I've written the following code
import java.awt.BorderLayout;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
final public class Test
{
JFrame frame;
DrawPanel drawPanel;
boolean up = false;
boolean down = true;
boolean left = false;
boolean right = true;
private int timeStep = 0;
private int ballYTravel = 100;
private int BALL_NUM = 24;
public static void main(String... args)
{
new Test().go();
}
private void go()
{
frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
drawPanel = new DrawPanel();
frame.getContentPane().add(BorderLayout.CENTER, drawPanel);
frame.setResizable(false);
frame.setSize(800, 600);
frame.setLocationByPlatform(true);
frame.setVisible(true);
moveIt();
}
class DrawPanel extends JPanel
{
private static final long serialVersionUID = 1L;
public double getY(int i, int t) {
return 200 + ballYTravel / 2 * (Math.sin(timeStep * (i / 200 + 0.08)));
}
public void paintComponent(Graphics g)
{
for (int k = 0; k < BALL_NUM; k++ ) {
g.fillRect(100 + 20 *k , (int) getY(k, timeStep), 6, 6);
}
timeStep++;
}
}
private void moveIt()
{
while (true)
{
try
{
Thread.sleep(10);
}
catch (Exception e)
{
e.printStackTrace();
}
frame.repaint();
}
}
}
It runs and animates, however it is not animating in the same fashion as the Javascript code I referenced it from which can be found here http://codepen.io/anon/pen/ZYQoQZ
any help in understanding why is appreciated
There are (possibly) two basic problems...
In getY, you are ignoring the parameter t and using timeStep instead, while, technically, this probably isn't going to make a MASSIVE difference, it is an area of concern
You have an integer division issue. i/200 will result in int result, where you really want a double. Change it to i/200d
For example...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
final public class Test {
private int timeStep = 0;
private final int ballYTravel = 100;
private final int BALL_NUM = 24;
public static void main(String... args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new DrawPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
class DrawPanel extends JPanel {
private static final long serialVersionUID = 1L;
public DrawPanel() {
new Timer(10, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
timeStep++;
repaint();
}
}).start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 200);
}
public double getY(int i, int t) {
return 100 + ballYTravel / 2 * (Math.sin(t * (i / 200d + 0.08)));
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int k = 0; k < BALL_NUM; k++) {
g.fillRect(10 + 20 * k, (int) getY(k, timeStep), 6, 6);
}
}
}
}
You're also breaking the paint chain, which is going to cause you issues in the long run, make sure you are calling super.paintComponent...
For more details see...
Performing Custom Painting
Painting in AWT and Swing
Concurrency in Swing
How to use Swing Timers
Initial Threads
Your transliteration reveals several problems:
Swing GUI objects should be constructed and manipulated only on the event dispatch thread.
Don't use setSize() when you really mean to override getPreferredSize().
Invoke pack() to let the container adopt its preferred size.
Use javax.swing.Timer to pace the animation.
Revised code, incorporating #Mad's fix and using drawOval():
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
final public class Test {
JFrame frame;
DrawPanel drawPanel;
private int timeStep = 0;
private int ballYTravel = 100;
private int BALL_NUM = 24;
public static void main(String... args) {
new Test().go();
}
private void go() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
drawPanel = new DrawPanel();
frame.add(BorderLayout.CENTER, drawPanel);
frame.setResizable(false);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
Timer t = new Timer(10, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
drawPanel.repaint();
}
});
t.start();
}
});
}
private class DrawPanel extends JPanel {
public double getY(int i, int t) {
return 200 + ballYTravel / 2 * (Math.sin(t * (i / 200d + 0.08)));
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int k = 0; k < BALL_NUM; k++) {
g.drawOval(100 + 20 * k, (int) getY(k, timeStep), 8, 8);
}
timeStep++;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(700, 500);
}
}
}
Related
My program is to convert the letters to some signals.My main method generates some random letters. The letter is passed to another method which calls repaint() method based on the Letter generated.The PaintComponent() method is used to drew a circle filled with white color.When i execute the program i get only a Jframe. I don't see the circle.Please help.
