButton(); }
}
class TopPanel extends JPanel {
TopPanel() {
setLayout(new FlowLayout(FlowLayout.CENTER));
add(new JLabel("This is an amazing game "));
}
}
class BoardPanel extends JPanel {
Player player;
BoardPanel() {
setBorder(BorderFactory.createLineBorder(Color.BLACK, GAP));
final GridLayout layout = new GridLayout(MoveModel.getBoardRows(),
MoveModel.getBoardCols());
setLayout(layout);
for (int i = 0; i <MoveModel.getBoardRows(); i++) {
for (int j = 0; j < MoveModel.getBoardCols(); j++) {
add(new Tile());
}
}
player = new Player();
player.setBounds(new Rectangle(1000,1000, 1000,1000));
}
#Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
player.paint(g);
}
}
class Tile extends JLabel {
Tile() {
setPreferredSize(new Dimension(MoveModel.getSquareSize(), MoveModel.getSquareSize()));
setBorder(BorderFactory.createLineBorder(Color.ORANGE, GAP));
}
}
class Player extends JLabel{
#Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.fillRect(MoveModel.getPlayerX(), MoveModel.getPlayerY(), MoveModel.getPlayerSize(),MoveModel.getPlayerSize());
}
}
class BottomPanel extends JPanel {
JButton rndMoveButton = new JButton("Random Move");
JButton moveEastButton =new JButton("move East");
BottomPanel(){
add(rndMoveButton);
add(moveEastButton);
}
JButton getRndMoverButton() { return rndMoveButton; }
JButton getMoveEastButton() { return moveEastButton; }
}
}
class MoveModel{
private final int boardRows = 9, boardCols = 9, squareSize = 50;
int playerX = 0;
private int playerY = 0;
private final int playerSize =25;
int getPlayerX() { return playerX; }
void setPlayerX(final int playerX) { this.playerX = playerX; }
int getPlayerY() {return playerY; }
void setPlayerY(final int playerY) { this.playerY = playerY; }
int getPlayerSize() {return playerSize; }
int getBoardRows() {return boardRows; }
int getBoardCols() {return boardCols; }
int getSquareSize() {return squareSize; }
}
Output:

When painting BoardPanel you can mask the entire area with mask color (black) and clear part of the mask :
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
//mask all over
g.setColor(Color.BLACK);
g.fillRect(0, 0,getWidth(), getHeight());
//clear part of mask
Rectangle r = getVisibleBounds();
g.clearRect(r.x, r.y, r.width, r.height);
player.paint(g);
}
private Rectangle getVisibleBounds() {
//bounds returned may be outside painted area
return new Rectangle(moveModel.getPlayerX() - VISIBLE_SIZE/ 2,
moveModel.getPlayerY() - VISIBLE_SIZE/ 2, VISIBLE_SIZE, VISIBLE_SIZE);
}
The complete one-file (Mov.java) code can be copy-pasted from here

