Develop Reference

Trying to add label on panel

I am trying to put a label in every single panel I create but I only get the label in the last panel created. Its for a game of snakes and ladders and I am trying to initiate the board for the game. I need every panel to have a number.
public InitBoard() {
JPanel jPanel1 = new JPanel(new GridLayout(10, 10, 0, 0));
JPanel[][] pa = new JPanel[10][10];
//jPanel1.setSize(1024,1080);
int counter=1;
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
JPanel tiles = new JPanel();
tiles.setBorder(BorderFactory.createLineBorder(Color.BLACK));
number++;
label1.setText(String.valueOf(number));
tiles.add(label1);
if(counter == 1) {
tiles.setBackground(Color.green);
}
if (counter == 2) {
tiles.setBackground(Color.red);
}
if(counter == 3 ){
tiles.setBackground(Color.cyan);
}
counter++;
pa[i][j] = tiles;
jPanel1.add(pa[i][j]);
if(counter ==5){
counter =1;
}
}
}
add(jPanel1, BorderLayout.CENTER);
setSize(960, 960);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
}
Following image is shown when I run the file.
Any help is appreciated in advance.

I can't see this from the code that you posted, but it seems that you are re-using the same JLabel instance (label1) for all the tiles. This somehow leads to the label being overwritten and re-used for all tiles except the last one.
Just use this line:
tiles.add(new JLabel(String.valueOf(number)));
instead of what you currently have:
label1.setText(String.valueOf(number));
tiles.add(label1);
Making this change, I got your code to work as intended, showing a number on every tile. If the numbers need to be stored somewhere or if you need to be able to change them later, you might want to create an array similar to the one you have for the JPanels (pa).