package morsecode;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Random;
import java.awt.*;
public class MorseCode extends Frame {
public static void main(String[] args) {
MorseCode mc = new MorseCode();
MorseCode frame = new MorseCode();
final String chars = "abcdefghijklmnopqrstuvwxyz1234567890";
char word;
for(int i=1;i<=1;i++)
{
Random rand = new Random();
int x = rand.nextInt(36);
word = chars.charAt(x);
System.out.print(word);
frame.setBackground(Color.BLACK);
frame.addWindowListener(
new WindowAdapter()
{
#Override
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
);
frame.setSize(400, 400);
frame.setVisible(true);
mc.toMorseCode(word);
}
}
void toMorseCode(char letter)
{
switch(letter)
{
case 'A' | 'a':
repaint();
Thread.sleep(1000);
repaint();
Thread.sleep(2000);
break;
case 'B' | 'b':
repaint();
Thread.sleep(1000);
repaint();
Thread.sleep(1000);
repaint();
Thread.sleep(1000);
repaint();
Thread.sleep(2000);
break; ..............
}
}
public void paintComponent(Graphics g) {
Graphics2D ga = (Graphics2D)g;
ga.setColor(Color.white);
ga.fillOval(125,125,150,150);
}
}
Two things...
First, calling Thread.sleep(2000); within the Event Dispatching Thread will prevent the EDT from processing events on the event queue, including paint events.
Second, Frame doesn't have a paintComponent.
Adding the #Override annotation and trying to call super.paintComponent would have highlighted this issue as the code wouldn't have compiled.
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
First of all, start by using a JPanel to hold your core logic and perform your custom painting.
Second, use a javax.swing.Timer to perform animation. See How to use Swing Timers for more details
Updated
The basic concept is relatively simple. You need some kind of second/background thread which can generate the delays between the changes in the output. You then need to update the UI before each delay based on what type of information you are trying to display.
The implementation becomes tricky because Swing, like most GUI frameworks, is single threaded and not thread safe.
This means, you can not block the GUI thread, doing so will prevent the UI from been repainted, amongst other things and you must update the state of any UI component from within the context of the GUI thread.
This means that while you can use a Thread to run in the background, you must ensure that all changes/modifications to the UI are carried out only from within the EDT.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MorseCodeTest {
public static void main(String[] args) {
new MorseCodeTest();
}
public MorseCodeTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static final int GAP = 500;
public static final int DOT = 1000;
public static final int DASH = 4000;
public interface Transmitter {
public void setTap(boolean tap);
}
public class TestPane extends JPanel implements Transmitter {
private MorseCode code;
private boolean tapped;
public TestPane() {
code = MorseCode.create('A').addDot().addDash();
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
Signalar signalar = new Signalar(TestPane.this, code);
signalar.execute();
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (tapped) {
Graphics2D g2d = (Graphics2D) g.create();
int diameter = Math.min(getWidth(), getHeight()) / 2;
int x = (getWidth() - diameter) / 2;
int y = (getHeight() - diameter) / 2;
g2d.fillOval(x, y, diameter, diameter);
g2d.dispose();
}
}
#Override
public void setTap(boolean tap) {
tapped = tap;
repaint();
}
}
public class Signalar extends SwingWorker<Void, Boolean> {
private final MorseCode code;
private final Transmitter transmitter;
public Signalar(Transmitter transmitter, MorseCode code) {
this.code = code;
this.transmitter = transmitter;
}
#Override
protected void process(List<Boolean> chunks) {
transmitter.setTap(chunks.get(chunks.size() - 1));
}
#Override
protected Void doInBackground() throws Exception {
for (Tone tone : code.getTones()) {
publish(true);
Thread.sleep(tone.getDelay());
publish(false);
Thread.sleep(GAP);
}
return null;
}
}
public static class Tone {
private final int delay;
public Tone(int delay) {
this.delay = delay;
}
public int getDelay() {
return delay;
}
}
public static class DashTone extends Tone {
public DashTone() {
super(DASH);
}
}
public static class DotTone extends Tone {
public DotTone() {
super(DOT);
}
}
public static class MorseCode {
private final char value;
private final List<Tone> tones;
public static MorseCode create(char value) {
MorseCode code = new MorseCode(value);
return code;
}
public MorseCode(char value) {
this.value = value;
this.tones = new ArrayList<>(25);
}
public char getValue() {
return value;
}
public MorseCode addDash() {
return addTone(new DashTone());
}
public MorseCode addDot() {
return addTone(new DotTone());
}
public MorseCode addTone(Tone tone) {
tones.add(tone);
return this;
}
public Iterable<Tone> getTones() {
return tones;
}
}
}
I want my button to change color on the mod == 0 of i % 3. The paintComponent(...) is called when the form is re-sized and index is passed in so I would think that this should change the color of my button ever time I start moving the form around the screen.
