Develop Reference

GUI doesn't respond to mouse click and drag while running from another class

I have 2 classes: TestingPanel and SnipIt.
SnipIt is used for selecting an area on the screen.
TestingPanel is the main frame, containing a button to run method Snip() and receiving the return values.
If I test the SnipIt class separately, it works. But if I create a SnipIt object and run method Snip() from TestingPanel class, it doesn't work. The GUI just freezes and doesn't respond to mouse click or drag event. I guess something block the thread handle the mouse events but I'm not sure.
I have been stuck for couple hours and still don't know what caused the issue. Please help.
TestingPanel
package Testing;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class TestingPanel {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
TestingPanel window = new TestingPanel();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public TestingPanel() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 200, 160);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JButton btnSnip = new JButton("Snip");
btnSnip.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
getSelectionSize();
}
});
btnSnip.setBounds(47, 87, 89, 23);
frame.getContentPane().add(btnSnip);
}
private void getSelectionSize() {
int[] size = new int[4];
Thread worker = new Thread(new Runnable() {
public void run() {
SnipIt sn = new SnipIt();
sn.snip();
while(!sn.complete) {
try {
Thread.sleep(800);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
size[0] = sn.returnSize()[0];
size[1] = sn.returnSize()[1];
size[2] = sn.returnSize()[2];
size[3] = sn.returnSize()[3];
}
});
worker.start();
try {
worker.join();
} catch (InterruptedException e1) {
e1.printStackTrace();
}
System.out.println(size[0] + " " + size[1] + " " + size[2] + " " + size[3]);
}
}
SnipIt
package Testing;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Area;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class SnipIt {
private int recX = 0;
private int recY = 0;
private int recWidth = 0;
private int recHeight = 0;
public boolean complete = false;
/*
public static void main(String [] args)
{
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
SnipIt s = new SnipIt();
s.snip();
}
});
}
*/
public void snip() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame();
frame.setUndecorated(true);
frame.setBackground(new Color(0, 0, 0, 0));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new SnipItPane());
frame.setBounds(getVirtualBounds());
frame.setVisible(true);
}
#SuppressWarnings("serial")
public class SnipItPane extends JPanel {
private Point mouseAnchor;
private Point dragPoint;
private SelectionPane selectionPane;
private ControlPane controlPane;
public SnipItPane() {
setOpaque(false);
setLayout(null);
selectionPane = new SelectionPane();
controlPane = new ControlPane();
add(selectionPane);
add(controlPane);
MouseAdapter adapter = new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
mouseAnchor = e.getPoint();
dragPoint = null;
selectionPane.setLocation(mouseAnchor);
selectionPane.setSize(0, 0);
controlPane.setLocation(mouseAnchor);
controlPane.setSize(0, 0);
}
#Override
public void mouseDragged(MouseEvent e) {
dragPoint = e.getPoint();
int width = dragPoint.x - mouseAnchor.x;
int height = dragPoint.y - mouseAnchor.y;
int x = mouseAnchor.x;
int y = mouseAnchor.y;
if (width < 0) {
x = dragPoint.x;
width *= -1;
}
if (height < 0) {
y = dragPoint.y;
height *= -1;
}
selectionPane.setBounds(x, y, width, height);
selectionPane.revalidate();
int controlY = y + height + 5;
controlPane.setBounds(x, controlY, width, 25);
controlPane.revalidate();
repaint();
}
};
addMouseListener(adapter);
addMouseMotionListener(adapter);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Rectangle bounds = new Rectangle(0, 0, getWidth(), getHeight());
Area area = new Area(bounds);
area.subtract(new Area(selectionPane.getBounds()));
g2d.setColor(new Color(102, 102, 102, 80));
g2d.fill(area);
}
}
#SuppressWarnings("serial")
public class ControlPane extends JPanel {
private JButton btnClose;
public ControlPane() {
setOpaque(false);
btnClose = new JButton("Save");
setLayout(new BorderLayout());
this.add(btnClose, BorderLayout.NORTH);
btnClose.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
complete = true;
SwingUtilities.getWindowAncestor(ControlPane.this).dispose();
}
});
}
}
#SuppressWarnings("serial")
public class SelectionPane extends JPanel {
public SelectionPane() {
setOpaque(false);
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
recX = getX();
recY = getY();
recWidth = getWidth();
recHeight = getHeight();
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
float strokeWidth = 1.0f;
float dash1[] = {10.0f};
BasicStroke dashed =
new BasicStroke(strokeWidth,
BasicStroke.CAP_BUTT,
BasicStroke.JOIN_MITER,
10.0f, dash1, 0.0f);
g2d.setColor(Color.BLACK);
g2d.setStroke(dashed);
g2d.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
g2d.dispose();
}
}
public static Rectangle getVirtualBounds() {
Rectangle bounds = new Rectangle(0, 0, 0, 0);
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice lstGDs[] = ge.getScreenDevices();
for (GraphicsDevice gd : lstGDs) {
bounds.add(gd.getDefaultConfiguration().getBounds());
}
return bounds;
}
public int[] returnSize() {
int[] size = new int[4];
size[0] = recX;
size[1] = recY;
size[2] = recWidth;
size[3] = recHeight;
return size;
}
}

You're running the Snipit application in a background thread and then freezing that thread with Thread.sleep and a while true block, something guaranteed to freeze the GUI. Read Lesson: Concurrency in Swing and then be sure to always run Swing applications on the single Swing event thread, and do any long running or sleeping code in a background thread.