Changing the position of images on the JFrame

So I am making this ABC learning game , What I want to do is if I click on the A button more than once then , the three Images will change their position, What I want to do is this
![enter image description here][1]
When I click on A button, the three image will appear on the screen, the first is apple as I set it that way in the loop, but the second two images will appear randomly, though sometimes one o them is apple again, I could fix that.
My Question is, how can I change that position of the Apple to the second and second image to the first and third image to the second position if the "A" button is clicked more than once.
SO, the result will be the apple will change position based on the click "A" button and other two picture changes their position and chosed randomly from the array.
So, here is my code for the JPanel, where everything takes place.Most of the code is explained in the comments
import java.awt.*;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.awt.event.*;
import java.text.AttributedCharacterIterator;
import java.util.Random;
import javax.swing.ImageIcon;
/**
*
* #author Dip
*/
public class AbcGeniusPanel extends JPanel implements ActionListener {
//Declare the necessary Variables here
private JButton[] buttons; //create an array for buttons
private BorderLayout layout; //Declare object of BorderLayout
private Image image = null;
private boolean showImage = false;
//Initialize all the variables here
static int index = 0;
int randNumber = 0, id = 0;
int q = 0, w = 0;
int buttonClick = 0;
//Store all the imahges that will appear on the screen into an String type array
private static String[] imageList = {"src/Images/1.png", "src/Images/2.png", "src/Images/3.png", "src/Images/4.png", "src/Images/5.png", "src/Images/6.png", "src/Images/7.png", "src/Images/8.png", "src/Images/9.png", "src/Images /10.png",
"src/Images/11.png", "src/Images/12.png", "src/Images/13.png", "src/Images /14.png", "src/Images/15.png",
"src/Images/16.png", "src/Images/17.png", "src/Images/18.png", "src/Images /19.png", "src/Images/20.png",
"src/Images/21.png", "src/Images/22.png", "src/Images/23.png", "src/Images /24.png", "src/Images/25.png",
"src/Images/26.png"
};
//Define the constructor here
public AbcGeniusPanel() {
ImageIcon[] alphabets = new ImageIcon[26];
setBackground(Color.yellow);
//Load the images for alphabet images into the alphabets array using a for loop
for (int i = 0; i < alphabets.length; i++) {
alphabets[i] = new ImageIcon("C:\\Users\\Dip\\Desktop\\Java Projects\\AbcGeniusApp\\src\\Alphabets\\" + (i + 1) + ".png");
}
//Create a JPnael object
JPanel panel = new JPanel();
//Set a layoutManager on the panel
//panel.setLayout(new FlowLayout(FlowLayout.CENTER)); //This is not workling good
panel.setLayout(new GridLayout(2, 13, 5, 5)); //This is good for now
//Create an array for holdoing the buttons
buttons = new JButton[26];
//This Loop will Store the buttons in the buttons array attatching each image for each button
//Try passing Images inside the JButton parameter later.
for (int i = 0; i < 26; i++) {
buttons[i] = new JButton(alphabets[i]);
}
// Now Setting up a new Borderlayout so that we can set the whole gridLayout at the botton of the panel
setLayout(new BorderLayout(2, 0));
//add the panel to the Border layout
add(panel, BorderLayout.SOUTH);
//Add evenHandling mechanism to all the buttons
for (int k = 0; k < 26; k++) {
buttons[k].addActionListener(this);
}
for (int count1 = 0; count1 < 26; count1++) {
panel.add(buttons[count1]);
}
}
//This Method will generate a random Number and return it
public int random_number() {
int rand_num;
Random generator = new Random(System.currentTimeMillis());
rand_num = generator.nextInt(26);
return rand_num;
}
//This method will draw the font on the Panel
public void paintComponent(Graphics g) {
Font font; //Declare Font object here
font = new Font("Wide Latin", Font.BOLD, 22); //Set font
super.paintComponent(g); //Ensure the drawing in super class
g.setFont(font); //Set the font
g.setColor(Color.RED);
String text = "CLICK ON THE RIGHT IMAGE!"; //Display the text
g.drawString(text, 255, 20);
}
//To draw the picture on the screen we need to override the paint Method
#Override
public void paint(Graphics g) {
super.paint(g);
//Here, x and y will determine the x and y position os each image
int x = 0, y = 0;
// the varibale q is declared above
for (q = 0; q < 3; q++) //This loop will generate three images on the screen
{
if (showImage) {
x = x + 265; //X-Position of the image
y = 90; //Y-Position of the image
//q is declared as q=0, so this will always be true
if (w == 1 || q == 0) {
g.drawImage(image, x, y, image.getWidth(null), image.getHeight(null), null); //This method will put the image on the screen
showImage = true;
w = 0;
}
while (true) //this loop will run anyway
{
//go inside this loop only when the generated random
//doesn't match with the index of the button that was pressed
while ((randNumber = random_number()) != index) {
index = randNumber; //Now put the randomVlaue in the index
this.image = new ImageIcon(imageList[randNumber]).getImage();
showImage = true;
//make w=1 so that we can break from the outer loop
w = 1;
//break from the inner loop
break;
}
//Since we have made the w=1, so we are breaking out of the outer loop
if (w == 1) {
break;
}
}
}
}
}
#Override
public void actionPerformed(ActionEvent event) {
Object source = event.getSource();
id = 0;
while (true) {
//id is set to zero, for example if the button A (buttons[0])is not pressed then it will go below
//to increase id until it matches the index of the button that we pressed
if (source == buttons[id]) {
//get the image of that same index of the buttons and then set the showImage true
//SO the the paint function above can draw the image
this.image = new ImageIcon(imageList[id]).getImage();
showImage = true;
//save the index of the button that is presed in another variable
//then break from the while loop
index = id;
break;
} else {
id++;
//This is necessary to make sure that id will cross 26
//becasue we have only 26 letters or the array index is 26
//so highest value can be 26 only
id = id % 26;
}
}
repaint();
}
}

