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Generate square wave in JFrame

I have inefficient code of a square wave. I have 2 buttons, 1 table and something like a coordinate system where the square appears in. I want the wave to scroll/move in real time until it hits the end of the coordinate system instead of just appearing by selecting both of the buttons. Additionally, if anyone has a better way of drawing a square wave please tell me.
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawLine(20, 300, 20, 450);
g2d.drawLine(20, 350, 400, 350);
g2d.drawLine(20, 400, 400, 400);
g2d.drawLine(20, 450, 400, 450);
if (this.jButtonSTART.isSelected() & this.jButtonAND.isSelected()) {
this.draw(g2d);
}
}
public void draw(Graphics2D g2d) {
boolean up = true;
while (x <= 380) {
g2d.setColor(Color.blue);
if (x > 0 && x % 95 == 0) {
up = !up;
g2d.drawLine(20 + x, up ? 315 : 350 + y, 20 + x, up ? 350 : 315 + y);
} else {
if (up) {
g2d.drawLine(20 + x, 315 + y, 21 + x, y + 315);
} else {
g2d.drawLine(20 + x, 350 + y, 21 + x, y + 350);
}
}
x++;
}
x = 0;
}

Simple way to draw your square wave and move it:
Create a BufferedImage that is longer than your GUI. It should have length that matches a the period of your square wave and be at least twice as long as the GUI component that it's displayed in.
Draw within the paintComponent method override of a JPanel, not the paint method.
Call the super's paintComponent method first within your override.
You'll draw the image using g.drawImage(myImage, imageX, imageY, this) where imageX and imageY are private instance fields of the JPanel-extending drawing class.
In a Swing Timer, advance imageX with each tick of the Timer, that is each time its ActionListener's actionPerformed method is called).
Then call repaint() on the drawing JPanel within the same actionPerformed method.
Done.
for example, note that this code does not do exactly what you're trying to do, but does show an example of Swing animation using a Swing Timer and paintComponent.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
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.image.BufferedImage;
import javax.swing.*;
#SuppressWarnings("serial")
public class MoveWave extends JPanel {
private static final int PREF_W = 400;
private static final int PREF_H = 200;
private static final int TIMER_DELAY = 40;
public static final int DELTA_X = 2;
public static final int STARTING_MY_IMAGE_X = -PREF_W;
private static final Color COLOR_1 = Color.RED;
private static final Color COLOR_2 = Color.BLUE;
private static final Color BG = Color.BLACK;
private static final int CIRCLE_COUNT = 10;
private BufferedImage myImage = null;
private int myImageX = STARTING_MY_IMAGE_X;
private int myImageY = 0;
public MoveWave() {
setBackground(BG);
myImage = new BufferedImage(2 * PREF_W, PREF_H, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = myImage.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(new GradientPaint(0, 0, COLOR_1, 20, 20, COLOR_2, true));
for (int i = 0; i < CIRCLE_COUNT; i++) {
int x = (i * 2 * PREF_W) / CIRCLE_COUNT;
int y = PREF_H / 4;
int width = (2 * PREF_W) / CIRCLE_COUNT;
int height = PREF_H / 2;
g2.fillOval(x, y, width, height);
}
g2.dispose();
new Timer(TIMER_DELAY, new TimerListener()).start();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (myImage != null) {
g.drawImage(myImage, myImageX, myImageY, this);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
myImageX += DELTA_X;
if (myImageX >= 0) {
myImageX = STARTING_MY_IMAGE_X;
}
repaint();
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("MoveWave");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new MoveWave());
frame.setResizable(false);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}

