Develop Reference

Java game involving adjacent JButtons

I'm making a small game involving a grid of JButtons (MxN) and the main premise is to click on buttonA and then on buttonB, coloring buttonB and adjacent buttons of the same color as buttonB with the color of buttonA. I have made it so you are able to choose 3 possible difficulties. The colors are randomly generated. The main problem is getting the colors to change.
This is the method that I call after selecting the difficulty of the game:
public static void gameMechanics(int m, int n) {
final String[] pickedColour = {""};
final String[] placedColour = {""};
JButton[][] picked = new JButton[m][n];
JButton[][] placed = new JButton[m][n];
picked[m][n].addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
pickedColour[0] = picked[m][n].getText();
}
});
placed[m][n].addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
placedColour[0] = placed[m][n].getText();
}
});
if (pickedColour[0] == "R" && placedColour[0] != "R") {
placed[m][n].setBackground(Color.RED);
placed[m][n].setText("R");
}
else if (pickedColour[0] == "G" && placedColour[0] != "G") {
placed[m][n].setBackground(Color.GREEN);
placed[m][n].setText("G");
}
else if (pickedColour[0] == "B" && placedColour[0] != "B") {
placed[m][n].setBackground(Color.BLUE);
placed[m][n].setText("B");
}
}

I would consider using JPanels and painting them, using a MouseListener instead.
However, if you're set on using JButtons, try this:
button.setBackground(Color.GREEN);
button.setOpaque(true);
Note that this might not work if you're setting the look and feel using UIManager.
Also, you're doing a ton of extra work to map the color to the button - it could get confusing and cause errors down the road. Instead, you might try creating your own class:
class ColoredButton extends JButton {
private static final long serialVersionUID = 3040767030924461426L;
private Color color;
public ColoredButton(Color c) {
this.color = c;
this.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
changeColor();
}
});
}
public void changeColor() {
this.setBackground(this.color);
this.setOpaque(true);
}
}
Now, you can construct a new ColoredButton:
// Now, this button will turn green when clicked
ColoredButton temp = new ColoredButton(Color.GREEN);

Getting value from JRadioButton

I'd like to change value of my variable "name" when I select right button and click "ok" on my JRadio Frame.
For example when i select r1 and hit "ok" I'd like to have name=="Fast" in the entire package.
package Snake;
public class Radio extends JFrame {
private int delay = 100;
private String name;
JTextField t1;
JButton b;
JRadioButton r1, r2;
JLabel l;
public void selectSpeed() {
b = new JButton("Ok");
r1 = new JRadioButton("Fast");
r2 = new JRadioButton("Slow");
l = new JLabel("Speed: ");
ButtonGroup bg = new ButtonGroup();
bg.add(r1);
bg.add(r2);
add(b);
add(r1);
add(r2);
add(l);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (r1.isSelected()) {
name = "Fast";
} else {
name = "Slow";
}
l.setText("Speed: " + name); // name=="Fast" when r1 is selected
} // name=="Slow" when r2 is selected
});
if (name == "Fast") { // and now name is empty...
delay = 50;
}
if (name == "Slow") {
delay = 500;
}
setLayout(new FlowLayout());
setSize(400, 400);
setVisible(true);
}
public int setSpeed() {
selectSpeed();
return delay;
}
}

If you want to change the delay on button click, You need to write the logic in the ActionListener itself because the code you have written to change the delay will run only once and that too at the start of the execution of your program and at that time, name will be empty.
Then when ever you click the button, It will only execute the ActionListener So delay will not be changed at any time. And other mistake you are making is that you are comparing Strings in wrong way. For more information take a look at it How do I compare Strings in Java?
To change delay dynamically on button click, you need to change it in the ActionListener.
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (r1.isSelected()) {
name = "Fast";
delay = 50;
} else {
name = "Slow";
delay = 500;
}
l.setText("Speed: " + name); // name=="Fast" when r1 is selected
} // name=="Slow" when r2 is selected
});

You need to do it in your JRadioButton listener. For example, like here, at first you change the variable "name" and later in the current listener you check conditions, but you need remember that to compare the strings you need to use "equals":
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (r1.isSelected()) {
name = "Fast";
} else {
name = "Slow";
}
l.setText("Speed: " + name); // name=="Fast" when r1 is selected
if (name.equals("Fast")) { // and now name is empty...
delay = 50;
}
if (name.equals("Slow")) {
delay = 500;
}
} // name=="Slow" when r2 is selected
});