Possible solutions to your issue:
Make the Snipit window an undecorated modal dialog. This way program flow from the calling code stops when the dialog is visible and resumes when no longer visible.
Or Make the Snipit window JFrame an instance field of the class and allow outside classes to add listeners to it so that they will be notified when it closes.
e.g.,
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dialog.ModalityType;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Area;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class TestSnipit {
private static void createAndShowGui() {
boolean runTest = true;
if (runTest) {
TestingPanel.main(null);
} else {
SnipIt.main(null);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class TestingPanel {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
TestingPanel window = new TestingPanel();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public TestingPanel() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 200, 160);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JButton btnSnip = new JButton("Snip");
btnSnip.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
getSelectionSize();
}
});
btnSnip.setBounds(47, 87, 89, 23);
frame.getContentPane().add(btnSnip);
}
private void getSelectionSize() {
int[] size = new int[4];
// !!
SnipIt sn = new SnipIt();
sn.snip(frame);
// Thread worker = new Thread(new Runnable() {
// public void run() {
// SnipIt sn = new SnipIt();
// sn.snip();
//
// while (!sn.complete) {
// try {
// Thread.sleep(800);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
// }
//
size[0] = sn.returnSize()[0];
size[1] = sn.returnSize()[1];
size[2] = sn.returnSize()[2];
size[3] = sn.returnSize()[3];
// }
// });
//
// worker.start();
//
// try {
// worker.join();
// } catch (InterruptedException e1) {
// e1.printStackTrace();
// }
System.out.println(size[0] + " " + size[1] + " " + size[2] + " " + size[3]);
}
}
class SnipIt {
private int recX = 0;
private int recY = 0;
private int recWidth = 0;
private int recHeight = 0;
public boolean complete = false;
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
SnipIt s = new SnipIt();
s.snip(null); // !!
}
});
}
public void snip(Window owner) { // !!
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
// JFrame frame = new JFrame();
JDialog frame = new JDialog(owner, null, ModalityType.APPLICATION_MODAL); // !!
frame.setUndecorated(true);
frame.setBackground(new Color(0, 0, 0, 0));
// frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); // !!
