I'm creating a program that features a grid of 12 JPanels. When the "add image" button is pressed, an image appears in the first JPanel in the grid and a counter is incremented by one. From then onwards, every time the "add image" is clicked again, an image would be added to the next JPanel. For some reason, the button only adds an image to the first JPanel and then stops working. Here's the code I've got so far.
public class ImageGrid extends JFrame {
static JPanel[] imageSpaces = new JPanel[12];
int imageCounter = 0;
ImageGrid() {
this.setTitle("Image Grid");
setSize(750, 750);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel p3 = new JPanel();
p3.setLayout(new GridLayout(3, 4, 10, 5));
p3.setBackground(Color.WHITE);
p3.setOpaque(true);
p3.setBorder(BorderFactory.createEmptyBorder(0, 5, 5, 5));
for (int j = 0; j < imageSpaces.length; j++) {
imageSpaces[j] = setImageSpace();
p3.add(imageSpaces[j]);
}
MyButtonPanel p1 = new MyButtonPanel();
add(p1, BorderLayout.SOUTH);
add(p3, BorderLayout.CENTER);
}
public JPanel setImageSpace() {
JPanel test;
test = new JPanel();
test.setOpaque(true);
test.setPreferredSize(new Dimension(100, 100));
return test;
}
class MyButtonPanel extends JPanel implements ActionListener {
final JButton addImage = new JButton("Add Image");
ImageIcon lorryPicture = new ImageIcon(ImageGrid.class.getResource("/resources/lorry.png"));
JLabel lorryImage = new JLabel(lorryPicture);
MyButtonPanel() {
add(addImage);
addImage.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == addImage) {
imageSpaces[imageCounter].add(lorryImage);
revalidate();
repaint();
imageCounter++;
}
}
}
public static void main(String[] args) {
ImageGrid test = new ImageGrid();
test.setVisible(true);
}
}
You should be revalidating and repainting the panel, (which is the containter being affected by the addition), not the frame
imageSpaces[imageCounter].add(lorryImage);
imageSpaces[imageCounter].revalidate();
imageSpaces[imageCounter].repaint();
Diclaimer: This may work as a simple fix, but also note that a component (in this case your JLabel lorryImage) can only have one parent container. The reason the above fix still works is because you don't revalidate and repaint the previous panel, the label was added to. So you may want to think about doing it correctly, and adding a new JLabel to each panel.
if (e.getSource() == addImage) {
JLabel lorryImage = new JLabel(lorryPicture);
imageSpaces[imageCounter].add(lorryImage);
imageSpaces[imageCounter].revalidate();
imageSpaces[imageCounter].repaint();
imageCounter++;
}
Disclaimer 2: You should add a check, to only add a label if the count is less than the array length, as to avoid the ArrayIndexOutOfBoundsException
Side Notes
Swing apps should be run from the Event Dispatch Thread (EDT). You can do this by wrapping the code in the main in a SwingUtilities.invokeLater(...). See more at Initial Threads
You could also just use a JLabel and call setIcon, instead of using a JPanel
Related
I have a JLabel with ImageIcons of t-shirts. I want to make each t-shirt have the ability to be clicked and then it will lead to another window. How can I make each t-shirt a button while maintaining the pictures?
This is just part of one of my methods and I want the shirts to become JButtons.
Here is my code:
final JFrame shirts = new JFrame("T-shirts");
JPanel panel = new JPanel(new GridLayout(4, 4, 3, 3));
for (int i = 1; i < 13; i++) {
l = new JLabel(new ImageIcon("T-shirts/"+i+".jpg"), JLabel.CENTER);
l.setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
l.setFont(l.getFont().deriveFont(20f));
panel.add(l);
}//end of for loop
shirts.setContentPane(panel);
shirts.setSize(1000, 1000);
shirts.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
shirts.setVisible(true);
There is no need to change to a JButton. The simplest option here is to implement a MouseListener.
This will allow you to test for mouse clicked events:
yourLabelName.addMouseListener(new MouseAdapter()
{
public void mouseClicked(MouseEvent e)
{
//point to the frame you want it to go to from here
yourFrame = new JFrame("Next JFrame");
frame.setVisible(true);
}
});
UPDATE
shirts.this.add(l);
That will add the label to the next JFrame
Hope this helps.
Let me know of the outcome :)
I decided to use a GridLayout LayoutManager for my Java Swing app because each cell within the grid is supposed to be exactly the same size.