Well I see my mistake now, Thank you.
But it still does not work the way I like. I'd like to change the "delay" value every time I select right button on JRadio and hit "ok" and with this changed value I'd like to go to the other class.
There is the code of a class where I need value of "delay":
package Snake;
public class Gameplay extends Paint implements KeyListener, ActionListener {
private Timer timer;
private int q = 0;
Radio radio = new Radio();
public Gameplay() {
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
timer = new Timer(radio.selectSpeed(), this); //here i need flexible "delay" value
timer.start();
}

Applet not running java

I'm wondering why my applet isn't running. I'm using netbeans, and the program works fine with no errors, but I can't seem to get the applet screen to appear to test all the functions of my program.I was wondering if someone can point out what I am doing wrong in starting my applet up. I haven't done to many things with applets, so I'm quite curious why it isn't upping and running for me. I really didn't want to post the full code of my program, but I've no idea if there's an error in my code, or I'm just not doing the right thing to actually start the applet or something.
I do not get any errors while running my program, that applet simply does not appear and run in itself. Otherwise I get no errors from neatbeans while running my program.
import java.awt.event.*;
import javax.swing.*;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.FlowLayout;
public class Program7 extends JApplet implements ActionListener, ItemListener
{
//static varaibles
private static int GuiHeight = 90;
private static int Square = 50;
//gui varaibles
private JRadioButton drawSquare;
private JRadioButton mess;
private JTextField messageFeild;
private JCheckBox color;
private JButton button;
private JComboBox location;
//modable global varaibles
private int width, height, drawX, drawY;
private Color drawColor;
private String draw;
#Override
public void init()
{
//creating the panels
JPanel drawChoice;
JPanel drawSet;
//setting group onject to link certain buttons together
ButtonGroup ObjGroup;
//setting layout to make things look nice
setLayout(new FlowLayout());
//ibtializing other varaibles
width = 0;
height = 0;
drawX = 0;
drawY= 0;
drawColor = Color.BLACK;
draw = "";
//intialzing the gui interface
drawSquare = new JRadioButton("Draw a Square!");
mess = new JRadioButton("Write a Message!");
location = new JComboBox(new String[]{"", "Random Pick", "Top Left"});
color = new JCheckBox("Draw in Color!");
button = new JButton("Draw it!");
//linking the buttons together
ObjGroup = new ButtonGroup();
ObjGroup.add(drawSquare);
ObjGroup.add(mess);
//adding event handlers to the buttons
location.addItem(this);
button.addActionListener(this);
color.addItemListener(this);
drawSquare.addActionListener(this);
mess.addActionListener(this);
messageFeild = new JTextField(20);
//adding to the first paels
drawChoice = new JPanel();
drawChoice.add(drawSquare);
drawChoice.add(mess);
drawChoice.add(messageFeild);
//adding to the applet
add(drawChoice);
//adding to the second panel
drawSet = new JPanel();
drawSet.add(new JLabel("Select where to draw!"));
drawSet.add(location);
drawSet.add(color);
drawSet.add(button);
//adding to the applet
add(drawSet);
}
#Override
public void paint(Graphics g)
{
//calling super constructor
super.paint(g);
//getting width
width = getWidth();
height = getHeight();
//setting graphics color
g.setColor(drawColor);
if (location.getSelectedItem() != "")
{
//ifstatement checking for inputs
if(draw == "Square"||draw == "square"||draw == "SQUARE")
{
//creating rectange
g.fillRect(drawX, drawY, width, height);
}
if(draw == "Message"|| draw == "MESSAGE"||draw == "message")
{
//writing message
g.drawString(messageFeild.getText(), drawX, drawY);
}
}
}
#Override
public void actionPerformed(ActionEvent e)
{
//repainting
repaint();
}
#Override
public void itemStateChanged(ItemEvent e)
{
//if statement checking for the various changes being made by the user in the pograms interface
//if statement check checking to see if there's a square or to write a message
if (e.getSource() == drawSquare && e.getStateChange() == ItemEvent.SELECTED)
{
draw = "Square";
messageFeild.setEnabled(false);
}
if (e.getSource() == mess && e.getStateChange() == ItemEvent.SELECTED)
{
draw = "Message";
messageFeild.setEnabled(true);
}
//if statement set checking for locational input
if (e.getSource() == location)
{
if(location.getSelectedItem() == "Random Pick")
{
drawX=(int)(Math.random()*(width+1));
drawY=(int)(GuiHeight+ Math.random()*(height-GuiHeight+1));
}
if(location.getSelectedItem() == "Top Left")
{
drawX=0;
drawY=GuiHeight;
}
}
//if statement to check for color change
if(e.getSource()==color && e.getStateChange()==ItemEvent.SELECTED)
{
drawColor = Color.GREEN;
}
if(e.getSource()==color && e.getStateChange()==ItemEvent.DESELECTED)
{
drawColor = Color.BLACK;
}
}
public static void main(String[] args) {
}
}