frame.setLayout(new BorderLayout());
frame.add(new SnipItPane());
frame.setBounds(getVirtualBounds());
frame.setVisible(true);
}
#SuppressWarnings("serial")
public class SnipItPane extends JPanel {
private Point mouseAnchor;
private Point dragPoint;
private SelectionPane selectionPane;
private ControlPane controlPane;
public SnipItPane() {
setOpaque(false);
setLayout(null);
selectionPane = new SelectionPane();
controlPane = new ControlPane();
add(selectionPane);
add(controlPane);
MouseAdapter adapter = new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
mouseAnchor = e.getPoint();
dragPoint = null;
selectionPane.setLocation(mouseAnchor);
selectionPane.setSize(0, 0);
controlPane.setLocation(mouseAnchor);
controlPane.setSize(0, 0);
}
#Override
public void mouseDragged(MouseEvent e) {
dragPoint = e.getPoint();
int width = dragPoint.x - mouseAnchor.x;
int height = dragPoint.y - mouseAnchor.y;
int x = mouseAnchor.x;
int y = mouseAnchor.y;
if (width < 0) {
x = dragPoint.x;
width *= -1;
}
if (height < 0) {
y = dragPoint.y;
height *= -1;
}
selectionPane.setBounds(x, y, width, height);
selectionPane.revalidate();
int controlY = y + height + 5;
controlPane.setBounds(x, controlY, width, 25);
controlPane.revalidate();
repaint();
}
};
addMouseListener(adapter);
addMouseMotionListener(adapter);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Rectangle bounds = new Rectangle(0, 0, getWidth(), getHeight());
Area area = new Area(bounds);
area.subtract(new Area(selectionPane.getBounds()));
g2d.setColor(new Color(102, 102, 102, 80));
g2d.fill(area);
}
}
#SuppressWarnings("serial")
public class ControlPane extends JPanel {
private JButton btnClose;
public ControlPane() {
setOpaque(false);
btnClose = new JButton("Save");
setLayout(new BorderLayout());
this.add(btnClose, BorderLayout.NORTH);
btnClose.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
complete = true;
SwingUtilities.getWindowAncestor(ControlPane.this).dispose();
}
});
}
}
#SuppressWarnings("serial")
public class SelectionPane extends JPanel {
public SelectionPane() {
setOpaque(false);
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
recX = getX();
recY = getY();
recWidth = getWidth();
recHeight = getHeight();
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
float strokeWidth = 1.0f;
float dash1[] = { 10.0f };
BasicStroke dashed = new BasicStroke(strokeWidth, BasicStroke.CAP_BUTT,
BasicStroke.JOIN_MITER, 10.0f, dash1, 0.0f);
g2d.setColor(Color.BLACK);
g2d.setStroke(dashed);
g2d.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
g2d.dispose();
}
}
public static Rectangle getVirtualBounds() {
Rectangle bounds = new Rectangle(0, 0, 0, 0);
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice lstGDs[] = ge.getScreenDevices();
for (GraphicsDevice gd : lstGDs) {
bounds.add(gd.getDefaultConfiguration().getBounds());
}
return bounds;
}
public int[] returnSize() {
int[] size = new int[4];
size[0] = recX;
size[1] = recY;
size[2] = recWidth;
size[3] = recHeight;
return size;
}
}
A side issue unrelated to your initial problem is your use of null layougs. While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.

Java Game - Not Painting until After Thread.sleep

I'm currently coding a game and I'm trying to have it where if you click on the first button on the front page, it shows a transition screen for 5 seconds, and then shows the game. Here is my code:
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ForgottenMain extends JPanel implements KeyListener,MouseListener{
/**
*
*/
private static final int TIMER_DELAY = 35;
private static final long serialVersionUID = -4926251405849574401L;
public static BufferedImage attic,flashlight,player,killer,frontpage,transition;
public static boolean onFrontPage,up,down,left,right,inAttic,onTransition;
public static int px,py,kx,ky;
public static Thread th1,th2;
public static JFrame frame = new JFrame("Forgotten");
public static void main(String[] args){
onFrontPage = true;
px = 600;
py = 400;
ForgottenMain fm = new ForgottenMain();
frame.add(fm);
frame.setSize(1200,800);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setResizable(false);
frame.setVisible(true);
frame.add(new ForgottenMain());
fm.repaint();
}
public ForgottenMain(){
init();
}
public void init(){
setSize(1200,800);
setVisible(true);
frame.addKeyListener(this);
frame.addMouseListener(this);
try{
player = ImageIO.read(new File("char.png"));
flashlight = ImageIO.read(new File("flashlightimage.png"));
attic = ImageIO.read(new File("attic.png"));
killer = ImageIO.read(new File("killer.png"));
frontpage = ImageIO.read(new File("frontpageoutline.png"));
transition = ImageIO.read(new File("transitionoutline.png"));
} catch (Exception e){
e.printStackTrace();
}
// Gameloop
new javax.swing.Timer(TIMER_DELAY, new ActionListener() {
public void actionPerformed(ActionEvent e) {
gameLoop();
}
}).start();
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
int fx = px - 1033;
int fy = py - 635;
kx = 500;
ky = 500;
// Removes the flickering of the images
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// Resets the screen to make sure that it only shows the character once
g2.clearRect(0, 0, 1200, 800);
// Draws the background attic
if(inAttic == true){
System.out.println("Drawing attic");
g2.drawImage(attic,0,0,this);
}
if(onFrontPage == true){
g2.drawImage(frontpage, 0, 0, this);
}
// Draws the player
if(onFrontPage == false && onTransition == false){
g2.drawImage(player, px, py, this);
// Draws the Serial Killer
g2.drawImage(killer, kx, ky, this);
// Draws the flashlight
g2.drawImage(flashlight, fx, fy, this);
}
if(onTransition == true){
g2.drawImage(transition, 0, 0, this);
System.out.println("Drawing Transition");
try {
System.out.println("Sleeping for 5 Seconds");
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Done sleeping.");
onTransition = false;
inAttic = true;
}
System.out.println(px + " " + py);
}
public void gameLoop(){
}
#Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("MouseLocation: " + arg0.getX() + ", " + arg0.getY());
}
#Override
public void mouseEntered(MouseEvent arg0) {
}
#Override
public void mouseExited(MouseEvent arg0) {
}
#Override
public void mousePressed(MouseEvent e) {
if(e.getX() > 499 && e.getY() > 343 && e.getX() < 748 && e.getY() < 391){
onFrontPage = false;
onTransition = true;
repaint();
}
}
#Override
public void mouseReleased(MouseEvent arg0) {
}
My problem is, in the paint method, in the if statement testing if onTransition is equal to true, it's supposed to draw the image transition, wait 5 seconds, and then draw the game.