I have two components on the screen but both will not show up this might be a factor.
Code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class testform {
public static void main (String[] p) {
testBall3 j1 = new testBall3();
myButton b1 = new myButton("test");
JPanel testPane = new JPanel();
testPane.setBackground(Color.green);
testPane.setLayout(new BorderLayout());
j1.setPreferredSize(new Dimension(10,10));
//testPane.add(b1);
testPane.add(j1);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(testPane);
frame.pack();
frame.setSize(300, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//j1.setColorBall(Color.BLACK);
//j1.repaint();
}
}
class myButton extends JButton {
private static final long serialVersionUID = 1L;
public myButton(String s) {
super(s);
}
public void setPrefferedSize(Dimension d) {
//this.setBounds(x, y, width, height)
setPreferredSize(d);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
index += i;
System.out.println(i);
if (index % 3 == 0) {
setBackground(Color.RED);
}
else {
setBackground(Color.BLACK);
}
}
}
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JComponent;
class testBall3 extends JComponent
{
private static final long serialVersionUID = 1L;
private Color colorBall = Color.red;
private int x1, y1;
int index = 0;
public void setColorBall(Color c)
{
this.colorBall = c;
}
public testBall3()
{
super();
System.out.println("MyBall (0)");
}
public testBall3(int x, int y, int diameter)
{
super();
this.setLocation(x, y);
this.setSize(diameter, diameter);
System.out.println("MyBall (1)");
x1 = x;
y1 = y;
}
public void paintBorder(Graphics g)
{
super.paintBorder(g);
g.setColor(Color.YELLOW);
g.fillOval(100, 100, 50, 50);
System.out.println("PaintBorder");
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(colorBall);
g.fillOval(x1, y1, 10, 10);
System.out.println("paintComponent");
}
public void paint(Graphics g)
{
super.paint(g);
paintComponent(g);
paintBorder(g);
paintChildren(g);
System.out.println("Paint");
}
}
But paintComponent doesn't take a second parameter, how are you passing it? I would think that instead of trying to pass i, you would want make i an attribute of class myButton instead and initialize it to 0 upon instantiation. That is, if you want each button to have its own counter. That sounds like the better plan.
You've got a lot of strange stuff going on...
You've got a component where you override all four major painting methods for no good reason.
In this component, your paint method override calls the super method, and calls the other 3 methods, which in essence will make those 3 methods be called twice.
You've got program logic (advancement of i) inside of your myButton's paintComponent method -- something that should never be done. You do not have full control over when or even if this method is called.
You are calling setBackground(...) from within paintComponent, something which shouldn't be done.
Your class names do not begin with an upper case letter, going against coding conventions, and potentially confusing anyone who tries to read your code.