draw ellipse relative to panel java

Basically I want to draw an ellipse which its size is relative to JPanel in Java.
for example: Ellipse2D e = new Ellipse2D.Double(0, 0, w, h)
Which w and h is the size of the panel. So by doing this, the ellipse will automatically resize when the panel is changing its size.
I have tried this but actually it doesn't work, I wrote this code for testing only.
public class Help extends JFrame{
public static void main(String [] agrs){
Help h = new Help();
h.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
h.init();
}
public void init(){
this.setLayout(new FlowLayout());
this.setSize(2000, 1000);
JPanel a = new JPanel();
a.setPreferredSize(new Dimension(1000, 500));
a.setBorder(BorderFactory.createLineBorder(Color.yellow, 3));
Help_Option k = new Help_Option(a.getPreferredSize().width/2, a.getPreferredSize().height/4);
k.setPreferredSize(new Dimension(1000, 400));
a.add(k);
this.add(a);
this.validate();
this.setVisible(true);
}
}
class Help_Option extends JComponent implements MouseMotionListener{
private static int x, y;
private Ellipse2D ellipse = new Ellipse2D.Double(0, 0, x, y);
private Color c = Color.MAGENTA;
public Help_Option(int x, int y){
Help_Option.x = x;
Help_Option.y = y;
this.addMouseMotionListener(this);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.BLUE);
g2d.draw(ellipse);
g2d.setColor(c);
g2d.fill(ellipse);
g2d.setColor(Color.BLACK);
g2d.setFont(new Font("TimesRoman", Font.BOLD, 20));
g2d.drawString("Here I am", 250, 100);
}
public void setColor(Color c){
this.c = c;
}
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
if(ellipse.contains(e.getX(), e.getY())){
setColor(Color.GREEN);
repaint();
}else{
setColor(Color.MAGENTA);
repaint();
}
}
}

Thank you for your code snippet. In order to make it work, you need to initalize the ellipse in the Help_Option-Constructor otherwise it is draw at 0, 0 with the widht and height of 0 and 0.
...
private Ellipse2D ellipse = null; //also works w/o this assignment.
private Color c = Color.MAGENTA;
public Help_Option(int x, int y){
Help_Option.x = x;
Help_Option.y = y;
ellipse = new Ellipse2D.Double(0, 0, x, y);
this.addMouseMotionListener(this);
}
...
If I change the code accordingly, the ellipse stays at its size even though I resize the window.
Please give me a hint (screenshot) what you mean.

I want to draw an ellipse which its size is relative to JPanel in Java.
Then you need to create the Ellipse object in the paintComponent() method. You can use the getWidth() and getHeight() methods to get the current size of the panel.

Java: Drawing using Graphics outside the class which draws the main canvas

I'm trying to develop a Tic Tac Toe game in Java using Graphics.
My problem is: I don't want to add any other methods inside my Grid.class (which draws the lines 3x3), but i want to draw my X or O from a class called Game. My grid class looks like the following:
import java.awt.Graphics;
import javax.swing.JPanel;
public class Grid extends JPanel{
private final int ITEM_WIDTH = 30;
private final int ITEM_HEIGHT = 30;
private final int OUTER_WIDTH = 90;
private final int OUTER_HEIGHT = 90;
public void paintComponent(Graphics g){
super.paintComponent(g);
drawOuter(g);
drawGrid(g);
}
public void drawOuter(Graphics g){
g.drawRect(0, 0, OUTER_WIDTH, OUTER_HEIGHT);
}
public void drawGrid(Graphics g){
//Vertikális
for(int i = ITEM_WIDTH; i < OUTER_WIDTH; i += ITEM_WIDTH){
g.drawLine(i, 0, i, OUTER_HEIGHT);
}
//Horizontális
for(int i = ITEM_HEIGHT; i < OUTER_HEIGHT; i += ITEM_HEIGHT){
g.drawLine(0, i, OUTER_WIDTH, i);
}
}
Thank you for your helps