Close InternalJFrame without selected the frame

I am really new for Java. I have question about getting the JInternalFrame . I searched the web and find the example. I modified the example a little bit, adding a close menuitem but it didn't work my code. In the project if I closed the JInternalFrame without select it first, then I have error. I tried to loop through the WindowMenu for getting the selected JcheckboxMenuitem, but it didn't get any components. Would someone tell me what to do.
There is the code:
// This is example is from Kjell Dirdal.
// Referenced from http://www.javaworld.com/javaworld/jw-05-2001/jw-0525-mdi.html
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.PropertyVetoException;
import javax.swing.DefaultDesktopManager;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JComponent;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JViewport;
import javax.swing.event.MenuEvent;
import javax.swing.event.MenuListener;
public class KjellDirdalNotepad extends JFrame {
private MDIDesktopPane desktop = new MDIDesktopPane();
private JMenuBar menuBar = new JMenuBar();
private JMenu fileMenu = new JMenu("File");
private JMenuItem newMenu = new JMenuItem("New");
private JScrollPane scrollPane = new JScrollPane();
private JMenuItem closeMenu=new JMenuItem("Close");
private int index=1;
private WindowMenu wMenu=null;
public KjellDirdalNotepad() {
menuBar.add(fileMenu);
wMenu=new WindowMenu(desktop);
menuBar.add(wMenu);
fileMenu.add(newMenu);
fileMenu.add(closeMenu);
setJMenuBar(menuBar);
setTitle("MDI Test");
scrollPane.getViewport().add(desktop);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(scrollPane, BorderLayout.CENTER);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
newMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
desktop.add(new TextFrame(String.valueOf(index)));
index=index+1;
}
});
//I added the close menu
closeMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
JInternalFrame f=desktop.getSelectedFrame();
if (f==null)
{
for (Component child: wMenu.getComponents()){
if (child instanceof WindowMenu.ChildMenuItem){
JCheckBoxMenuItem item=(JCheckBoxMenuItem) child;
if( item.isSelected()){
DisplayTestMsg(item.getText());
}
}
}
}
else{
f.dispose();
}
}
});
}
public void DisplayTestMsg(String msg){
//custom title, error icon
JTextArea textArea=new JTextArea(msg);
textArea.setColumns(30);
textArea.setLineWrap( true );
textArea.setWrapStyleWord( true );
textArea.setSize(textArea.getPreferredSize().width, 1);
JOptionPane.showMessageDialog(null,
textArea,
"Test",
JOptionPane.WARNING_MESSAGE);
}
public static void main(String[] args) {
KjellDirdalNotepad notepad = new KjellDirdalNotepad();
notepad.setSize(600, 400);
notepad.setVisible(true);
}
}
class TextFrame extends JInternalFrame {
private JTextArea textArea = new JTextArea();
private JScrollPane scrollPane = new JScrollPane();
public TextFrame(String title) {
setSize(200, 300);
setTitle("Edit Text-" + title);
setMaximizable(true);
setIconifiable(true);
setClosable(true);
setResizable(true);
scrollPane.getViewport().add(textArea);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(scrollPane, BorderLayout.CENTER);
}
}
/**
* An extension of WDesktopPane that supports often used MDI functionality. This
* class also handles setting scroll bars for when windows move too far to the
* left or bottom, providing the MDIDesktopPane is in a ScrollPane.
*/
class MDIDesktopPane extends JDesktopPane {
private static int FRAME_OFFSET = 20;
private MDIDesktopManager manager;
public MDIDesktopPane() {
manager = new MDIDesktopManager(this);
setDesktopManager(manager);
setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
}
public void setBounds(int x, int y, int w, int h) {
super.setBounds(x, y, w, h);
checkDesktopSize();
}
public Component add(JInternalFrame frame) {
JInternalFrame[] array = getAllFrames();
Point p;
int w;
int h;
Component retval = super.add(frame);
checkDesktopSize();
if (array.length > 0) {
p = array[0].getLocation();
p.x = p.x + FRAME_OFFSET;
p.y = p.y + FRAME_OFFSET;
} else {
p = new Point(0, 0);
}
frame.setLocation(p.x, p.y);
if (frame.isResizable()) {
w = getWidth() - (getWidth() / 3);
h = getHeight() - (getHeight() / 3);
if (w < frame.getMinimumSize().getWidth())
w = (int) frame.getMinimumSize().getWidth();
if (h < frame.getMinimumSize().getHeight())
h = (int) frame.getMinimumSize().getHeight();
frame.setSize(w, h);
}
moveToFront(frame);
frame.setVisible(true);
try {
frame.setSelected(true);
} catch (PropertyVetoException e) {
frame.toBack();
}
return retval;
}
public void remove(Component c) {
super.remove(c);
checkDesktopSize();
}
/**
* Cascade all internal frames
*/
public void cascadeFrames() {
int x = 0;
int y = 0;
JInternalFrame allFrames[] = getAllFrames();
manager.setNormalSize();
int frameHeight = (getBounds().height - 5) - allFrames.length * FRAME_OFFSET;
int frameWidth = (getBounds().width - 5) - allFrames.length * FRAME_OFFSET;
for (int i = allFrames.length - 1; i >= 0; i--) {
allFrames[i].setSize(frameWidth, frameHeight);
allFrames[i].setLocation(x, y);