However, right now it's waiting 5 seconds, then quickly drawing the transition screen and then the game. For some reason they are out of order.
How can I fix this? I have tried alternate methods of waiting 5 seconds, for example using currentTimeMillis();, but have the same outcome.

You have some serious problems:
you add panels twice
you have some circuitous use of frame etc
Beyond that the following will work: you have to realize that you don't have control of the painting process. Therefore you should launch a new thread to count the sleep and let the paint do its work uninhibited.
(Also I have removed static - if you really want them you can try to put them back in - if it doesnt work you just throw them out)
class F extends JPanel implements MouseListener{
/**
*
*/
private static final int TIMER_DELAY = 35;
private static final long serialVersionUID = -4926251405849574401L;
public BufferedImage attic,flashlight,player,killer,frontpage,transition;
public boolean onFrontPage,up,down,left,right,inAttic,onTransition;
public int px,py,kx,ky;
public static Thread th1,th2;
public JFrame frame = new JFrame("Forgotten");
public F(){
init();
}
public void init(){
setSize(1200,800);
setVisible(true);
onFrontPage = true;
px = 600;
py = 400;
frame.add(this);
frame.setSize(1200,800);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setResizable(false);
frame.setVisible(true);
frame.addMouseListener(this);
try{
// player = ImageIO.read(new File("char.png"));
// flashlight = ImageIO.read(new File("flashlightimage.png"));
// attic = ImageIO.read(new File("attic.png"));
// killer = ImageIO.read(new File("killer.png"));
attic = ImageIO.read(new File(...));
frontpage = ImageIO.read(new File(...));
transition = ImageIO.read(new File(...));
} catch (Exception e){
e.printStackTrace();
}
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
int fx = px - 1033;
int fy = py - 635;
kx = 500;
ky = 500;
// Removes the flickering of the images
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// Resets the screen to make sure that it only shows the character once
g2.clearRect(0, 0, 1200, 800);
// Draws the background attic
if(inAttic == true){
System.out.println("Drawing attic"+System.currentTimeMillis());
g2.drawImage(attic,0,0,this);
}
if(onFrontPage == true){
g2.drawImage(frontpage, 0, 0, this);
}
// Draws the player
if(onFrontPage == false && onTransition == false){
g2.drawImage(player, px, py, this);
// Draws the Serial Killer
g2.drawImage(killer, kx, ky, this);
// Draws the flashlight
g2.drawImage(flashlight, fx, fy, this);
}
if(onTransition == true){
Graphics gt=transition.getGraphics();
gt.setColor(Color.red);
gt.drawString("xxx"+System.currentTimeMillis(), 10, 100);
g2.drawImage(transition, 0, 0, this);
onTransition = false;
inAttic = true;
}
System.out.println(px + " " + py);
}
public void gameLoop(){
}
#Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("MouseLocation: " + arg0.getX() + ", " + arg0.getY());
}
#Override
public void mouseEntered(MouseEvent arg0) {
}
#Override
public void mouseExited(MouseEvent arg0) {
}
#Override
public void mousePressed(MouseEvent e) {
onFrontPage = false;
onTransition = true;
Thread th=new Thread() {
public void run() {
repaint();
System.out.println("Drawing Transition"+System.currentTimeMillis());
try {
System.out.println("Sleeping for 5 Seconds"+System.currentTimeMillis());
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Done sleeping."+System.currentTimeMillis());
repaint();
}
};
th.start();
}
#Override
public void mouseReleased(MouseEvent arg0) {
}
}

Why JLabels disappeare?