how to refresh the colors of button contained in a JFrame?

I am coding a little game in which i have taken a grid of JButtons in a JFrame and i want to refresh the colors of the buttons contained in a JFrame,which is already visible.As explained below
void foo(){
mainFrame.setVisible(true);//mainFrame is defined at class level.
//color update code for the buttons.
mainFrame.setVisible(true);
}
Result i am getting is not as expected and my screen gets freeze .Isn't it the right way to achieve what i wanted?
EDIT
ok i am explaining it in detail what i want to achieve.i have a class,as:-
import javax.swing.*;
import java.awt.*;
import java.util.*;
class Brick extends JButton{
public void setRandomColors(){
int random = (int) (Math.random()*50);
if(random%13==0){
this.setBackground(Color.MAGENTA);
}
else if(random%10==0){
this.setBackground(Color.red);
}
else if(random%9==0){
this.setBackground(Color.yellow);
}
else if(random%7==0){
this.setBackground(Color.orange);
}
else if(random%2==0){
this.setBackground(Color.cyan);
}
else{
this.setBackground(Color.PINK);
}
}
public void setBlackColor(){
this.setBackground(Color.black);
}
}
class Grid {
JFrame mainGrid = new JFrame();
ArrayList<Brick> bunchOfBricks = new ArrayList<>();
int gridLength = 8;//gridlenth is equals to gridweight as i have considered a Square grid.
int totalBricks = gridLength*gridLength;
public void formBunchOfBricks(){
for(int i=0;i<totalBricks;i++){
bunchOfBricks.add(new Brick());
}
}
public void formColoredGrid(){
Brick aBrick;
mainGrid.setLayout(new GridLayout(8,8));
for(int i=0;i<totalBricks;++i){
aBrick = (bunchOfBricks.get(i));
aBrick.setRandomColors();
mainGrid.add(aBrick);
}
mainGrid.setVisible(true);//its ok upto here iam getting randomly colored Frame of Bricks or so called JButtons.
delay(15);//Sorry for this one,i warn you not to laugh after looking its defination.
}
/*
I want following function to do following things:-
1.it should firstly display the Grid whose all buttons are black Colored.
2.After some time the original colored,first Row of grid formed by formColoredGrid should be displayed and all the rest Rows should be black.
3.Then second row turns colored and all other rows should be black......and so on upto last row of Grid.
*/
public void movingRows(){
setGridBlack();
delay(1);//see in upper method,for this horrible thing.
for(int i=0;i<gridLength;++i){
setGridBlack();
for (int j=0;j<gridLength;++j){
Brick aBrick = bunchOfBricks.get((gridLength*i)+j);
aBrick.setRandomColors();//Bricks are colored Row by Row.
}
delay(5);//already commented this nonsense.
mainGrid.setVisible(true);//using setVisible again,although this frame is already visible,when i called formColoredGrid.
setGridBlack();
}
//oh! disappointing,i have almost broken my arm slamming it on table that why the function result in a screen full of black buttons.
}
public void setGridBlack(){
for(int i=0;i<totalBricks;i++){
bunchOfBricks.get(i).setBlackColor();
}
}
public void delay(int a){
for ( int i=0;i<90000000;++i){
for(int j=0;j<a;++j){
}
}
}
public static void main(String args[]){
Grid g1 = new Grid();
g1.formBunchOfBricks();
g1.formColoredGrid();
g1.movingRows();
}
}
Please Help me what is the way out?