x = x + FRAME_OFFSET;
y = y + FRAME_OFFSET;
}
}
/**
* Tile all internal frames
*/
public void tileFrames() {
java.awt.Component allFrames[] = getAllFrames();
manager.setNormalSize();
int frameHeight = getBounds().height / allFrames.length;
int y = 0;
for (int i = 0; i < allFrames.length; i++) {
allFrames[i].setSize(getBounds().width, frameHeight);
allFrames[i].setLocation(0, y);
y = y + frameHeight;
}
}
/**
* Sets all component size properties ( maximum, minimum, preferred) to the
* given dimension.
*/
public void setAllSize(Dimension d) {
setMinimumSize(d);
setMaximumSize(d);
setPreferredSize(d);
}
/**
* Sets all component size properties ( maximum, minimum, preferred) to the
* given width and height.
*/
public void setAllSize(int width, int height) {
setAllSize(new Dimension(width, height));
}
private void checkDesktopSize() {
if (getParent() != null && isVisible())
manager.resizeDesktop();
}
}
/**
* Private class used to replace the standard DesktopManager for JDesktopPane.
* Used to provide scrollbar functionality.
*/
class MDIDesktopManager extends DefaultDesktopManager {
private MDIDesktopPane desktop;
public MDIDesktopManager(MDIDesktopPane desktop) {
this.desktop = desktop;
}
public void endResizingFrame(JComponent f) {
super.endResizingFrame(f);
resizeDesktop();
}
public void endDraggingFrame(JComponent f) {
super.endDraggingFrame(f);
resizeDesktop();
}
public void setNormalSize() {
JScrollPane scrollPane = getScrollPane();
int x = 0;
int y = 0;
Insets scrollInsets = getScrollPaneInsets();
if (scrollPane != null) {
Dimension d = scrollPane.getVisibleRect().getSize();
if (scrollPane.getBorder() != null) {
d.setSize(d.getWidth() - scrollInsets.left - scrollInsets.right, d.getHeight()
- scrollInsets.top - scrollInsets.bottom);
}
d.setSize(d.getWidth() - 20, d.getHeight() - 20);
desktop.setAllSize(x, y);
scrollPane.invalidate();
scrollPane.validate();
}
}
private Insets getScrollPaneInsets() {
JScrollPane scrollPane = getScrollPane();
if (scrollPane == null)
return new Insets(0, 0, 0, 0);
else
return getScrollPane().getBorder().getBorderInsets(scrollPane);
}
private JScrollPane getScrollPane() {
if (desktop.getParent() instanceof JViewport) {
JViewport viewPort = (JViewport) desktop.getParent();
if (viewPort.getParent() instanceof JScrollPane)
return (JScrollPane) viewPort.getParent();
}
return null;
}
protected void resizeDesktop() {
int x = 0;
int y = 0;
JScrollPane scrollPane = getScrollPane();
Insets scrollInsets = getScrollPaneInsets();
if (scrollPane != null) {
JInternalFrame allFrames[] = desktop.getAllFrames();
for (int i = 0; i < allFrames.length; i++) {
if (allFrames[i].getX() + allFrames[i].getWidth() > x) {
x = allFrames[i].getX() + allFrames[i].getWidth();
}
if (allFrames[i].getY() + allFrames[i].getHeight() > y) {
y = allFrames[i].getY() + allFrames[i].getHeight();
}
}
Dimension d = scrollPane.getVisibleRect().getSize();
if (scrollPane.getBorder() != null) {
d.setSize(d.getWidth() - scrollInsets.left - scrollInsets.right, d.getHeight()
- scrollInsets.top - scrollInsets.bottom);
}
if (x <= d.getWidth())
x = ((int) d.getWidth()) - 20;
if (y <= d.getHeight())
y = ((int) d.getHeight()) - 20;
desktop.setAllSize(x, y);
scrollPane.invalidate();
scrollPane.validate();
}
}
}
/**
* Menu component that handles the functionality expected of a standard
* "Windows" menu for MDI applications.
*/
class WindowMenu extends JMenu {
private MDIDesktopPane desktop;
private JMenuItem cascade = new JMenuItem("Cascade");
private JMenuItem tile = new JMenuItem("Tile");
public WindowMenu(MDIDesktopPane desktop) {
this.desktop = desktop;
setText("Window");
cascade.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
WindowMenu.this.desktop.cascadeFrames();
}
});
tile.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
WindowMenu.this.desktop.tileFrames();
}
});
addMenuListener(new MenuListener() {
public void menuCanceled(MenuEvent e) {
}
public void menuDeselected(MenuEvent e) {
removeAll();
}
public void menuSelected(MenuEvent e) {
buildChildMenus();
}
});
}
/* Sets up the children menus depending on the current desktop state */
private void buildChildMenus() {
int i;
ChildMenuItem menu;
JInternalFrame[] array = desktop.getAllFrames();
add(cascade);
add(tile);
if (array.length > 0)
addSeparator();
cascade.setEnabled(array.length > 0);
tile.setEnabled(array.length > 0);
for (i = 0; i < array.length; i++) {
menu = new ChildMenuItem(array[i]);
menu.setState(i == 0);
menu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
JInternalFrame frame = ((ChildMenuItem) ae.getSource()).getFrame();
frame.moveToFront();
try {
frame.setSelected(true);
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
});
menu.setIcon(array[i].getFrameIcon());
add(menu);
}
}
/*
* This JCheckBoxMenuItem descendant is used to track the child frame that
* corresponds to a give menu.
*/
class ChildMenuItem extends JCheckBoxMenuItem {
private JInternalFrame frame;
public ChildMenuItem(JInternalFrame frame) {
super(frame.getTitle());
this.frame = frame;
}
public JInternalFrame getFrame() {
return frame;
}
}
}