Task: There are 2 labels which connect with each other by line, user must be able to move each of the labels with mouse and the connection between lables must move accordingly.
Here is my code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
class BackgroundJPanel extends JPanel {
BackgroundJPanel() {
this.setBounds(0, 0, 200, 200);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.orange);
g.fillRect(0, 0, 198, 198);
g.setColor(Color.black);
g.drawRect(0, 0, 198, 198);
}
}
class LinkJPanel extends JPanel {
JLabel[] labels = null;
LinkJPanel(JLabel[] labelsIn) {
labels = labelsIn;
this.setBounds(0, 0, 200, 200);
this.setOpaque(false);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawLine(labels[0].getX(), labels[0].getY(),
labels[1].getX(), labels[1].getY());
}
}
class LabelJPanel extends JPanel {
AllPanel allPanel = null;
LabelJPanel(AllPanel allPanelIn) {
allPanel = allPanelIn;
this.setOpaque(false);
JLabel[] labels = allPanel.labels;
labels[0] = new JLabel("11");
this.add(labels[0]);
labels[1] = new JLabel("22");
this.add(labels[1]);
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
this.addMouseMotionListener(myMouseAdapter);
this.addMouseListener(myMouseAdapter);
}
class MyMouseAdapter extends MouseAdapter {
JLabel labelToMove = null;
int startDeltaX = -1;
int startDeltaY = -1;
JLabel whichLabel(MouseEvent e) {
for (JLabel label : allPanel.labels) {
int deltaX = e.getX() - label.getX();
int deltaY = e.getY() - label.getY();
if ((deltaX >= 0)
&& (deltaX < label.getPreferredSize().width)
&& (deltaY >= 0)
&& (deltaY < label.getPreferredSize().height)) {
return label;
}
}
return null;
}
#Override
public void mousePressed(MouseEvent e) {
labelToMove = whichLabel(e);
if (labelToMove != null) {
startDeltaX = labelToMove.getX() - e.getX();
startDeltaY = labelToMove.getY() - e.getY();
}
}
#Override
public void mouseDragged(MouseEvent e) {
if (labelToMove != null) {
updateLocation(e);
}
}
#Override
public void mouseReleased(MouseEvent e) {
labelToMove = null;
}
public void updateLocation(MouseEvent e) {
int newXCoord = e.getX() + startDeltaX;
int newYCoord = e.getY() + startDeltaY;
labelToMove.setBounds(newXCoord, newYCoord,
labelToMove.getPreferredSize().width,
labelToMove.getPreferredSize().height);
//allPanel.backgroundJPanel.repaint();
allPanel.linkJPanel.repaint();
}
}
}
class AllPanel extends JPanel {
BackgroundJPanel backgroundJPanel = null;
LinkJPanel linkJPanel = null;
LabelJPanel labelJPanel = null;
JLabel[] labels = null;
AllPanel() {
this.setLayout(new BorderLayout());
this.setPreferredSize(new Dimension(200, 200));
labels = new JLabel[2];
backgroundJPanel = new BackgroundJPanel();
this.add(backgroundJPanel);
linkJPanel = new LinkJPanel(labels);
this.add(linkJPanel);
labelJPanel = new LabelJPanel(this);
this.add(labelJPanel);
this.setComponentZOrder(backgroundJPanel, 2);
this.setComponentZOrder(linkJPanel, 1);
this.setComponentZOrder(labelJPanel, 0);
}
}
class MyFrame extends JFrame {
MyFrame() {
this.setTitle("Test");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(new AllPanel());
this.pack();
this.setVisible(true);
this.setResizable(false);
}
}
public class Test {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new MyFrame();
}
});
}
}
I use 3 JPanel - one for background, one for draw connection line, one for drawing 2 labels. JPanel for drawing labels has MouseMotion and Mouse listeners. When some mouse action appears code check which one of the label must be move and then change that label coordinates and repaint JPanel with connection line.
All work fine until I try also repaint JPanel with background. If I uncomment the line
//allPanel.backgroundJPanel.repaint();
after action JLabels and line start disappeare.
Can someone explane why this happen?