My suggestion would be try to keep things as simple as possible.
Create ImageIcons that hold your X and O images
Have a GridLayout of JLabels placed in your JPanel above.
Swapping the JLabel's ImageIcon when I wanted to display an X, an O, or a blank.
Proof of concept code. Clicking on the JLabels several times will show the icons. The code has no Tic-Tac-Toe logic though:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
#SuppressWarnings("serial")
public class XorOorBlank extends JPanel {
private static final int IMG_WIDTH = 100;
private static final Color BACKGROUND = Color.LIGHT_GRAY;
private static final Color X_COLOR = Color.red;
private static final Color O_COLOR = Color.blue;
private static final Stroke X_STROKE = new BasicStroke(8f);
private static final int GAP = 8;
private static final int SIDE = 3;
private Icon blankIcon = createBlankIcon();
private Icon xIcon = createXIcon();
private Icon oIcon = createOIcon();
public XorOorBlank() {
setBackground(BACKGROUND);
setLayout(new GridLayout(SIDE, SIDE, GAP, GAP));
MouseListener mouseListener = new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
JLabel label = (JLabel) e.getSource();
Icon icon = label.getIcon();
if (icon == blankIcon) {
icon = xIcon;
} else if (icon == xIcon) {
icon = oIcon;
} else if (icon == oIcon) {
icon = blankIcon;
}
label.setIcon(icon);
}
};
for (int i = 0; i < SIDE; i++) {
for (int j = 0; j < SIDE; j++) {
JLabel label = new JLabel(blankIcon);
label.addMouseListener(mouseListener);
add(label);
}
}
}
private Icon createBlankIcon() {
BufferedImage img = new BufferedImage(IMG_WIDTH, IMG_WIDTH,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setColor(Color.white);
g2.fillRect(0, 0, IMG_WIDTH, IMG_WIDTH);
g2.dispose();
ImageIcon icon = new ImageIcon(img);
return icon;
}
private Icon createXIcon() {
BufferedImage img = new BufferedImage(IMG_WIDTH, IMG_WIDTH,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setColor(Color.white);
g2.fillRect(0, 0, IMG_WIDTH, IMG_WIDTH);
g2.setColor(X_COLOR);
g2.setStroke(X_STROKE);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int x1 = GAP;
int y1 = x1;
int x2 = IMG_WIDTH - GAP;
int y2 = x2;
g2.drawLine(x1, y1, x2, y2);
g2.drawLine(x2, y1, x1, y2);
g2.dispose();
ImageIcon icon = new ImageIcon(img);
return icon;
}
private Icon createOIcon() {
BufferedImage img = new BufferedImage(IMG_WIDTH, IMG_WIDTH,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setColor(Color.white);
g2.fillRect(0, 0, IMG_WIDTH, IMG_WIDTH);
g2.setColor(O_COLOR);
g2.setStroke(X_STROKE);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int x1 = GAP;
int y1 = x1;
int x2 = IMG_WIDTH - 2 * GAP;
int y2 = x2;
g2.drawOval(x1, y1, x2, y2);
g2.dispose();
ImageIcon icon = new ImageIcon(img);
return icon;
}
private static void createAndShowGui() {
JFrame frame = new JFrame("X or O");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new XorOorBlank());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Note: not a paintComponent method to be found.
This displays:

You have a few choices...
You Could
Extend from Grid, overriding it's paintComponent method and draw the X/Os within it (calling super.paintComponent)
You Could
Create a interface which provide a simple "draw" method, which when implemented, would paint either X/O. You could then simply add an new instance of this to the Grid class and have it paint the X/O via some kind of loop within the paintComponent method
You Could
Use, something like GridBagLayout or even OverlayLayout and place another panel over the top of the Grid class, or, using BorderLayout, add the panel directly to the Grid class, which would then be responsible for painting the X/O
You Could
Do what Hovercraft Full Of Eels has suggested...