If you want to remove the JPanel when a button is pressed, you can call JFrame.remove(panel) such as:
final JFrame frame = new JFrame("test");
final JPanel panel = new JPanel();
//add the panel at the start
frame.add(panel);
// when the buttons clicked
button.addActionListener(new ActionListener() {
#Override
public void ActionPerformed(ActionEvent e) {
frame.remove(panel);
frame.repaint();
};
});

I figured it out. I added the method on Class WindowMenu as belows. This method is called when the close button is click without selected internal frame.
public JInternalFrame getFrontFrame(){
InternalFrame[] array = desktop.getAllFrames();
JInternalFrame f=(JInternalFrame)array[0];
return f;
}

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

JTextField not accepting my text

So I have the following code, and whenever I run the program it gives me an error. It all seems correct to me, but it isn't.
It is supposed to take the value of whatever is in the textfields and move the square to that position, and whenever the user enters a new value it is supposed to change the square to whatever the textfield says it should be. Can anybody fix this, or at least tell me whats wrong? Sorry about the code, it got even more screwed up when I started trying to debug it.
The error is
Exception in thread "main" java.lang.NullPointerException
at com.theDevCorner.Game$OptionPanel.<init>(Game.java:228)
at com.theDevCorner.Game$GridPane.<init>(Game.java:81)
at com.theDevCorner.Game.<init>(Game.java:35)
at com.theDevCorner.Game.main(Game.java:52)
Code
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Game extends JPanel implements ActionListener {
private static final long serialVersionUID = 1L;
private GridPane gridPane;
private DragPanel drag;
public boolean isMouseClicked = false;
public static JMenuBar bar = new JMenuBar();
public int gridY = 1;
public int gridX = 1;
public Game() {
setLayout(new BorderLayout());
OptionPanel options = new OptionPanel();
options.addActionListener(this);
add(options, BorderLayout.NORTH);
gridPane = new GridPane();
gridPane.setBorder(BorderFactory.createLineBorder(Color.white));
add(gridPane);
drag = new DragPanel(options);
drag.setBorder(BorderFactory.createLineBorder(Color.white));
drag.setBackground(new Color(100, 100, 125));
add(drag, BorderLayout.WEST);
}
public static void main(String args[]) {
Game game = new Game();
JFrame frame = new JFrame();
frame.setTitle("Game");
frame.setVisible(true);
frame.setAlwaysOnTop(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(game);
frame.pack();
frame.setLocationRelativeTo(null);
}
#Override
public void actionPerformed(ActionEvent e) {
System.out.println(e);
if (e.getActionCommand().equalsIgnoreCase("grid")) {
gridPane.setGridOn(!gridPane.isGridOn());
}
if (e.getActionCommand().equalsIgnoreCase("square")) {
gridPane.setSqaureOn(!gridPane.isSquareOn());
}
if (e.getActionCommand().equalsIgnoreCase("vgrid")) {
gridPane.setVertOn(!gridPane.isVertOn());
}
}
public class GridPane extends JPanel {
public OptionPanel op = new OptionPanel();
private static final long serialVersionUID = 1L;
private boolean gridOn = false;
private boolean squareOn = false;
private boolean vertOn = false;
public int x = 0,y = 0,w = 0,h = 0;
public GridPane() {
setBackground(Color.BLACK);
}
public boolean isGridOn() {
return gridOn;
}
public boolean isSquareOn() {
return squareOn;
}
public boolean isVertOn() {
return vertOn;
}
public void setGridOn(boolean value) {
if (value != gridOn) {
