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Updating a components position while code is running?

I am using Eclipse WindowBuilder to build a GUI for my Java program. I am currently stuck as I have created a button and I have give the X and Y locations different variables. These variables change in a 'While' loop when the button is clicked and sends out an event.
I have tried looking at multi-threading. However I don't think this is the most viable option. Also if I did multi-thread I don't know which bit of the code I would have to put in the separate thread.
New button = Button button(X, Y, 100,100);
I am trying to increase the x and Y coords

Awt and Swing are not thread safe so, if you are trying to update a UI in the same thread you will have the "application freeze" behavior and the button will not change it's position if you click on it several times. You could disable the button meanwhile the loop is being executed and before starting the loop check that the button is not disabled. For example:
walkerButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
walkerButtonActionPerformed(evt);
}
});
private void walkerButtonActionPerformed(java.awt.event.ActionEvent evt) {
// if walker button is disabled exit the method
if (!walkerButton.isEnabled()) {
return;
}
// Disable the button before starting the loop
walkerButton.setEnabled(false);
int steps = 20;
int stepDistance = 2;
while (steps > 0) {
// Set the walker button new location
int x = walkerButton.getX() + stepDistance;
int y = walkerButton.getY() + stepDistance;
walkerButton.setLocation(x, y);
steps--;
}
// Enable the button after the loop execution
walkerButton.setEnabled(true);
}
Read also:
Java awt threads issue
Multithreading in Swing

Which button was clicked in Java?

I'm working (failing pretty bad so far tbh) on a battleship game for my high school Java programming class. So far I have the game board for both the computer and the player and I have generated the ships for the computer and made sure the player can sink them. Both of the boards have a grid layout, and each of them is assigned to a 2-D array for both the player and the computer and is part of the specific Grid Layout (to be honest I don't really understand a lot of the code because it was supplied by our teacher, so I can't really tell which parts are relevant and which aren't - which is also why I am not posting any of my code).
What I want to do now is let the Player place their ships by letting them pick a starting place by clicking on the board.
inside of a for loop
1: a button in buttonsPlayer is clicked
2: when a button is clicked, the two coordinates are calculated and stored as x, y coordinates
3: a ship is generated with the starting coordinates of x, y
I know how to generate a ship with random x and y starting coordinates as I have done that before. Is there a way to get a button's number in an array after clicking on a button?
(I did read through like 5 other threads on here that seemed to ask the same question, but I don't really get any of the answers)

You could create a class that extends JButton and adds more functionality to a JButton like so:
public class BoardPiece extends JButton{
private int x,y;
//rest of class including getters and setters
}
This will bring all the functionality of JButton along with it and you can add in essentially meta-data about each square.
Then in your event listener you would be able to just call .getX() and .getY() like so:
boardPiece.addActionListener((e)->{
BoardPiece clicked = (BoardPiece)e.getSource();
int x = clicked.getX();
// and so on
});

A JButton has an 'action command' which allows you to put information in it to distinquish it from other buttons.
using
JButton.setActionCommand
JButton.getActionCommand
So if you encode the coordinates of that button in that string, in your actionListener you can
JButton b = (JButton) eventListener.getSource();
and
String cmd = b.getActionCommand();
and then process that cmd string to figure out where on the board you are.

You can give a JButton an ActionCommand, e.g.
JButton button1 = new JButton("Button 1");
button1.setActionCommand("Button1id");`
Then if you implement an ActionListener to listen for the buttonpress, you can write code like
#Override
public void actionPerformed(ActionEvent ae) {
String buttonid = ae.getActionCommand();
}
By checking the value of buttonid, you will know which button was pressed.

Trying to animate a die roll in Java

I'm attempting to "animate" a die roll in Java. I currently have an icon (called "diceImage") set up that, when a button is clicked (called "diceRoll"), updates to a new random image of a die face. What I would like to do is have it change image (to a random die face) numerous times over a couple of seconds before stopping on a final image.
The problem I have is not with generating a random number, or rolling it numerous times, it's with the updating the image numerous times within a loop. The code below, which rolls the die 10 times is what I have so far:
private void diceRollActionPerformed(java.awt.event.ActionEvent evt) {
for (int i = 1; i <= 10; i++) {
rollDice();
pause(100);
}
}
This links to the following two methods (the first of which generates the random number, and sets the icon image):
private void rollDice() {
Random r = new Random();
int randomNumber = r.nextInt(6) + 1;
diceImage.setIcon(new javax.swing.ImageIcon(getClass().getResource("/Game/Images/Dice " + randomNumber + ".png")));
}
The method below is "supposed" to pause the programme briefly between updating the image (this was taken from a programming course I was on where we had to animate an image of a car moving across the screen):
private void pause(int sleepTime) {
try {
Thread.sleep(sleepTime);
} catch (InterruptedException e) {
System.exit(-1);
}
}
All this programme seems to do is pause and then print the final dice roll. It doesn't show any of the "intermediate" faces. Does anyone have any ideas on why this isn't working?
Any help is greatly appreciated.