Repaint() not calling paint() in Java

Let me start off by saying I know I've violated some basic Java principles in this messy code, but I'm desperately trying to finish a program by Tuesday for a social science experiment, and I don't know Java, so I'm basically just fumbling through it for now.
With that disclaimer out of the way, I have a separate program working where a circle is moving around the screen and the user must click on it. It works fine when its in its own separate class file, but when I add the code to my main program, it's no longer working. I don't even really understand why repaint() calls my paint() function — as far as I'm concerned, it's magic, but I've noticed that repaint() calls paint() in my test program, but not in the more complicated actual program, and I assume that's why the circle is no longer painting on my program.
Entire code is below:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import javax.swing.*;
import java.awt.event.*;
import java.awt.geom.Ellipse2D;
import java.io.FileReader;
import java.io.IOException;
import java.util.Calendar;
public class Reflexology1 extends JFrame{
private static final long serialVersionUID = -1295261024563143679L;
private Ellipse2D ball = new Ellipse2D.Double(0, 0, 25, 25);
private Timer moveBallTimer;
int _ballXpos, _ballYpos;
JButton button1, button2;
JButton movingButton;
JTextArea textArea1;
int buttonAClicked, buttonDClicked;
private long _openTime = 0;
private long _closeTime = 0;
JPanel thePanel = new JPanel();
JPanel thePlacebo = new JPanel();
final JFrame frame = new JFrame("Reflexology");
final JFrame frame2 = new JFrame("The Test");
JLabel label1 = new JLabel("Press X and then click the moving dot as fast as you can.");
public static void main(String[] args){
new Reflexology1();
}
public Reflexology1(){
frame.setSize(600, 475);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Reflexology 1.0");
frame.setResizable(false);
frame2.setSize(600, 475);
frame2.setLocationRelativeTo(null);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame2.setTitle("Reflexology 1.0");
frame2.setResizable(false);
button1 = new JButton("Accept");
button2 = new JButton("Decline");
//movingButton = new JButton("Click Me");
ListenForAcceptButton lForAButton = new ListenForAcceptButton();
ListenForDeclineButton lForDButton = new ListenForDeclineButton();
button1.addActionListener(lForAButton);
button2.addActionListener(lForDButton);
//movingButton.addActionListener(lForMButton);
JTextArea textArea1 = new JTextArea(24, 50);
textArea1.setText("Tracking Events\n");
textArea1.setLineWrap(true);
textArea1.setWrapStyleWord(true);
textArea1.setSize(15, 50);
textArea1.setEditable(false);
FileReader reader = null;
try {
reader = new FileReader("EULA.txt");
textArea1.read(reader, "EULA.txt");
} catch (IOException exception) {
System.err.println("Problem loading file");
exception.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException exception) {
System.err.println("Error closing reader");
exception.printStackTrace();
}
}
}
JScrollPane scrollBar1 = new JScrollPane(textArea1, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
AdjustmentListener listener = new MyAdjustmentListener();
thePanel.add(scrollBar1);
thePanel.add(button1);
thePanel.add(button2);
frame.add(thePanel);
ListenForMouse lForMouse = new ListenForMouse();
thePlacebo.addMouseListener(lForMouse);
thePlacebo.add(label1);
frame2.add(thePlacebo);
ListenForWindow lForWindow = new ListenForWindow();
frame.addWindowListener(lForWindow);
frame2.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e){
if(e.getKeyChar() == 'X' || e.getKeyChar() == 'x') {moveBallTimer.start();}
}
});
frame.setVisible(true);
moveBallTimer = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent e) {
moveBall();
System.out.println("Timer started!");
repaint();
}
});
addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
if(frame2.isVisible()){ moveBallTimer.start(); }
}
});
}
private class ListenForAcceptButton implements ActionListener{
public void actionPerformed(ActionEvent e){
if (e.getSource() == button1){
Calendar ClCDateTime = Calendar.getInstance();
System.out.println(ClCDateTime.getTimeInMillis() - _openTime);
_closeTime = ClCDateTime.getTimeInMillis() - _openTime;
//frame.getContentPane().remove(thePanel);
//thePlacebo.addKeyListener(lForKeys);