this.gridOn = value;
repaint();
}
}
public void setVertOn(boolean value) {
if (value != vertOn) {
this.vertOn = value;
repaint();
}
}
public void setSqaureOn(boolean value) {
if (value != squareOn) {
this.squareOn = value;
repaint();
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(320, 240);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Toolkit tk = Toolkit.getDefaultToolkit();
if (gridOn) {
System.out.println("Grid works");
g.setColor(Color.white);
for (int i = 0; i < tk.getScreenSize().height; i += 64) {
gridY++;
g.drawLine(0, (64 * gridY), tk.getScreenSize().width, (64 * gridY));
}
}
gridY = -1;
gridX = -1;
if (vertOn) {
System.out.println("vert grid works");
g.setColor(Color.white);
for (int ig = 0; ig < tk.getScreenSize().width; ig += 64) {
gridX++;
g.drawLine((64 * gridX), 0, (64 * gridX), tk.getScreenSize().height);
}
}
if (squareOn) {
System.out.println("Square works");
g.setColor(Color.red);
x = Integer.parseInt(op.squareX.getText());
y = Integer.parseInt(op.squareY.getText());
w = Integer.parseInt(op.squareW.getText());
h = Integer.parseInt(op.squareH.getText());
g.fillRect(x,y,w,h);
}
x = 0;
y = 0;
w = 64;
h = 64;
}
}
public class DragPanel extends JPanel {
OptionPanel op;
public DragPanel(OptionPanel op) {
this.op = op;
this.add(this.op.squareButton);
this.op.squareButton.setActionCommand("square");
}
public void addActionListener(ActionListener listener) {
System.out.println(listener);
this.op.squareButton.addActionListener(listener);
}
}
private static class Square {
}
private class OptionPanel extends JPanel {
public JButton grid;
public JButton vgrid;
public JButton squareButton;
public JTextField squareX;
public JTextField squareY;
public JTextField squareW;
public JTextField squareH;
public int x,y,w,h;
public Square square = new Square();
public OptionPanel() {
//Sets the stuff for the panel
setBackground(new Color(155, 0, 255));
setLayout(new GridBagLayout());
//end
//The Show Grid Button Stuff
grid = new JButton("Show Horizontal Grid");
grid.setActionCommand("grid");
//end
//The vertical grid
vgrid = new JButton("Show Vertical Grid");
vgrid.setActionCommand("vgrid");
//end
//The Square tool button stuff
squareButton = new JButton("Sqaure Tool");
//end
squareX = new JTextField(gridPane.x); //<----- THIS IS WHERE THE PROBLEM IS!!!!!
squareY = new JTextField("1",3);
squareW = new JTextField("1",3);
squareH = new JTextField("1",3);
//The gridbagConstraints things
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.NORTH;
//kind of like padding
gbc.weighty = 1;
//sets the positions
gbc.gridx = 0;
gbc.gridy = 0;
//add it
add(grid, gbc);
//changes position for the second button
gbc.gridx = -1;
gbc.gridy = 0;
// adds it
add(vgrid, gbc);
//end
add(squareX, gbc);
add(squareY, gbc);
add(squareW, gbc);
add(squareH, gbc);
}
public void addActionListener(ActionListener listener) {
//adds action listeners
grid.addActionListener(listener);
vgrid.addActionListener(listener);
squareButton.addActionListener(listener);
squareX.addActionListener(listener);
squareY.addActionListener(listener);
squareW.addActionListener(listener);
squareH.addActionListener(listener);
}
}
Update
I need help with this portion of the code still:
squareX = new JTextField("0" + gridPane.x,3); //<----- THIS IS WHERE THE PROBLEM IS!!!!!
squareY = new JTextField("0" + gridPane.y,3);
squareW = new JTextField("0" + gridPane.w,3);
squareH = new JTextField("0" + gridPane.h,3);
It seems that the main errors are coming from when I try to do something like this...