This question is asked several times a day. If you sleep in the event dispatch thread, you're preventing it from doing its job: react to events and repaint the screen.
Your animation should be done in another thread. Read the tutorial about concurrency in Swing, and use a Swing Timer.

The pause() you are using is when u need to animate moving stuff like a car for example , but just changing the icon of a JLabel which is the dice here doesn't need pause ( unless you just want it to be delayed a bit) ...
but anyways , to solve your issue , you need to call repaint() on that JLabel or updateGraphics(). Setting the Icon for the JLabel doesn't make the new Icon get displayed , you just need to repaint() it .
of course like JB Nizet said , for the app not to hang you need to call repaint on a new Thread .Thought you have to learn how to use Thread well cuz it can be very tricky at times .
good luck

Making moving motion with labels using threads in java

I'm having a problem I'm making a pool game and I need the ballos to react when I simulate a hit, the program works like this, you click the direction and power to hit the ball and the click go, the go button is in the GUI class where my labels are created, the button calls a method from my main class that recieves the parameter and then with a while in it, changes the X and Y of the ball till the power is reduced to 0 and then stops, the code is working, but the ball moves until the while stops. So the while works and when the power int is 0 the while goes out and then the new X,Y are painted.
This is the funcion that the button calls, the button sends all the parameters
public void golpe(int pbola, int pvelocidad, String pdireccion, JLabel[] listalabels) throws InterruptedException{
listabolas[pbola].setVelocidad(pvelocidad);
listabolas[pbola].setDireccion(pdireccion);
while (listabolas[pbola].getVelocidad() > 0) {
moverBola(pbola, listalabels);
//System.out.println(listabolas[pbola].getPosX());
//System.out.println(listabolas[pbola].getPosY());
Thread.sleep(500);
//This line is supposed to change the X and Y of the object over and over
//but only does it till the end
listalabels[pbola].setLocation(listabolas[pbola].getPosX(), listabolas[pbola].getPosY());
}
}
Here is the function moverbola(), only copied one "if" so that the code doesn't look to big
private void moverBola(int pbola, JLabel[] listalabels) {
if (listabolas[pbola].getDireccion().equals("SE")) {
int pposX = listabolas[pbola].getPosX();
listabolas[pbola].setPosX(pposX + 1);
int pposY = listabolas[pbola].getPosY();
listabolas[pbola].setPosY(pposY + 1);
}

Swing is a single threaded framework. That is, all interactions with UI are expected to occur from within a single thread, known as the Event Dispatching Thread.
Any action that blocks this thread, will prevent the EDT from updating the screen or processing any new events.
Your while-loop is blocking the EDT, preventing it from painting any updates until after the while-loop is completed.
Take a look at Concurrency in Swing for more details.
There are a number of approaches you could take...
You could use a Thread, but this causes problems as you need to ensure that any changes you make to the UI are re-synced back to the EDT and this can become messy...
For example
You could use a javax.swing.Timer that ticks at a regular interval and you would update any internal parameters from within it's assigned ActionListener. Because the tick events occur within the EDT, it is save to update the screen from within it.
For example
You could use a SwingWorker to run the task in the background. It has methods for re-syncing updates back to the EDT, but might be a little over kill for your purposes...
Updated with a possible Timer example
Caveat- It is very hard to produce a reasonable example with only a code snippet, but, something like this might work
public void golpe(final int pbola, int pvelocidad, String pdireccion, final JLabel[] listalabels) throws InterruptedException{
listabolas[pbola].setVelocidad(pvelocidad);
listabolas[pbola].setDireccion(pdireccion);
Timer timer = new Timer(40, new ActionListener() {
public void actionPerformed(ActionEvent evt) {
if (listabolas[pbola].getVelocidad() == 0) {
((Timer)evt.getSource()).stop();
} else {
moverBola(pbola, listalabels);
}
}
});
timer.setRepeats(true);
timer.start();
}