Jpanel repaint with mouse movement event

Ok here is the thing I am making a function grapher and I want when you move your mouse over a line it will show the coordinates. So I set up just a basic drawstring on the panel to show the mouse coords but I can not get to repaint well normally. It seems to be painting just fine but it is not clearing the contents before painting here is the code I have thus far.
public class Grapher extends JPanel implements MouseMotionListener{
private final int BORDER_GAP = 15;
private final int MAX_SCORE = 20;
private final int PREF_WIDTH = 800;
private final int PREF_HEIGHT = 650;
private final int GRAPH_POINT_WIDTH = 12;
private static final int GRAPH_INTERVAL = 15;
private static Point mse;
private List<Point> values;
public Grapher(List<Point> values) {
setMse(new Point(0,0));
this.values = values;
addMouseMotionListener(this);
}
public void paintComponent(Graphics g){
super.paintComponents(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
float xScale = ((float) getWidth() - 2 * BORDER_GAP) / (values.size()-1);
float yScale = ((float) getHeight() - 2 * BORDER_GAP) / (MAX_SCORE-1);
g2d.drawString(xScale+"", 50, 50);
g2d.drawString(yScale+"", 50, 70);
g2d.drawString(getWidth()/2+"", 50, 90);
g2d.drawString(mse.x +" " + mse.y, 50, 30);
//create axis
g2d.setColor(new Color(0x7e7e7e));
//x line
g2d.drawLine(BORDER_GAP, (getHeight() - BORDER_GAP)/2, getWidth() - BORDER_GAP, (getHeight() - BORDER_GAP)/2);
//y line
g2d.drawLine(getWidth()/2, getHeight() - BORDER_GAP, getWidth()/2, BORDER_GAP);
}
public Dimension getPreferredSize(){
return new Dimension(PREF_WIDTH, PREF_HEIGHT);
}
private static void createAndShowGui(){
List<Point> values = new ArrayList<Point>();
int maxDataPoints = 20;
for (int i = -GRAPH_INTERVAL; i <= GRAPH_INTERVAL; i++) {
String val = "";
try {
val = EquationSolver.solveEquation(variableReplace('x', i));
} catch (Exception e) {
val ="0";
e.printStackTrace();
}
System.out.println(i + "= " + val);
values.add(new Point(i, Integer.parseInt(val)));
}
Grapher panel = new Grapher(values);
JFrame frame = new JFrame("Grapher");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(panel);
frame.pack();
//frame.setLocationByPlatform(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run(){
createAndShowGui();
}
});
}
#Override
public void mouseMoved(MouseEvent e) {
setMse(new Point(e.getX(), e.getY()));
removeAll();
repaint();
}
#Override
public void mouseDragged(MouseEvent e) {
setMse(new Point(e.getX(), e.getY()));
//repaint();
}
Ok here is some images as to what the code is doing
the top numbers are the mouse position.
A fresh start to program: http://snag.gy/BFrUj.jpg.
After i move the mouse around a little: http://snag.gy/lNqie.jpg
Thanks for any help.

I would suggest the major problem you are having is related to g.dispose()
The graphics context is shared, meaning that if you dispose of the graphics context, nothing else can paint to it. Unless you create the context, you should never dispose it
Your other problem is, you are not actually calling super.paintComponent, which is responsible for preparing the graphics context for painting (by clearing the are to be painted), but instead, you are calling super.paintComponents(g) ... not the s at the end...

For some reason when I draw straight onto the panel it does that overlaying effect but if i add a white rectangle as a background that solves the problem.
...
float xScale = ((float) getWidth() - 2 * BORDER_GAP) / (values.size()-1);
float yScale = ((float) getHeight() - 2 * BORDER_GAP) / (MAX_SCORE-1);
g2d.setColor(Color.white);
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.setColor(new Color(0x7e7e7e));
g2d.drawString(xScale+"", 50, 50);
g2d.drawString(yScale+"", 50, 70);
g2d.drawString(getWidth()/2+"", 50, 90);
g2d.drawString(mse.x +" " + mse.y, 50, 30);
...
That appears to be a fix for the problem. If anyone can explain why drawing straight to the panel overlays or has a better solution please do answer.