//frame.getContentPane().add(thePlacebo);
//frame.repaint();
//moveBallTimer.start();
frame.setVisible(false);
frame2.setVisible(true);
frame2.revalidate();
frame2.repaint();
}
}
}
private class ListenForDeclineButton implements ActionListener{
public void actionPerformed(ActionEvent e){
if (e.getSource() == button2){
JOptionPane.showMessageDialog(Reflexology1.this, "You've declined the license agreement. DO NOT RESTART the program. Please go inform a researcher that you have declined the agreement.", "WARNING", JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}
}
}
private class ListenForWindow implements WindowListener{
public void windowActivated(WindowEvent e) {
//textArea1.append("Window is active");
}
// if this.dispose() is called, this is called:
public void windowClosed(WindowEvent arg0) {
}
// When a window is closed from a menu, this is called:
public void windowClosing(WindowEvent arg0) {
}
// Called when the window is no longer the active window:
public void windowDeactivated(WindowEvent arg0) {
//textArea1.append("Window is NOT active");
}
// Window gone from minimized to normal state
public void windowDeiconified(WindowEvent arg0) {
//textArea1.append("Window is in normal state");
}
// Window has been minimized
public void windowIconified(WindowEvent arg0) {
//textArea1.append("Window is minimized");
}
// Called when the Window is originally created
public void windowOpened(WindowEvent arg0) {
//textArea1.append("Let there be Window!");
Calendar OlCDateTime = Calendar.getInstance();
_openTime = OlCDateTime.getTimeInMillis();
//System.out.println(_openTime);
}
}
private class MyAdjustmentListener implements AdjustmentListener {
public void adjustmentValueChanged(AdjustmentEvent arg0) {
AdjustmentEvent scrollBar1;
//System.out.println(scrollBar1.getValue()));
}
}
public void paint(Graphics g) {
//super.paint(g);
frame2.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.RED);
g2d.fill(ball);
System.out.println("Calling fill()");
}
protected void moveBall() {
//System.out.println("I'm in the moveBall() function!");
int width = getWidth();
int height = getHeight();
int min, max, randomX, randomY;
min =200;
max = -200;
randomX = min + (int)(Math.random() * ((max - min)+1));
randomY = min + (int)(Math.random() * ((max - min)+1));
//System.out.println(randomX + ", " + randomY);
Rectangle ballBounds = ball.getBounds();
//System.out.println(ballBounds.x + ", " + ballBounds.y);
if (ballBounds.x + randomX < 0) {
randomX = 200;
} else if (ballBounds.x + ballBounds.width + randomX > width) {
randomX = -200;
}
if (ballBounds.y + randomY < 0) {
randomY = 200;
} else if (ballBounds.y + ballBounds.height + randomY > height) {
randomY = -200;
}
ballBounds.x += randomX;
ballBounds.y += randomY;
_ballXpos = ballBounds.x;
_ballYpos = ballBounds.y;
ball.setFrame(ballBounds);
}
public void start() {
moveBallTimer.start();
}
public void stop() {
moveBallTimer.stop();
}
private class ListenForMouse implements MouseListener{
// Called when the mouse is clicked
public void mouseClicked(MouseEvent e) {
//System.out.println("Mouse Panel pos: " + e.getX() + " " + e.getY() + "\n");
if (e.getX() >=_ballXpos && e.getX() <= _ballXpos + 25 && e.getY() <=_ballYpos && e.getY() >= _ballYpos - 25 ) {
System.out.println("TRUE");
}
System.out.println("{e.getX(): " + e.getX() + " / " + "_ballXpos: " + _ballXpos + " | " + "{e.getY(): " + e.getY() + " / " + "_ballYpos: " + _ballYpos);
}
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}
// System.out.println("e.getX(): " + e.getX() + " / " + "_ballXpos: " + _ballXpos);
// Mouse over
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
// Mouse left the mouseover area:
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}
Could anyone tell me what I need to do to get repaint() to call the paint() method in the above program? I'm assuming the multiple frames is causing the problem, but that's just a guess. Thanks.

You should not paint directly on JFrame. JPanel or extension of JComponent should be used. For painting override paintComponent() rather than paint(). Don't forget to call super.paintComponent(g);.
Also, keep in mind that repaint() only schedules component update, it does not trigger immediate paint().
For more details see Performing Custom Painting and Painting in AWT and Swing.