From the Java Tutorials:
A GridLayout object places components in a grid of cells. Each component takes all the available space within its cell, and each cell is exactly the same size.
And even in the description of the GridLayout class:
The GridLayout class is a layout manager that lays out a container's components in a rectangular grid. The container is divided into equal-sized rectangles, and one component is placed in each rectangle.
However, my code seems to make a certain cell twice as large as the others. I added 3 JPanels to a Container with GridLayout, and gave each JPanel a different background color. This was the result:
Clearly, the first JPanel (red background) is twice as big as the others (green and yellow). The code that produced this is the following:
public void updateListFrameContentPane(Container mainPane) {
mainPane.setLayout(new GridLayout(1,0));
JPanel listPanel = new JPanel();
listPanel.setLayout(new BoxLayout(listPanel, BoxLayout.Y_AXIS));
listPanel.add(friendsLabel);
listPanel.add(listScrollPane);
listPanel.setBackground(Color.RED);
mainPane.add(listPanel);
for(JPanel chatPanel : chatPanels) {
chatPanel.setBackground((Math.random()>0.5 ? Color.YELLOW : Color.GREEN));
mainPane.add(chatPanel);
}
}
All I do is set the Container's layout to GridLayout with 1 row and any number of columns, and then add 3 JPanels to that. So why is the first JPanel so much larger? Strangely this only happens when two or more chatPanels are added. When there is only one, it formats correctly.
Kiheru is right. revalidate/repaint after changing the contents of a container. Here's a rough but working example:
public class GridLayoutExample {
private JFrame frame;
private Map<String,JPanel> chatBoxes = new HashMap<String,JPanel>();
private String lastKey = "0";
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
GridLayoutExample window = new GridLayoutExample();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public GridLayoutExample() {
initialize();
}
private void addChatBox() {
/*
* JPanel (border layout)
* - JPanel (Border South, Border layout)
* - - JTextField ( Border center )
* - - JButton ( Border east )
* - JLabel (Border North )
* - JTextArea (Border Center);
*/
int lk = Integer.valueOf(lastKey)+1;
lastKey = Integer.toString(lk);
JPanel np = new JPanel();
np.setLayout(new BorderLayout(0,0));
np.setBackground((lk%2 == 0) ? Color.GREEN : Color.YELLOW);
JPanel south = new JPanel();
south.setLayout(new BorderLayout(0,0));
np.add(south,BorderLayout.SOUTH);
JButton b = new JButton("New Button");
south.add(b,BorderLayout.EAST);
JTextField field = new JTextField();
south.add(field,BorderLayout.CENTER);
JLabel label = new JLabel(lastKey);
label.setHorizontalAlignment(SwingConstants.CENTER);
np.add(label,BorderLayout.NORTH);
JTextArea text = new JTextArea();
np.add(text,BorderLayout.CENTER);
chatBoxes.put(lastKey, np);
frame.getContentPane().add(np);
frame.revalidate(); // CRITICAL MISSING LINES
frame.repaint(); // CRITICAL MISSING LINES
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 923, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new GridLayout(1, 0, 0, 0));
JPanel panel = new JPanel();
panel.setBackground(Color.RED);
frame.getContentPane().add(panel);
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
JLabel lblNewLabel = new JLabel("Online Users");
panel.add(lblNewLabel);
JList list = new JList();
list.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
addChatBox();
}
});
list.setModel(new AbstractListModel() {
String[] values = new String[] {"Alpha", "Beta", "Gamma", "Delta", "Epsilon"};
public int getSize() {
return values.length;
}
public Object getElementAt(int index) {
return values[index];
}
});
panel.add(list);
}
}
I chose to revalidate/repaint the entire frame, but it may be possible to have it work while repainting a lesser container. Certainly without the critical lines marked above, it doesn't matter how often you click on the list elements, nothing new will show up. With those lines, every time you click, a new chatbox is added.
Huh... just noticed this. If the red area is considered two separate panels, then they're all the exactly correct size. Have you perhaps accidentally added an extra panel?
I'm trying to make a simple menu for my game. I have 4 buttons in the center and I want to make them a little bit bigger and center them.