How to "paint" on JLabels on a JPanel?

I have a set of JLabels, each containing a letter (via seText()), opaque and background set to white, on a JPanel with a GridLayout so the labels are forming a table.
I am doing a simple animation of highlighting certain rows and columns then there intersection. I can use the setBackground() of labels for this purpose, but thought I'd have more "choices" if a was able to use a Graphics object (maybe drawing a circle around intersection, then clearing it).
I tried to extend JLabel, or drawing on the JPanel directly(using getGraphics() in a method) but it didn't work, I think the drawing is behind the labels in this case. I can't figure out where should the "painting" code be placed in either case, nothing appeared on the screen.
in short, a method like the following, can be used to draw on top of labels?
should it be a JLabel or a JPanel method?
public void drawsomething() {
Graphics2D g2d = (Graphics2D) getGraphics();
g2d.fillRect(100, 100, 100, 100);
}

What if you override paintChildren() ?
protected void paintChildren(Graphics g) {
super.paintChildren(g);
//paint your lines here
}

You might want to try a JLayeredPane to paint your specific drawings on top of the existing JComponents
see example here http://docs.oracle.com/javase/tutorial/uiswing/components/layeredpane.html

I really don't know much about drawing stuff yet, but just created one small sample code for you to look at, hopefully you can get some information out of it. In order to paint on the JLabel you can use it's paintComponent(Graphics g) method.
A Sample Code :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DrawingOnJLabel extends JFrame
{
private CustomLabel label;
private int flag = 1;
private JPanel contentPane;
public DrawingOnJLabel()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
contentPane = new JPanel();
contentPane.setBackground(Color.WHITE);
label = new CustomLabel(200, 200);
label.setLabelText("A");
label.setValues(50, 50, 100, 100, 240, 60);
final JButton button = new JButton("CLEAR");
button.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
if (flag == 1)
{
label.setFlag(flag);
flag = 0;
button.setText("REPAINT");
contentPane.revalidate();
contentPane.repaint();
}
else if (flag == 0)
{
label.setFlag(flag);
flag = 1;
button.setText("CLEAR");
contentPane.revalidate();
contentPane.repaint();
}
}
});
}
});
contentPane.add(label);
add(contentPane, BorderLayout.CENTER);
add(button, BorderLayout.PAGE_END);
setSize(300, 300);
setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new DrawingOnJLabel();
}
});
}
}
class CustomLabel extends JLabel
{
private int sizeX;
private int sizeY;
private int x, y, width, height, startAngle, arcAngle;
private int flag = 0;
private String text;
public CustomLabel(int sX, int sY)
{
sizeX = sX;
sizeY = sY;
}
// Simply call this or any set method to paint on JLabel.
public void setValues(int x, int y, int width, int height, int startAngle, int arcAngle)
{
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.startAngle = startAngle;
this.arcAngle = arcAngle;
repaint();
}
public void setFlag(int value)
{
flag = value;
repaint();
}
public Dimension getPreferredSize()
{
return (new Dimension(sizeX, sizeY));
}
public void setLabelText(String text)
{
super.setText(text);
this.text = text;
flag = 0;
repaint();
}
public void paintComponent(Graphics g)
{
if (flag == 0)
{
g.setColor(Color.RED);
g.drawString(text, 20, 20);
g.setColor(Color.BLUE);
g.drawOval(x, y, width, height);
g.fillOval(x + 20, y + 20, 15, 15);
g.fillOval(x + 65, y + 20, 15, 15);
g.fillRect(x + 40, y + 40, 5, 20);
g.drawArc(x + 20, y + 30, 55, 55, startAngle, arcAngle);
}
else if (flag == 1)
{
g.clearRect(x, y, width, height);
}
}
}

Use paintComponent(Graphics g) instead of paint(Graphics g). That will paint over the GUI