Add 3 JLabels or JButtons (whatever will be displaying the images) into a JPanel container. The JPanel will likely use a GridLayout(1, 3, horizontal_gap, 0) layout.
Place all images as ImageIcons into an ArrayList.
Shuffle the ArrayList when needed
After shuffling place the Icons into the JLabels/JButtons in a for loop using the setIcon(...) method.
Note that
your JPanel should override paintComponent, not paint. The paint method is responsible for painting a component's children and borders, and it does not use double buffering by default, making a more dangerous method to override.
Putting in a while (true) loop into your Swing GUI without regard to threading is extremely dangerous.
Putting this into a painting method such as paint is GUI suicide. Never do this since a painting method is a major determinant in the perceived responsiveness of your program. If you slow it down, the program will be perceived as being slow and poorly responsive, and thus it must be lean and fast as possible, and you should have painting and only painting code within it.
Your paint method has program logic in it, something that also shouldn't be done. You don't have full control over whether or even if a painting method will be called, and so program logic should never be placed inside one of these.
As MadProgrammer well notes, don't use the src path for your images as this won't exist once you build your program into a jar file. Better to Create a resource directory in the jar file, and to refer to your images as resources, not as files.

How to implement actionListener on BufferedImage multiple times

I am currently designing an image editor in a GUI which has several buttons which, when clicked, should apply different effects on the loaded image. I have the effects working with an ActionListener but if I try to click an effect after already clicking another effect, the image turns black instead of applying the desired effect. How do I apply multiple effects to the same image? Here is my code for the ButtonPanel class, which includes the ActionListener and code for the effects(only three of the effects have been implemented as of yet):
class ButtonPanel extends JPanel
{
//JButton makeBlue;
BufferedImage img;
ImagePanel ip = new ImagePanel();
ButtonPanel(ImagePanel x)
{
final JButton makeBlue = new JButton ("Make Blue");
final JButton makeRed = new JButton ("Make Red");
final JButton makeGreen = new JButton ("Make Green");
final JButton invertColors = new JButton ("Invert Colors");
final JButton makeGreyscale = new JButton ("Greyscale");
final JButton makeWarhol = new JButton ("Warhol");
final JButton flipVertical = new JButton ("Flip Vertical");
final JButton flipHorizontal = new JButton ("Flip Horizontal");
final JButton rotateClockwise = new JButton ("Rotate Clockwise");
setBackground(Color.RED);
ip = x;
//int width, height;
//setBackground(Color.RED);
//int height = 0;
add(makeBlue);
add(makeRed);
add(makeGreen);
add(invertColors);
add(makeGreyscale);
add(makeWarhol);
add(flipVertical);
add(flipHorizontal);
add(rotateClockwise);
ActionListener action =
new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
BufferedImage img = ip.getImg();
if (e.getSource()== makeBlue)
{
int width = img.getWidth(); //# of pixel columns
int height = img.getHeight(); //# of pixels rows
for(int i=0; i<width;i++)
{
for(int j=0; j<height; j++)
{
int value = img.getRGB(i,j);
int y = 0xFF0000FF;
value = value & y;
img.setRGB(i,j,value);
}
}
ip.setImage(img);
setBackground(Color.GREEN);
repaint();
}
else if(e.getSource()== makeRed)
{
int width = img.getWidth(); //# of pixel columns
int height = img.getHeight(); //# of pixels rows
for(int i=0; i<width;i++)
{
for(int j=0; j<height; j++)
{
//fill in code here
int value = img.getRGB(i,j);
int y = 0xFFFF0000;
value = value & y;
//System.out.println(value);
img.setRGB(i,j,value);
}
}
ip.setImage(img);
repaint();
}
else if(e.getSource()== makeGreen)
{
int width = img.getWidth(); //# of pixel columns
int height = img.getHeight(); //# of pixels rows
for(int i=0; i<width;i++)
{
for(int j=0; j<height; j++)
{
//fill in code here
int value = img.getRGB(i,j);
int y = 0xFF00FF00;
value = value & y;
img.setRGB(i,j,value);
}
}
ip.setImage(img);
repaint();
}
}
};
makeBlue.addActionListener(action);
makeRed.addActionListener(action);
makeGreen.addActionListener(action);
makeWarhol.addActionListener(action);
flipVertical.addActionListener(action);
flipHorizontal.addActionListener(action);
rotateClockwise.addActionListener(action);
makeGreyscale.addActionListener(action);
invertColors.addActionListener(action);
}
}
Any help would be appreciated. Thanks.