OptionPanel options = new OptionPanel();
options.addActionListener(this);
add(options, BorderLayout.NORTH);
gridPane = new GridPane();
You create the OptionPanel before your create the GridPane, so the gridPane variable is null when your optionPanel tries to access that variable.

Create the gridPane before you create the OptionPanel
Your code should be
gridPane = new GridPane();
OptionPanel options = new OptionPanel();
options.addActionListener(this);
add(options, BorderLayout.NORTH);
gridPane.setBorder(BorderFactory.createLineBorder(Color.white));
add(gridPane);

You're first NullPointerException can be fixed by doing something like...
public Game() {
setLayout(new BorderLayout());
gridPane = new GridPane();
gridPane.setBorder(BorderFactory.createLineBorder(Color.white));
OptionPanel options = new OptionPanel();
options.addActionListener(this);
add(options, BorderLayout.NORTH);
add(gridPane);
drag = new DragPanel(options);
drag.setBorder(BorderFactory.createLineBorder(Color.white));
drag.setBackground(new Color(100, 100, 125));
add(drag, BorderLayout.WEST);
}
You're second NullPointerException is more tricky...
You have a cyclic dependency problem...
Class A is trying to create Class B, which is trying to create class C when class C depends on an instance of B...
To clarify...GridPane has an instance of OptionPane, but OptionPane is depended on the state of GridPane, which is null, because GridPane can't initalise until OptionPane has been initialised...confused yet...
You can solve this by using a lazy loading approach. That is, not try to insitate the OptionPane till you need it...
public class GridPane extends JPanel {
public OptionPanel op;
// Other variables...
// Other methods...
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
// Other paint code...
if (squareOn) {
if (op == null) {
op = new OptionPanel();
}
System.out.println("Square works");
g.setColor(Color.red);
x = Integer.parseInt(op.squareX.getText());
y = Integer.parseInt(op.squareY.getText());
w = Integer.parseInt(op.squareW.getText());
h = Integer.parseInt(op.squareH.getText());
g.fillRect(x, y, w, h);
}
}
}
How ever. I don't think this is going to achieve what you want in the long run, as the state of the OptionPane will be different between the classes...(GridPane and OptionPane won't share the same instance....)
A better solution would be to remove these direct dependencies, so that you can pass some the same reference of some kind of model between GridPane and OptionPane, which would allow it to act as the glue between them...