The last part worked but I can't seem to call any of my JButtons and do a .setSize / .setPreferedSize(new Dimension()) on it.
public class mainMenu extends JFrame {
private JButton start, highscore, help, stoppen;
public mainMenu() {
super("Master Mind");
maakComponenten();
maakLayout();
toonFrame();
}
private void maakComponenten() {
start = new JButton("Start");
start.setBackground(Color.gray);
highscore = new JButton("Higscores");
help = new JButton("Help");
stoppen = new JButton("Stoppen");
}
private void maakLayout() {
JPanel hoofdmenu = new JPanel();
hoofdmenu.setLayout(new BoxLayout(hoofdmenu, BoxLayout.Y_AXIS ));
hoofdmenu.add(start);
start.setAlignmentX(CENTER_ALIGNMENT);
hoofdmenu.add(highscore);
highscore.setAlignmentX(CENTER_ALIGNMENT);
hoofdmenu.add(help);
help.setAlignmentX(CENTER_ALIGNMENT);
hoofdmenu.add(stoppen);
stoppen.setAlignmentX(CENTER_ALIGNMENT);
super.add(hoofdmenu);
}
private void toonFrame() {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setVisible(true);
setSize(500,500);
}
public static void main(String[] args) {
new mainMenu();
}
}
As an example, to change the size of the "Start" button,
change :
start1 = new JButton("Start");
to
start1 = new JButton("Start") {
{
setSize(150, 75);
setMaximumSize(getSize());
}
};
The problem is that JFrames use BorderLayout by default, which means that your JPanel will naturally fill the space.
Before adding your JPanel, call the following code to change the JFrame's layout to null and use the JPanel's settings instead.
this.setLayout(null);
JPanel hoofdmenu = new JPanel();
hoofdmenu.setBounds(0,0, 400, 100);
Alternatively, you could set the maximum size of the JButtons
Dimension maxSize = new Dimension(100, 100);
start.setMaximumSize(maxSize);
highscore.setMaximumSize(maxSize);
help.setMaximumSize(maxSize);
stoppen.setMaximumSize(maxSize);
Here's another example following behind the previous two - I'm making a soundboard program, and this is actually a sample from it - The JPanel actually is needed, agreeing to the second post.
JFrame frame = new JFrame();
JPanel menuPanel = new JPanel();
JButton Button1 = new JButton("<BUTTON NAME 1>");
Button1.setSize(80, 30);
Button1.setLocation(4, 4);
JButton Button2 = new JButton("<BUTTON NAME 2>");
Button2.setSize(80, 30);
Button2.setLocation(90, 4);
Ah, and another thing - You created the buttons in a different block from the second piece of code. Doing that causes the other blocks to not see it. You need to declare them outside the block so all the blocks can see them.
I've created simple JDialog to gain initial data for my application. Elements (JLabel, JTextField and JButton) are arranged by BoxLayout inside the BorderLayout. (Code at the end). So far it looks like this:
I have two problems:
I would like to center JButton in it's row. I tried startBtn.setAlignmentX(Component.CENTER_ALIGNMENT);, but it doesn't work properly, mess appears.
I want to add some left/right padding to TextField. First solution from this topic works fine, but other elements are moved right left padding value.
Can anybody give a hint how to place it? I'm new to Java and have no idea.
Here's code of my InitDialog class:
public class InitDialog extends JDialog {
JTextField dataTF;
JButton startBtn;
public InitDialog(JFrame owner) {
super(owner, "Rozpocznij test", Dialog.ModalityType.DOCUMENT_MODAL);
initUI();
}
public final void initUI() {
System.out.println("InitDialog::initUI");
JPanel outer = new JPanel(new BorderLayout());
JPanel inner = new JPanel();
outer.setBorder(new EmptyBorder(new Insets(20, 20, 20, 20)));
JLabel msg = new JLabel("<html>Podaj ilości liczb w zestawach testowych<br />(przedzielone średnikiem):");
inner.add(msg);
inner.add(Box.createVerticalStrut(15));
dataTF = new JTextField();
dataTF.setBorder(null);
dataTF.setText("50; 100; 200");
inner.add(dataTF);
inner.add(Box.createVerticalStrut(15));
startBtn = new JButton("Rozpocznij test");
inner.add(startBtn);
inner.setLayout(new BoxLayout(inner, BoxLayout.Y_AXIS));
outer.add(inner);
add(outer);
setSize(300, 180);
//setDefaultCloseOperation(DISPOSE_ON_CLOSE);
addWindowListener(new WindowAdapter() {
#Override public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
setResizable(false);
setLocationRelativeTo(getRootPane());
}
}
BoxLayout alignment is not what you think it is.