Your problem is that you're extracting all of one color out of the image, and then replacing the original image in your ImagePanel with the new extracted image that is, say if the green button is pressed, all green. Then when you try to extract red from the ImagePanel's image, you get all black because the image is now only green.
You need to save the original image somewhere if you want to extract the original colors. Perhaps you should give ImagePanel a method, getOriginalImage() or some such, and have it store two images, one the displayed image and one the changed one.
Better still, use an Model-View-Control pattern and store your images elsewhere off the GUI.

There are two ways to accomplish this. You can either have your class be the ActionListener (which is the way you have it set up now), or you can have a unique ActionListener for each button. As a design decision I prefer the latter, as you can have more precise control and easier to read code this way.
Each of your buttons, menu items, and any other Object you want to have a unique effect should each have it's own ActionListener. You can either write a new class file for each ActionListener, an inner class, or an anonymous inner class for each. I prefer anonymous inner classes placed in line of your constructor or setup method like this:
JButton testButton = new JButton("Test");
testButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
// do stuff here
System.out.println("You clicked me!");
}
});
This method allows you to ignore huge conditional branches and unnecessary comparisons. Implement the interface uniquely for each component that needs the listener.

SWT Button Grid

It's a problem that it's annoying me for 3 days now.
I have to rewrite the UI of a little tictactoe(Gomoku of n x n) game.
the problem is that when i created the swing GUI , i made a new class that inherits JButton properties and added an int for rows and an int for columns. I cannot do that with SWT(no inheritance). is there a way for me to add the values of i and j to the button.
Here is the example in Swing:
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
final MyJButton button = new MyJButton(i, j);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
MoveResult move = game.move(button.getRow(), button.getCol());
switch (move) {
case ValidMove:
button.setBackground(game.getCurrentPlayer().getColor());
game.changePlayer();
break;
}
}
}
}
}
}
I give the i and j for the game class which give it to a table clas to check the move.
if (table.getElement(x, y) != PieceType.NONE) return MoveResult.InvalidMove;
private PieceType[][] table;
is there a way to do the same in SWT, any indication is welcomed .
this is what i made
buttonpanel = new Composite(shell, SWT.NONE);
buttonpanel.setLayout(new org.eclipse.swt.layout.GridLayout(cols, true));
buttonTable = new Button[rows][cols];
for (int i = 0; i < rows; ++i){
for (int j = 0; j < cols; ++j) {
gridData.heightHint = 45;
gridData.widthHint = 45;
Button button = new Button(buttonpanel, SWT.PUSH);
button.setLayoutData(gridData);
buttonTable[i][j] = button;
buttonTable[i][j].addSelectionListener(new buttSelectionListener());
// buttonpanel.pack();
}
}

I see two solutions :
use Button's setData method (defined in the Widget superclass) to associate an object containing your x and y (you'll found those data in the event object provided to your listener)
use different listeners for each button
In your case, the first solution seems the most natural one.
This means creating a class holding x and y (let's call it Cell), and doing
button.setData(new Cell(i, j));
and in you listener using
game.move(e.data.x, e.data.y);

Options include:
Subclass Button, and override its checkSubclass() method to indicate that you're taking responsibility for not subclassing harmfully.
Make each Button a Composite, which allows subclassing, and put a Button in the Composite.
Make a separate listener for each button.
In a single listener, search through the buttonTable for the button that calls the listener.

Two icons in a JLabel?

I have an icon in a JLabel as shown below:
Is it possible to add another icon (e.g. a flag representing a country) between the color icon and the text? For example, I want to add an icon depicting the U.S. flag between the red icon and US. Thanks!

Yes, use nested JLabel with BoxLayout in the container label:
JLabel container = new JLabel();
container.setLayout(new BoxLayout(container, BoxLayout.X_AXIS));
JLabel icon1Label = new JLabel();
JLabel icon2Label = new JLabel();
icon1Label.setIcon(icon1);
icon2Label.setIcon(icon2);
container.add(icon1Label);
container.add(icon2Label);

Try CompoundIcon
Edit: Heisenbug's layout-based solution is the
trivial answer.