Your problem is in code not shown here:
//color update code for the buttons.
You're likely running a loop that never ends on the Swing event thread, possibly a never-ending while loop that polls the state of something(a guess), freezing your GUI. Solution: don't do this; don't use a continuous polling loop. Instead, change the colors based on responses to events as Swing is event-driven.
For better more specific help, please show the offending code and tell us more about your program.
Edit
If you're trying to show colored rows, one by one marching down the board, then my guess is right, you'll want to use a Swing Timer, one that uses an int index to indicate which row is being displayed in color. You'd increment the index inside of the Timer's ActionPerformed class, and then when all rows have been displayed stop the Timer. For example something like so:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyGrid extends JPanel {
private static final int GRID_LENGTH = 8;
private static final Color BTN_BACKGROUND = Color.BLACK;
private static final Color[] COLORS = { Color.MAGENTA, Color.CYAN,
Color.RED, Color.YELLOW, Color.ORANGE, Color.PINK, Color.BLUE,
Color.GREEN };
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private static final int TIMER_DELAY = 800;
private JButton[][] buttonGrid = new JButton[GRID_LENGTH][GRID_LENGTH];
private Map<JButton, Color> btnColorMap = new HashMap<>();
private Random random = new Random();
public MyGrid() {
setLayout(new GridLayout(GRID_LENGTH, GRID_LENGTH));
for (int row = 0; row < buttonGrid.length; row++) {
for (int col = 0; col < buttonGrid[row].length; col++) {
JButton btn = new JButton();
btn.setBackground(BTN_BACKGROUND);
// !! add action listener here?
add(btn);
buttonGrid[row][col] = btn;
}
}
new Timer(TIMER_DELAY, new TimerListener()).start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public void resetAllBtns() {
for (JButton[] row : buttonGrid) {
for (JButton btn : row) {
btn.setBackground(BTN_BACKGROUND);
}
}
}
private class TimerListener implements ActionListener {
private int row = 0;
#Override
public void actionPerformed(ActionEvent e) {
resetAllBtns(); // make all buttons black
if (row != buttonGrid.length) {
for (int c = 0; c < buttonGrid[row].length; c++) {
int colorIndex = random.nextInt(COLORS.length);
Color randomColor = COLORS[colorIndex];
buttonGrid[row][c].setBackground(randomColor);
// !! not sure if you need this
btnColorMap.put(buttonGrid[row][c], randomColor);
}
row++;
} else {
// else we've run out of rows -- stop the timer
((Timer) e.getSource()).stop();
}
}
}
private static void createAndShowGui() {
MyGrid mainPanel = new MyGrid();
JFrame frame = new JFrame("MyGrid");
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();
}
});
}
}
Please have a look at the Swing Timer Tutorial as well.
Edit 2
You ask:
but what is the reason of failure of this program,is it the useless delay function?
Your delay method does nothing but busy calculations on the Swing event thread:
public void delay(int a) {
for (int i = 0; i < 90000000; ++i) {
for (int j = 0; j < a; ++j) {
}
}
}
It's little different from a crude attempt at calling Thread.sleep(...), and is crude because you can't explicitly control how long it will run as you can with thread sleep. Again, the problem is that you're making these calls on the Swing event dispatch thread or EDT, the single thread that is responsible for all Swing drawing and user interactions. Blocking this thread will block your program making it non-running or frozen.

Simple ActionListener within a 2D array of JButtons

Okay so I am making a 2d array of JToggleButtons. I got the action listener up and going, but I have no way to tell which button is which.
If I click one, all it returns is something like
javax.swing.JToggleButton[,59,58,19x14,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource#53343ed0,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=14,bottom=2,right=14],paintBorder=true,paintFocus=true,pressedIcon=,rolloverEnabled=false,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=]
Is there anyway to stick some sort of item or number in the button object to associate each button?
And then when the button is clicked I can retrieve that item or number that was given to it?
Here is my button generator code. (How could I make "int l" associate (and count) to each button made, when it is called, it will return that number, or something along those lines.
JToggleButton buttons[][] = new JToggleButton[row][col];
int l = 0;
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
buttons[i][j] = new JToggleButton("");
buttons[i][j].setSize(15,15);
buttons[i][j].addActionListener(new e());
panel.add(buttons[i][j]);
l++;
}
}
ActionListner
public class e implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
System.out.println(source);
}
}
variable "source" is what I use to get my data, so how can int l, be returned through "source" (as its unique value for the unique button clicked) as a button is clicked?
Thanks,
-Austin