For example you can apply the following changes. TestPanel will paint the ball.
class TestPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.RED);
g2d.fill(ball);
}
}
Then, update thePlacebo panel:
JPanel thePlacebo = new TestPanel();
Add repaint in moveBall():
thePlacebo.repaint();
Here is an example based on original code:
package so;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.Random;
import javax.swing.*;
public class TestBall {
private static void createAndShowUI() {
final TestPanel panel = new TestPanel();
panel.validate();
JFrame frame = new JFrame("TestBall");
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(300, 300));
frame.setLocationRelativeTo(null);
frame.setVisible(true);
ActionListener timerAction = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
panel.moveBall();
}
};
Timer timer = new Timer(1000, timerAction);
timer.setRepeats(true);
timer.start();
}
static class TestPanel extends JPanel {
public static int BALL_SIZE = 25;
private Ellipse2D ball = new Ellipse2D.Double(0, 0, BALL_SIZE,
BALL_SIZE);
Random rand = new Random();
public TestPanel() {
this.addMouseListener(new MouseAdapter() {
// Called when the mouse is clicked
public void mouseClicked(MouseEvent e) {
if (ball.contains(e.getPoint())) {
System.out.println("hit the ball");
}
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.RED);
g2d.fill(ball);
}
public void moveBall() {
Rectangle ballBounds = ball.getBounds();
ball.setFrame(ballBounds);
ballBounds.x = rand.nextInt(getWidth() - BALL_SIZE + 1) + 1;
ballBounds.y = rand.nextInt(getHeight() - BALL_SIZE + 1) + 1;
ball.setFrame(ballBounds);
repaint();
}
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}

Java: Moving an object at an angle and changing angle with KeyPress

Ok, so what i want is the rectangle to always be moving, but when you press the left and right arrow is changes the direction by either increasing or decreasing the angle. With this code the sqaure moves as it should in the correct direction, but when i press the keys the direction does not change.
import java.awt.*;
import java.awt.Color;
import javax.swing.Timer;
import javax.swing.*;
import java.awt.Graphics;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyAdapter;
public class Fields extends JPanel implements ActionListener, KeyListener{
Timer tm = new Timer(5, this);
double x = 250, y = 250, vel = 0.2, angle = 90;
public void paintComponent(Graphics g)
{
super.paintComponent(g);
this.setBackground(Color.BLACK);
g.setColor(Color.GREEN);
g.fillRect((int)x, (int)y, 5, 5);
tm.start();
}
public void keyTyped(KeyEvent e)
{
if (e.getKeyCode() == 37) {angle--;}
if (e.getKeyCode() == 39) {angle++;}
}
public void keyReleased(KeyEvent e)
{
if (e.getKeyCode() == 37) {angle--;}
if (e.getKeyCode() == 39) {angle++;}
}
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == 37) {angle--;}
if (e.getKeyCode() == 39) {angle++;}
}
public void actionPerformed(ActionEvent e)
{
x += (velX * (float)Math.cos(Math.toRadians(angle - 90)));
y += (velX * (float)Math.sin(Math.toRadians(angle - 90)));
repaint();
}
public Fields()
{
this.addKeyListener(this);
}
public static void main(String[] args)
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(500, 500);
Fields fi = new Fields();
f.add(fi);
f.setVisible(true);
}
}

As started in my comments...
Don't start the timer in paintComponent, this method gets called repeatedly and can be called often in quick succession.
Use key bindings
.
public class TestAnimation01 {
public static void main(String[] args) {
new TestAnimation01();
}
public TestAnimation01() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new Fields());
frame.setSize(400, 400);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Fields extends JPanel implements ActionListener {
Timer tm = new Timer(125, this);
double x = 250, y = 250, vel = 0.2, angle = 90;
private int velX = 4;
private int velY = 4;
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
this.setBackground(Color.BLACK);
g.setColor(Color.GREEN);
g.fillRect((int) x, (int) y, 5, 5);
}
public void actionPerformed(ActionEvent e) {
x += (velX * (float) Math.cos(Math.toRadians(angle - 90)));
y += (velX * (float) Math.sin(Math.toRadians(angle - 90)));
repaint();
}
public Fields() {
setFocusable(true);
InputMap im = getInputMap(WHEN_FOCUSED);
ActionMap am = getActionMap();
// left 37
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "goLeft");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "goRight");
am.put("goLeft", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
angle--;
repaint();
}
});
am.put("goRight", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
angle++;
repaint();
}
});
tm.setRepeats(true);
tm.setCoalesce(true);
tm.start();
requestFocusInWindow();
}
}
}
There's a bunch of other things you've not covered, such as edge conditions (what happens when it leaves the screen) and individual x/y speeds, but I'm sure you'll work it out