If you want to change the state of a component on resize, use a ComponentListener.
e.g.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
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 javax.swing.*;
#SuppressWarnings("serial")
public class Foo2 extends JPanel {
protected static final Color MAGIC_BACKGROUND = Color.red;
protected static final int MAGIC_NUMBER = 3;
private static final int TIMER_DELAY = 20;
private int index = 0;
private JButton myButton = new JButton("My Button");
protected int DELTA_SIZE = 2;
public Foo2() {
add(myButton);
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
index++;
if (index % MAGIC_NUMBER == 0) {
myButton.setBackground(MAGIC_BACKGROUND);
} else {
myButton.setBackground(null);
}
}
});
new Timer(TIMER_DELAY, new ActionListener() {
private Toolkit toolkit = Toolkit.getDefaultToolkit();
private int screenWidth = toolkit.getScreenSize().width;
private int screenHeight = toolkit.getScreenSize().height;
#Override
public void actionPerformed(ActionEvent e) {
if (getWidth() >= screenWidth || getHeight() >= screenHeight) {
((Timer)e.getSource()).stop();
} else {
int width = getWidth() + DELTA_SIZE;
int height = getHeight() + DELTA_SIZE;
setPreferredSize(new Dimension(width, height));
Window win = SwingUtilities.getWindowAncestor(Foo2.this);
win.pack();
win.setLocationRelativeTo(null);
}
}
}).start();
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Foo2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Foo2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
According to http://docs.oracle.com/javase/7/docs/technotes/guides/2d/flags.html#opengl
I set the system property as following in order to JVM uses the gpu opengl hw acceleration if available.
there is no crash, and the verbose message says the pipeline is activated OpenGL pipeline enabled for default config on screen 0.
public static void main(String args[]) {
System.setProperty("sun.java2d.opengl", "True");
try {
UIManager.setLookAndFeel(new WindowsClassicLookAndFeel());
} catch (Exception ex) {}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new RootForm().setVisible(true);
}
});
//no difference
// java.awt.EventQueue.invokeLater(new Runnable() {
// public void run() {
// new RootForm().setVisible(true);
// }
// });
//no difference
// new Thread(new Runnable() {
// #Override
// public void run() {
// new RootForm().setVisible(true);
// }
// }).start();
}
but the swing form gets freezed! even repaint() call doesn't work.
What is the problem would be?
Platform: Win7X64, GPU: AMD HD5870 (updated driver).
Thanks in advance.
EDIT
I tried it several times and I got it work. and no the new problem. it works randomly. very weird. works whenever it wants.
Works fine for me...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestOpenGL {
public static void main(String args[]) {
System.setProperty("sun.java2d.opengl", "True");
new TestOpenGL();
}
public TestOpenGL() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private int yPos = 0;
private int yDelta = 2;
private JLabel label;
public TestPane() {
setLayout(new GridBagLayout());
label = new JLabel("Bouncy, Bouncy...");
add(label);
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
yPos += yDelta;
if (yPos > getHeight()) {
yPos = getHeight();
yDelta *= -1;
} else if (yPos < 0) {
yPos = 0;
yDelta *= -1;
}
label.setText("Bouncy, Bouncy...# " + yPos);
repaint();
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.GREEN);
int x = (getWidth() - 2) / 2;
g2d.drawOval(x, yPos - 2, 4, 4);
g2d.dispose();
}
}
}
Is it possible to repaint a JPanel from within a loop in another object? I have a JFrame that consists of a JPanel (DrawPanel) and a SA object. I would like to update/repaint the JPanel during the while loop in this SA object. I started a new thread, but still panel.repaint() does not execute.
public class Mainform extends JFrame {
private DrawPanel DrawPanel;
public static void main(String[] args) {
DrawPanel panel = new DrawPanel();
SA sa = new SA(panel);
Thread t = new Thread(sa);
t.start();
//...
}
}
public class DrawPanel extends JPanel implements MouseMotionListener, MouseListener {
public DrawPanel() {
super();
setBackground(Color.WHITE);
addMouseWheelListener(this);
addMouseListener(this);
addMouseMotionListener(this);
}
//...