very simple way is add ClientProperty to the JComponent, add to your definition into loop e.g.
buttons[i][j].putClientProperty("column", i);
buttons[i][j].putClientProperty("row", j);
buttons[i][j].addActionListener(new MyActionListener());
rename e to the MyActionListener and change its contents
public class MyActionListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
JToggleButton btn = (JToggleButton) e.getSource();
System.out.println("clicked column " + btn.getClientProperty("column")
+ ", row " + btn.getClientProperty("row"));
}
EDIT:
for MinerCraft clone isn't required to implements ony of Listeners, there is only about Icon, find out that in this code (don't implement any of Listeners anf remove used ItemListener)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ButtonsIcon extends JFrame {
private static final long serialVersionUID = 1L;
private Icon errorIcon = UIManager.getIcon("OptionPane.errorIcon");
private Icon infoIcon = UIManager.getIcon("OptionPane.informationIcon");
private Icon warnIcon = UIManager.getIcon("OptionPane.warningIcon");
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
ButtonsIcon t = new ButtonsIcon();
}
});
}
public ButtonsIcon() {
setLayout(new GridLayout(2, 2, 4, 4));
JButton button = new JButton();
button.setBorderPainted(false);
button.setBorder(null);
button.setFocusable(false);
button.setMargin(new Insets(0, 0, 0, 0));
button.setContentAreaFilled(false);
button.setIcon((errorIcon));
button.setRolloverIcon((infoIcon));
button.setPressedIcon(warnIcon);
button.setDisabledIcon(warnIcon);
add(button);
JButton button1 = new JButton();
button1.setBorderPainted(false);
button1.setBorder(null);
button1.setFocusable(false);
button1.setMargin(new Insets(0, 0, 0, 0));
button1.setContentAreaFilled(false);
button1.setIcon((errorIcon));
button1.setRolloverIcon((infoIcon));
button1.setPressedIcon(warnIcon);
button1.setDisabledIcon(warnIcon);
add(button1);
button1.setEnabled(false);
final JToggleButton toggleButton = new JToggleButton();
toggleButton.setIcon((errorIcon));
toggleButton.setRolloverIcon((infoIcon));
toggleButton.setPressedIcon(warnIcon);
toggleButton.setDisabledIcon(warnIcon);
toggleButton.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
if (toggleButton.isSelected()) {
} else {
}
}
});
add(toggleButton);
final JToggleButton toggleButton1 = new JToggleButton();
toggleButton1.setIcon((errorIcon));
toggleButton1.setRolloverIcon((infoIcon));
toggleButton1.setPressedIcon(warnIcon);
toggleButton1.setDisabledIcon(warnIcon);
toggleButton1.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
if (toggleButton1.isSelected()) {
} else {
}
}
});
add(toggleButton1);
toggleButton1.setEnabled(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
}

Just add the row and column data to each listener. You could add an explicit constructor, but I suggest adding a little method (which may have more added to it later).
buttons[i][j].addActionListener(e(i, j));
...
private ActionListener e(final int i, final int j) {
return new ActionListener() {
// i and j available here
...
(In JDK8 you should be able to use a lambda to reduce the syntax clutter.)
And then renaming it with a better name.

I made a minesweeper game and ran into a similar problem. One of the only ways you can do it, is to get the absolute location of the clicked button, then divide that by the x and y between buttons, so for me it was
if ((e.getComponent().getX() != (randx) * 25 && e.getComponent().getY() != (randy) * 25) &&bomb[randx][randy] == false) {
This code was to check if the area had bombs. So I had 25 x and y difference between location of bombs. That will just give you a general idea on how to do this.
I believe: (x - x spacing on left side) / buffer - 1 would work.

Instead of 'e.getSource()' you can always call 'e.getActionCommand()'. For each button you can specify this by:
JButton button = new JButton("Specify your parameters here"); /*you get these from getActionCommand*/
button.setText("title here"); /*as far as I remember*/