To get what you want this is the line you need
msg.setAlignmentX(Component.CENTER_ALIGNMENT);
I'm trying to create a board for a game, i first made a frame then if the user //enters the rows and columns as numbers and pushes the start button, it should remove all //whats on frame and add a panel with a grid layout having buttons everywhere
Here is the code ( Problem is the frame gets cleared and nothing appears)
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Frame extends JFrame implements ActionListener{
private static final long serialVersionUID = 1L;
JButton newButton;
JButton Start;
JTextArea row;
JTextArea col;
JLabel background;
JLabel rows;
JLabel columns;
JLabel Error;
JPanel myPanel;
JCheckBox box;
public Frame()
{
//adding frame
setTitle("DVONN Game");
setSize(1000, 700);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(null);
//making start button
Start = new JButton(new ImageIcon("Start"));
Start.setBounds(500, 30, 300, 300);
Start.setOpaque(true);
Start.addActionListener(this);
//make background
background = new JLabel();
background.setBounds(0, -300, 2000, 1500);
background.setIcon(Color.BLUE));
rows = new JLabel("Enter the rows");
columns = new JLabel("Enter the columns");
rows.setForeground(Color.WHITE);
columns.setForeground(Color.WHITE);
rows.setBounds(10,10,100,30);
columns.setBounds(10,45,105,30);
row = new JTextArea();
col = new JTextArea();
row.setBounds(120,10,100,30);
col.setBounds(120,45,100,30);
Error = new JLabel("Enter numbers plz!");
Error.setBounds(10, 100, 400, 30);
Error.setForeground(Color.RED);
Error.setVisible(true);
box = new JCheckBox("Enable Random Filling");
box.setBounds(10, 200, 150, 20);
box.setVisible(true);
myPanel = new JPanel();
myPanel.setBounds(30, 30, 700, 500);
myPanel.setVisible(true);
newButton = new JButton();
newButton.setOpaque(true);
getContentPane().add(box);
getContentPane().add(rows);
getContentPane().add(columns);
getContentPane().add(row);
getContentPane().add(col);
getContentPane().add(Start);
getContentPane().add(background);
this.validate();
this.repaint();
}
public static void main(String[]args)
{
new Frame();
}
//adding actions for start button
public void actionPerformed(ActionEvent e) {
boolean flag = true;
String r1 = row.getText();
String c1 = col.getText();
int x = 0,y = 0;
try{
x = Integer.parseInt(r1);
y = Integer.parseInt(c1);
} catch(NumberFormatException l) {
flag = false;
}
int size = x * y;
if (flag == true) {
this.getContentPane().removeAll();
this.validate();
this.repaint();
myPanel.setLayout(new GridLayout(x, y));
while(size != 0)
{
myPanel.add(newButton);
size --;
}
this.getContentPane().add(myPanel);
} else {
this.getContentPane().add(Error);
}
}
}
There are several issues with this code
Is it really needed to post that much code. A simple UI with one button to press, and then another component which should appear would be sufficient for an SSCCE
The use of null layout's. Please learn to use LayoutManagers
Each Swing component can only be contained once in the hierarchy. So this loop is useless since you add the same component over and over again (not to mention that a negative size would result in an endless loop)
while(size != 0){
myPanel.add(newButton);
size --;
}
Have you tried debugging to see whether size is actually >0. Since you silently ignore ParseExceptions you might end up with a size of 0 which will clean the content pane and add nothing
Then do as goldilocks suggests and call validate after adding the components. See the javadoc of the Container#add method
This method changes layout-related information, and therefore, invalidates the component hierarchy. If the container has already been displayed, the hierarchy must be validated thereafter in order to display the added component.
Call validate() and repaint() after the new elements have been added instead of after the old ones have been removed.
You don't need to be calling setVisible() on individual components, call it after pack() on the Frame itself, and you shouldn't use validate() and repaint() in the constructor. Ie, replace those with:
pack();
setVisible(true);
or you can do that on the object after the constructor is called.
Try to replace
public static void main(String[]args)
{
new Frame();
}
by
public static void main(String[]args)
{
new Frame().setVisible(true);
}
Remove the call to this.setVisible in the constructor and make this your main method.
public static void main(String[] args) {
final Frame fr = new Frame();
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
fr.setVisible(true);
}
});
}
This will make sure that the frame elements will be in place before it becomes visible.