Java Swing mouseDragged callback speed

I have a question regarding the callback speed of the mouseDragged message of the MouseMotionListener in Java Swing. This post is sort of related but it's not entirely the same so I started a question of my own.
I'm making a small in-house application with no eye on commercial distribution that is basically a digitalized TCG (Trading Card Game) emulator. For any of you familiar with MtG (Magic the Gathering), you might've heard from such a similar program. I'm trying to create something that looks sort of like this, but less fancy.
My GUI consists of a JFrame with menu and then some panels containing various buttons and labels, but I'll only go over the relevent parts to explain my problem.
In essence, I'm using a vertical split JSplitPane with a JPanel on the left, with in that a JScrollPane with a JList in it, which represents at any time the cards in your hand that you can play. On the right side of the split, I have a JLayeredPane with a background image in the DEFAULT_LAYER (subclass of JPanel that overrides the draw function to add an image) and, on various layers above the PALETTE_LAYER, I display the cards that are in play (gathered in an ArrayList) by means of custom CardPanels (another subclass of JPanel that illustrates a card). The entire JLayeredPane is thus a representation of the table in front of you with all the cards you've already played.
I first started by adding a MouseListener and a MouseMotionListener to the JLayeredPane to pick up events, allowing me to register a mouse press, check if this was above a card, then use the mouse dragged event to move the card around and finally mouse release to place it back . This all works perfectly fine and if I add logging information I can see the mouseDragged callback function is called often, allowing for a visually fast dragging motion without lag.
Today I decided to add functionality to allow the user to drag a card from his hand to the "table" (instead of double clicking on the card in the JList), so I added the appropriate listeners to the JList along with filling in some functions like MousePressed and MouseReleased. On a mouse press, I check what card from the list was clicked, I lock the list, create a custom CardPanel (but don't add it anywhere yet, I just allocate and initiate it!) and set a flag. In mouse dragged, I check if this flag is set. If it is, I check where the cursor is. If it is anywhere above the JLayeredPane, I add the CardPanel to the DRAG_LAYER and set another flag. If this second flag is set in successive calls to mouse dragged, I don't add the panel again but I just change the location. This functionality is practically the same as the one in my previous mouse dragged callback. On mouse release, I unlock the list and add the CardPanel on the correct layer in the JLayeredPane.
Everything is working as intended so I'm pretty sure my code is okay, but there is just one slight issue:
When dragging a card from the list to the layered pane (instead of from the layered pane to the layered pane), I notice the mouseDragged callback is called at a pretty low frequency by the JList (approx 10 times per second), introducing some visually disturbing lag (compared to approx 30 times per second in the first case of dragging).
I'm going to add some code snippets as to clarify my problem but I'm afraid adding all the code to allow you to run it yourself would be serious overkill.
The main question in this post is: does anybody know why the mouseDragged is called faster by one MouseMotionListener than by another MouseMotionListener? The listener to the JLayeredPane component makes fast successive calls, the listener to the JList calls significantly slower.
Note: I'm developing in Netbeans and I'm using the built-in graphical Swing Interface Builder. I'm using a JFrame form as my main class.
public class MyFrame extends JFrame{
...
protected JLayeredPane layeredPane;
protected JList cardsInHandList;
...
...
protected ArrayList<String> cardsInHand;
...
private void attachListeners(){
layeredPane.addMouseListener(new MouseAdapter(){
public void MousePressed(MouseEvent e){
// set a flag, start a drag
}
public void MouseReleased(MouseEvent e){
// unset a flag, stop a drag
}
});
layeredPane.addMouseMotionListener(new MouseMotionAdapter(){
public void MouseDragged(MouseEvent e){
// drag the card around
// gets called a lot!
// actual code:
if (e.getButton() == MouseEvent.BUTTON1) {
if (!dragging) return; // the flag
int x = e.getX() - 10;
int y = e.getY() - 10;
// snap to grid
x /= GRIDX;
x *= GRIDX;
y /= GRIDY;
y *= GRIDY;
// redraw the card at its new location
draggedCard.setLocation(x, y);
}
}
});
cardsInHandList.addMouseListener(new MouseAdapter(){
public void MousePressed(MouseEvent e){
// set a flag, start a drag
}
public void MouseReleased(MouseEvent e){
// unset a flag, stop a drag
}
});
cardsInHandList.addMouseMotionListener(new MouseMotionAdapter(){
public void MouseDragged(MouseEvent evt){
// check cursor location, drag if within bounds of layeredPane
// gets called a whole lot less!! _Why?_
// actual code:
if (!draggingFromHand) return; // the flag
// check location of cursor with own method (contains() didn't work for me)
if (isCursorAtPointAboveLayeredPane(evt.getLocationOnScreen())) {
// calculate where and snap to grid
int x = (int) (evt.getLocationOnScreen().getX() - layeredPane.getLocationOnScreen().getX())-10;
int y = (int) (evt.getLocationOnScreen().getY() - layeredPane.getLocationOnScreen().getY())-10;
// snap to grid
x /= GRIDX;
x *= GRIDX;
y /= GRIDY;
y *= GRIDY;
if(!draggingFromHandCardPanelAdded){
layeredPane.add(draggingFromHandCardPanel, JLayeredPane.DRAG_LAYER);
draggingFromHandCardPanelAdded = true;
} else {
draggingFromHandCardPanel.setLocation(x,y);
}
}
}
});
}
I'll try to build a short runnable example reproducing the problem and then attach the code somewhere but right now I got to skoot.
Thanks in advance
PS: I am aware that there is another way to drag in Java, involving TransferHandlers and all that but it just seems like too much hassle and it isn't an actual answer to my question of how come the one callback seems to be called more than the other, so please don't tell me to use that instead.

Once you drag outside the list, Java start generating synthetic mouse events for the list, which might be the cause. See the javadoc for JComponent#setAutoscrolls(boolean).
You might get better results using a global event listener, see
http://tips4java.wordpress.com/2009/08/30/global-event-listeners/