I just did this recently - I wanted to be able to combine multiple icons in a single row into a single icon. The way I did it was to go down to the BufferedImage level and compose the two images manually into a single image, and then use that as my JLabel icon. There are other ways of achieving the same effect, but I didn't want to have to change my UI component hierarchy.
I ended up creating a class that combines multiple images and caches them. I used it like this:
ImageIcon icon1 = ...;
ImageIcon icon2 = ...;
ImageIcon labelIcon = new CachedCompositeIcon( icon1, icon2 ).getIcon();
jLabel.setIcon( labelIcon );
Here's the source:
/** This is a convenience class to handle creating a single composite icon from several icons, and caching the
* created icons to eliminate duplicate work. This class is basically used as a key into a map, allowing us to
* define both a hashCode and equals in a single place.
*/
public class CachedCompositeIcon
{
private static final byte ICON_PADDING = 2;
private static final HashMap<CachedCompositeIcon, ImageIcon> CACHED_ICONS =
new HashMap<CachedCompositeIcon, ImageIcon>( 4 );
private final ImageIcon[] m_icons;
public CachedCompositeIcon(final ImageIcon... icons) {
m_icons = icons;
}
public ImageIcon getIcon() {
if ( !CACHED_ICONS.containsKey( this ) ) {
CACHED_ICONS.put( this, lcl_combineIcons() );
}
return CACHED_ICONS.get( this );
}
/** Generates an icon that is a composition of several icons by appending each icon together with some
* padding between them.
*
* #return An icon that is the concatenation of all the icons this was constructed with.
*/
private ImageIcon lcl_combineIcons() {
// First determine how big our composite icon will be; we need to know how wide & tall to make it.
int totalWidth = (m_icons.length - 1) * ICON_PADDING; // Take into account the padding between icons
int minHeight = 0;
for ( int i = 0; i < m_icons.length; ++i ) {
totalWidth += m_icons[i].getIconWidth();
if ( m_icons[i].getIconHeight() > minHeight ) {
minHeight = m_icons[i].getIconHeight();
}
}
// Create an image big enough and acquire the image canvas to draw on
final BufferedImage compositeImage = new BufferedImage( totalWidth, minHeight, BufferedImage.TYPE_INT_ARGB );
final Graphics graphics = compositeImage.createGraphics();
// Iterate over the icons, painting each icon and adding some padding space between them
int x = 0;
for ( int i = 0; i < m_icons.length; ++i ) {
final ImageIcon icon = m_icons[ i ];
graphics.drawImage( icon.getImage(), x, 0, null );
x += icon.getIconWidth() + ICON_PADDING;
}
return new ImageIcon( compositeImage );
}
/** Generates a hash that takes into account the number of icons this composition includes and the hash &
* order of those icons.
*
* #return A hash code.
*/
#Override
public int hashCode() {
int weakHash = m_icons.length;
for ( int i = 0; i < m_icons.length; ++i ) {
weakHash += m_icons[i].hashCode() * (i + 1);
}
return weakHash;
}
/** Two instances are equal if and only if they include the same icons and they're in the same order.
*
* #param obj An object to check for equality with this.
*
* #return true if the two objects are equal, false otherwise.
*/
#Override
public boolean equals(final Object obj) {
if ( !(obj instanceof CachedCompositeIcon) ) {
return false;
}
final CachedCompositeIcon other = (CachedCompositeIcon) obj;
if ( m_icons.length != other.m_icons.length ) {
return false;
}
for ( int i = 0; i < m_icons.length; ++i ) {
if ( m_icons[i].hashCode() != other.m_icons[i].hashCode() ) {
return false;
}
}
return true;
}
}

this is pretty possible, JLabel is Swing JComponent and you can add any JComponent to the another JComponent, that's same for JLabel
label.setLayout(new GridLayout(0, 2, 10, 10));
label.add(myIcon1);
label.add(myIcon2);
if you add f.e. JPanel to the JLabel then don't forget to setOpaque(false);