}
public class SA implements Runnable {
private DrawPanel panel;
public SA(DrawPanel p) {
this.panel = p;
init();
}
public void run() {
while (true) {
//...
panel.repaint();
}
}
}
EDIT: run is public
The basic answer is "yes".
This assumes that the component you are trying to repaint is
Added to a container
That container is attached to some kind of native peer (ie a window)
That window is visible.
The RepaintManager is generally smart enough to know not to waste time painting something that isn't displayable.
The following example is rather basic, but will increment a counter within the paintComponent of a JPanel each time it is called. The Runnable, which is attached to a Thread, will update every second...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class RepaintTest {
public static void main(String[] args) {
new RepaintTest();
}
public RepaintTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
TestPane tp = new TestPane();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(tp);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
Thread thread = new Thread(new Repainter(tp));
thread.setDaemon(true);
thread.start();
}
});
}
public class Repainter implements Runnable {
private JPanel panel;
public Repainter(JPanel panel) {
this.panel = panel;
}
#Override
public void run() {
while (true) {
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
}
panel.repaint();
}
}
}
public class TestPane extends JPanel {
private int repaints = 0;
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics g2d = (Graphics2D) g.create();
repaints++;
FontMetrics fm = g2d.getFontMetrics();
String text = Integer.toString(repaints);
int x = (getWidth() - fm.stringWidth(text)) / 2;
int y = ((getHeight() - fm.getHeight()) / 2) + fm.getAscent();
g2d.drawString(text, x, y);
g2d.dispose();
}
}
}
I need only one ring to be created on MyPanel (extends JPanel) initialization. Then I need to change (in a loop iterate() ) position of ring on MyPanel. How and what to add to this code?
import javax.swing.SwingUtilities;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.BorderFactory;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
public class mull {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JPanel p = createAndShowGUI();
iterate(p);
// "The method iterate(MyPanel) in the type mull is not applicable for the arguments (JPanel)"
}
});
}
private static JPanel createAndShowGUI() {
System.out.println("Created GUI on EDT? "+
SwingUtilities.isEventDispatchThread());
JFrame f = new JFrame("Swing Paint Demo");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// how to grab link to this panel - in order to use it in iteration loop ?
MyPanel p = new MyPanel();
f.add(p);
// f.add(new MyPanel());
f.pack();
f.setVisible(true);
return p;
}
private static void iterate(JPanel p){
// the loop should change square position on each iteration
// how to implement ?
for (int i = 0; i < 999; i++){
((MyPanel) p).moveSquare(100 + i*10, 200 + i*10); // here is problem:
//"Cannot make a static reference to the non-static method moveSquare(int, int) from the type MyPanel"
}
}
}
class MyPanel extends JPanel {
private int squareX = 50;
private int squareY = 50;
private int squareW = 200;
private int squareH = 200;
public MyPanel() {
setBorder(BorderFactory.createLineBorder(Color.black));
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
moveSquare(e.getX(),e.getY());
}
});
addMouseMotionListener(new MouseAdapter() {
public void mouseDragged(MouseEvent e) {
moveSquare(e.getX(),e.getY());
}
});
}
// originally this method was private - in orger to access it within mull, it vas changed to public
public void moveSquare(int x, int y) {
int OFFSET = 1;
if ((squareX!=x) || (squareY!=y)) {
repaint(squareX,squareY,squareW+OFFSET,squareH+OFFSET);
squareX=x;
squareY=y;
repaint(squareX,squareY,squareW+OFFSET,squareH+OFFSET);
}
}
public Dimension getPreferredSize() {
return new Dimension(900,700);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("This is my custom Panel!",10,20);
g.setColor(Color.RED);
g.fillRect(squareX,squareY,squareW,squareH);
g.setColor(Color.BLACK);
g.drawRect(squareX,squareY,squareW,squareH);
}
}